This was the setup for shooting "Face of a hobo, for sure!".
The spider was anesthetized with CO2 (carbon dioxide) from a lens duster. Then it was restrained with a tie-down strap of dental floss between its abdomen and cephalothorax, and posed by moving several legs out of the way.
Shooting through the wall of the clear plastic container allowed a continuous dose of CO2.
Continuous CO2 was a critical aspect for this particular spider, which would wake up active and cranky in about 30 seconds when exposed to normal air.
Different spiders seem to have hugely different sensitivities to CO2.
With the hobo, the challenge was to keep it knocked out long enough to restrain it. I eventually ended up having to install the restraining strap while bathing the critter in continuous CO2. But I have a different funnel-weaver that stays knocked out for about 20 minutes after a minimal dose.
I have no idea what the long-term effects of CO2 treatment are. It is a standard anesthetic for fruit flies, but the literature cautions against using it in some kinds of studies due to long-term behavioral changes.
Illumination was dual head fiber optic through a kleenex tissue diffuser, roughly 45 degrees from each side to avoid reflections from the box. White paper behind the box provided a uniform gray background for the subject.
--Rik
).