AO Cycloptic Photo Tube Components

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geo_man
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AO Cycloptic Photo Tube Components

#1 Post by geo_man » Wed Mar 13, 2019 9:27 am

Hi all: how do I complete installation of this Cycloptic photo adapter for use with a simple USB-type camera? I know I need an extender tube, not sure what else. Is there an off the shelf, inexpensive solution? Thanks in advance.
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apochronaut
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Re: AO Cycloptic Photo Tube Components

#2 Post by apochronaut » Wed Mar 13, 2019 12:00 pm

What is the diameter of the port?

geo_man
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Re: AO Cycloptic Photo Tube Components

#3 Post by geo_man » Wed Mar 13, 2019 12:12 pm

Thanks. I don't know, as I don't yet(?) have one. Maybe someone else will provide an answer.

apochronaut
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Re: AO Cycloptic Photo Tube Components

#4 Post by apochronaut » Wed Mar 13, 2019 2:58 pm

I thought you had found one. I don't have one of those either but looking at an image of the original short photo tube that was supplied, it looks like it has the same dimensions as the long photo tube that was made for the 10/20 models, so a similar system that works well on the 10/20 and the 4 for that matter, should work.
Originally, a shutter mechanism and physical camera adapter sat on top of the tube; cat.# 680 A or B, depending on the film format. The unit has a viewing eyepiece, so you can see the camera view. I haven't used one of those but usually they don't cover any more than 50% of the viewing field. Some people don't mind that .

If you want to capture as much of the field as is possible it might be better to put a dedicated eyepiece into the photo tube and clamp a telescope photo adapter over the tube or one of the older microscope camera adapters that fitted that way. Many cheaper ones now, are designed to fit into an eyepiece tube. You want your photo eyepiece in there, instead of the adapter, so the camera adapter needs to go over the eyepiece and tube. There were various older ones that worked that way. I've seen Asahi, Konica I think too and the 1 1/4" telescope adapters on ebay can be drilled and tapped for 3 plastic thumb screws in order to clamp onto the tube. You then just acquire the correct converter rings to get from whatever the purchased camera adapter provides( usually M42 but sometimes other) to get to your camera's mount. You can then position the camera body relative to the objectives in such a way that you get an ideal f.o.v. and parfocality, by moving the camera up and down the tube, with the eyepiece stationary in the tube. Sometimes distance pieces, such as one or more macro rings or an extension tube are needed, in addition to the correct adapters. Having a focusing eyepiece helps a bit and occasionally the eyepiece might need to be lifted with an o-ring or collar but there aren't really any rules. Do whatever you need to do to achieve as full a field with parfocality as you can.. Bellows are an option too.

I've done a few such systems on AO and B & L stuff and the results are really good. Full, flat fields with minimal cropping.

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wporter
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Re: AO Cycloptic Photo Tube Components

#5 Post by wporter » Wed Mar 13, 2019 3:10 pm

The rig as pictured is missing two components that you may need to adapt a camera, usb or otherwise: the second relay lens, and the tube. See the thread:

viewtopic.php?f=9&t=6074&p=54790&hilit=cycloptic#p54790

Go down the post to my images #1 & #2 to see the components. The 2nd relay is in a black lens holder, and the tube screws over the male threaded portion of the holder. You will then need an adapter for the tube to the camera, and an eyepiece inside the top of the extension tube to project the image.

You may be able to get an image without the eyepiece, but I think you will need the second relay lens at least. Maybe not. I'll see what I can get out of mine if I take the lens out.

geo_man
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Re: AO Cycloptic Photo Tube Components

#6 Post by geo_man » Wed Mar 13, 2019 3:17 pm

Thanks Guys, a lot for me to absorb! I'll study your posts more carefully.

One item i'm trying to find first is the tube.

