MicrobeHunter.com Microscopy Forum

Nice finds and darkfield!
Photos 031 and 065 seem to be Litonotus.
I did not see photo 100 or a Heliozoan though.

Welcome, Duncan! Have you thought about getting a Spencer scope like your 1930 one? I am guessing it may not cost you much more than a new one. And many forum members here hold the opinion that an old professional Spencer may not be optically inferior than new hobbyist scopes. Build quality is signi...

Welcome, Ray!
Please feel free to ask questions, whenever you have one in mind.

Very nice! Thank you for sharing.

Rod, Sorry for my misunderstanding. So the "40" in your previous mask photos is 0.4 inch not 40x. Have you tried centering each individual component, especially the condenser, with phase telescope? I remember I had decent darkfield and Rheinberg results at NA 0.65 and a pretty big mask size (IIRC ar...

Rod,

Inspired by you, I will try that "Quasi - DIC" blue mask too, with slight modification. What is the blue diameter you use for NA 0.65? I assume you have compared different sizes and pick the best size?

Thank you!

I have seen similar incidences at least 3 times, under LED darkfield. Of those 3, I pressed down cover slip firmly the first time and did not press the last time (don't remember the second time). I doubt those were caused by heat, since LED darkfield did not produce much heat. Why do you think it wa...

My Nikon CFW10 eyepieces are actually old standard 23mm and will fit all tubes of that size. It is just that AmScope's original EPs theoretically may be the best optical fit for AmScope objectives. YMMV though. 30 mm compound EPs are common for modern infinity scopes and some old Leitz use that size...

Eyepiece does affect optical length and brightness/contrast. But magnification between different brands of DIN 10x eyepieces should not vary too much. AmScope objective may need (chromatic and spherical) compensation from AmScope eyepiece, which Nikon eyepiece would NOT provide correctly (not a matc...

Thank you, Rod. I enjoy your comparison videos. Especially darkfield and blue oblique.

Thank you for the beautiful image and informational comments. I was wondering how often such a diatom shine under pol. I have seen that type of diatom a lot, but never tried pol on them.

Phil, Are you sure those are paramecium at 40x objective and 10x photo eyepiece? I am not saying it is impossible, but the paramecium I recorded (at 30x obj+10x eyepiece) was at least 8 (if not 12) times bigger. The overall shapes do look like paramecium, but a protozoologist may require a much clos...

Did you move fine focus between?
Is it possible that you closed down condenser diaphragm a lot for the brightfield, while left it almost fully open for COL?

What Charles said. OK to go w/o cover with oil objective (immersed in oil), but fix blood sample first in that case. Or use cover and oil with fresh (wet, not fixed) blood - you don't want cells to shift around. Plus: for dry 40x objective, you need cover slip to get reasonable image quality. (It is...

Great darkfield images and very interesting finds! Thank you for sharing.

How do you reduce out-of-focus halos from subject in darkfield? Does cardioid condenser do better than paraboloid condenser in that regard? I would appreciate your kind advice.

Please keep us posted, eiman. Thank you!

I am highly interested in:
1) getting darkfield out of 65/1.1 and 70/1.23 and
2) how much more resolving LOMO oblique condenser is, compared to DIY oblique, with Klaus Kemp test diatoms.

eiman, For me, that Leitz 25x oil provides more convenience and scanning ability rather than resolution/NA. A dry 20x NA 0.65 or 0.75, theoretically, won't be able to image through oil (left by immersion) without quality degradation. Yes, WD is sufficient, but image quality through oil won't be that...

I especially like the DIC photo.
I photographed one of those in darkfield (which looks very different than brightfield or DIC), but I failed to lit it evenly and the photo came up terrible. Even worse, I flooded it away with immersion water before I could film it

Thank you, Kurt. Yes, I thought about the zoo scenario. That phacus is probably around 20 microns across. So if I am 5 mm tall, that phacus may look like a leaf in my hand. It would get funny though, if I am 50 micron tall - then nothing would be like it in our world. A green inflatable boat, maybe,...

Very sharp and beautiful image! Thank you Seb!

Rod's photos continue to amaze me. That photo almost has a 3D stranding-out effect to it, even though it is a single image at 1000x shot by a phone! I used a similar objective on my AO before and my image quality was not even close. Rod must be hiding his magic methodology from us........please tell...

Thank you, gents. You are very kind. JimT, I encourage you to try darkfield on all protists. Maybe some intensely green or red protists won't benefit much from daekfield. But it is difficult to predict what could work and what not. Based on what Rod said and my own limited observation, I am guessing...

Charlie, I personally think darkfield goes better with diatoms (and other translucent subjects) due to higher contrast. COL seems to reveal dense internal muscular structures (say, of a rotifer) better. I like both methods, with a slight preference for darkfield. But that was just my preference, and...

To illustrate what I meant by out-of-focus halos, I am uploading 3 photos. "P1" is a photo taken with flash and has more halos than still captures ("2" and "3") from video. It was not easy to focus well with photo "P1". I made the mistake by focusing with camera LCD screen (as I was tweaking flash a...

Excellent details! What NA does your 40x objective have?
Would you be so kind in letting me see a single shot in middle of the focus, please? I am just curious how much more stacking provides on top of DIC's great focus depth.

The subject is great for DF too. Rod, I agree, different subjects respond differently to darkfield. I shot a rotifer video using the same objective on the same slide, but lighting was either too bright or too dark to show all internal details (although I did not pay much attention at the time of re...

Phacus video in darkfield. https://youtu.be/iJwuMDm9BrY I am guessing this particular phacus is more transparent than green (we don't have much sunshine or green algae lately). Video was shot with 30x or 40x objective at NA around 0.8 - 0.95 (sorry, cannot remember exact details), afocal micro 4/3 c...

I don't think anyone here "thinks that only brand name scopes are worth considering or that brand name scopes represent an "Upgrade" regardless of their condition when bought". I am not even sure there is clear consensus as to what "brand names" are. For example, some consider AO Spencer and B&L goo...

Charlie, I apologize, but I don't understand some of your questions. For those that I do understand what you were asking about, here is my humble opinion: Quote "Or are you useing an oil-bridge between condenser and the slide which your WI objective is water bridged to?" Unquote For high NA darkfiel...

Charlie, I apologize if my following comment does not agree with you. To be honest, your 052 image looks like COL with grey background. It is a good image. However, darkfield in my book should have background close to black, as opposed to grey. Such an grey image is produced when darkfield stop is n...