First take on imaging

[imkap]

Good evening everyone, I've attached a Sony a6000 mirrorless camera on my Zeiss GFL binocular. Used a telescope adapter with a T2 and printed a ring which I put over the sides a KPL 8x eyepiece so it now fits snuggly and stays on.

I've made 2 images of a diatom we found in the sea, BF and DF (printed filters, not a dedicated condenser).

I'm not sure what is the best way to proceed, one could obviously go to buy some lens and spend money on different stuff to have a better image. But I feel that a lot can be done with knowledge in preparing slides for different subjects, different photo techniques etc. So I'd like some comments from more experienced microscopist photographers...

Is there anyway besides software processing that would increase the depth of field, especially on DF?
If I'd close the iris and prolong exposition, I should have a larger depth of field?
Everything always looks sharper visually...

Also I'm thinking about getting a trinocular head, but they are quite expensive. And I have a problem with buying a microscope on a quite good bargain, so don't feel I should pay for a head more than for a microscope with 20 accessories Would a trinocular head be (specific Zeiss standard) an advance in image quality, or it's just more convenient to use? If using projective eyepiece I'd get a better image then a KPL?

Zeiss KPL 8x eyepiece, Zeiss 25x plan

[MicroBob]

For critical testing of camera adaptations I would suggest to use an object micrometer, covered with a tiny drop of immersion oil and a cover slip (idealy exactly 0,17mm). This makes it easier to evaluate the differences.
An eyepiece in its normal position doesn't project onto the sensor so it has to be lifted some mm, then the camera brought into parfocla focus. Depending on the objects one works on it is more or less important to make good use of the full image. For a big plant section it is!
In this lifted position the optical components are not used as intended any more and errors can start to show. So it has to be checked critically whether this happens in an intensity which matters in practical use. My experience with a KPL 8, lifted for good use of the image circle on APS-C was not very good towards the borders. With Rolf Vossens hybrid eyepieces I got much better results. So this would be the way I would suggest to go. They consit of a low power field lens and high power eye lens, mixed carefully they give nice results.

What to look for in a camera adaptation:
- planar sharpness over the field
- color correction ok towards the borders
- no hot spot
- not too much dust (shows much more than in field photography)
- ridgid setup

The trino tube won' t improve quality or necessarily make the adaptation easier, it is just more convenient. There are different versions: 100-0/0-100 and beam splitter. They have different advantages. Since you got your microscope cheap you may have money left to spend on nice add-ons!

Bob

[josmann]

Lovely images! Dark field is a great way to get the most out of your numerical aperture - it definitely will make things look sharp. Just like in normal photography, there is a trade-off between sharpness and depth of field.

The light in a darkfield image is scattered or refracted and so closing the condenser down will not improve depth of field. You would have to do this by putting a circular aperture mask over the rear of the objective to reduce the objective's numerical aperture (which would also reduce sharpness) or use a lower numerical aperture lens.

[imkap]

Here is another one, I cleaned the dust this time (in Photoshop )

This one was very sharp visually, but I just can't capture the same sharpness on the camera... Not sure if I'm asking too much, or it has something to do with EP positioning/quality or whatever... I'll try to do an image without the head, directly inside the objective turret and see what happens...

For critical testing of camera adaptations I would suggest to use an object micrometer

I'll get one, it seems like a great thing to have for various purposes...

Since you got your microscope cheap you may have money left to spend on nice add-ons!

That is true, but it seems to me that I could benefit more from other add-ons, maybe a different condenser, an eyepiece 6-10 mag which I didn't get with my scope, a more powerful light source (I'm waiting for the LEDs ordered online, they are very slow to come). To spend 200€ on a trino head it's just way off for me, probably in time I'll get some better chance... I'd rather buy a stereo microscope for that kind of money (or a bit more).
And also it is best to work with what you have, I think that in the end experience and knowledge is what should make the difference, of course it should be followed with equipment, but I think I might have more than enough at my current level.

I've looked at Rolf Vossen web page and I think it is great, it's great that he is using the GFL also. I think he's an example of a man whose knowledge is above the equipment. I have 8x kpl old style and 10x KPL of new style so not sure if it is possible to connect them. I have some delaminated ones, so can try some DIY with those...

Lovely images! Dark field is a great way to get the most out of your numerical aperture - it definitely will make things look sharp. Just like in normal photography, there is a trade-off between sharpness and depth of field.

Thanks, I might try some focus stacking with darkfield, didn't study the matter yet on the forums. Maybe if someone has a nice link it would be great There is always some trade-off...

I have this reflection when imaging, it must be a problem in the head (not mine, microscope's)... Some of the black prism paint has fallen off, that seems to be most obvious as a problem. Although it does disappear when I close the field iris the half way and it happens on higher mag mostly. So that made me thinking if the problem might be somewhere else, it would be nice to try an another head. When moving the condenser or the flip top thing, the reflection doesn't move so it is not that. I did try to image without the head and there are no reflections, so maybe I'll try to make new paint to the prisms. Not sure how to make a perfect circle on the prism, wouldn't want to ruin it completely. Maybe I'll try some matte black tape, but then I'm even less sure I'll do it precisely...



darkened in PS

[MicroBob]

Analog micro photography needed much more frustration tolerance so there are fewer trino tubes on the used markets than demand today and the prices are high. After many years of active microscopy and a lot of fairly good photos I started only recently to use a trino head, so it is not that high on my list. For use with a bino tube I would suggest a light DSLM, idealy with a pancake objective of slightly wider angle, sitting on top of an eyepiece. This is a light ans short setup, not stressing the inclined tube too much. And the screen faces the user, so very practical too. Here to solutions with a Pentax Q7 and Nikon 1J5. This is also very practical when one uses more than one microscope and can move the camera over from one to the next.