I have this one already but haven't set it up on my AO 110.

https://www.ebay.com/itm/PARFOCAL-C-MOU ... 2749.l2649

This one is also available.

https://www.ebay.com/itm/PARFOCAL-TUBE- ... xy63FS5wCR

Will either of these work in your opinion? I don't have access to a lathe.


Thanks again!

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wporter
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Re: AO Cycloptic Photo Tube Components

#7 Post by wporter » Wed Mar 13, 2019 4:58 pm

Your existing hole (where what I call the second relay lens goes) is about 0.873" or 22.17mm I.D.

You can indeed get an image without the second relay lens and an eyepiece. I can't vouch for the quality, but holding my camera sensor up near the hole, it definitely shows a vignetted image.

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Re: AO Cycloptic Photo Tube Components

#8 Post by geo_man » Thu Mar 14, 2019 11:40 am

Thanks again!

The OD of the machined portion of my existing tube (that goes into the camera) is ~20mm so I guess that's a fit.

The length of the full diameter tube to the end of the c_mount threads is ~94mm.

So, my question is, is there a reasonable chance (guarantee not requested) that a USB type camera with a ".5x fixed microscope adapter lens" connected to this C-mount thread would produce a good image?

Thanks again for any additional insight.
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apochronaut
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Re: AO Cycloptic Photo Tube Components

#9 Post by apochronaut » Thu Mar 14, 2019 5:08 pm

The length of the tube is critical in order to obtain parfocality and in order to place the photo eyepiece in the correct location so that parfocality and field coverage can be maximized and coordinated together.
A further issue is whether the photo eyepiece or relay lens is incorporating the proper corrections for the system, so that the field can be maximized without peripheral distortion. You can't just stick any old relay lens in there.

I have a .5X photo relay lens here; probably not dissimilar to one used for many USB cameras. The image it gave was pretty bad used through a Cycloptic eyepiece tub. Focused in the center and very quickly drifting out of focus off axis with lots of peripheral ca. Totally unsuited to that microscope's optical requirements.

The parfocal tube for the AO diasopic,epicscopic and inverted stands is too long. Those are 150mm total length. Based on the image in the catalogue, the correct shorter photo tube is only about 100mm. total length. Putting a properly corrected eyepiece in there; a cat.# 437 focusing eyepiece or a #146 and then building up your adapter around having one of those in the tube, will allow you to get a fully functional system without compromise on either field size or corrections across the field.

Those short photo tubes are hard to find. It is possible that the 94mm tube with the c mount would work. Is the hole in the top big enough to accept a 23 mm eyepiece or could it be adapted to accept one?

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wporter
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Re: AO Cycloptic Photo Tube Components

#10 Post by wporter » Thu Mar 14, 2019 6:20 pm

No, the hole in the body, that normally takes the 2nd relay lens (at 22.17mm), is significantly too small for the usual 23mm eyepiece, without machining.

geo_man
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Re: AO Cycloptic Photo Tube Components

#11 Post by geo_man » Thu Mar 14, 2019 6:58 pm

Thanks again Phil and wporter for all your support. I started this by wondering if I should purchase an available AO Cycloptic photo adapter on eBay so I could connect a USB camera I plan to buy sometime. I will continue to learn about this topic and maybe in the future I'll pursue. For now its iPhone for me and someone with more knowledge and skill can buy the nice adapter.

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Re: AO Cycloptic Photo Tube Components

#12 Post by apochronaut » Thu Mar 14, 2019 7:18 pm

wporter wrote:No, the hole in the body, that normally takes the 2nd relay lens (at 22.17mm), is significantly too small for the usual 23mm eyepiece, without machining.
I think the lens you are referring to here as a relay lens is the same lens as the magnifier lens which sits just below the prism in the optical tube; one on each side. It is part of the optical system of the microscope; not very big, only about 1/2" or so. Because the photo photo tube adapter is placed below the optical body tube, that lens is missing in it's optical path but to have the same optical path for both the viewing body and the photo tube body, that lens must be in place, so one is provided . It is not actually a relay lens.

