Unidentified spider

royalwinchester · Post by **royalwinchester** » Thu Dec 29, 2016 12:49 am

NikonUser · Post by **NikonUser** » Thu Dec 29, 2016 9:10 am

One of the Running Crab Spiders, Philodromus possibly P. rufus

leonardturner · Post by **leonardturner** » Thu Dec 29, 2016 1:28 pm

Nice images. I wonder if spiders admire each others feathery hair arrangements--seems too good to waste on mundane functionality.

royalwinchester · Post by **royalwinchester** » Thu Dec 29, 2016 3:12 pm

NikonUser: Thanks! It looked a bit like a crab spider, with the longer front legs, but didn't have the large sort of trapezoidal abdomen I had associated with crab spiders, and wasn't found in an ambush location, like crabs I've found before.

leonardturner: Thank you! It really surprised me when I saw those branching, feather-like hairs!

rjlittlefield · Post by **rjlittlefield** » Thu Dec 29, 2016 5:55 pm

Excellent rendering of the feathery hairs!

When shown like in your images they're really obvious, but at lower resolution or lesser lighting, they're very hard to see. For example, compare yours with http://bugguide.net/node/view/930661/bgpage where you can barely make them out.

The first time I ever noticed feathery hairs was when I photographed a pedipalp from a house spider (HERE). They were glaringly obvious in the image, but almost impossible to see under a stereo microscope.

I gather that feathery hairs are quite common. Mine were from Hololena nedra. That's in Agelenidae (funnel weavers), a completely different family from Philodromidae which contains Philodromus.

--Rik

royalwinchester · Post by **royalwinchester** » Thu Dec 29, 2016 6:09 pm

Man, Rik!
That pedipalp is so crisp and detailed! Fantastic! That's what I want to achieve some day! And it's two images stitched? That's so impressive.

rjlittlefield · Post by **rjlittlefield** » Thu Dec 29, 2016 7:03 pm

royalwinchester wrote:And it's two images stitched?

No, not stitched. The bit about "two images, no gap" was just a trick to get around forum limitations on image size, so that I could display what visually appears to be a single large image but is actually two smaller ones. The BBcode is just this:

Code: Select all

&#40;two images, no gap&#41;
&#91;img&#93;http&#58;//www.janrik.net/MiscSubj/2008/SpiderPedipalp20080105/TopHalf.jpg&#91;/img&#93;&#91;size=0&#93;
&#91;/size&#93;&#91;img&#93;http&#58;//www.janrik.net/MiscSubj/2008/SpiderPedipalp20080105/BottomHalf.jpg&#91;/img&#93;

The size=0 newline puts the two images one above the other, with no visible gap between them, at least in all the browsers that I tried at the time. Unfortunately page rendering is a moving target. I think the trick still works, but there may be some browsers that now show some sort of gap.

Also,

That pedipalp is so crisp and detailed! Fantastic! That's what I want to achieve some day!

Thanks -- I liked the way it came out too. You'll get there quite quickly, I think. It's just a matter of lighting, optics, and stacking, and it seems you have the lighting and stacking under control already. I'm not sure what you have for optics, but if you need better, that's now "just" a matter of funding. A lot of good options are well known and we can help you with those if needed.

In current terms, the optics that I used there back in 2008 were actually pretty clunky: a 38mm f/2.8 Olympus bellows lens at f/4, extended to about 8X magnification, so running at about NA 0.1 on the subject side. And the stereo pairs were "true stereo", shot as two stacks from different viewpoints.

These days I would use a Mitutoyo M Plan Apo 10X NA 0.28 microscope objective, giving almost 3X higher resolution. Then I would shoot just one stack, and use the synthetic stereo capability of Zerene Stacker to make the pairs and/or a rocking sequence. Technology marches on...

--Rik

royalwinchester · Post by **royalwinchester** » Thu Dec 29, 2016 7:30 pm

I'm stacking with a Stackshot, though I *think* there are a few minor issues. Namely, I think there is a bit of play in the system. Some is perhaps in the stackshot, and some in the lens to camera mount interface. I also think I don't always get the optical axis and the stackshot axis perfectly aligned as I am manually screwing an ARCA swiss clamp to the stackshot platform. This is all mounted on a Markins ball head on a RRS beefy tripod.

Optically, thanks to this forum, I think I have bypassed an expensive multi-purchase route. This was taken with my new Mitutoyo 10X 0.28 NA. For the 10X shots it's mounted on a Nikon Micro 200mm f/4 (I'd guess that's the weak link in the optical train?) For 5-6X I used my Voigtlander APO 125 f/2.5 CV Lanthar.

I'm constantly experimenting with lighting and diffusion. These were shot with a Paul C. Buff ABR800 ring flash, through a tissue, with a white bounce card opposite. There are minor light output fluctuations, but your software seems to handle these without any issue. Sometimes I use a couple Nikon speedlights.

I got a cheap stereo microscope for Christmas, and this was the first time I used it to mount the subject, and clean some tiny threads and flakes off of it, and to survey for my shots.

For vibration I have the XYZR topped with dual axis goniometer stage bolted to a small, but heavy optical breadboard. I shoot with 5 seconds of settle, mirror up, 3sec exposure delay, electronic front curtain shutter (Nikon D500 style) with the strobe and high enough shutter speed so there is no ambient light contribution. Just over 8s per shot.

My stereo shots were done with the synthetic pairs generated by Zerene.