eye piece projection

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davikokar
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Joined: Fri May 21, 2021 6:03 am

eye piece projection

#1 Post by davikokar » Fri May 21, 2021 6:21 am

hi,
I am using a microscope Swift380T. I tried to take pictures with different systems but the results are not very satisfying. With a canon DSRL I am connecting it to the trinocoluar port with an adapter without optics (https://www.amazon.it/gp/product/B07FLX ... UTF8&psc=1) and also with one that has an optic (https://www.amazon.de/gp/product/B007LB ... UTF8&psc=1), but the results are blurry in both cases. The best result I got is with the cell phone, mounted directly to the eyepiece with a universal adapter (https://www.amazon.it/gp/product/B07JRD ... UTF8&psc=1).

What I would like to try is to do eye piece projection with a DSRL camera. This means an adapter that allow to take pictures with a DSRL through the eyepiece. Eye piece projection adapters for DSRL cameras exist for telescopes, where this tecnique is used. I find it difficult to find a proper adapter for microscopy. Does anyone have suggestions? Thanks

Voyager-1
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Joined: Fri Mar 12, 2021 7:48 pm

Re: eye piece projection

#2 Post by Voyager-1 » Fri May 21, 2021 11:27 am

davikokar,
post a picture through the microscope or your setup (camera on microscope), to get an idea of what you doing.
No way to help without knowing more.
Welcome to the forum!
V

apochronaut
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Re: eye piece projection

#3 Post by apochronaut » Fri May 21, 2021 12:13 pm

Projection eyepieces or photo lenses for microscopes have a set of dependancies. There are two focal lengths to consider, front and back, plus whatever corrections are built into the optics, plus the f.o.v. of the optic, which determines sensor coverage, which is also determined by the magnification of the optic. That all ties into whether you are looking to have a parfocal system or not.

In addition to that, the objectives employed need to be as plan and well corrected as is possible to get a good image.

This all adds up to point out that you can't just stick any lens in there or no lens at all and get a decent image. The connecting devices, tubes, fittings etc. are irrelevant to image quality. They are just devices to get your sensor in the right place, with adequate non-reflective i.d, , like plumbing fittings. The type of camera is irrelevant. It could be a Hasselblad H6D-400C MS or a Brownie Starflash. Neither is going to give a characteristically acceptable image if the photo optic isn't working properly.

You need to find the correct distance for an eyepiece in that tube and then find the correct distance from it to get the right sensor coverage. Either by trial and error or by following the instructions from someone who has done it. In lieu of that.
Start by measuring from the objective shoulder up through the photo tube to 160mm. That's where the resting shoulder of the eyepiece needs to be. Get as cheap a 5X eyepiece as you can on ebay. Any will do, or if you get a deal on a proper photo eyepiece, even better.
Then, find where your sensor needs to be. You can use sticks or toilet paper tubes or drainpipes for spacers...anything that works. Once you have your distance to your sensor roughly you can buy some parts to properly mount the camera but put a short helical focuser( about 25.00 on ebay) in the distance pieces. Bellows work too. You will probably find that after you get everything focused, you will want to get a better photo relay lens, so there will be adjustments.

Since you have non-plan optics, your field will be curved and have peripheral distortions. Some eyepieces are better at correcting some of those problems. For standard 160mm optics I have found Wild 5 or 6X eyepieces to be as good as any.
I have a 160mm system based on a Wild 6X as the photo relay optic.

Swift and other marketers of similar entry level microscopes are really dropping the ball. TRINOCULAR TUBE, TRINOCULAR HEAD , they scream from the advertising pages. Don't any of them ever tell you how to use them? Or do they just grab their 389.00 and scurry into a hole to count it?

MicroBob
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Re: eye piece projection

#4 Post by MicroBob » Fri May 21, 2021 12:45 pm


davikokar
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Re: eye piece projection

#5 Post by davikokar » Fri May 21, 2021 12:52 pm

Thanks for the detailed answer. I'm not sure I understood everything. I see there is some manual work to do to align things, I expected that. In my intention I would use an adapter that contains the eyepiece and that can be attached to the camera and to the trinocular port. The adapter should allow some movements to properly align everything. I saw something similar for telescope (https://www.amazon.it/gp/product/B07TBZ ... UTF8&psc=1), but cannot find anything for microscope. So my question is if there is something similar for microscope and if you can point out a link to it. Thank you.

apochronaut
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Re: eye piece projection

#6 Post by apochronaut » Fri May 21, 2021 12:57 pm

That is by far the best illustrative paper on the subject, I have seen. Note that he appears to be using an old school chrome on brass photo adapter base as his basic mounting infrastructure. Probably 40 or 50 years old.

apochronaut
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Re: eye piece projection

