Two afocal photomicrography setups (now three)

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Pau
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Two afocal photomicrography setups (now three)

Post by Pau »

The afocal setup consists in the use of the camera taking lens over the microscope eyepiece mimicking the eye. The camera lens is often called relay lens, although the relay magnification term IMO is better referred to the total secondary magnification, in this case due to both the eyepiece and camera lens.

The formula to calculate the relay magnification of afocal systems is:

(eyepiece magnification) X (camera lens FL) /250

To adequately capture a field matching the eyepiece view the recommended total relay magnification is about:
For FF 2.5X, for APSC 1.6X and for 4/3 1.2X for microscopes with eyepieces with 18 or 20mm FN.

With a 10X eyepiece this means 63mm lens for FF, 40mm for APSC and 30mm for 4/3 approximately, or to rely on the "35mm equivalence" of 60-65mm

For wide field microscopes with high quality objectives and eyepieces with FN of 23, 25 or 28mm the relay magnification can be reduced proportionally to capture wider field

For smaller sensors you can calculate the adequate relay magnification proportionally to the sensor size

It can be used in any microscope, but not all the camera lenses and eyepieces are equally good. In general a high eyepoint eyepiece (sometimes marked with eyeglasses symbol) and a lens with the entrance pupil wide enough and not too recessed from the frontal lens surface are recommended. Long range zooms usually don't work well.
Of course this is the only method with cameras with non removable lens and cell phones.

Despite it can be used with monocular and binocular microscopes, a trinocular head is much more convenient to allow simultaneous or alternative view through the eyepieces.

In my Zeiss scope the trinocular head allows 80% to the photo port and 20% to the eyepieces, or 100% to the eyepieces.


I present two setups I use with a Canon APSC DSLR (pictured a 20d but I now use a 7D):

1- Olympus OM Zuiko 50mm 1.8 coupled with a chinese OM to EOS adapter
The camera is held without contact with the eyepiece, with about 5mm between the lens surface and the eyepiece
Image

Closer view. To positioning the camera a bubble level is very useful. To center the camera a good trick is to close the lens diaphragm vignetting the image and center it. In the first small picture you can see its hexagonal form vignetting with the lens diaphragm closed at F16, in the second one the vignette disappears at F8
Some hood (not pictured) is convenient to prevent any external light entering to the camera lens
Image

Comparison of the Field Of View with different eyepieces. Pictures 1, 2 and 3 with the Olympus 50mm 1.8 lens. Picture 4 with the Zeiss 63mm adapter discussed later.
Image

2- Some makers like Zeiss and Leitz used this approach in their camera adapters. Here is a Zeiss T2 mount SLR adapter. It has inside a 63mm relay lens and it clamps to the trinocular 40mm tube with the lens just over the eyepiece. It provides 0.25X magnification factor. I mostly use it with a 6.3X eyepiece because it provides a good match for APSc sensors: 1.575X, you can see it in the last image of the above picture.
Image

The camera mounted with this adapter in the Zeiss Standard microscope.
The image quality is similar than with the Olympus lens, but it's easier to mount and does not need further fixations if used with the vibration free mode Canon EFSC. If the camera transmits vibrations to the scope the first setup is easier to isolate.
Image

- I've added a third setup, see at the next page
Last edited by Pau on Sun Dec 31, 2017 2:27 am, edited 3 times in total.
Pau

Charles Krebs
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Post by Charles Krebs »

Pau,

Thanks for posting this and for the clear photographs. It is a method that does not get the attention it deserves, and if done properly can give excellent results. It is particularly useful with an SLR body when eyepiece chromatic correction is needed but there are no corrective projection type photo-eyepieces (Like the Olympus NFKs) available to match up nicely with the sensor size.

Cactusdave
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Post by Cactusdave »

Interesting to see that Zeiss x0.25 adapter in use with an eyepiece. I've got one in my box(es! :wink: ) of bits and was never totally sure what it was for. Thought it was for a small sensor video camera. I'll get it out now and have a play.
Leitz Ortholux 1, Zeiss standard, Nikon Diaphot inverted, Canon photographic gear

Pau
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Post by Pau »

Dave, it's what it is designed for:

You can download the Zeiss brochure:
http://www.zeiss.com/C1256F8500454979/0 ... hy35mm.pdf , pages 2-6 and 2-9
Pau


Cactusdave
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Post by Cactusdave »

Thanks for drawing that brochure to my attention Pau. In fact I had found it before by Googling the Zeiss part number on the side of the adapter, when I was trying to work out what it did. I had not really read it through thoroughly though. I had seen it referred to the 'Axio' line of Zeiss microscopes and was not sure it would work with my Zeiss Standard trinocular. Also I had not understood about the use of a X10 photo eyepiece with the adapter to give the total magnification of X2.5 which keeps being referred to in the brochure. The X0.25 reduction factor seemed to point to use with a small sensor camera like a C-mount video camera. So I hadn't appreciated that I had a really useful piece of equipment in my hands and I'm very grateful. :D
Leitz Ortholux 1, Zeiss standard, Nikon Diaphot inverted, Canon photographic gear

Cactusdave
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Post by Cactusdave »

I was so interested in your use of the Zeiss X0.25 phototube, that I missed another interesting aspect of the setup you show in your photos. This is a really interesting Zeiss/Leitz hybrid you have.