The actual photo lens or relay lens needs to sit in the top of the photo tube, where the C mount is. That's the hole about which, I am wondering whether it is big enough. That's where a # 146 eyepiece or 437 needs to sit.

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Re: AO Cycloptic Photo Tube Components

#13 Post by geo_man » Thu Mar 14, 2019 7:36 pm

The ID of the photo tube at the C-mount is only ~16mm. My eyepiece can neither fit into it or over it.

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Re: AO Cycloptic Photo Tube Components

#14 Post by apochronaut » Thu Mar 14, 2019 10:35 pm

Ream it out to receive a 23mm eyepiece and you are away to the races. Other option is to find the short tube that was factory fitted to the #638 photo tube adapter. You don't see them like you do the 150mm tube made for the trinocular heads because they were an absolutely necessary part of the #638 and usually would be with them, whereas the 150mm photo tube was an accessory part that might or might not have been used in a trinocular head. There must be some out there, though.

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Re: AO Cycloptic Photo Tube Components

#15 Post by geo_man » Fri Mar 15, 2019 12:50 am

Thanks Phil. I understand the way forward. I really appreciate the expert advice.

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Re: AO Cycloptic Photo Tube Components

#16 Post by geo_man » Fri Mar 15, 2019 9:01 am

apochronaut wrote:Ream it out to receive a 23mm eyepiece and you are away to the races. Other option is to find the short tube that was factory fitted to the #638 photo tube adapter. You don't see them like you do the 150mm tube made for the trinocular heads because they were an absolutely necessary part of the #638 and usually would be with them, whereas the 150mm photo tube was an accessory part that might or might not have been used in a trinocular head. There must be some out there, though.
This one might work!

https://www.ebay.com/itm/PARFOCAL-TUBE- ... 2323422958

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Re: AO Cycloptic Photo Tube Components

#17 Post by apochronaut » Fri Mar 15, 2019 11:58 am

That's the 150mm one, I've been referring to. What you will get with that is a very small section of the center of the field and it won't be parfocal, if you can focus at all. If you had the photo tube adapter, you could just hold a camera over the open port and determine pretty close to how long you actually need. The illustration in the Cycloptic catalogue shows a similar photo tube but it is much shorter; around 2/3 of the one providencecoins is selling.
Does anyone out there have one of those short photo tubes and can post a picture of it ?

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Re: AO Cycloptic Photo Tube Components

#18 Post by MichaelG. » Fri Mar 15, 2019 2:10 pm

apochronaut wrote:Does anyone out there have one of those short photo tubes and can post a picture of it ?
Would I be right in assuming that it's the one pictured on p29 of this:
http://www.microscopy-uk.org.uk/mag/art ... oscope.pdf

?

MichaelG.
Too many 'projects'

geo_man
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Re: AO Cycloptic Photo Tube Components

#19 Post by geo_man » Fri Mar 15, 2019 4:11 pm

thanks guys. providencecoins will make a custom one if i can determine measurements.

Phil suggested holding a camera above the open port and finding focus distance. would that be the same as holding the recommended eyepiece?

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Re: AO Cycloptic Photo Tube Components

#20 Post by apochronaut » Fri Mar 15, 2019 8:33 pm

yes. page 29 shows the correct tube. Including the section that fits into the # 638 phototube adapter it is in the 100mm length range.

Someone with one of those could supply the actual dimensions. If the top section where the eyepiece goes in is fairly long, you have a reasonable amount of leeway to move the camera section up or down, because the camera sensor is going to be 60 or so mm from the eyepiece but the top of the tube needs to be fairly precise, the place where the eyepiece rests.

geo_man
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Re: AO Cycloptic Photo Tube Components

#21 Post by geo_man » Sat Mar 16, 2019 8:06 pm

Hi all, I found and purchased an original AO photo tube and will post its dimensions when I receive it. Thanks again for the support.

