Diatoms in Circular Oblique Light Update 06/05

WalterD · Post by **WalterD** » Tue Apr 28, 2020 3:24 am

The 104 Forms type slide created by Klaus Kemp is still with me and I found the opportunity to experiment a bit more with darkfield, an 100x iris objective and (circular) oblique light. After a lot of fiddling around I found a setup that provided images with detail as well as a more 3-dimensional appearance. Here are the first six:

1 Arachnoidiscus ornatus
2 Auliscus sculptus
3 Triceratium favus
4 Amphitetras antediluviana
5 Eupodiscus radiatus
6 Coscinodiscus jonesianus

micro_pix · Post by **micro_pix** » Tue Apr 28, 2020 6:53 am

.

Outstanding! Great detail and lighting.

David

nanometer · Post by **nanometer** » Tue Apr 28, 2020 7:28 am

Wow--these are excellent!

Olympusman · Post by **Olympusman** » Tue Apr 28, 2020 8:20 am

Nice stuff.

Mike

Saul · Post by **Saul** » Tue Apr 28, 2020 9:43 am

Walter, beautiful set !

Macro_Cosmos · Post by **Macro_Cosmos** » Tue Apr 28, 2020 10:04 am

I love and appreciate Klaus' work. I believe the slides he sell are undervalued. Another company called "Diatom Labs" offers similar services but at a higher premium.

Lovely photos, I can't wait to go out and hunt for these little gems.

Lou Jost · Post by **Lou Jost** » Tue Apr 28, 2020 10:28 am

After a lot of fiddling around I found a setup that provided images with detail as well as a more 3-dimensional appearance.

Nice work. Can you give us some hints?

carlos.uruguay · Post by **carlos.uruguay** » Tue Apr 28, 2020 11:06 am

Woooow!! a beauty!!!!!!!!!!!!!!!

Sumguy01 · Post by **Sumguy01** » Tue Apr 28, 2020 8:42 pm

Very nice.
Thanks for sharing.

WalterD · Post by **WalterD** » Wed Apr 29, 2020 11:25 pm

Thanks all for the kind remarks.

@Macro_Cosmos:
Yes I was glad to have the opportunity to buy this slide from Klaus Kemp, who's been a master in diatom preparation for decades.
And I don't know anybody else offering commercial type slides this good with this variety of types.

@ Lou:
The fiddling around included:
Changing over from the Ortholux II to the Orthoplan setup, abandoning the mirror house and speedlite flash setup, introducing a 10W understage led, switching over to 0,8Na darkfield condenser, determining the best condenser height, iris diaphragm opening and camera parameters.

Today I've added six more:

7 Artinoptychus splendens
8 Actinoptychus senarius
9 Stephanodiscus niagarae
10 Cocconeis pediculus upper valve (l) and lower.
11 Triceratium pentacrinus
12 Stephanodiscus hantschii

Lou Jost · Post by **Lou Jost** » Thu Apr 30, 2020 5:31 am

Thanks for the tips Walter. May I ask two more questions? What magnifications are these, and what camera sensor size?

WalterD · Post by **WalterD** » Thu Apr 30, 2020 10:31 pm

You're welcome, Lou!
The sensor of the camera is the CMOS type APS-C sized, which is "medium frame". The Periplan 6,3x 30mm eyepiece in this setup results in a large field number, FN28. The Objective is a 100x/ 1.32-0.6 iris immersion objective.
Below 2 pictures of the setup including the led light.

Before COL I tried differential interference contrast on the other scope (the Ortholux). Results were very colorful but also less realistic i.m.o.

The last image was also done with DIC but desaturated and inverted in Photoshop.

Lou Jost · Post by **Lou Jost** » Fri May 01, 2020 10:04 am

Thanks very much for the additional information. The colorful photos are very beautiful even if unrealistic.

iconoclastica · Post by **iconoclastica** » Fri May 01, 2020 11:45 am

You keep amazing me, Walter!

Smokedaddy · Post by **Smokedaddy** » Fri May 01, 2020 9:36 pm

Did you put a stop on the field lens? Totally amazing ... jaw dropping to say the least.

Very 3D like, not to mention the resolution. Sure wish I could come close to any of those images.

-JW: