Sunday, March 6, 2011

Notes on the Photography of Aquatic Insects

I thought I'd make some comments on how I go about taking my pictures.  But let me say at the outset that I'm not only an amateur entomologist, I'm also an amateur photographer.  There could well be "good" photographers out there reading this blog: your suggestions and criticisms are certainly welcomed.

1. First of all, a note on viewing the photos.  Now, you probably already know this -- but I didn't until I was fooling around last week.   If you click on a photo while reading the blog, it enlarges the photo: the quality is much improved.  When you're done, simply close the enlargement and you'll go back to the blog.

2. A reminder that I have a Flickr account where I post a lot of my photos:  I've just recently added two new "sets" or "folders": Personal Favorites, and Live Photos Only.  I'm very partial to the "live photos," and hope to end up with live photos of every family and genus (of Mayflies, Stoneflies, and Caddisflies) that I can find in our streams.  If you haven't preserved any larvae or nymphs, you would not be aware of the change that occurs when the alcohol does them in: the vibrant colors are almost always lost -- they're either entirely "bleached" out, or in the least, they're dulled by transformation.   One quick example:

Fingernet caddis, live photo:

Fingernet caddis, preserved:

I preserved this spiny crawler that I found in the Rapidan River, and in the preserved sample, all of the bright colors were gone; it appeared to be dull and dark -- and that's a shame.

One more example.  Note what happens to an Ameletid minnow mayfly when it's preserved.
Live photo:
After preservation:

So whenever possible you certainly want to go with live photos.  How do we do it?

3. My equipment:  My camera -- despite what it cost me -- is seen as a "starter" in the SLR class.  I have a Canon EOS Rebel Xsi.  But more important than the camera itself is the lens.  A good macro lens is a must for good close-ups of these very small insects.  I have a Canon EFS 60mm f/2.8 Macro USM, and I'm very happy with it.  DO NOT buy a cheap 10X adapter that screws on to the front of your regular lens: it's a waste of money and time.   I am currently shooting my photos on "manual focus" (MF) at a shutter speed of 1/200th of a second and an ISO of 200.  I need a speed that allows me to get pictures of insects that sometimes move in a hurry without sacrificing "depth of field" (i.e. I want as much of the insect to be in sharp focus as possible).  If there are photographers out there who have more success with different settings, please pass that information along.

4. My "stage": To take most of my shots, I put the insect into a petri dish filled with water.  That helps to confine their movement.  However, it has its problems.  That's because all of these guys immediately head for the side of the dish, meaning the side of the dish ends up in the photo (as with the spiny crawler above).  Still, this can have some interesting consequences: you can, for example, end up with good "reflection" photos as with the humpless caddis below.

What goes under the dish for the "background"?  At the moment, I put my handkerchief under the dish for a lot of my shots.  This gives me texture and contrast, and for most insects seems to work very well.
E.g. the photo of this roach-like stonefly.

Unfortunately, this means I always end up back at my car with a soaked handkerchief and a very wet pocket!  So there are other things that I can suggest.  For example, if you can find some nice colored leaves and/or moss, they can work very well with some photos, as with this Lepidostomatid.

I've also put the dish on top of sand and gravel (Perlodid stonefly, genus Clioperla):

And ice crystals work very well (a large winter stonefly, genus Taeniopteryx):

And if you're out sampling, some insects photograph well in the ice cube tray you're using for sorting (brushlegged mayflies).

In the spring, I imagine there will be grasses and flowers in a lot of my photos.

6. Microscope photography:  While I prefer to photograph at the stream, there are times when things have to be done at home in the lab.  Even a good macro lens can't get a good shot of a tiny, tiny insect -- you must use a scope.  The same is true for photos of the anatomical features that we use for identification.  How do we do this?  Actually, it's not all that hard.  All you need -- in addition to a good microscope, of course! -- is a "T adapter," a gadget that attaches to your camera just like a lens.  It's inexpensive and available on-line.  This consists of a tube that fits over an eyepiece on your microscope, so the eyepiece effectively turns into the lens.   And this is what allows us to get photos like this of the mesosternum of a Perlodid stonefly.

But using a microscope for your photos is not always a snap (sorry, forgive the pun).  It can be difficult getting the lighting correct, and focussing can be a problem.  But the biggest problem I've found is that I often end up with "bright spots" on the photo (there are some in the photo above), which are reflections of the microscope lights.  I always try to "edit" these out -- but my results have been mixed.

No comments:

Post a Comment