Nothing escapes!

Lyssomanes viridis juvenile
The other day while doing some work on the deck I spotted a tiny spider, only a few millimeters long, and as I observed it for a moment I got this freaky focus problem while looking at its dark eyes. Having seen this before, I captured it for a quick photo session.

This is a very young magnolia green jumping spider (Lyssomanes viridis,) notable in that it is one of the few species where you can see the ocular anatomy of jumping spiders in action, real time. I’ve covered this before, but in short, the two main eyes (anterior median) are specialized for jumping and tracking prey; while outwardly immobile, inside the cephalothorax the eyes can move independently, and because of the translucent chitin of the magnolia green jumper, this can be seen. It’s definitely a weird (but extremely cool) effect, made more bizarre by the lens throwing the retina at a different apparent focal distance than the rest of the spider, seeming to float further off in the depths.
magnolia green jumping spider Lyssomanes viridis with visible retina
My subject here is only half the size of the previous one and probably only a few weeks old. It was a struggle to try and get enough images, since the spider was (like most jumpers) a little hyperactive and somewhat shy, so either moving around enough to make focus difficult or dodging to the underside of the leaf. Not to mention that, at this magnification, the range of optimum focus is perhaps a millimeter in depth, so between my own body movement and that of the spider, the spider was out of focus more often than in, and I was endeavoring not to trip the shutter during those times. This may seem excessive, but I shot 86 frames, partially in trying to get a sequence of images as the eyes moved around. Many of them will be discarded, but I have enough to serve my purposes. I will, however, still be watching for a larger specimen, especially as we get towards egg laying time.
magnolia green jumping spider Lyssomanes viridis with retina and eye reflection
This image is cool because the strobe was at the right angle to produce a reflection from the one eye while showing the retina in the other – you can also see how most of the legs were out of focus, despite this being shot at f16. These spiders are so cool I’m strongly considering setting up a few in a terrarium, maintaining them with fruit flies while they reach adulthood. I guess I probably shouldn’t have released this one…

magnolia green jumping spider Lyssomanes viridis eye animationWhile I wanted a little more eye motion than I managed to capture, I still couldn’t resist making an animated gif from a rapid sequence that I’d fired off – the actual frames I got were spaced slightly farther apart in timing than what appears here, but not significantly. The slight change in perspective is strictly my own movement; I’m lucky to have kept focus while doing so. And yes, I’ve talked about the difficulties in using a tripod for stuff like this – it just ain’t gonna happen.

But hey, while we’re on the subject, I’ll tell you what I did in this case, which is what I often do. A leaf was set up in a small clamp attached to a stand, and placed on the tabletop on the porch. This brought the spider up to a decent working height, and I was able to brace my forearms against the table and limit the amount of twitching that might take place. When the spider wandered around, I was often able to just lean a little and re-obtain focus (maintaining it while the spider moved wasn’t likely to happen, but being able to lock back on when the spider paused wasn’t too difficult.) At times, I had to readjust the leaf angle and position, something the clamp rig assisted with significantly, and could flip the leaf over to chase the spider back on top as needed. It’s little things like this that can make the pursuit a bit less frustrating.

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Okay, it’s almost certainly not true that nothing escapes my attention – there’s actually no way I could tally what does. But I feel safe in saying that, from doing this so long, I probably spot a few more things than the ‘average person’ would – whoever that is…

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