Does a DSLR adapter need a lens in it?

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diggitydawg
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Does a DSLR adapter need a lens in it?

#1 Post by diggitydawg » Fri Dec 13, 2019 6:57 pm

Hi! I'm new to microscopy. I have a Swift microscope with a 23.2 mm trinocular port, and I want to use my DSLR (Canon 7D) with it.

I've looked on amazon and found a few, but it seems like there are two "classes" of them, with some about $15, and the others about $100. Obviously I want to spend less if possible (that's a big diff), but I also don't want to waste money on something that won't work.

Here's an example of the one that's about $100: https://www.amazon.com/AmScope-CA-CAN-S ... B005OZ5NXU

And here's an example of one of the cheap ones: https://www.amazon.com/SVBONY-Microscop ... 07QYZKSP8/

I thought I recall seeing somewhere that adapters need to have a lens in them to work, but the cheap ones have positive reviews of people saying they work. What's going on? are they just fake reviews? or do these adapters work, but badly and the people just don't know/care?

Does the adapter need a lens in it, and that's why the pricier one is pricier? thanks for any advice.

MicroBob
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Re: Does a DSLR adapter need a lens in it?

#2 Post by MicroBob » Fri Dec 13, 2019 8:36 pm

Hi,
it is possible to get an image on the sensor by lifting the eyepiece a bit and let it project on the sensor in a certain distance. Without eyepiece and any other optics in it's place I can't figure out how this will bring an image on the sensor. The more expensive adapter works after a principle that is understandable for me, but I wouldn't expect a good image quality.
A very promision option is to use a smartphone camera directly on the eyepiece, perhaps with a bought or homemade adapter.

Bob

Scarodactyl
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Re: Does a DSLR adapter need a lens in it?

#3 Post by Scarodactyl » Fri Dec 13, 2019 11:07 pm

One with no lenses will produce an image, but it won't fill the sensor and will require a lot of refocusing. The parfocal image is right about where the bottom of the eyepiece would sit. This is inconvenient and also pushes the optics out of spec so quality will suffer.
The generic 2x adapters are ok to good on some systems, awful on others. Quality control also isn't a guarantee. [Ie, this is not a good solution]
Does the swift use compensating eyepieces?
edit: holy cow this post is almost incomprehensible. sorry everyone!
What I meant was that a photo adapter with no lenses can't produce an image that's in focus when the viewing eyepieces are in focus, because it would have to put the camera sensor an inch or so below the eyepiece tube which isn't physically possible.
Last edited by Scarodactyl on Mon Dec 16, 2019 2:20 am, edited 1 time in total.

diggitydawg
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Re: Does a DSLR adapter need a lens in it?

#4 Post by diggitydawg » Sat Dec 14, 2019 6:59 pm

Scarodactyl wrote:
Fri Dec 13, 2019 11:07 pm
One with no lenses will produce an image, but it won't fill the sensor and will require a lot of refocusing. The parfocal image is right about where the bottom of the eyepiece would sit. This is inconvenient and also pushes the optics out of spec so quality will suffer.
The generic 2x adapters are ok to good on some systems, awful on others. Quality control also isn't a guarantee.
Does the swift use compensating eyepieces?
Hi, thanks for the advice. When you say "right about where the bottom of the eyepiece would sit", what do you mean? Just to be clear, I'm talking about using the trinocular tube, so what eyepiece would that be?

Are the generic 2x adapters like the cheap (lensless) one I posted, or the more expensive one?

Sorry, I'm not exactly sure what those are yet, I'm new to this :P

Scarodactyl
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Re: Does a DSLR adapter need a lens in it?

#5 Post by Scarodactyl » Sat Dec 14, 2019 7:15 pm

The trinoc port has a 23mm opeing at the top, so it is basically a third ocular. If you stick an eyepiece in there it will work like the other two (not all of them are set up quite like this, but they tend to be. You can test by trying one of your oculars in it and seeing it it produces a focused image). Where the bottom of the eyepiece sits in the tube is about where the image is, and the eyepiece collects it and brings it up so to speak.

The generic 2x is the 100 dollar one. You can get them a bit cheaper from other sellers on eBay. I would not get one in this case though. Better to find a third eyepiece and a 40mm pancake lens for your camera. The pancake lens, focused to infinity and suspended right over the eyepiece, will usually give you a very nice image.

diggitydawg
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Re: Does a DSLR adapter need a lens in it?

#6 Post by diggitydawg » Sun Dec 15, 2019 6:16 pm

Scarodactyl wrote:
Sat Dec 14, 2019 7:15 pm
The trinoc port has a 23mm opeing at the top, so it is basically a third ocular. If you stick an eyepiece in there it will work like the other two (not all of them are set up quite like this, but they tend to be. You can test by trying one of your oculars in it and seeing it it produces a focused image). Where the bottom of the eyepiece sits in the tube is about where the image is, and the eyepiece collects it and brings it up so to speak.

The generic 2x is the 100 dollar one. You can get them a bit cheaper from other sellers on eBay. I would not get one in this case though. Better to find a third eyepiece and a 40mm pancake lens for your camera. The pancake lens, focused to infinity and suspended right over the eyepiece, will usually give you a very nice image.
thanks again. Ahh, I see. But in the case of the pancake lens, how would I suspend it, some kind of rig? or is there a standard setup people use?

When you say it would be better, do you mean better quality?

apochronaut
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Re: Does a DSLR adapter need a lens in it?

#7 Post by apochronaut » Sun Dec 15, 2019 11:18 pm

All of the eyepiece type adapters; those that are designed to fit INTO your 23.2mm eyepiece tube impose limitations on your ability to make good photos and capture a full microscope field. They don't tell you this stuff in their product literature. You can't use a photo eyepiece with the 12.99 adapter because the adapter is already in the ocular tube. The more expensive adapter also goes into the tube but has a built in lens, which is unlikely to produce good well corrected images with corner to corner sharpness, and a flat field. Photo eyepieces or lenses that do that, cost 3 times the price of that adapter. Both of those systems are mediocre and if you want to obtain pictures that challenge the ability of your Canon 7D to capture them, you will need a bit of D.I.Y'ing.