#7 Post by apochronaut » Fri May 21, 2021 1:14 pm

davikokar wrote:
Fri May 21, 2021 12:52 pm
Thanks for the detailed answer. I'm not sure I understood everything. I see there is some manual work to do to align things, I expected that. In my intention I would use an adapter that contains the eyepiece and that can be attached to the camera and to the trinocular port. The adapter should allow some movements to properly align everything. I saw something similar for telescope (https://www.amazon.it/gp/product/B07TBZ ... UTF8&psc=1), but cannot find anything for microscope. So my question is if there is something similar for microscope and if you can point out a link to it. Thank you.
Probably best to read those links above and pretty much forget about telescopes. Telescope objectives are quite simple compared to microscope objectives. They bear a lot of similarity to each other in terms of how they present the image to the eyepiece and there is no diversion to a trinocular tube with simple apparatus. Curvature of field isn't as much of an issue nor are optical corrections. This is true with a conventional 160mm tube length microscope too, if you accept those defects and if you use an eyepiece tube as a place to pick up the image, so yes you can buy similar devices to photograph through an eyepiece tube, even dedicated eyepiece cameras that fit in the tube.
Once you move to the trinocular , that is a different situation. You can mimic the eyepiece tube possibilities if you like but there become options to have a better more complete system.

Greg Howald
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Re: eye piece projection

#8 Post by Greg Howald » Fri May 21, 2021 1:22 pm

I had a similar problem not long ago and I solved it using a paper towel roll by making one tube slide inside another. Then I just adjusted the tubes until the camera was in focus, measured the length and cut a piece of pvc pipe the proper length. Ez to do.
Greg

MicroBob
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Re: eye piece projection

#9 Post by MicroBob » Fri May 21, 2021 4:58 pm

apochronaut wrote:
Fri May 21, 2021 12:57 pm
... old school chrome on brass photo adapter base as his basic mounting infrastructure. Probably 40 or 50 years old.
The adapter Rolf uses was made by Ihagee, the company that made the Exakta SLRs, one of the inventors of the SLR. Exaktas were much used in applications where a Leica rangefinder wouldn't do, e.g. telephoto work, microscope, telescope, scientifical stuff. They were strange beasts, made for lefthanded people with 6 fingers on each hand, three eyes and two brains. These adapters are among the very best and fairly frequent on german ebay.
Most other camera brands of the manual focus SLR time had a similar adapter, also most bigger camera accessory companies.

Rolfs trick is that he uses a mix of the lenses and barrels of different eyepieces to form a projective with just the right properties. The most basic way of eyepiece projection is to just lift the eyepiece from its parfocal position and use it to project the image on the camera sensor. This can work very well but the Zeiss KPL 8x I tested in this application didn't give a great image.

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75RR
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Re: eye piece projection

#10 Post by 75RR » Fri May 21, 2021 5:37 pm

.
I quite like the ihagee adapter. If you are thinking of getting one make sure that it is complete, not all are!
.
Attachments
ihagee-exakta-m4-3.jpg
ihagee-exakta-m4-3.jpg (82.1 KiB) Viewed 3920 times
ihagee bits.jpg
ihagee bits.jpg (64.66 KiB) Viewed 3920 times
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

Hobbyst46
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Re: eye piece projection

#11 Post by Hobbyst46 » Fri May 21, 2021 6:48 pm

The Ihagee adapter is a very fine adapter. That allows free rotation of the camera without loosing stability.
However, being made of steel, studry and thick-walled, it is fairly heavy, especially for a small microscope with an up-and down-going arm. I replaced the original steel top ring with a cheap Chinese aluminum ring to reduce the weight somewhat. They function about the same.
It probably lacks some parts as shown by 75RR above, but is just fine to directly couple the 25mm photo-tube to a camera via M42 rings.
Attachments
Adapter, left- original top ring, right- replacement light weight Chinese ring.jpg
Adapter, left- original top ring, right- replacement light weight Chinese ring.jpg (45.27 KiB) Viewed 3909 times

apochronaut
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Re: eye piece projection

#12 Post by apochronaut » Fri May 21, 2021 6:51 pm

I use one of those on a series 4 . Mine is a little different, perhaps Varex vintage? It has a neat little hinge that lifts the top section off so the eyepiece can easily be lifted out. I also have an Asahi I use on another 4 and sometimes I move it over to a 10 or 20. It is as well made in a similar fashion but has a quite cumbersome bayonet to release in order to lift out the optic. Here though, the Asahi adapters outnumber Exakta stuff 50:1. Exakta was marketed by a big camera dealer in New York. The RTL 1000 was sold in fair numbers in the U.S. Maybe in Canada too but I never saw one sold here. I ended up with one, courtesy of an American. A Varex too and some quite fine lenses.
East German stuff gets short shrift. So much was tossed on the junkpile. Musima guitars, those beautiful inlaid Migma mandolins, Trowa Lefima and Tacton percussion, Dresdener orchestra snares, Microtech Gefell/Georg Neumann, Jena, Meyer on and on.

MicroBob
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Re: eye piece projection

#13 Post by MicroBob » Fri May 21, 2021 7:39 pm

In case someone is interested in Exakta cameras: Ivor Matanle has a chapter on them in his book: https://www.amazon.de/Collecting-Using- ... 0500279012
which is very interesting to read. It was a very big system and several companies made objective with Exakta fit. There also was a russian camera that was fairly similar, the "Sport" from about 1960. One specialty of the Exakta were the long maximum exposure times of several seconds. For dependable everyday use there were better SLR cameras from mid-60s on. Before my late start with digital photography I restored a lot of cameras of this time and used them afterwards.

Bob

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