Dark diatom

Wim van Egmond · Post by **Wim van Egmond** » Fri Mar 18, 2011 8:00 am

I am going through my archive. This is a stack of a little diatom. A living specimen. I guess it is a Cymbella but I am in a hurry so have not checked.

It was shot with a 40X planapo with an aperture inside. (oil immersion)

I use the darkfield stop in a phase condenser, immerse the condenser; water works well. I close the objective's aperture until the background becomes dark.

The stack was done automatically in Helicon. The organism was moving but I followed its movement and the software could put the stack together, tiny errors are visible but I don't mind. I used the bottom image of the stack to get rid of the halos. This trick often works very well!

Wim

Pau · Post by **Pau** » Fri Mar 18, 2011 11:21 am

Nice!, I like both darkfield and diatoms and this is an excellent image.

What kind of objective and condenser are you using?. With a Zeiss ultra darkfield condenser 1.2/1.4 I'm able to do darkfield with a NPl Fluotar 50/1 oel objective, without aperture.

Cactusdave · Post by **Cactusdave** » Fri Mar 18, 2011 1:03 pm

Stunning picture of a living diatom. Quite a technical feat with the movement of the diatom as well. Can you explain what you mean by 'I used the bottom image of the stack to get rid of the halos' please? Sounds like I might be missing a trick.

rjlittlefield · Post by **rjlittlefield** » Fri Mar 18, 2011 3:15 pm

Cactusdave wrote:Can you explain what you mean by 'I used the bottom image of the stack to get rid of the halos' please? Sounds like I might be missing a trick.

I suspect Wim is referring to retouching from whichever frame has the cleanest outline. With a convex subject like this one, that would be the bottom (farthest) frame.

--Rik

Wim van Egmond · Post by **Wim van Egmond** » Sat Mar 19, 2011 12:12 am

Thank you, Yes Rik, that is right. I use the image with the clearest outline and to create a background without the halos.

With transparent subjects like diatoms and most aquatic organisms automatic stacking creates an image that is very flat so when I make a stack I always combine it with one image that has out of focus areas in it. It makes it more natural.

And I think it is nice to have a contrast between detailed areas and blurry parts. The blurry bits give an image a nice dreamy look.

I used a Zeiss 40/1 planapo. But not with the full apperture. With an 1.2/1.4 condenser it should be possible to use the full aperture. Do you have examples in the forum, Pau?

Wim

Mitch640 · Post by **Mitch640** » Sat Mar 19, 2011 7:05 am

Such amazing detail, and beautiful too. An artistic glassblower might make some nice art out of this.

Pau · Post by **Pau** » Sat Mar 19, 2011 10:51 am

Wim van Egmond wrote:I used a Zeiss 40/1 planapo. But not with the full apperture. With an 1.2/1.4 condenser it should be possible to use the full aperture. Do you have examples in the forum, Pau?
Wim

Wim, thanks for your answer. I did post one of a diatom frustule:
http://www.photomacrography.net/forum/v ... highlight=

Jean-marc · Post by **Jean-marc** » Sat Mar 19, 2011 3:33 pm

Hello Wim,

Very good work

JM

gjones · Post by **gjones** » Mon Mar 21, 2011 8:51 am

Very artistic!! You could hang this in a gallery!!!

Ecki · Post by **Ecki** » Mon Mar 21, 2011 12:46 pm

Very nice!