Are photo eyepieces needed?

Here you can discuss everything related to taking light micrographs and videos.
Post Reply
Message
Author
noobzilla
Posts: 13
Joined: Sun Dec 27, 2020 11:08 pm

Are photo eyepieces needed?

#1 Post by noobzilla » Sun Jan 10, 2021 1:38 am

I have a trinocular Leica DMLB set-up. I contacted someone on ebay who has a 37mm adapter (also sells various adapters). I asked if an eyepiece goes in there but he said no and thinks that a photo eyepiece is not necessary. Any opinion on this?

P.S. Sister in law has an extra Olympus PEN EPL2, but it looks like it can't live view and take pictures at the same time. Gonna have to dig around and find a camera for my microscope.

apochronaut
Posts: 6233
Joined: Fri May 15, 2015 12:15 am

Re: Are photo eyepieces needed?

#2 Post by apochronaut » Sun Jan 10, 2021 4:00 pm

Direct to sensor is possible with certain systems but for some systems and if parfocality is a requirement , a critically located photo relay lens can help adjust that while retaining the correct f.o.v. and camera frame relationship. In rare instances and usually though with older systems a photo relay lens sometimes can be found to provide better peripheral corrections than the eyepieces do.

hans
Posts: 977
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Are photo eyepieces needed?

#3 Post by hans » Sun Jan 10, 2021 9:50 pm

According to this there needs to be something between the tube lens and sensor to get a fully corrected image:
https://www.leica-microsystems.com/scie ... icroscopy/
Attachments
HCS_Figure_3_Astigmatism_Field-Curvature.png
HCS_Figure_3_Astigmatism_Field-Curvature.png (66.49 KiB) Viewed 11288 times

MichaelG.
Posts: 3970
Joined: Mon Apr 10, 2017 8:24 am
Location: North Wales

Re: Are photo eyepieces needed?

#4 Post by MichaelG. » Sun Jan 10, 2021 10:56 pm

That’s a useful note, Hans
Thanks for the link.

MichaelG.
Too many 'projects'

hans
Posts: 977
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Are photo eyepieces needed?

#5 Post by hans » Sun Jan 10, 2021 11:07 pm

PeteM linked it in this older thread where there is some further speculation about what corrections take place where and how much they differ from the preceding Reichert systems:
viewtopic.php?f=5&t=8625

Scarodactyl
Posts: 2760
Joined: Sat Mar 03, 2018 9:09 pm

Re: Are photo eyepieces needed?

#6 Post by Scarodactyl » Mon Jan 11, 2021 1:27 am

Newhoper has good mechanical quality in the parts he sells but I think he takes a bit of a one-size-fits-all approach optically. You can certainly get an image even without all the corrections or with wrong corrections and for some applications that might be plenty good enough. Usually hobbyists are a bit pickier than that about getting full performance out of the optics.

Leitzcycler
Posts: 254
Joined: Mon Sep 09, 2019 11:55 am

Re: Are photo eyepieces needed?

#7 Post by Leitzcycler » Tue Jan 12, 2021 7:48 am

This camera adapter came with my Leitz Orthoplan. It has no lens inside at all or any place for attaching an eyepiece. If the Orthoplan system needs a projection lens/phototube with an eyepiece for proper image correction - as far as I have understood right - why this adapter has been manufactured in the first place?
Attachments
Leitz adapter.JPG
Leitz adapter.JPG (80.53 KiB) Viewed 11192 times

hans
Posts: 977
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Are photo eyepieces needed?

#8 Post by hans » Tue Jan 12, 2021 8:31 am

Leitzcycler wrote:
Tue Jan 12, 2021 7:48 am
This camera adapter came with my Leitz Orthoplan. It has no lens inside at all or any place for attaching an eyepiece. If the Orthoplan system needs a projection lens/phototube with an eyepiece for proper image correction - as far as I have understood right - why this adapter has been manufactured in the first place?
Is it possible, even if it does fit into the head directly, that there are supposed to be some other parts in between like this:
Attachments
orthoplan-camera.jpg
orthoplan-camera.jpg (148.71 KiB) Viewed 11182 times

Leitzcycler
Posts: 254
Joined: Mon Sep 09, 2019 11:55 am

Re: Are photo eyepieces needed?