[imkap]

Mine looks similar, just without an objective... It's a pretty light camera, so I just need a light objective now. I'll try this, thanks.
You made the adapters to screw into filter thread?

[MicroBob]

For the Sony a Sigma 30mm 1:2,8 might be a useful lens. I made the adapters on the lathe. One should use an eyepiece that is dedicated to the camera as the distance eyepiece-camera lens has to be adjusted precisely. With a hybrid eyepiece it might be possible to get a shot setup without camera objective, but I haven't tried yet.
My new setup on the top of the Phomi is a bit longer. The hybrid eyepiece probably sits in the middle of the upper, wider tube. In this positon I make very good use of the image circle.

[MicroBob]

Here some measurements are shown that explain the importance of EFSC:

https://www.mikroskopie-forum.de/index. ... 23#msg6423

They reflect what I experienced with a SONY NEX 5 (without "N")

[imkap]

I don't understand German, but maybe I deciphered succesfully with a translate plugin...
I never really turned off the EFSC on my camera, only once when I was searching for what all of the million menu options mean Realized I don't need to turn it off ever... I got used to the sound of only one shutter, so it sounds weird otherwise

[MicroBob]

I think there are some less frequent situations where it is better to switch off EFSC but I can't remember. The Sonys from NEX 5N on had it activated by default.

[imkap]

I think there are some less frequent situations where it is better to switch off EFSC but I can't remember. The Sonys from NEX 5N on had it activated by default.

Some people say that it ruins the bokeh and the official word is that it may be problematic at very fast shutter speed, black line could appear on the image. I've never seen one, but I suppose it could happen.

I just read the Rolf Vossen article about hybrid EP and can't make any as I don't have KPL 10x just 8x and the differently constructed KPL 10x wide. So it's a shame, but in time probably one should come my way. I have moved the EP up in the barrel a few mm and can't see much difference, except it is more close to parfocality with visual...

I have realized that by increasing the distance of the camera from the eyepiece, the image gets projected larger on the sensor, smaller portion of the image is on the picture. So does it make sense to do something like that, or it is the same effect like cropping in software? I don't have the extensions so can't really test except in hand which is not very precise, Maybe I get/make an extension tube with which you could "zoom" in and out...

[MicroBob]

Rolf's latest and best version for Zeiss West 160mm is based on a Zeiss C5 and a Leitz Periplan eyepiece, perhaps easier to find. Old KPL10 are not very common in Germany too.
To set up the adaptation one chooses a certain amount of lift (or no lift) and adjusts camera position until it is parfocal. Then one checks whether the image circle is used to a good degree. So an adjustable tube between projective and camera is indispensable.

How important is good coverage of the image circle? It depends. The maximum amount of information is available in the image when it is used to it's maximum. For someone who mostly takes photos with the 100:1 of objects that still are far from filling the frame it is no problem at all. If you have to change to the 40:1 n.a. 0,65 to get all into the picture with your less then ideal adaptation you sacrifice a lot of resolution. For someone who takes photos of bigger plant sections it could mean that stitcing is needed or special low power objectives would have to be bought. So for general use I would suggest to try to find an adaptation that makes good use of the image circle.

The absolute resolution of microscope objectives is dependant on the magnification ratio: Low power objective cover so much area at a fairly good resolution that they offer a high image content, equivalent to maybe 24 Megapixels. A 100:0 objective only needs 3-6 megapixels to pick up all information content. So usually it is not necessary to have he most modern camera but it is advisable to make good use of the image circle.

[imkap]

This morning I went to my marine biologist friend's workplace. He has a big Olympus stereomicroscope with zoom up to 150x, DF, BF lighting from below and 2 lamps from above. We were observing some sea slugs and the image is great. It is so great to have all the options in one scope.
Some time age, maybe some of you remember, he was offering me a Zeiss Jena Amplival/Fluoval microscope with fluorescent lighting for indefinite loan, but in the end I didn't take it as it is too big. I don't have a desk that big at home
But maybe I'll take it sometime... It has 4 APO objectives and some block piece, you can put in and out behind the head, not sure what it is, maybe filters for fluorescence or something similar.

Inside the trinocular I found a MF-Projektiv K 3,2:1 eyepiece so I borrowed that to use on my scope. The image seems a bit sharper than with a KPL eyepiece, which is great. But I think the camera needs to be a bit further from the EP, as the image doesn't really fill the whole sensor, not sure how long of a tube can I fit on a binocular.
I also tried to put the KPL 8x lens on a projective tube, the image was slightly larger on the sensor, but I think just a bit less sharp...

I think I should switch to something bigger than diatoms for starters, maybe I'm asking too much from my scope and camera at least for now...

I think this was Olympus SPlan 20 and 3,2 projective

[imkap]

Here is another take, Olympus 20x and 6,3 Jena Projektiv... Now they are a bit larger and not sure how to get them sharper to see the cell structure as mostly diatoms aren't aligned perfectly horizontal, not really posing for me... Maybe my lens just aren't sharp enough, or I just don't know how... Any advice is welcome



and a video from a few days ago, I posted this on my facebook too so added a bit of music