Heliozoan

Beatsy · Post by **Beatsy** » Wed May 07, 2014 5:06 pm

From a fresh pond water sample. The main body is about 75um diameter. I think it's Raphidiophrys pallida.

Images are 20-shot focus stacks taken on a Canon 5d MkII. DIC with a 100W halogen lamp used in both. I had to delete-and-repeat a few times thanks to annoying diatoms and ciliates getting in the way or bumping the heliozoan half way through a stack set. The frustrations of shooting "live" eh

Plan 16x objective + 3.2x internal relay lens

Neofluar 40x objective + 3.2x internal relay lens

carlos.uruguay · Post by **carlos.uruguay** » Thu May 08, 2014 3:53 am

Very very nice

arturoag75 · Post by **arturoag75** » Thu May 08, 2014 4:05 am

Very nice!
is the 16 an achromatic objective?
arturo

Pau · Post by **Pau** » Thu May 08, 2014 7:42 am

Excellent images!

I wonder if your stacks do suffer a movement artifact showing more axopodia and bubbles than the real ones as they don't stop moving while taking the frames.

Some time ago I posted a stack of a much smaller heliozoan showing this problem:
http://www.photomacrography.net/forum/v ... 235#102235

Beatsy · Post by **Beatsy** » Thu May 08, 2014 7:55 am

Artruro, it's a Zeiss Plan objective. Not Apo but I think they're corrected for one more colour than a plain achromat.

Pau, I'm sure the axipodia and bubbles are all real. Surprising how many there are when not confined to a narrow focal plane. I got a couple of "broken" ones where individuals moved out of place during stacking and I spot-removed those. But the rest are in focus along their full length and only a tiny fraction is in focus in any single frame so it would be impossible to introduce a full-length "ghost" during stacking. The beast was very slowly drifting laterally, but not rolling at all (except when bumped by other critters and I restarted the stack when that happened)

Thanks all for the comments.

Olympusman · Post by **Olympusman** » Thu May 08, 2014 9:17 am

Nice detail on a very difficult subject to photograph. Sometimes when I encounter slow drifting or the problem with passing protists disturbing the subject, I put the camera in sequential drive mode and focus through the stack planes while holding down the remote for a rapid-fire stack.

piermicro · Post by **piermicro** » Thu May 08, 2014 10:03 am

very nice

arturoag75 · Post by **arturoag75** » Thu May 08, 2014 12:20 pm

Beatsy wrote:Artruro, it's a Zeiss Plan objective. Not Apo but I think they're corrected for one more colour than a plain achromat.
.

thanks...simple and very useful lens

Jacek · Post by **Jacek** » Thu May 08, 2014 12:28 pm

Very nice