First: If your Swift does not have plan objectives, you need to upgrade them to plan.
Second: The expensive adapter above , is a waste of money. You want something like the 12.99 one but one that fits outside the ocular tube and also one made to accept M 42 threads, not your camera bayonet. Like this one : https://www.ebay.com/itm/1-25inch-T-Mou ... SwNpRb8ii4 . You then get an M42 to EOS adapter., like this :https://www.ebay.com/itm/M42-mount-lens ... Sw0xtb~PwG. You drill and tap 6 holes in the insert part of the telescope adapter to take 6 nylon thumbscrews. You then attach your adapter to the outside of the microscope trinocular tube. This allows you to move the adapter up and down the tube a bit in order to increase or decrease the field coverage some. That gets an adapter in place that can mount your camera and as well allows you to install a usefull photo eyepiece inside it. The next part you need is a focusing helicoid extension that goes between the telescope adapter and the M42-EOS adapter, such as this: https://www.ebay.com/itm/M42-to-M42-Adj ... SwFV9XyTez These come in several variable lengths in a series from 12mm to 90mm. Since your sensor is APS-C, you will need an extension , somewhere in the neighbourhood of 50mm, from the eyepiece to the sensor in order to fill the sensor with the maximum field. That will depend on which eyepiece you use too.
You can't just put any photo eyepiece in there and expect excellent results. That will take some playing around. The idea is to match the eyepiece magnification and corrections with your objectives, tube length and sensor size. I have enough of this stuff floating around here; even Swift 160mm objectives and photo eyepieces too, to do some tests for you on a 160mm system. Once you have a ballpark for the length, you can go ahead and order the length of helicoid focuser that will cover your needs for extension. You can also use extension tubes but I have found that these inexpensive helicoid focusers work very well and allow for more precise setting of the field to frame relationship. I will take a few minutes tomorrow morning and report back.

Scarodactyl
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Re: Does a DSLR adapter need a lens in it?

#8 Post by Scarodactyl » Mon Dec 16, 2019 2:17 am

I agree you shouldn't bother with either of the adapters in the original post.
Using a photo eyepiece will work very well if you can find a compatible one (and it's quite likely Apo will be able to tell you what you need for that, given his extensive experience with these lenses). The alternative of using a 40mm pancake lens over an eyepiece is nice because it doesn't require a more specialized and sometimes-hard-to-find photo eyepiece, just a normal viewing eyepiece. However it doesn't always work (it requires the eyepiece to have a sufficiently high eyepoint for the lens to pick up) and it also has the hefty cost of buying a nice pancake 40mm lens built in (a canon 40mm pancake ran me 90 usd plus shipping). Mounting the lens above the eyepiece is something of an exercise in improvisation, since you need to either suspend it independently above the eyepiece on its own stand, or find some sort of clamping mechanism like Apochronaut described in his post to hold onto the outside of the trinoc port and screw onto the ocular. I can tell you exactly how I've done it on a Leitz system but I've never worked on a Swift so you'll need to take some measurements to find an appropriate clamp for this system.

diggitydawg
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Re: Does a DSLR adapter need a lens in it?

#9 Post by diggitydawg » Mon Dec 16, 2019 2:30 am

apochronaut wrote:
Sun Dec 15, 2019 11:18 pm
All of the eyepiece type adapters; those that are designed to fit INTO your 23.2mm eyepiece tube impose limitations on your ability to make good photos and capture a full microscope field. They don't tell you this stuff in their product literature. You can't use a photo eyepiece with the 12.99 adapter because the adapter is already in the ocular tube. The more expensive adapter also goes into the tube but has a built in lens, which is unlikely to produce good well corrected images with corner to corner sharpness, and a flat field. Photo eyepieces or lenses that do that, cost 3 times the price of that adapter. Both of those systems are mediocre and if you want to obtain pictures that challenge the ability of your Canon 7D to capture them, you will need a bit of D.I.Y'ing.

First: If your Swift does not have plan objectives, you need to upgrade them to plan.
Second: The expensive adapter above , is a waste of money. You want something like the 12.99 one but one that fits outside the ocular tube and also one made to accept M 42 threads, not your camera bayonet. Like this one : https://www.ebay.com/itm/1-25inch-T-Mou ... SwNpRb8ii4 . You then get an M42 to EOS adapter., like this :https://www.ebay.com/itm/M42-mount-lens ... Sw0xtb~PwG. You drill and tap 6 holes in the insert part of the telescope adapter to take 6 nylon thumbscrews. You then attach your adapter to the outside of the microscope trinocular tube. This allows you to move the adapter up and down the tube a bit in order to increase or decrease the field coverage some. That gets an adapter in place that can mount your camera and as well allows you to install a usefull photo eyepiece inside it. The next part you need is a focusing helicoid extension that goes between the telescope adapter and the M42-EOS adapter, such as this: https://www.ebay.com/itm/M42-to-M42-Adj ... SwFV9XyTez These come in several variable lengths in a series from 12mm to 90mm. Since your sensor is APS-C, you will need an extension , somewhere in the neighbourhood of 50mm, from the eyepiece to the sensor in order to fill the sensor with the maximum field. That will depend on which eyepiece you use too.
You can't just put any photo eyepiece in there and expect excellent results. That will take some playing around. The idea is to match the eyepiece magnification and corrections with your objectives, tube length and sensor size. I have enough of this stuff floating around here; even Swift 160mm objectives and photo eyepieces too, to do some tests for you on a 160mm system. Once you have a ballpark for the length, you can go ahead and order the length of helicoid focuser that will cover your needs for extension. You can also use extension tubes but I have found that these inexpensive helicoid focusers work very well and allow for more precise setting of the field to frame relationship. I will take a few minutes tomorrow morning and report back.
Wow, thanks so much for the detailed reply!

Let me see if I understand this correctly, please correct me if I'm wrong. It will have: eyepiece (like my 25x that I currently use to look through) inside the trinocular tube, then the T-mount to M42 adapter is connected to the *outside* of the trinocular tube, held there by the nylon screws, then the helicoid extension is connected to the M42 side of the adapter, and then the M42 to EOS is attached to the top of that, which connects to my camera?

So these helicoid extenders, they're adjustable, to let me hit the exact height? and they'll stay at that height (and not slide down under the camera weight) ?

So I'm guessing that the setup, at a given height, will only work for one objective magnification, is that right?

diggitydawg
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Re: Does a DSLR adapter need a lens in it?

