From a small strew mounted in Darax. All focus stacks shot at 100x under 365nm UV brightfield illumination.
I think the first one is Cymbopleura apiculata (could be C. anglica too, but I don't think it's that).
Second is Pinnularia sp. with pores resolved (185nm spacing)
Last is Tabellaria fenestrata with some pores resolved. Although they 200nm apart each pore is surrounded by a raised ring which leaves less space between pores and makes them harder to resolve. There is a free PDF about Tabellaria available here...
https://www.researchgate.net/publication/354324769_A_review_of_Tabellaria_species_from_freshwater_environments_in_Europe (free download PDF)
This is where I found out about the raised rings. There are some good SEM images in this document.
Cheers
Beats
Hi Beats
Your photos are very detailed. Congratulations.
If you shoot with 365nm in bright field, what settings do you have on the camera? Which camera are you using? I have heard that some people use an astro camera? Like an ASI for example.
Greetings from Siegfried
Thank you Siegfried
I use a Sony A7riv that was converted for full-spectrum imaging by removing UV and IR filters from the sensor. When I use UV illumination, I run a video cable from the camera to a monitor to see the image without frying my retinas. I direct *all* light to the camera too, none to the eyepieces, in case I try to use them by mistake.
I run the camera in manual mode at ISO 100. Exposure is controlled with shutter speed - usually between 1/200th and 1/10th second depending on which condenser I'm using. My Heine condenser is very light-hungry and needs the long exposure to get a bright, noise-free image. The simple brightfield condenser, which I use most, lets plenty of light through so a faster shutter speed is OK. UV light is generated with a Convoy torch reflected directly into the condenser from underneath.
The other advantage of the A7riv is that it supports pixel shift. I mostly use 4-shot which ensures that every pixel has true RGB (or UV) samples and not "approximated" values calculated from the Bayer matrix. That vastly improves colour (and UV) resolution in the final image. 16-shot pixel shift mode improves actual resolution too but I don't use that much. It's very slow and generates loads of huge files for post-processing.
I can still use the A7riv for ordinary photography but metering and colour balance are slightly incorrect now (as expected). This can be completely fixed with a clip-in filter (inside the body) which blocks UV and IR again. But this camera rarely leaves the microscope now so I haven't bothered with that. I have other Sony bodies I can use off-microscope anyway (i.e. back in the real world :) ).
Cheers
Beats
Hi Beats
Many thanks for your information. I will also look into the exposure with 365nm.
Greetings from Siegfried