AO Cycloptic Photo Tube Components

Everything relating to microscopy hardware: Objectives, eyepieces, lamps and more.
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geo_man
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Re: AO Cycloptic Photo Tube Components

#31 Post by geo_man » Wed Apr 03, 2019 9:46 am

Congrats on the find! I'm jealous! Please post some pics when you're ready!

apochronaut
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Re: AO Cycloptic Photo Tube Components

#32 Post by apochronaut » Wed Apr 03, 2019 11:57 am

Cycloptics are pretty picky as to the way the eyepiece is corrected. In the day when it was originally made, plan optics were just coming into a more common usage. The objectives that AO were using on their biological scopes were pretty flat, only if the 146 or 147 eyepieces were used, which seem to be designed as plan compensating types. The same holds true with the Cycloptic optics, the 146 eyepieces assist in completing the edge corrections. I'm not sure where the SZ7 sits in terms of it's corrections, when compared to the Cycloptic but it is probably pretty similar, since the B & L U.W.F. 15X correct very well on the Cycloptic.

Cycloptic literature suggests using a 146 in the photo tube as well, so the magnification factor is the same but you might just try out the 31-15-71 B & L eyepiece, if it is a good one. I vaguely recall trying them out in the viewing head of a Cycloptic though , and there might have been some lateral ca. If that is true, then it will only be exacerbated in the images.


I think Topcon is the same mount as Exakta, so which Canon mount are you looking for , EOS?
Here is Exakta>EOS. https://www.ebay.com/itm/Exakta-EXA-Mou ... Sw7R9cFJnw

Scarodactyl
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Re: AO Cycloptic Photo Tube Components

#33 Post by Scarodactyl » Wed Apr 03, 2019 4:27 pm

Thanks, I'll have to track down another appropriate AO eyepiece if I don't already have one somewhere.

That does look the same as the topcon adapter, and a bit cheaper than the one I bought. I'll keep that in mind for next time, since I have another one of these topcon adapters.

By the way, if anyone wants a cycloptic head with rattling prisms I would be happy to send it to them for the cost of shipping.

apochronaut
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Re: AO Cycloptic Photo Tube Components

#34 Post by apochronaut » Wed Apr 03, 2019 4:58 pm

Why not try out the B & L 31-15-71 for a few pictures and then swap over one of the # 146s and do a comparison. Maybe it works o.k.?? ...would save a few $ .

Scarodactyl
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Re: AO Cycloptic Photo Tube Components

#35 Post by Scarodactyl » Wed Apr 03, 2019 5:59 pm

I will--I got a large collection of somewhat dirty eyepieces a while back, both b&l and ao, so I probably have something that will work after cleaning anyway. I have to wait on the adapter to get a good test in, but from my crude tests holding the camera above an eyepiece in (a 147b, a 146 out of one of the eyepieces, and the pictured b&l) I could get what looked like an OK image (aside from the leaked light) but it was definitely not parfocal. Is it supposed to be?

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wporter
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Re: AO Cycloptic Photo Tube Components

#36 Post by wporter » Wed Apr 03, 2019 7:04 pm

Looking over my old post (viewtopic.php?f=9&t=6074&p=54790&hilit=cycloptic#p54790, in the next to the last post, I see that my resolution tests were done without an eyepiece after the camera adapter; that is, there was nothing between the top lens of the photo adapter (where the aluminum tube screws on top of) and the camera sensor. In fact, I had tried an Olympus NFK 3.3 and got bad distortion. So you might forget about finding the perfect eyepiece for a moment, and just try it without one.

I ended up shortening the aluminum tube, and using the very short remnant as part of a screw-and-glue camera bayonet mount for my M4/3 camera body, all in order to get the camera sensor parfocal with the view through the binocular head. Unfortunately, this required making such a short camera attachment that there is barely enough room to put on the camera body without physical interference (see pix).

apochronaut
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Re: AO Cycloptic Photo Tube Components

#37 Post by apochronaut » Thu Apr 04, 2019 12:22 am

I found that with the Olympus NFK's too, when used in the visual tube for afocal but with no camera objective; eyepiece to sensor, so pretty much an identical set up to the one in the photo tube. In fact, I tried a whole rasher of eyepieces( about 40) and only a very few were acceptably corrected for that system. # 146 was the best, perfect actually, and a Wild 6X and one Kyowa 2.5X photo eyepiece were good too.
In the Cycloptic literature, they clearly intend an eyepiece or lens to be inserted in the top of that tube and in the illustrations there are two options. One is to use a # 146 eyepiece( specified), with the camera mounted on a separate stand that is adjustable in x and y, so it can be critically centered over the eyepiece. The camera back is mounted on a bellows, so it can be adjusted for parfocality. That assembly is cat. # 682G camera on a stand, I think. They would have made great scrap, though.....cast iron base. The photo tube adapter, which is essentially similar in form to the Topcon one purchased above , except it has a horizontal framing eyepiece coming off at right angles to the tube # 638., has a built in shutter. It accepted both 35mm and polaroid backs but they both need the # 146 eyepiece fitted into the photo tube.

