Return to Texas Entomology - Compiled by Mike Quinn
everything in manual mode, 100 ISO, 1/250 sec. and at f16 (though the
effective f-stop is higher at >1x magnification). I overexpose
nearly everything ~2 stops due to the white background.
Note that the camera's light meter adjusts itself as if it was looking
at an 18% gray scene. If you don't "over expose" two stops, then the
camera will turn the nice white background into a dingy neutral gray.
This is one of *the* most common errors (not correctly adjusting the
exposure) that I see for critters shot against white backgrounds.
If I'm shooting at 2, 3, or 4x, I back off on the F-Stop using f13 or f11 to avoid diffraction issues that would result from using a tiny aperture. Note, the Effective f-number = f-number x (magnification + 1). See discussion here.
I initailly shot everything simultaneously in both JPEG and
RAW, but now only shot in JPEG format.
By day's end, we
may have six, eight, 10 or more live vials. We generally put the vial of
waiting-to-be-shot critters on top of a hotel ice bucket.* This naturally cools
the critters down a little bit, often long enough to get off a few shots before they start accelerating.
I generally shoot straight down on the bug for the primary shot. As the bug crawls around, I follow it with the camera perpendicular to the surface it's crawling on.
After the first series of pix, I enlarge the images on the back of the camera to check the condition of the bug as they sometimes have debris on them, often from the tissue in the vial. If such is present, I rub a finger over the top of the bug which usually is sufficient to clear the insect of unwanted debris. While checking the first series of photos, I place a suitable bottle top over the critter to keep it in place.
It helps to have an axillary light source to keep the
bug well lit as opposed to using the flash's weak focusing lights
(which have to be turned back on after each shot if one is using a Canon ringflash). When on the
road, I'll ask my assistant to train a flashlight on the subject. At
home I use two lamps set on either side of the shooting platform.
I can often get a nice shot after about four or five shots, though
occasionally I may shoot a dozen pix.
Occasionally, I shoot head shots, lateral shots, etc. if it seems
warranted. (If it's gonna be a long night, I usually stop after getting
the first reasonably decent dorsal shot.)
Lord knows it helps to have the likes of Ed Riley spurring you on, assuring you that "this is a really good beetle!", while deep-sixing the common stuff that you already shot one time or another. (Unfortunately, Ed's drive doesn't diminish in the morning, and we usually get to the breakfast table before the grad students drag in!)
If you have time, one trick that occasionally works for calming down bugs is to put
it under a dark bottle bottle cap for a few minutes. Lift the cap and they
often stay put momenarily.
For the fastest (least cooperative) bugs e.g. many carabids, we often put a glass vial of EtOAc on top of them until they seem to slow down enough for our purposes. While this is generally effective, it also often (understandably) leads to excessive grooming on the bug's part once the vial is removed. If a particularly large dose of EtOAc is required to slow them down, they sometimes loose functionality in their hind legs... This condition may or may not be readily apparent in the resulting photos.
For large fast bugs, I often switch to the 100mm macro lens which has auto focus. I can usually get off a shot before it reaches the edge of the platform.
A quick dose of EtOAc also acts like smellling salts to "wake up" tightly curled up beetles.
After selecting the best photos for each subject, I try to crop
everything square if possible. Sometimes this means
cropping part of a hind leg (or less preferably an
antenna) to get a tight shot.
Next, I generally lighten the white background until just before it
washes out. After the 2-stop overexposure and further lightening,
I sometimes boost the shadows
slightly to compensate the dark areas which can get muddied.
I almost never use the "sharpening feature."
I also turn the image if necessary, 90º or 180º to get the bug as vertical as possible (with its head up) to facilitate side-by-side comparison of like species.
Hope this helps, Mike
22 Aug. 2021 © Mike Quinn / firstname.lastname@example.org / Texas Entomology / Texas Beetle Information