#10 Post by diggitydawg » Mon Dec 16, 2019 2:51 am

Scarodactyl wrote:
Mon Dec 16, 2019 2:17 am
I agree you shouldn't bother with either of the adapters in the original post.
Using a photo eyepiece will work very well if you can find a compatible one (and it's quite likely Apo will be able to tell you what you need for that, given his extensive experience with these lenses). The alternative of using a 40mm pancake lens over an eyepiece is nice because it doesn't require a more specialized and sometimes-hard-to-find photo eyepiece, just a normal viewing eyepiece. However it doesn't always work (it requires the eyepiece to have a sufficiently high eyepoint for the lens to pick up) and it also has the hefty cost of buying a nice pancake 40mm lens built in (a canon 40mm pancake ran me 90 usd plus shipping). Mounting the lens above the eyepiece is something of an exercise in improvisation, since you need to either suspend it independently above the eyepiece on its own stand, or find some sort of clamping mechanism like Apochronaut described in his post to hold onto the outside of the trinoc port and screw onto the ocular. I can tell you exactly how I've done it on a Leitz system but I've never worked on a Swift so you'll need to take some measurements to find an appropriate clamp for this system.
Yeah, I'd like to avoid buying another lens for my DSLR...I plan to go mirrorless in the near future ;)

I'm pretty handy and have some machining experience, so I don't mind having to do some building. I'm kind of confused though: isn't attaching a DSLR to a microscope a pretty common thing? do most people end up doing a homemade DIY solution, or do they just buy dedicated microscope cameras?

Here (pdf) is the manual for my specific Swift microscope, btw: http://swiftoptical.com/uploads/pdf/SW350TManual.pdf you can see that it actually has several threadings in an adapter that lead up to putting the eyepiece in.

apochronaut
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Re: Does a DSLR adapter need a lens in it?

#11 Post by apochronaut » Mon Dec 16, 2019 1:27 pm

diggitydawg wrote:
Mon Dec 16, 2019 2:30 am
apochronaut wrote:
Sun Dec 15, 2019 11:18 pm
All of the eyepiece type adapters; those that are designed to fit INTO your 23.2mm eyepiece tube impose limitations on your ability to make good photos and capture a full microscope field. They don't tell you this stuff in their product literature. You can't use a photo eyepiece with the 12.99 adapter because the adapter is already in the ocular tube. The more expensive adapter also goes into the tube but has a built in lens, which is unlikely to produce good well corrected images with corner to corner sharpness, and a flat field. Photo eyepieces or lenses that do that, cost 3 times the price of that adapter. Both of those systems are mediocre and if you want to obtain pictures that challenge the ability of your Canon 7D to capture them, you will need a bit of D.I.Y'ing.

First: If your Swift does not have plan objectives, you need to upgrade them to plan.
Second: The expensive adapter above , is a waste of money. You want something like the 12.99 one but one that fits outside the ocular tube and also one made to accept M 42 threads, not your camera bayonet. Like this one : https://www.ebay.com/itm/1-25inch-T-Mou ... SwNpRb8ii4 . You then get an M42 to EOS adapter., like this :https://www.ebay.com/itm/M42-mount-lens ... Sw0xtb~PwG. You drill and tap 6 holes in the insert part of the telescope adapter to take 6 nylon thumbscrews. You then attach your adapter to the outside of the microscope trinocular tube. This allows you to move the adapter up and down the tube a bit in order to increase or decrease the field coverage some. That gets an adapter in place that can mount your camera and as well allows you to install a usefull photo eyepiece inside it. The next part you need is a focusing helicoid extension that goes between the telescope adapter and the M42-EOS adapter, such as this: https://www.ebay.com/itm/M42-to-M42-Adj ... SwFV9XyTez These come in several variable lengths in a series from 12mm to 90mm. Since your sensor is APS-C, you will need an extension , somewhere in the neighbourhood of 50mm, from the eyepiece to the sensor in order to fill the sensor with the maximum field. That will depend on which eyepiece you use too.
You can't just put any photo eyepiece in there and expect excellent results. That will take some playing around. The idea is to match the eyepiece magnification and corrections with your objectives, tube length and sensor size. I have enough of this stuff floating around here; even Swift 160mm objectives and photo eyepieces too, to do some tests for you on a 160mm system. Once you have a ballpark for the length, you can go ahead and order the length of helicoid focuser that will cover your needs for extension. You can also use extension tubes but I have found that these inexpensive helicoid focusers work very well and allow for more precise setting of the field to frame relationship. I will take a few minutes tomorrow morning and report back.
Wow, thanks so much for the detailed reply!

Let me see if I understand this correctly, please correct me if I'm wrong. It will have: eyepiece (like my 25x that I currently use to look through) inside the trinocular tube, then the T-mount to M42 adapter is connected to the *outside* of the trinocular tube, held there by the nylon screws, then the helicoid extension is connected to the M42 side of the adapter, and then the M42 to EOS is attached to the top of that, which connects to my camera?

So these helicoid extenders, they're adjustable, to let me hit the exact height? and they'll stay at that height (and not slide down under the camera weight) ?

So I'm guessing that the setup, at a given height, will only work for one objective magnification, is that right?
You have most of it correct and bear in mind that this is about the least expensive way to go about this. There are alternate systems for sure, some off the shelf at 700.00. Your choice.
The set up would do as you understand it to but you can't use 25X eyepieces. You will need to use whatever eyepieces collect the maximum possible f.o.v. from the microscope objective and as well fill the sensor. Parfocality would be a bonus. My guess is that you will be using somewhere around a 5X for the photo tube. Since you are probably using non-plan objectives, that complicates things because you will only be able to use a portion of the circle created by the objective. The rest will contain too much distortion and aberration. Plan objectives are a must for quality photography.
DSLRs aren't the best design for photographing on a microscope. They became the tool of choice for hotshots because they were the only game in town that had a full frame. Now that mirrorless full frame cameras are gaining traction, they will take over. If I was doing it , I would buy an APS-C mirrorless body but since what you have, is an APS-C DSLR; the idea is to make it work. The system as described is pretty stable, as long as the workmanship on the adapter tube is good. You may need to use the mirror lock up function on your DSLR. Your objectives should be parfocal or thereabouts, so the camera system should focus well with all of your objectives. There will need to be a bit more of trimming with long working distance low power objectives.

Why are you using 25X eyepieces? They have no reasonable possibility of providing decent images beyond any objective magnification of 10X. The technical reasons for this are found in any discussion regarding empty magnification. It has been brought forward dozens of times on this forum and references can be found on line. 25X eyepieces have some relevance to stereo microscopy and used to be of value with older apochromatic systems, allowing one to use a 10X objective at 250X in order to increase working distance some but they have little relevance to an average achromatic microscope.

The optics provided for your Swift microscope are primarily for C mount cameras and dedicated microscope cameras with very small sensors. As the sensor size increases, the optics and often the photo tube length must change in order to fill the sensor.

diggitydawg
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Re: Does a DSLR adapter need a lens in it?

