Thursday, April 3, 2014
Experimenting with lights: taking pictures on cloudy days
I've made an investment -- a new piece of photo equipment -- and today was the first time I used it. I try very hard to use only natural light in taking my photos. But since we're averaging 1-2 days of sunlight a week at the moment (!) I've purchased a "ring light" for cloudy days. Actually ring lights are recommended for use with most macro lenses, and they're almost a must with the powerful 65 mm. They range in price from $25.00 to $500.00: mine was slightly over $100.00. And I was pleased with the results. I stayed with a film speed of ISO 100, trying out a number of shutter speeds (from 1/40 sec. to 1/100 sec.). Next time I'll try ISO 200 and probably shoot at 1/50 - 1/60 sec. Have to experiment with the technique, but it sure beats sitting around doing nothing.
And now to that little Perlodid stonefly in the photo at the top of the page. The find of the day. We were in Sugar Hollow at a little stream where I've seen this one before. In May it will look something like this.
This is one of three Isoperlas (genus) that we've found in our streams that remains unidentified at the level of species -- it can't be keyed out. In the EPT lists that I've compiled, it's called Isoperla sp.1. (See, for example, the entry posted on 10/3/12.) The head pattern is very distinctive with a large pale area in the ocellar triangle and pale slashes at the rear of the head behind the ecdysial suture.
Maybe this year is the year -- with help from Steve Beaty -- that we'll discover the name of this species. But it was great to see it again in our streams.
Common findings today: lots of Peltoperlids (roach-like stoneflies); flatheaded mayflies Epeorus pleuralis, Chloroperlids (Green stoneflies), the common netspinner Diplectrona modesta, and the BIG Perlodid stonefly Malirekus hastatus.
1. Malirekus hastatus
2. A Green stonefly, genus Sweltsa
3. One of many flatheaded mayflies, Epeorus pleuralis
4. And the netspinner Diplectrona modesta. Not the best photo, but the "dark U-shaped pattern" on the frontoclypeus (Beaty, "The Trichoptera of North Carolina" p. 74) sure shows up very well.