Help needed to design adaptor for Mirrorless camera

[hans]

Still not as sharp as I would like to get...

I have found it difficult to judge in absolute terms how close a photo is to optimal, especially comparing with looking through the eyepieces, for example. What is making you think you are not seeing the inherent resolution limit of the microscope and that there is additional room for improvement? The difference between live view and the actual photo was a good indication, do you still see some difference?

[Marco68]

I have tried also the self timer but no further improvement.
Hans,
you are right ..Live view and pictures i get are pretty close now. I am only frustrated from the quality of what i can get, despite all the efforts, compared to what i see in the different SN and forum . I am probably only envious
I think it does not depends on the quality of the lens. I need probably to look and improve somewhere else (lightening? The way i collect samples ? ..)

[hans]

...lightening?

Yeah, a good next step might be to try to get the illumination a bit more even (the background appears to have some odd green/magenta blotches) and better matched to the natural white point of your camera's sensor. EXIF data in your latest photo shows automatic white balance. If you set it to manual with daylight preset the photos will give a better idea what is actually going on. It looks like the Leica DMLS has tungsten/halogen illumination with blue filter? Do you know if the blue filter is working? In the predecessor Reichert 410 the blue filter is often broken or missing.

[Marco68]

Thanks Hans,

yes the Leica DMLS has an halogen lamp that gives a yellowish illumination. I have never bought the blue filter and I have just processed that image to remove the yelllowish colour.

I will try as you suggest to set the white balance to manual. But I am little bit puzzled :.. can this improve the sharpness of the image ? I am not sure what affects the image sharpness (a part from the lens quality).

[75RR]

Was looking at your camera attachment design - does it allow you to vary the distance between the camera sensor and the eyepiece? A little tweaking might help
.

[Marco68]

Hi 75RR

Yes, with the 6 screws you should theorically be able to vary the distance.
However, as the microscope works as a camera lens, i just use the focus knob rather then changing the position of the camera. I think the effect should be the same?

[75RR]

What does the 32mm refer to?

[Marco68]

It is just the distance between the eyepiece and the camera body. I need the space for the ring (adaptor Fuji to M42) which is about 25mm.
Ps: being a beginner...I had a very practical approach: before designing the adaptor, i placed the camera on a tripod and moved it back and forth from the eyepiece to find the distance to have the image in focus and with approx 30mm the image was ok.

[75RR]

.
This would be easier if you had a trinocular and not just for the convenience but because all/most instructions are for that type of setup.

It can still be done on a binocular but it is a little more finicky.

You can use the camera to focus on the sample (as you are doing), but only after setting the camera up to be parfocal with the other eyepiece of the binocular.

Additionally, if you are using a normal eyepiece as a projection eyepiece it has to be raised to convert the virtual image it projects into a real one.

See links:

http://www.krebsmicro.com/pdf/trinoc_a3.pdf

http://krebsmicro.com/parfocal/index.html

[Marco68]

Thanks. nice documents. I guess my set up is the one called "3) "Direct projection"" in the first document

[hans]

... But I am little bit puzzled :.. can this improve the sharpness of the image ? I am not sure what affects the image sharpness (a part from the lens quality).

Yeah, not necessarily related to sharpness, was just suggesting the uneven background color could be another symptom of something worth looking into, that would be easier to troubleshoot with the camera set to a known white balance preset.

[75RR]

Thanks. nice documents. I guess my set up is the one called "3) "Direct projection"" in the first document

I think it is number 1) in the first document and if you are using a 'normal' eyepiece then the second paragraph is the one you need to look at.

In the second document it would be Step 1B that you want.

[hans]

In the second document it would be Step 1B that you want.

Good point, when I first read through I got the impression this was part of the initial design process, but now I see Marco has already said that the configuration is not parfocal:

2) I tested the optimal distance of the camera (without lens) from the eyepiece. To make this test I have mounted the camera on the tripod to get stability. Basically the microscope will work as a "lens" for the camera and in my case, I found that the image is in focus and with the right dimension when the camera opening (where you mount the bayonet) is at 32 mm from the eyepiece. (please check my previous message here)
Please note that you need to re-focus the microscope when you pass from the eye view to the view through the camera. ( i think experts say it is not "parafocal" )