#9 Post by Leitzcycler » Tue Jan 12, 2021 8:44 am

Thanks. I know and I have also the phototube which fits into the trinocular head and the eyepiece can be fitted inside the tube. I have no upper parts yet, however planning to make.

What I mean is that the adapter has c-mount thread and a digicamera can be inserted directly. I assume this is how it was planned to be used. I don't think the upper parts: phototube, eyepiece etc was ment to be added to this c-mount. Am I right?

hans
Posts: 977
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Are photo eyepieces needed?

#10 Post by hans » Tue Jan 12, 2021 7:26 pm

Leitzcycler wrote:
Tue Jan 12, 2021 8:44 am
What I mean is that the adapter has c-mount thread and a digicamera can be inserted directly.
Understood, I was just suggesting it might actually be some final, camera-specific adapter like circled below that also happens to fit directly into the camera port but is not intended to be used that way.
Leitzcycler wrote:
Tue Jan 12, 2021 8:44 am
I assume this is how it was planned to be used. I don't think the upper parts: phototube, eyepiece etc was ment to be added to this c-mount. Am I right?
With the binocular eyepieces in focus and the adapter inserted directly is there an image 17.5 mm (C-mount flange focal distance) above the flange?

If it is intended to be inserted directly, maybe the additional eyepiece corrections were not considered necessary due to low resolution and/or small sensor sizes of the cameras it was originally designed to be used with?
Attachments
orthoplan-camera-adapter.jpg
orthoplan-camera-adapter.jpg (135.34 KiB) Viewed 11138 times

Leitzcycler
Posts: 254
Joined: Mon Sep 09, 2019 11:55 am

Re: Are photo eyepieces needed?

#11 Post by Leitzcycler » Tue Jan 12, 2021 7:42 pm

Thanks. Maybe so. The adapter is rather heavy, robust and made of steel, which gives me the impression it is intended to be used directly and not on top of the tower (red part). While the lower phototube I have is very light and made of aluminium...

rmb
Posts: 35
Joined: Fri Dec 01, 2017 5:38 pm
Location: scotland near Edinburgh

Re: Are photo eyepieces needed?

#12 Post by rmb » Sat Jan 23, 2021 7:31 pm

When my ancient hp laptop died the tucsen camera i had been using refused to run on the new computer at anything other than a low resolution/low frame rate. There was also strobing. Not sure if camera is kaput or too old for the NUC 10th gen i5 chip.
Anyway too frightened to spend on a more modern usb camera i bought a sony a5000 and an e mount to c mount adapter. This screws directly onto the AO trinocular tube - so no photo eyepiece involved. I dont know where you would fit it. I tried positioning the camera with an AO eyepiece in the way to see it it would pick up a magnified image but no luck. The camera is parfocal but of course the image is too small to fill the whole camera sensor without the digital zoom. It also doesnt tether. So in the case of an AO 20 which is an infinty scope, you dont need a photo eyepiece it appers. The tucsen camera sensor was tiny in comparison at 5meg and perhaps sat behind a lens so gave a full picture on the monitor. When it was working it was wysiwyg and i still crave that sort of utility

apochronaut
Posts: 6233
Joined: Fri May 15, 2015 12:15 am

Re: Are photo eyepieces needed?

#13 Post by apochronaut » Sun Jan 24, 2021 2:11 pm

No you don't but if you want a well corrected capture that covers the full field of view, you do.

Leitzcycler
Posts: 254
Joined: Mon Sep 09, 2019 11:55 am

Re: Are photo eyepieces needed?