I see Leitz Periplan eyepieces, a Zeiss Standard frame, a Zeiss intermediate tube, with some kind of slider in it, Leitz objectives which look like NPL Fluotars, a Zeiss rotating stage and a Zeiss phase (and DIC?) condenser.

I'd be interested to hear how these components work together and what methods of illumination (Phase, DIC, etc) you use with them.
Leitz Ortholux 1, Zeiss standard, Nikon Diaphot inverted, Canon photographic gear

Pau
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Post by Pau »

Cactusdave wrote:I see Leitz Periplan eyepieces, a Zeiss Standard frame, a Zeiss intermediate tube, with some kind of slider in it, Leitz objectives which look like NPL Fluotars, a Zeiss rotating stage and a Zeiss phase (and DIC?) condenser.

I'd be interested to hear how these components work together and what methods of illumination (Phase, DIC, etc) you use with them.
Hi Dave,

Yes, the objectives are Leitz NPL Fluotar and the condenser is for phase and DIC. The modified intermediate piece has an Olympus DIC slider. I explained this setup in another post now a bit buried under newer ones:
http://www.photomacrography.net/forum/v ... hp?t=15606
Not a perfectly matched DIC arrangement but working.

I only have one Leitz Phase objective, a PL fluotar 100 1.32 Ph3 and the ring is quite wider than the Zeiss one, so not functional with the Zeiss condenser (I just use it for brightfield). For Phase Contrast I have a set of Zeiss Neofluar: 16X, 40X and 100X. Usually I find Phase useful for observation but not very pleasent for photo because the halos, but surely I need to work more to really apreciate it.

Did you find and test your 0.25X adapter?. I would be interested in your results.
Pau

Cactusdave
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Post by Cactusdave »

Thanks Pau. I had seen your original posting on your interesting hybrid DIC setup, but as you say these things soon get lost in newer posts. It was nice to see an actual photo of your setup.

Yes I found my 0.25 phototube and have carefully cleaned the rather dusty lens and added a T-mount to EOS adapter and a newly acquired 10X20 S KPL eyepiece so it's ready to use. Space limitations mean I don't have a Zeiss Standard on my bench to try it with at the moment. My limited space is occupied by the faithful but large Nikon Diaphot and my black Ortholux 1 which I'm using for some incident light work. I hope to get a Standard out soon.
Leitz Ortholux 1, Zeiss standard, Nikon Diaphot inverted, Canon photographic gear

Pau
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Post by Pau »

Cactusdave wrote:Thanks Pau. I had seen your original posting on your interesting hybrid DIC setup, but as you say these things soon get lost in newer posts. It was nice to see an actual photo of your setup.
Dave, not sure if I wrote it enough clear, in the post of the last link ( http://www.photomacrography.net/forum/v ... hp?t=15606 ) I uploaded detailed images of the setup we previously discussed in the original thread.

Thanks for your comments.
Pau

Cactusdave
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Post by Cactusdave »

Thanks Pau, yes I had missed that post. Now I really appreciate what you have been doing with your hybrid DIC setup.
Leitz Ortholux 1, Zeiss standard, Nikon Diaphot inverted, Canon photographic gear

flyer2o12
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Post by flyer2o12 »

Hey guys,

I have access to a couple of microscopes. I'm wondering if any of you guys with experience with micrography on these optical instruments would have some advice as to how to connect a Canon SLR to them?

They are:

Zeiss Axio Imager 2,

Nikon Eclipse Ti Confocal Microscope

and the

Olympus BX60


Thank you

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Post by Pau »

This is high end stuff! Add a Leica and you have the complete quartet.

Those kind of instruments may have good cameras attached, don't them?, the confocal one wouldn't work as confocal without it. In principle the easiest approach would be to use them if present.

Unfortunately I don't have experience with this monsters, but being current or recent models the manuals would be likely easy to find at the makers websites.

Of course afocal would always work (not for confocal images BTW) because this research scopes are surely bundled with wide field high eyepoint eyepieces.
Pau

Alan Wood
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Post by Alan Wood »

flyer2o12 wrote:I have access to a couple of microscopes. I'm wondering if any of you guys with experience with micrography on these optical instruments would have some advice as to how to connect a Canon SLR to them?

Olympus BX60
Olympus made equipment for attaching an OM 35mm camera to a trinocular head: the U-SPT photo tube, PE 2.5x photo eyepiece and Photomicro Adapter L.

To use a Canon SLR, just add a cheap Chinese OM/EOS adapter to the top of the Adapter L.

The PE 2.5x photo eyepiece works well with the 5D Mark II, which has a sensor the same size as 35m film.

For cameras with an APS-C sensor, you need the much more expensive PE 2x photo eyepiece. Alternatively, use the 2.5x and put up with a smaller field of view.

http://www.alanwood.net/photography/oly ... ter-l.html
http://www.alanwood.net/photography/oly ... es.html#pe

Alan Wood

johnsankey
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an inexpensive method

Post by johnsankey »

See http://johnsankey.ca/closeup.html for my simple way of coupling to any microscope with a good eyepiece.

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