#12 Post by diggitydawg » Mon Dec 16, 2019 2:49 pm

apochronaut wrote:
Mon Dec 16, 2019 1:27 pm

You have most of it correct and bear in mind that this is about the least expensive way to go about this. There are alternate systems for sure, some off the shelf at 700.00. Your choice.
The set up would do as you understand it to but you can't use 25X eyepieces. You will need to use whatever eyepieces collect the maximum possible f.o.v. from the microscope objective and as well fill the sensor. Parfocality would be a bonus. My guess is that you will be using somewhere around a 5X for the photo tube. Since you are probably using non-plan objectives, that complicates things because you will only be able to use a portion of the circle created by the objective. The rest will contain too much distortion and aberration. Plan objectives are a must for quality photography.
DSLRs aren't the best design for photographing on a microscope. They became the tool of choice for hotshots because they were the only game in town that had a full frame. Now that mirrorless full frame cameras are gaining traction, they will take over. If I was doing it , I would buy an APS-C mirrorless body but since what you have, is an APS-C DSLR; the idea is to make it work. The system as described is pretty stable, as long as the workmanship on the adapter tube is good. You may need to use the mirror lock up function on your DSLR. Your objectives should be parfocal or thereabouts, so the camera system should focus well with all of your objectives. There will need to be a bit more of trimming with long working distance low power objectives.

Why are you using 25X eyepieces? They have no reasonable possibility of providing decent images beyond any objective magnification of 10X. The technical reasons for this are found in any discussion regarding empty magnification. It has been brought forward dozens of times on this forum and references can be found on line. 25X eyepieces have some relevance to stereo microscopy and used to be of value with older apochromatic systems, allowing one to use a 10X objective at 250X in order to increase working distance some but they have little relevance to an average achromatic microscope.

The optics provided for your Swift microscope are primarily for C mount cameras and dedicated microscope cameras with very small sensors. As the sensor size increases, the optics and often the photo tube length must change in order to fill the sensor.
thanks again!

I definitely don't mind buying at least one plan objective. I can have one plan obj that's just for photography.

I understand about the eyepiece and the MILC; hopefully sometime in the future I'll replace the system with a nice setup for a Sony a6300 or something.

Do I need to use the mirror lockup if I'm using live view? or, is that what you mean by it? because I think that's what live view does...

Ah, I don't have any great reason for using the 25x's. I know about empty magnification, but didn't know it applied to them, so thanks for letting me know.

thanks, this is all a great learning experience.

diggitydawg
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Re: Does a DSLR adapter need a lens in it?

#13 Post by diggitydawg » Mon Dec 16, 2019 4:32 pm

So I think I found a few combined parts on amazon that should help me, tell me if this looks right:

This should get me the T-mount to M42 (male) adapter, as well as the M42 (female) to EOS camera mount adapter: https://www.amazon.com/Gosky-Telescope- ... 013DID11A/

then, one of these should get me a M42 (female) to M42 (male) helicoid focus extension: https://www.amazon.com/Fotasy-Helicord- ... 019GKN22M/

And then I'll need a 5x eyepiece, would one like this be good? https://www.amazon.com/Optical-Huygens- ... 07PN99BJN/

I also found this one, that might have the both the parts the first link had, in addition to an extender tube? https://www.amazon.com/SVBONY-Photograp ... 0114BB908/

thanks!

Hugonl35
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Re: Does a DSLR adapter need a lens in it?

#14 Post by Hugonl35 » Mon Dec 16, 2019 5:26 pm

I'm also interested in using my Canon 80D (APS-C) on a standard 23.2mm tube, would this 2x adapter work?

https://www.optics-pro.com/camera-adapt ... n-/p,53926

With this adapter ring to Canon EF Mount:

https://www.optics-pro.com/camera-adapt ... os/p,47716

I read somewhere that an APS-C sensor needs about a 1.3x magnification for the eye tube image to fill the whole sensor and a full frame needs about 2x magnification? I already bought a c-mount camera with 1/2.3 inch sensor for my stereo microscope that will hopefully mount without any problems, using a 0.5x adapter, but I'm assuming it's not the greatest quality. This is why for my compound microscope I'd like to venture into APS-C size sensor.

Scarodactyl
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Re: Does a DSLR adapter need a lens in it?

#15 Post by Scarodactyl » Mon Dec 16, 2019 5:41 pm

That's exactly the same adapter that Amscope sells, just photographed from a different angle.

Hugonl35
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Re: Does a DSLR adapter need a lens in it?

#16 Post by Hugonl35 » Mon Dec 16, 2019 6:01 pm

Scarodactyl wrote:
Mon Dec 16, 2019 5:41 pm
That's exactly the same adapter that Amscope sells, just photographed from a different angle.
I understand it's the same principle, with the same form factor, I never thought it could be the exact same product :shock: I was just hoping that because it's 3x the price of Amscope that it might be 3x the quality..

Maybe I should just go for an expensive one, like from lmscope (https://www.lmscope.com/en/Leistungsmer ... er_en.html) which apparently uses "plan achromatic precision optics"

According this PDF (https://www.lmscope.com/pdf/FOV_LM_Digi ... ter_en.pdf) it can produce the full FOV of a 10x piece on an APS-C sensor (picture 8).

I will be mounting it on an infinity plan apochromatic system, so probably even the expensive lmscope adapter might bring in some color shifting, spoiling the apochromatic image of the objectives? Well any way, my main focus isn't photography, just observation and projecting it on a larger screen, with the occasional picture.

apochronaut
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Re: Does a DSLR adapter need a lens in it?

#17 Post by apochronaut » Mon Dec 16, 2019 6:38 pm

Hugonl35 wrote:
Mon Dec 16, 2019 6:01 pm
Scarodactyl wrote:
Mon Dec 16, 2019 5:41 pm
That's exactly the same adapter that Amscope sells, just photographed from a different angle.
I understand it's the same principle, with the same form factor, I never thought it could be the exact same product :shock: I was just hoping that because it's 3x the price of Amscope that it might be 3x the quality..

Maybe I should just go for an expensive one, like from lmscope (https://www.lmscope.com/en/Leistungsmer ... er_en.html) which apparently uses "plan achromatic precision optics"

According this PDF (https://www.lmscope.com/pdf/FOV_LM_Digi ... ter_en.pdf) it can produce the full FOV of a 10x piece on an APS-C sensor (picture 8).

I will be mounting it on an infinity plan apochromatic system, so probably even the expensive lmscope adapter might bring in some color shifting, spoiling the apochromatic image of the objectives? Well any way, my main focus isn't photography, just observation and projecting it on a larger screen, with the occasional picture.
you should start your own thread. diggitydawg is kind of in limbo at the moment and needs to sort this stuff out.