Scarodactyl
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Re: AO Cycloptic Photo Tube Components

#38 Post by Scarodactyl » Thu Apr 04, 2019 1:01 am

I'll probably just use a bit of tape to make the eyepiece sit a bit higher to force it to be parfocal. That will put it outside its designed range but we'll see if it wrecks the image too badly. Updates to come when the canon adapter arrives.

apochronaut
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Re: AO Cycloptic Photo Tube Components

#39 Post by apochronaut » Thu Apr 04, 2019 12:57 pm

I have used an o-ring to do that job. R-12 to R-18 work well. R-18 fits snugly and offers a .130 lift. The other sizes have to be stretched over the eyepiece barrel and offer progressively less lift, down to about .050 or so. You can of course gang them.

Scarodactyl
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Re: AO Cycloptic Photo Tube Components

#40 Post by Scarodactyl » Tue Apr 09, 2019 6:22 am

I got the adapter in yesterday. The tube opening is tight enough that I can put the eyepirce at any height I want without it sliding down. For now I only tried the AO 10x and a b&l 10x. Alas, no configuration I tried, at any eyepiece he8ght or camera distance, seems to produce a parfocal image. I don't want to modify the tube, since this is honestly more a historical interest piece than something I'd use much (and looking at it again it will need some cleaning before it takes properly good pictures anyway). Still, it is odd that it doesn't seem to want to cooperate. I will puzzle with it a bit more. Maybe the camera needs a lot more distance? But I may end up getting it cleaned and then passing the project on to someone else.

geo_man
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Re: AO Cycloptic Photo Tube Components

#41 Post by geo_man » Tue Apr 09, 2019 9:47 am

Hi, can you get a clear, focused image that is not parafocal?

apochronaut
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Re: AO Cycloptic Photo Tube Components

#42 Post by apochronaut » Tue Apr 09, 2019 12:07 pm

Scarodactyl wrote:I got the adapter in yesterday. The tube opening is tight enough that I can put the eyepirce at any height I want without it sliding down. For now I only tried the AO 10x and a b&l 10x. Alas, no configuration I tried, at any eyepiece he8ght or camera distance, seems to produce a parfocal image. I don't want to modify the tube, since this is honestly more a historical interest piece than something I'd use much (and looking at it again it will need some cleaning before it takes properly good pictures anyway). Still, it is odd that it doesn't seem to want to cooperate. I will puzzle with it a bit more. Maybe the camera needs a lot more distance? But I may end up getting it cleaned and then passing the project on to someone else.

I would suspect that your camera to eyepiece distance is too long. It's hard to tell from the pictures of your topcon adapter, just how long it is, or what your converter depth is. You need about 50mm from eyepiece to sensor. So, clamp the adapter as low as you can on the tube . You can raise the eyepiece some. If you can't shrink the distance enough, another eyepiece could be used. I think a Kyowa was one that worked o.k. for me in the viewing head. The issue is that #146 eyepieces are plan compensating eyepieces and just about every other ones I have tried yielded lateral ca or curvature or both.

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wporter
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Re: AO Cycloptic Photo Tube Components

#43 Post by wporter » Tue Apr 09, 2019 2:17 pm

The unit will be parfocal with an eyepiece in it, but only visually. This is why I shortened mine,and dispensed with the eyepiece altogether. The lens just below the aluminum tube riser serves as a decent projection lens for my camera, and the camera image sensor is now parfocal with the view through the regular eyepieces. However, you do have to come up with your own attachment (I cut up my aluminum tube to make one, so there's no going back.)

The illustrations of the cycloptic with the adapter on it all show an eyepiece in the riser tube. I think this may be more for composing the photographic field than an implication that the eyepiece is needed for projection onto the camera (film, imager, etc.). It is true that most camera/microscope adapters, like my old Asahi Pentax Microscope Adapter II, need and eyepiece or projection eyepiece in them to work, but that is because they are fed directly from the objective lens. The Cycloptic might indeed benefit from a projection (eyepiece) in the 638 adapter depending on what projection you would want: the patent for the Cycloptic projection screen (US 3,572,884) shows a negative lens in the riser tube. If anyone has a manual for the AO 682G Photomicrographic camera, we could see what it has. Like Phil says, it may need an eyepiece stuck in there. Or it may use a lens built into the camera's bottom assembly.

apochronaut
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Re: AO Cycloptic Photo Tube Components

#44 Post by apochronaut » Tue Apr 09, 2019 8:10 pm

The series 4 and the Cycloptic both use the # 146 and 147 eyepieces as plan compensating eyepieces. Put almost any other eyepiece into the Cycloptic and all of a sudden, you have off axis ca. The same should hold true in the photo attachment, as is the case with the trinocular tube on the series 4, unless AO installed a compensating lens in the photo tube of the Cycloptic. My take on the two lenses in the photo attachment is that they are duplicates of the two lenses that occur in the head of the viewing body, in order to provide the appropriate magnification and corrections to match those that occur in the viewing body, prior to the eyepiece providing the finishing magnification and corrections for lateral ca and planarity. It would be possible for one of them or a combination of both to provide the required corrections of the eyepiece as well and dispense with an eyepiece to do that function but then, why would the manual recommend using a #146 eyepiece in the top of the photo tube? If the corrections already took place in the photo tube, putting a corrective eyepiece above that, would throw the corrections out again.
The AO photo adapter was designed to accept either a polaroid camera back or a 35mm camera back. Inclusive with each of those is a beam splitter and a right angle viewing eyepiece, so the design is such that when taking a photograph, the framing and focusing is done through what AO calls a focusing eyepiece. This eyepiece is situated above the photo tube eyepiece( # 146) and is parfocal with the film plane, since it is called by AO a focusing eyepiece. The implication is that the image provided by the photo eyepiece # 146 is not necessarily parfocal with those in the viewing body, so the microscope must be focused separately for a photograph by viewing through the focusing eyepiece.