Oops, just heard from dealer, they don't have it... Ugg

MichaelBrock
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Re: AO Cycloptic Photo Tube Components

#22 Post by MichaelBrock » Wed Mar 20, 2019 2:05 am

As you know I'm working on getting this together for my cycloptic as well. I purchased the photo adapter to someone on Facebook (Charles Pifer) and it also did not have the photo tube. I asked him for the dimensions of the one he has:

Dimensions: Total length is 62mm. Inside diameter at the top is 23mm (size of an eyepiece). You probably don't need these but if you want the same look, the lower portion is 37mm to the upper shoulder and then 25mm from shoulder to the top edge. The lower OD is 30mm (ID would be the same size as the opening. Upper OD, past the shoulder, is 25mm

His looks just like the one in the top image in this post :
viewtopic.php?f=9&t=6074&p=54790&hilit=cycloptic#p54790

I'm currently in the process of trying to turn a tube out of PVC... it's an ongoing process. I managed it for the longer photo tube for my AO 20 but I haven't had the time to focus on this one yet. If you do get providencecoins to make you one I would be interested (although he currently has be blocked for asking a question on one of his auctions).

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Re: AO Cycloptic Photo Tube Components

#23 Post by geo_man » Wed Mar 20, 2019 10:16 am

Thanks Michael. I'm somewhat confused but it probably all makes sense to someone!

I think my confusion relates to the fact that I don't have the second relay lens mounted in the black ring as noted by wporter.

The measurements I show below result in a mounted 146 eyepiece being in focus (using my eyes) above the photo adapter hole (without the relay lens). Maybe that's why I get a shorter distance (only 50mm above the adapter versus your 62mm)? I do see that the FOV is bigger than when looking through the normal eyepiece.

Maybe Phil can comment, if I can get the 146 or 437 eyepiece to be in clear focus with my eyes, will the setup work as described in the rest of the post?

p.s., Providencecoins will customize tube per measurements for $20 increased cost and of course not returnable.

Thanks.
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Re: AO Cycloptic Photo Tube Components

#24 Post by apochronaut » Wed Mar 20, 2019 5:53 pm

If you are getting an upright laterally correct image, that magnifies normally, with adequate corrections then it is probably o.k. but it is pretty hard to tell that by just holding an eyepiece over the adapter. I would make up a sealed tube from a toilet paper roll and install it in your port and see what you get. I'm pretty sure that missing negative lens at the port outlet will cause a magnification alteration at the very least.

wporter pointed out that there are two lenses in the 638 photo tube adapter. These are there to replace the ones that are inside the prism housings of the microscope. It looks like you are missing one of them. I presume the other, is intact.

Those optics are the only ones present, other than the primary objective and eyepieces, when the microscope is at the 15/20X setting. On other settings a more complex group of lenses are rotated in. The first of those lenses is situated before the prism and essentially functions as the back lens of all of the objectives in the system. On the 15/20x setting there is just the apochromat CMO and the back singlet, producing an inverted image. The primary objective is not really a 1X objective but functions as such in the context of further magnification in the back lens in this case and by further elements in the more complex objectives. Subsequent reduction by the negative lens in advance of the eyepiece brings about the apparent magnification of 1X. Image reversal is a part of the job these lenses do. I would expect the lens at the output of the photo adapter to be performing the same function as the negative lens just before the eyepiece in the visual head, which is primarily magnification reduction but there may be some corrections too. It seems likely that the two lenses in advance and behind the prism function as a sort of air spaced doublet and may be achromatic.
If the dimensions of the photo tube are the same as the visual tube, in terms of optical tube length, you probably could use the lens out of the end of a derelict prism housing to replace your missing lens.
I am unsure why they opted to install the first lens in between the mirrors but that probably means that the magnification factor of the lens in the photo tube is different than the one in the visual head and I also don't know how that might affect the characteristics of the second lens.
Perhaps, Bill could shed some light on that?