Hugonl35
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Re: Does a DSLR adapter need a lens in it?

#18 Post by Hugonl35 » Mon Dec 16, 2019 6:43 pm

apochronaut wrote:
Mon Dec 16, 2019 6:38 pm
you should start your own thread. diggitydawg is kind of in limbo at the moment and needs to sort this stuff out.
You're right, I'm sorry. Following the DIY solution with interest.

apochronaut
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Re: Does a DSLR adapter need a lens in it?

#19 Post by apochronaut » Mon Dec 16, 2019 7:22 pm

diggitydawg wrote:
Mon Dec 16, 2019 4:32 pm
So I think I found a few combined parts on amazon that should help me, tell me if this looks right:

This should get me the T-mount to M42 (male) adapter, as well as the M42 (female) to EOS camera mount adapter: https://www.amazon.com/Gosky-Telescope- ... 013DID11A/

then, one of these should get me a M42 (female) to M42 (male) helicoid focus extension: https://www.amazon.com/Fotasy-Helicord- ... 019GKN22M/

And then I'll need a 5x eyepiece, would one like this be good? https://www.amazon.com/Optical-Huygens- ... 07PN99BJN/

I also found this one, that might have the both the parts the first link had, in addition to an extender tube? https://www.amazon.com/SVBONY-Photograp ... 0114BB908/

thanks!
The first adapter will help get you there. As far as jumping in and buying a specific length helicoid focuser or a particular eyepiece at the moment, that is a bit premature. You don't know quite yet what amount of tube extension you need because you don't know what photo eyepiece is going to be best for the job. I can't overemphasize the importance of that photo eyepiece. It is going to be the lens of your camera, demanded on to replicate a magnified image as exactly as is possible. No one would buy a 10.00 lens for their camera, would they?
You have to look at it this way. The objective lens is required to produce an intermediate image of the object as faithfully as is possible, just like a 500.00 camera lens is expected to do. Objective lenses produce some level of distortion in that intermediate image, from lots to minimum. One common distortion is curvature of field, which plagues standard non-plan objectives. Using a common eyepiece to pick up the intermediate image, magnify and project it to your sensor, will not do anything to correct for any distortion created by the objective. Using a standard achromat objective and a common huygens eyepiece will result in only about 30% of the center of the field to be in focus and reasonably well corrected. So, on a sensor like yours, that amounts to only about 7-8mm in the middle, with increasing distortion towards the periphery.
Some photo eyepieces can partially correct for the defects that a standard achromat exhibits but they will never correct fully. In order to expect corner to corner sharpness and freedom from a number of distortions and malcorrections that microscope objective lenses can display, you need at least to have a planchromat and a perfectly compatible or even somewhat compensating eyepiece....and of the correct magnification.
In a standard optical tube of 160mm, eyepieces are somewhat predictable. A 10X, picking the intermediate image at the correct point in the tube , will magnify pretty close to 10X. With photo tubes, there is no R.M.S. standard adhered to. Sometimes the eyepiece is marked with the photo tube length, as with Olympus FK photo eyepieces. It is 125mm but when you put an Olympus FK 5X eyepiece in a photo tube of 200mm, it is no longer 5X. It is more like 8X and it's corrections are off. Most photo eyepieces do not tell you what tube length they are corrected for.
Unfortunately, when one has strayed from the tried and true with photo tubes and is setting up a camera system different than the one it was engineered for, all bets are off. There are some guidelines but to make the best system possible, trial and error is the only way to go. Sometimes you can get lucky and find someone that has opened that door in advance. Sometimes they are willing to continue to hold it open for you.

Hobbyst46
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Re: Does a DSLR adapter need a lens in it?

#20 Post by Hobbyst46 » Mon Dec 16, 2019 8:06 pm

Hi,
Apochronaut suggested a 1.25" adapter that needs some drilling and tapping to fit 6 locking thumbscrews.
Here is a somewhat similar adapter, that already has 3 such screws, from a UK seller:
https://www.ebay.co.uk/itm/One-1-25-Tel ... xy9eVRSxgO
(there are other sellers of similar items).

This has been originally mentioned by David Walker in Microscopy-UK years ago. I followed this track. Only that I had a custom mill-fabricated PVC sleeve to fill the space between the the outer diameter of my phototube (25mm) and the inner diameter of the telescope adapter, so the thumb screws only travel a small distance inside. That improves the mechanical stability of the assembly, in my opinion.

Another important point for photography - Canon DSLR's can be directly tethered to a personal computer, whereas Canon mirrorless cameras cannot (exceptions: EOS-M50 and EOS-R).
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

apochronaut
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Re: Does a DSLR adapter need a lens in it?

#21 Post by apochronaut » Mon Dec 16, 2019 8:51 pm

Without a spacer between the adapter and the phototube, 3 screws allows a fair amount of wiggle in the system. 6 screws spaced as wide apart as is possible vertically allows for much enhanced stability as well as a fair amount of precision control to adjust pitch. Metal screws can be a problem because when adjusting with 3 only, there could be a tendency to overtighten them due to the lessened stability. Thinner tubes could be crushed or dented a bit. 6 nylon thumbscrews, tighten enough and when accidentally overtightened will lose their threads becoming sacrificial, rather than damage the tube. Buying extra thumbscrews is a good idea. I bought 40 originally and have exhausted my supply, building such systems. I think only one had to be replaced so far.

apochronaut
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Re: Does a DSLR adapter need a lens in it?

#22 Post by apochronaut » Tue Dec 17, 2019 12:51 am

I spent a bit of time with some eyepieces and a 40X .65 Chinese made achromat objective, quite similar to what you have in your microscope. All of the photo eyepieces, Kyowa, several Olympus and Nikon, did not produce an image circle large enough to capture to the edge of a 20mm f.o.v. and in all cases the peripheral corrections were not great. Some of the other of the 20 or so eyepieces I trialled were better, in all ways but none provided the ability to photograph the entire visual field without fairly evident chroma .
Two of them were a little better,than the others, providing some corrections for the deficiencies in the objective outside of it's sweet spot. Those being a Wild 6X K H and a Reichert Plan 5X. Both produced an image circle of reasonable flatness almost identical to the visual field and although not exactly parfocal, they are pretty close.
I did also try a couple of older generic Huygens 5 X. One very old one, going back into the 20's wasn't too bad ; the other, also about that old was very poor, with lots of chromatic aberration off axis. It is possible the former is in fact a compensating eyepiece because it performs about as good as another 5X I tried that was compensating.
The system positioned the top surface of the photo eyepiece eyelens at between 190 and 200mm from the objective shoulder, depending on whether the eyelens mount was thick or thin. The mount for the APS-C camera needed to be a further 90 or so mm to the sensor from the eyelens, in order to fill the camera frame.
I did trial one 10X compensating , a fairly recent Vickers W.F. compens and it was able to fill the camera frame at much less elevation albeit with slightly more lateral c.a. than the Wild 6X.