#14 Post by Leitzcycler » Tue Jan 26, 2021 7:57 pm

In modern microscopes, like in the example in the picture, there seem to be a very short phototube. It looks like almost the same structure as using my Orthoplan c-mount adapter alone. What is the structure of these modern camera mounts? Do they contain any lenses inside? I don,t think they contain any photo eyepiece, so they don't need any correction lenses? I think these are infinite system, so they don't need a correction/projection eyepice?
Attachments
primostar camera.jpg
primostar camera.jpg (12.05 KiB) Viewed 10446 times

apochronaut
Posts: 6233
Joined: Fri May 15, 2015 12:15 am

Re: Are photo eyepieces needed?

#15 Post by apochronaut » Tue Jan 26, 2021 8:51 pm

In any lens system the corrections are perfect on axis and almost perfect a certain distance from the axis, depending on the design of the system. When a camera is capturing a small portion of a fairly well corrected field , say the 50% in the center to a postage stamp sized sensor, there will be minimal lateral ca. So, it can be close and not necessarily need a photo relay lens. You can usually see some lateral ca with such systems though, in the corners and often some distortion too. It all depends how well corrected the image coming to the eyepieces is.
When you are trying to capture an entire field of view to a large sensor, some method of relaying and projecting the image is necessary. The relay lens would need to exert whatever corrections the visual eyepieces have, while covering the sensor and hopefully achieving parfocality.

hans
Posts: 977
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Are photo eyepieces needed?

#16 Post by hans » Tue Jan 26, 2021 10:42 pm

Leitzcycler wrote:
Tue Jan 26, 2021 7:57 pm
In modern microscopes, like in the example in the picture, there seem to be a very short phototube. It looks like almost the same structure as using my Orthoplan c-mount adapter alone. What is the structure of these modern camera mounts? Do they contain any lenses inside? I don,t think they contain any photo eyepiece, so they don't need any correction lenses? I think these are infinite system, so they don't need a correction/projection eyepice?
The brochure ZEISS Primostar 3 Product Info shows adapters with reduction lenses:
Attachments
primostar3-camera.png
primostar3-camera.png (46.08 KiB) Viewed 10426 times

noobzilla
Posts: 13
Joined: Sun Dec 27, 2020 11:08 pm

Re: Are photo eyepieces needed?

#17 Post by noobzilla » Tue Jan 26, 2021 11:42 pm

Finally got the adapter to mount my camera to the Leica DMLB. The adapter I got can be configured with or without an eyepiece. Unfortunately the eyepiece I have has that rotating grip for focus which makes it not fit the adapter.

Here are some pictures I got using a Sony a7s ii vs with phone looking through eyepiece. I notice that I'm able to capture more of the total field of view the closer the camera is to the tube.

Prepared slide. Paramecium

camera at 100x
Image

phone through eyepiece 1000x (100x * 10x eyepiece)
Image

My set up
Image

noobzilla
Posts: 13
Joined: Sun Dec 27, 2020 11:08 pm

Re: Are photo eyepieces needed?

#18 Post by noobzilla » Tue Jan 26, 2021 11:56 pm

I just realized the different pieces of the adapter fits one another. Here's a configuration where the camera sits much lower.

Image

Image

Now I can see some black areas around the corner which is the end of the field of view.

rmb
Posts: 35
Joined: Fri Dec 01, 2017 5:38 pm
Location: scotland near Edinburgh

Re: Are photo eyepieces needed?

#19 Post by rmb » Tue Feb 23, 2021 12:11 am

Ii am intrigued by this business of relay lenses. If the eye ball is placed at the point of focus just above the eyepiece why does this not work for a naked camera sensor? Because the eye has a further lens arrangement that expands the image onto the retina?. With a relay lens sitting down inside a connecting tube is this projecting a magnified image onto the sensor - provided the sensor as at the right location. The ao20 is an infinity scope and the image up the trinocular produced by the telan lens forms another image at the parfocal distance up the tube which shines on the sensor. I measured the sensor size on the sony a5000 and the exit point area of the trinocular c mount tube for my ao20. In effect the tube can only illuminate 49% of the sensor making it a 10meg rather than a 20meg sensor. If i use the 2× digital zoom to fill the sensor i am not illuminating more sensor just spreading out the existing pixels.. Indeed is the straight from the telan lens an even smaller illuminating beam as it is smaller in diameter than the trinoc tube.
Or am i misunderstanding my optical pathways?