I did some measurements using a # 146 eyepiece and the next best( as good...actually better in some ways) eyepiece I had on hand as a photo eyepiece for the Series 4, since I do not have a photo tube for a Cycloptic. The exit pupil leaving the eyepieces mounted in the Series 4 photo tube, should be the same as that of the Cycloptic, so I can't see any reason why these measurements do not hold for the Cycloptic, in terms of parfocality. Field coverage is another issue. I know that the field coverage of the photo eyepiece in the Series 4 is identical to that of the viewing eyepieces because I can look in it and see that is the case. I don't know if that is the case with the Cycloptic but I can make a pretty good guess, that is the case.
The distance from the upper rim of the eyepiece to the sensor at parfocality is 60mm for the # 146 eyepiece. The field coverage is about 70% in linear measurement. I tried a number of other eyepieces marked at lower magnifications in an attempt to get parfocality as well as a field coverage equal to the visual field. Most had lateral ca that rendered them useless, some were close and a couple good.
Best of the lot was a Nikon CF photo 5x. It gives parfocality and an almost identical field to the visual eyepieces at 83mm from the top of the eyepiece mounted in the tube to the sensor, as well as being quite well corrected for the system. The problem with the Nikon is that it is a large eyepiece physically, about 1 1/8" across, so it will not fit inside many photo adapters and allow vertical adjustment of the adapter without the eyepiece tagging along. That is why I lean toward using a telescope adapter, coupled with multiple thumbscrews to the outside of the tube. This allows for more space inside for broad eyepieces, and the adapter can be vertically moved to adjust the eyepiece to sensor distance. Systems at some more expense use a focusing coupler or a focusing bellows.
Next in line was a Kyowa 2.5X SP photo and then a Wild 6xK H . Olympus NFK and FK eyepieces were poor.

Also of note is that these eyepiece magnifications are not absolute. They are relative and designed to be used in specific tubes on specific microscopes. Using them in another microscope tube is a whole other situation. As an example the Olympus NFK 5X LD 125 , is presumably meant to be used in a 125mm photo tube. In another tube, they are potentially malcorrected and do not magnify accurately. In actual use, one provides considerably more magnification than the Nikon CF photo 5X, which has less magnification than the Kyowa 2.5X SP photo by about 15%.

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wporter
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Re: AO Cycloptic Photo Tube Components

#45 Post by wporter » Tue Apr 09, 2019 9:16 pm

My take on the two lenses in the photo attachment is that they are duplicates of the two lenses that occur in the head of the viewing body, in order to provide the appropriate magnification and corrections to match those that occur in the viewing body, prior to the eyepiece providing the finishing magnification and corrections for lateral ca and planarity. It would be possible for one of them or a combination of both to provide the required corrections of the eyepiece as well and dispense with an eyepiece to do that function but then, why would the manual recommend using a #146 eyepiece in the top of the photo tube? If the corrections already took place in the photo tube, putting a corrective eyepiece above that, would throw the corrections out again.
Sounds probably right, Phil.

I found the catalog for the 682 and 1070 AO photomicrographic cameras on McNeely's site (http://user.xmission.com/~psneeley/Pers ... ameras.pdf, and it specifies photographic eyepieces 1058 (for 35mm) and 1059 (for 4"x5" & 3 1/4" x 4 1/4" formats) for use with the cameras (unless you buy the 35mm camera with the built-in compensating lens.) Oddly enough, they don't look like the 146/147 eyepieces, but barrel designs have been known to change.

apochronaut
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Re: AO Cycloptic Photo Tube Components

#46 Post by apochronaut » Wed Apr 10, 2019 4:10 pm

The only problem is, that although that catalogue portrays a series 4 microscope on the cover, the actual information is about series 10 microscopes, which have a whole other set of parameters associated with the optics. AO was good at using existing illustrations and sometimes information from earlier documents. Usually it didn't matter but sometimes it did. I guess they just didn't have a new cover illustration for the series 10 version of the manual.

The one dedicated to the series 4 and therefore relevant to the Cycloptic is the manual for photomicrographic cameras 679 and 680, on the Neeley site but it doesn't seem to be available there right now. It links to another site, I believe and I can't find it right now.

They did have another eyepiece for the series 4 and presumably the Cycloptic, to be used as a relay lens with the 4 x 5 polaroid back but it seems the # 146 or the focusing # 435 were the choice for a 35mm frame.

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