The better of the eyepieces still require some cropping or post processing in order to get them c.a. free.

That should help you get your measurements.

Images below of a bone section.
1) Wild 6X k H
2) Reichert plan 5X
3) Unbranded Huygens 5X
Attachments
DSC03103 (1280x852).jpg
DSC03103 (1280x852).jpg (266.61 KiB) Viewed 1396 times
DSC03110 (1280x852).jpg
DSC03110 (1280x852).jpg (235.79 KiB) Viewed 1396 times
DSC03106 (1280x852).jpg
DSC03106 (1280x852).jpg (245.06 KiB) Viewed 1396 times

diggitydawg
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Re: Does a DSLR adapter need a lens in it?

#23 Post by diggitydawg » Tue Dec 17, 2019 9:43 pm

apochronaut wrote:
Mon Dec 16, 2019 7:22 pm
diggitydawg wrote:
Mon Dec 16, 2019 4:32 pm
So I think I found a few combined parts on amazon that should help me, tell me if this looks right:

This should get me the T-mount to M42 (male) adapter, as well as the M42 (female) to EOS camera mount adapter: https://www.amazon.com/Gosky-Telescope- ... 013DID11A/

then, one of these should get me a M42 (female) to M42 (male) helicoid focus extension: https://www.amazon.com/Fotasy-Helicord- ... 019GKN22M/

And then I'll need a 5x eyepiece, would one like this be good? https://www.amazon.com/Optical-Huygens- ... 07PN99BJN/

I also found this one, that might have the both the parts the first link had, in addition to an extender tube? https://www.amazon.com/SVBONY-Photograp ... 0114BB908/

thanks!
The first adapter will help get you there. As far as jumping in and buying a specific length helicoid focuser or a particular eyepiece at the moment, that is a bit premature. You don't know quite yet what amount of tube extension you need because you don't know what photo eyepiece is going to be best for the job. I can't overemphasize the importance of that photo eyepiece. It is going to be the lens of your camera, demanded on to replicate a magnified image as exactly as is possible. No one would buy a 10.00 lens for their camera, would they?
You have to look at it this way. The objective lens is required to produce an intermediate image of the object as faithfully as is possible, just like a 500.00 camera lens is expected to do. Objective lenses produce some level of distortion in that intermediate image, from lots to minimum. One common distortion is curvature of field, which plagues standard non-plan objectives. Using a common eyepiece to pick up the intermediate image, magnify and project it to your sensor, will not do anything to correct for any distortion created by the objective. Using a standard achromat objective and a common huygens eyepiece will result in only about 30% of the center of the field to be in focus and reasonably well corrected. So, on a sensor like yours, that amounts to only about 7-8mm in the middle, with increasing distortion towards the periphery.
Some photo eyepieces can partially correct for the defects that a standard achromat exhibits but they will never correct fully. In order to expect corner to corner sharpness and freedom from a number of distortions and malcorrections that microscope objective lenses can display, you need at least to have a planchromat and a perfectly compatible or even somewhat compensating eyepiece....and of the correct magnification.
In a standard optical tube of 160mm, eyepieces are somewhat predictable. A 10X, picking the intermediate image at the correct point in the tube , will magnify pretty close to 10X. With photo tubes, there is no R.M.S. standard adhered to. Sometimes the eyepiece is marked with the photo tube length, as with Olympus FK photo eyepieces. It is 125mm but when you put an Olympus FK 5X eyepiece in a photo tube of 200mm, it is no longer 5X. It is more like 8X and it's corrections are off. Most photo eyepieces do not tell you what tube length they are corrected for.
Unfortunately, when one has strayed from the tried and true with photo tubes and is setting up a camera system different than the one it was engineered for, all bets are off. There are some guidelines but to make the best system possible, trial and error is the only way to go. Sometimes you can get lucky and find someone that has opened that door in advance. Sometimes they are willing to continue to hold it open for you.
First of all, thanks again for all the help!

okay, I think I see what you're saying, that there's no easy formula here and I need to do some experimentation. I'm trying to figure out what to get so I can do that.

I'm a bit confused. You said that I should get a plan objective. I can do that as long as it's not too expensive. But your photos are taken with a cheap 40x achromat objective like mine, right? I assume I need to get the objective, and then get an eyepiece that matches it, and then get the right helicoid adapter to match the necessary length. Is that right?

apochronaut
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Re: Does a DSLR adapter need a lens in it?

#24 Post by apochronaut » Tue Dec 17, 2019 11:57 pm

I trialed various eyepieces and took some pictures in order to approximate as much as possible what your system is capable of. It also should be noted that the camera sensor exagerrates chromatic aberration. The visual image that the Wild 6X eyepiece provides is actually quite good. I was a bit surprised, when the camera image displayed the level of peripheral chroma that it did.

Plan objectives will improve that considerably but they too will be achromats, so some residual ca will still be there. Some people don't mind it, some do and there are ways of removing it. A bigger problem might be coma, which all of the images show to more or less of a degree. Plan objectives also solve coma more or less, depending on how "plan" they are.

There is no necessity to have the diameter of the field captured to the sensor, equal the visual field. That's just the starting point that I like to aim for. I'm a microscopist first and a photographer second, so I like to see in the camera, what I see in the microscope field. One can adjust the height of the camera and or use a relay lens that provides a smaller image circle to the sensor, effectively boosting the magnification. An APS-C camera frame is pretty close to a 20mm f.o.v. in diameter ; about 10% larger, so if it is capturing only the center 55% of a 20mm f.o.v. visual field provided by a 10X objective, then it is effectively imaging as though a 20X objective were being used. However, vignetting the microscope frame in this way, cuts off a considerable portion of the poorly corrected or distorted portion of the image circle that a conventonal objective displays, thereby providing a photo that has better corner to corner image quality, albeit not representative of what was viewed through the eyepieces. For many, that is acceptible. Using a smaller sensor, as is the case with most budget microscope camera systems is another way of cropping out the periphery. It is an unfortunate fact, that the larger your camera sensor is, the better your microscope optics need to be to effectively utilize it, better in this case meaning as flat, large and aberration free an image circle as possible.