User avatar
mrsonchus
Posts: 4175
Joined: Tue Feb 03, 2015 9:42 pm
Location: Cumbria, UK

Re: Are photo eyepieces needed?

#20 Post by mrsonchus » Tue Feb 23, 2021 12:25 am

Hi, the optics don't project pixels remember, optical enlargement to cover more of a sensor with the image from an eyepiece or photo-eyepiece or intermediate optic will still be 'using' the full pixel-count of the sensor? I think it's the digital enlargement that adds no pixels merely interpolating to give a higher pixel image?
John B

hans
Posts: 977
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Are photo eyepieces needed?

#21 Post by hans » Tue Feb 23, 2021 5:01 am

rmb wrote:
Tue Feb 23, 2021 12:11 am
If the eye ball is placed at the point of focus just above the eyepiece why does this not work for a naked camera sensor? Because the eye has a further lens arrangement that expands the image onto the retina?
Yeah, that's correct.
rmb wrote:
Tue Feb 23, 2021 12:11 am
In effect the tube can only illuminate 49% of the sensor making it a 10meg rather than a 20meg sensor.
How exactly did you figure this? I think the eyepieces on these are 18 mm FN, which would be using roughly 66% of the pixels by area:

Code: Select all

>>> math.pi*9**2/(24*16)
0.662679700366597
And the intermediate image before the field stop in the eyepieces should be somewhat larger even. Maybe the C-mount tube is limiting things?

PeteM
Posts: 2963
Joined: Tue Dec 06, 2016 6:22 am
Location: N. California

Re: Are photo eyepieces needed?

#22 Post by PeteM » Wed Feb 24, 2021 6:18 am

noobzilla wrote:
Tue Jan 26, 2021 11:42 pm
Finally got the adapter to mount my camera to the Leica DMLB. . . .
N-zilla -- Hoping you can describe in some detail which setup (configuration and source of the adapter) provided you with the best images?

rmb
Posts: 35
Joined: Fri Dec 01, 2017 5:38 pm
Location: scotland near Edinburgh

Re: Are photo eyepieces needed?

#23 Post by rmb » Wed Feb 24, 2021 1:33 pm

i performed this experiment last night. I placed a piece of slightly opaque plastic film over the end of the trinocular tube - where then camera would screw onto the c-mount thread.
by turning up the microscope lighting and darkening the room i could then see the image projected up the tube from a slide displayed on the film. This is a real image - or as mr krebs calls it a finished one, in focus - that is parfocal - but obviously very small as the light disk at this point is about 20mm apart. Note this is on an infinity scope. it would be different on a 160mm tube length version. At this distance up the tube the in focus image is formed. i suppose in the binocular head this same image forms somewhere just below the eyepieces and the eyepieces are used to magnify it so it is easier to see. as the diameter of the disk is 20mm it has an area of 314mm2. my original calculation was based on the internal diameter of the trinocular tube - 15mm but i had forgotten that the light coming up it is a cone of illumination - so expands the disc of light. the camera sensor is nominally about 365mm2 which means about 85% of the sensor is used. Seems much better but as the disc of light is 20mm in diameter and the sensor is 15mm high some of the illumination is being lost above and below it. To fit all of the image produced by the microscope onto the sensor i would need to reduce it using a 0.75x lens - i gain more image captured but use less sensor. I have acquired an ancient AO camera attachment tube for film cameras with the built in lenses at the head end. now i am worried this might enlarge the image up the tube too much as it was intended for 35mm. I am missing something fundamental here i think.

As far as i can tell no normal dslr/digital cameras use a square sensor - but a lot of the dedicated scientific eyepiece style ones do - although the sensors are very small their pixel counts are rising.
the funny thing is the sony alpha 5000 takes very good video down the tube but the still images are just a bit off. maybe i should get a remote shutter release in case it is just vibration spoiling the pics.

noobzilla
Posts: 13
Joined: Sun Dec 27, 2020 11:08 pm

Re: Are photo eyepieces needed?