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Re: AO Cycloptic Photo Tube Components

#25 Post by geo_man » Wed Mar 20, 2019 7:14 pm

Thanks Phil. I looked again through a makeshift tube; the image looks good to me across the field, but it is inverted and lower magnification than through the eyepiece (15X setting on the magnichanger through the eyepieces is similar to 20X on the magnichanger through there photoport, both with 10x eyepiece).

I guess i could live with the inversion and altered magnification...

Oh well, more difficult than I expected when I bought that photo adapter on eBay!! haha

Thanks again for sharing your knowledge!

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Re: AO Cycloptic Photo Tube Components

#26 Post by apochronaut » Wed Mar 20, 2019 7:44 pm

The inversion is pretty irrelevant for photos . It may be possible to find a lower mag. eyepiece for the photo tube, if necessary. There were some 7.5X B & L Hyperplane. I never tried those. Perhaps a 6X Wild K H. That one works well in the series 4 phototube , which is obviously corrected to the same level as the Cycloptic because they use the same eyepieces. A shorter photo tube might work too, or sliding the camera adapter down the tube , closer to the eyepiece.

There is one other thing to watch out for, or rather that might put a monkey wrench into the works. You are looking at the image with your eye. I know for a fact that ca that isn't obvious to the eye can be really obvious to the sensor. It seems to become enhanced.
I can put an eyepiece into the phototube. Check it visually , think it good, snap a frame or two, put it on a laptop screen and there is ca I didn't see. If the last lens in that system is missing and was there, not only to rectify the orientation but also as a compensator for the erlier lens, it will probably show up as a lack of colour correction in the images.

Unfortunately, in lieu of this having been done before by someone; you are the pioneer.

geo_man
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Re: AO Cycloptic Photo Tube Components

#27 Post by geo_man » Wed Mar 20, 2019 8:10 pm

Thanks again, Phil. I think i'm going to jump off the wagon and return my incomplete photo adapter and wait until i can find a complete one! I'm excited to set one up, but i don't like being a pioneer with so little knowledge! :)

Thanks again to all who contributed!

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Re: AO Cycloptic Photo Tube Components

#28 Post by Scarodactyl » Wed Apr 03, 2019 1:16 am

I hope it's OK to revive this thread. I picked this beauty up with at my last local university surplus sale.
Image

This baby is pretty tricked out, with both a trinoc port and the switchable 1x/2x objective. The head's prisms were loose, perhaps the reason it was released to surplus. Fortunately I did have a spare head for it, as a friend of a friend gave me a stripped cycloptic a while back (no eyepieces or objective, boom stand mount). I got the head swapped on, but darn it was a chore to get it unscrewed, especially the broken head. But anyway, that worked.
Anyway, the trinocular port seems to work, and it has all the parts. The question is the last connection to the camera. I have this topcon adapter which I picked up with a parcel of mixed microscope parts years ago--I figured I'd use it on an SZ7, but it fits this photo tube just as well. For the final connection does it just need an eyepiece in the top of the photo tube, and a camera held the appropriate distance above? It's easy enough to get a topcon to canon adapter but they're not that cheap (not much demand for some reason).
Image
Image
Image

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wporter
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Re: AO Cycloptic Photo Tube Components

#29 Post by wporter » Wed Apr 03, 2019 2:39 am

does it just need an eyepiece in the top of the photo tube, and a camera held the appropriate distance above?
Yes, that is the design mode for the photo adapter. With a projection or regular eyepiece inserted into the shiny tube, and the camera clamped above it (without any camera lens on the camera).

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Re: AO Cycloptic Photo Tube Components

#30 Post by Scarodactyl » Wed Apr 03, 2019 3:03 am

Excellent, just like an sz7. I guess I will get that adapter and then try out some eyepieces to find the right power.

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