If therefore, one wants to maximize their use of an APS-C sensor, and avoid as much cropping and post processing as possible, I would think that the best tack to take is to get the objectives with the largest clean image circle as one can afford.

It is unlikely that a plan objective will alter the physical aspects of the system that much. I would be looking for a good plan or set that you can afford. The Chinese ones are not expensive and outside of infinity corrected series', it is doubtfull whether there is that much of a difference between them. They have been making the same designs since the 1980's. The vertical measurements that I calculated should be pretty close for whatever plan optics you employ. The helicoid focuser, doesn't really focus much when it is installed to move the camera up and down, while the optic stays stationary in the tube. It more regulates the diameter of the image circle, so you build up the physical distance to include a helicoid focuser between the modified telescope adapter and the M42-EOS adapter. In the system that I tested , if I were to allow 25mm of the total length to be taken up by the helicoid focuser, then a helicoid focuser that stretches from 17mm to 31mm would probably do fine. Low power objectives lose working distance as they are focused to a sensor on a longer photo tube and some describe a narrower image circle, so having more latitude in the helicoid focuser is better from that standpoint but any adjustable device becomes less physically rigid the more it is extended. Sometimes, objectives need to be shimmed in order to close the parfocal gap between them.

As far as an optic for yor system goes? I don't think you can go wrong with one of those Wild 6X K H eyepieces. I have used one with objectives that have much better peripheral correction than that Chinese achromat and it provided excellent images. Sometimes it takes a little time to get everything right and a change in optics might eventually be in order. With one of my systems, I was never pleased with the outcome for years. I wouldn't see chroma visually, then in the photos, a small amount would show up. One day , I tried an eyepiece ftom a stereomic as a relay lens and it was perfect. With these 23. 2mm eyepiece tube photo systems the relay lens isn't permanently installed. If one comes along that does a better job, it's as simple as one out and one in.
As far as objectives go; you are stuck with those of 45mm parfocal 160mm tube length . Fortunately, there were a lot of good ones made in that format. If you buy one plan objective, the Chinese ones are cheap but I have seen some really good deals on sets of really good brands that aren't sexy. Cooke-Baker/Vickers, tops the list at 100.00 for 4 Vickers Microplans and PZO are often cheap. You could probably nab a set of those, for not much more. I suspect that since most of the 45mm parfocal objectives made by the major companies , were made to provide an image circle for anywhere from 35mm to 4 x 5 with excellent correction and resolutiion that the chances of them being capable of meeting the requirements of an APS-C system would be pretty good. If you go looking for Vickers, be advised that they made a lot of Metallographs and metallurgical microscopes. Many of the objectives are marked MET, which use no cover glass and are not suitable for your requirements. The cover and no cover in that brand look very similar.

diggitydawg
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Re: Does a DSLR adapter need a lens in it?

#25 Post by diggitydawg » Fri Dec 20, 2019 4:16 pm

apochronaut wrote:
Tue Dec 17, 2019 11:57 pm
I trialed various eyepieces and took some pictures in order to approximate as much as possible what your system is capable of. It also should be noted that the camera sensor exagerrates chromatic aberration. The visual image that the Wild 6X eyepiece provides is actually quite good. I was a bit surprised, when the camera image displayed the level of peripheral chroma that it did.

Plan objectives will improve that considerably but they too will be achromats, so some residual ca will still be there. Some people don't mind it, some do and there are ways of removing it. A bigger problem might be coma, which all of the images show to more or less of a degree. Plan objectives also solve coma more or less, depending on how "plan" they are.

There is no necessity to have the diameter of the field captured to the sensor, equal the visual field. That's just the starting point that I like to aim for. I'm a microscopist first and a photographer second, so I like to see in the camera, what I see in the microscope field. One can adjust the height of the camera and or use a relay lens that provides a smaller image circle to the sensor, effectively boosting the magnification. An APS-C camera frame is pretty close to a 20mm f.o.v. in diameter ; about 10% larger, so if it is capturing only the center 55% of a 20mm f.o.v. visual field provided by a 10X objective, then it is effectively imaging as though a 20X objective were being used. However, vignetting the microscope frame in this way, cuts off a considerable portion of the poorly corrected or distorted portion of the image circle that a conventonal objective displays, thereby providing a photo that has better corner to corner image quality, albeit not representative of what was viewed through the eyepieces. For many, that is acceptible. Using a smaller sensor, as is the case with most budget microscope camera systems is another way of cropping out the periphery. It is an unfortunate fact, that the larger your camera sensor is, the better your microscope optics need to be to effectively utilize it, better in this case meaning as flat, large and aberration free an image circle as possible.

If therefore, one wants to maximize their use of an APS-C sensor, and avoid as much cropping and post processing as possible, I would think that the best tack to take is to get the objectives with the largest clean image circle as one can afford.

It is unlikely that a plan objective will alter the physical aspects of the system that much. I would be looking for a good plan or set that you can afford. The Chinese ones are not expensive and outside of infinity corrected series', it is doubtfull whether there is that much of a difference between them. They have been making the same designs since the 1980's. The vertical measurements that I calculated should be pretty close for whatever plan optics you employ. The helicoid focuser, doesn't really focus much when it is installed to move the camera up and down, while the optic stays stationary in the tube. It more regulates the diameter of the image circle, so you build up the physical distance to include a helicoid focuser between the modified telescope adapter and the M42-EOS adapter. In the system that I tested , if I were to allow 25mm of the total length to be taken up by the helicoid focuser, then a helicoid focuser that stretches from 17mm to 31mm would probably do fine. Low power objectives lose working distance as they are focused to a sensor on a longer photo tube and some describe a narrower image circle, so having more latitude in the helicoid focuser is better from that standpoint but any adjustable device becomes less physically rigid the more it is extended. Sometimes, objectives need to be shimmed in order to close the parfocal gap between them.