#24 Post by noobzilla » Thu Feb 25, 2021 7:51 pm

PeteM wrote:
Wed Feb 24, 2021 6:18 am
noobzilla wrote:
Tue Jan 26, 2021 11:42 pm
Finally got the adapter to mount my camera to the Leica DMLB. . . .
N-zilla -- Hoping you can describe in some detail which setup (configuration and source of the adapter) provided you with the best images?
I purchased the adapter kit here on ebay.

Several parts can be unscrewed and attached to other pieces. So far I like the shortest distance between the camera and the phototube (camera mount + phototube adapter). You have to message him to provide you 37mm instead of the 38mm on the listing. From left to right on the ebay listing image
[camera mount] - [height adjustable tube] - [tube for eyepiece lens] - [phototube adapter]

I'm still looking for an eyepiece that could fit. Maybe that could give me better view since I can still see better through the eyepieces I have.

p.s. still having a hard time shopping around for reasonably priced DIC parts for my DMLB :(

mootoom
Posts: 4
Joined: Sat Mar 27, 2021 8:12 pm

Re: Are photo eyepieces needed?

#25 Post by mootoom » Sat Mar 27, 2021 8:51 pm

Leitzcycler wrote:
Tue Jan 12, 2021 7:48 am
This camera adapter came with my Leitz Orthoplan. It has no lens inside at all or any place for attaching an eyepiece. If the Orthoplan system needs a projection lens/phototube with an eyepiece for proper image correction - as far as I have understood right - why this adapter has been manufactured in the first place?
Similar here. I bought a T2 ring with a 23.2mm adapter that fit directly into the trinocular/eyepiece tube, it cost me $30 and it is a piece of trash for microscopy. I suspect these kind of accessories are leftover trash predate the digital camera era, i.e. they are mean for film camera.

When I saw a T2 ring to 1.25inch(31.75mm) for TELESCOPE in Amazon for $10, I give it a try. If the inner tube is too large, I still can stuff something to fit in the eyepiece. And guess what, the "telescope adapter" fit 23.2mm eyepiece PERFECTLY, and it is microscopy image is better than the $30 adapter without any optical.

I also have 5x eyepiece that come with a 30.5mm to 23.2mm adapter, that allow me to use 23.2mm eyepiece on a stereo microscope. The T2 ring to telescope adapter simply kill two bird with one stone.

IMPORTANT NOTE :
Since the 1.25/31.5mm adapter will take on a 23.2mm eyepiece, that mean a longer eyepiece tube will protrude into your DSLR/mirrorless sensor. You must put a rubber band/sealing ring/tape to prevent the eyepiece sliding into the camera sensor.

Dubious
Posts: 426
Joined: Sun May 09, 2021 7:55 pm

Re: Are photo eyepieces needed?

#26 Post by Dubious » Tue Jun 29, 2021 5:07 am

Came across this thread, and I am similarly trying to find the best photo tube arrangement to connect an Amscope 5mb USB camera to a Leitz Laborlux. Interestingly, the trinocular head I am using--got it off Ebay with prisms stuck but have just got it working--came with the exact same C-mount adapter shown in the photo above (Germany #543345). With the .5x reducer removed from the camera, it screws directly onto the tube and is parfocal with the eyepieces (had to adjust both eyepieces only a bit); but, of course, since the camera's optical sensor is small, the image is blown up large. Reasonable quality, though, I suppose because the camera is seeing only the center of the field. Anyway, I'm waiting on more Ebay parts and hope to cobble together something (preferably using a correcting eyepiece) that will give the camera a larger part of the FOV.

When it comes to cameras cropping the FOV and as a result not showing the aberrations around the edge, all rectangular-frame cameras necessarily do some of that since they're working with the microscope's circular FOV; but I've noticed USB cameras often crop more than strictly necessary even when used with a microscope of the same modern brand. Maybe it's random--just the arbitrary pairings I've seen--but it could also be a deliberate strategy to make both camera and microscope appear to perform better.

Post Reply