Myxomycete - Ceratiomyxa fruticulosa

[AlisonP]

Hi folks, this is my first Image Gallery post. Thanks to the astounding amount of information on these forums, and such friendly and very detailed answers to a few questions that I posed, I purchased a Mitutoyo 10x objective a couple of months ago. I've mounted it to my Sony A7r2 camera using a Canon 70-200mm F4 as the tube lens. My specialty in photography is different from most of the bug folks here -- I photograph Myxomycetes, commonly know with the unfortunate name Slime Mold. They are amazing organisms, and most are stunningly beautiful. This is one of the first photos I made with the Mitty. It is the slime mold Ceratiomyxa fruticulosa, which is usually observed in clusters that look like sea coral. But here we have a detailed closeup of just two of the "fingers", about 0.8mm tall. Almost looks like an ice sculpture.

This is a focus stack of 105 images. It's not quite as sharp as my photos normally are. This was shot using IKEA Jansjo LED as continuous light. I've just purchased a second flash to see if using flash instead of continuous light sharpens my images.

The tiny bubble-like things around the outside edges are actually spores, attached by thin threads to the main part of the fruiting body. They overlap a lot, and I had a lot of problems with halos. Slabbing didn't help. I cleaned up in Photoshop most of the halos, but not all, as I didn't want to spend several more hours doing so. Any comments/suggestions welcome.

[grgh]

Lovely shot, I am sure you will find a few other members who really like photographing Myxomycetes.
so happy hunting.
Here in Lancashire not to many around, mind Ive not been getting out for the last three months.

[Lou Jost]

Very beautiful. We are a diverse bunch, and many of us love good images of things like this.

[physicsmajor]

I just did some fairly robust experimentation with the 10x Mity and a few different tube lenses, and learned some things which might be useful to you.

You didn't specify what f/number the tele zoom was set to. When using a telephoto lens as a tube lens, especially a zoom tele, one of the big steps forward in ease of postprocessing, sharpness, and contrast required me to stop down the tele a bit. At f/4, your Canon tele is probably introducing some axial chromatic aberrations and the stacking software sees that. The tele zooms virtually all have some of this. While in theory with a perfect tube lens, wider aperture means sharper, these zoom teles just do not perform wide open. I would suggest experimenting from f/5.6 to f/8, and you might really notice a difference. Apologies if you're already doing this.

Stopping down a little has an ancillary benefit of mildly increasing depth of field, which means fewer steps and less postprocessing.

[Lou Jost]

Physicsmajor, the usual practice here is to use the tube lens wide open. Rik has shown that stopping down the tube lens is generally not a good idea; the lens is already acting as if it is stopped down by the objective.

Normally, the most we do is stop down the tube lens until the image just begins to dim. For most tube lenses, this will reduce the flare without otherwise affecting the image.

Of course, actual experience trumps theory any day, so if you have experience with this particular lens, we should defer to that. But if not, I would recommend not stopping it down, or stopping it down only until you start affecting the exposure. Could you give us more details about your tests?

[AlisonP]

Physicsmajor, following the information in these forums, I did indeed do as Lou says and I always have the tele set to F4. I too am very interested to see info on your tests with smaller apertures.

[AlisonP]

Very beautiful. We are a diverse bunch, and many of us love good images of things like this.

Thank you Lou. I have looked at the Myxomycete photos on this site, and there certainly are some beautiful ones.