As far as an optic for yor system goes? I don't think you can go wrong with one of those Wild 6X K H eyepieces. I have used one with objectives that have much better peripheral correction than that Chinese achromat and it provided excellent images. Sometimes it takes a little time to get everything right and a change in optics might eventually be in order. With one of my systems, I was never pleased with the outcome for years. I wouldn't see chroma visually, then in the photos, a small amount would show up. One day , I tried an eyepiece ftom a stereomic as a relay lens and it was perfect. With these 23. 2mm eyepiece tube photo systems the relay lens isn't permanently installed. If one comes along that does a better job, it's as simple as one out and one in.
As far as objectives go; you are stuck with those of 45mm parfocal 160mm tube length . Fortunately, there were a lot of good ones made in that format. If you buy one plan objective, the Chinese ones are cheap but I have seen some really good deals on sets of really good brands that aren't sexy. Cooke-Baker/Vickers, tops the list at 100.00 for 4 Vickers Microplans and PZO are often cheap. You could probably nab a set of those, for not much more. I suspect that since most of the 45mm parfocal objectives made by the major companies , were made to provide an image circle for anywhere from 35mm to 4 x 5 with excellent correction and resolutiion that the chances of them being capable of meeting the requirements of an APS-C system would be pretty good. If you go looking for Vickers, be advised that they made a lot of Metallographs and metallurgical microscopes. Many of the objectives are marked MET, which use no cover glass and are not suitable for your requirements. The cover and no cover in that brand look very similar.
Hey, thanks again and sorry for the delay!

okay, I should be honest, my knowledge of optics and lenses is actually pretty weak. I hope to learn more, but I don't yet understand a lot of the good stuff you've told me.

I plan (hah!) on getting a plan obj, but as I understand what you've said, that won't affect other parts of the system that much. It seems like the main thing at this point is getting the eyepiece and a helicoid obj that matches it.

I searched for the Wild 6x one on Ebay, and these were the closest I found:

https://www.ebay.com/itm/LOT-Wild-Heerb ... SwH3ddFOx7

https://www.ebay.com/itm/MICROSCOPE-PAR ... SwDNdVxK38

https://www.ebay.com/itm/WILD-HEERBRUGG ... 3435942329

Are one of those yours?

From my googling, I found that the 'H' in Wild H is just the other part of the name, Wild Heerbrugg, and the "K" is for "compensating", so I guess I need both of those?

Sorry for all the dumb questions! and thank you again for all the help. I just don't know a lot of the basics here yet.

apochronaut
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Re: Does a DSLR adapter need a lens in it?

#26 Post by apochronaut » Mon Dec 23, 2019 4:08 am

The two last links are the same eyepiece, that I used. Both obviously need some cleaning. The two sellers are in fact the same surplus dealer and they usually sell items as is. However, in both listings they are being sold as being fully functonal and operate as intended. In my book that means , no mars or imperfections on the glass.
For photography the glass must be perfect, whereas for visual work, small imperfections in the right place are imperceptible

The way those listings are written, you could return them at the sellers expense, if they have permanent marks on the glass. An ebay seller cannot list something as fully functional in one part of listing and as is, elsewhere and not be expected by ebay to honour ebay's buyer protection. If they don't send you a shipping label for the return, ebay will refund your purchase price and shipping and leave the eyepiece with you.

I generally have found silosurplus to be fair. Their prices are shoot for the moon prices. They usually will take 1/2 or less. I would offer them 35.00 for the 79.00 one. They will probably come back at around 45-50. The 39.00 one has ding at the bottom of the barrel. It probably can be fixed enough to fit. It certainly doesn't function as intended and you might get it for 20.00. If the glass is clean, it would be fine too.

diggitydawg
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Re: Does a DSLR adapter need a lens in it?

#27 Post by diggitydawg » Mon Dec 23, 2019 2:51 pm

apochronaut wrote:
Mon Dec 23, 2019 4:08 am
The two last links are the same eyepiece, that I used. Both obviously need some cleaning. The two sellers are in fact the same surplus dealer and they usually sell items as is. However, in both listings they are being sold as being fully functonal and operate as intended. In my book that means , no mars or imperfections on the glass.
For photography the glass must be perfect, whereas for visual work, small imperfections in the right place are imperceptible

The way those listings are written, you could return them at the sellers expense, if they have permanent marks on the glass. An ebay seller cannot list something as fully functional in one part of listing and as is, elsewhere and not be expected by ebay to honour ebay's buyer protection. If they don't send you a shipping label for the return, ebay will refund your purchase price and shipping and leave the eyepiece with you.

I generally have found silosurplus to be fair. Their prices are shoot for the moon prices. They usually will take 1/2 or less. I would offer them 35.00 for the 79.00 one. They will probably come back at around 45-50. The 39.00 one has ding at the bottom of the barrel. It probably can be fixed enough to fit. It certainly doesn't function as intended and you might get it for 20.00. If the glass is clean, it would be fine too.
awesome, thanks! I think I'll try for the 39 one.

So I've been reading a bit about the optics, from this source: http://krebsmicro.com/photomic1/photomic1.html and I was wondering if you could clear something up with me. He says there that the way the eyepiece usually works in a 160mm compound is, the objective produces a real image right where the bottom of the eyepiece sits, and then the eyepiece converts that into a virtual image, so that the lens of your eye (or a camera lens) can convert that back into a real image for your retina (or camera sensor).

But in the setup we've been talking about, we're only using the eyepiece, no other lens. So why isn't the sensor getting only a virtual image also? or, because of the added distance between eyepiece and sensor, does the eyepiece still project a real image on the sensor?

(I need to review my basic optics clearly!)

Here's my current understanding of the setup, please correct me if anything is wrong:

Image

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wporter
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Re: Does a DSLR adapter need a lens in it?

#28 Post by wporter » Mon Dec 23, 2019 4:58 pm


Scarodactyl
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Re: Does a DSLR adapter need a lens in it?

#29 Post by Scarodactyl » Mon Dec 23, 2019 5:51 pm

There are two types of eyepieces. Viewing eyepieces and projective/photo eyepieces.
Viewing eyepieces project to infinity and the lens of your eye makes a real image. If you put a camera over a viewing eyepiece it needs another lens.
Photo eyepieces project a real image directly onto the camera sensor, no extra glass needed.

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Re: Does a DSLR adapter need a lens in it?

#30 Post by diggitydawg » Mon Dec 23, 2019 6:11 pm

Scarodactyl wrote:
Mon Dec 23, 2019 5:51 pm
There are two types of eyepieces. Viewing eyepieces and projective/photo eyepieces.
Viewing eyepieces project to infinity and the lens of your eye makes a real image. If you put a camera over a viewing eyepiece it needs another lens.
Photo eyepieces project a real image directly onto the camera sensor, no extra glass needed.
Hmmm, okay, that's kind of what I suspected. But now I'm confused. Is the Wild 6x eyepiece that apochronaut told me to get a photo/projection eyepiece? It doesn't say it anywhere on the page. Also, the first link (the lot of 4, this one: https://www.ebay.com/itm/LOT-Wild-Heerb ... SwH3ddFOx7 ) has one 6x one that explicitly says "phot" on the eyepiece, making me think that one is a photo eyepiece and the other 6x ones aren't...

Am I missing something?

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