extreme f-stop

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extreme f-stop

Post by NikonUser »

Currently I am running a 40w black-light moth trap in my garden and photographing some of the species caught for posting on BugGuide.
I need a quick-and dirty photographing system as I may get 50 live moths each morning. No niceties such as stacking.
So, 1 shot for each moth using 1 flash.
To get a decent working distance and a decent quality image of the micros with maximum depth of field I found this setup to work well:

Nikon D610 (full frame) + PN11 tube (52.5 mm) + PN11 tube + Nikon 200 mm macro (gives 1:1 image by itself) + Nikon 5T closeup lens
The FOV at maximum magnification = 13 mm; FOV for this moth = 23 mm. Image quality just as good at maximum magnification.
Camera set at 1/200 sec and f/32.

I am pleasantly surprised at the image quality considering the insane effective f-stop

Top image: full-frame of a White-triangle Clepsis (Clepsis persicana)
Bottom: image suitable for BugGuide posting, note the acceptable clarity of the wing scales (there is no interest in pixel-peeping!)
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

Posts: 924
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Location: Michigan, U.S.A.

Re: extreme f-stop

Post by MarkSturtevant »

Very interesting. I can't tell you the number of times that 'mass contributors' to BugGuide have provided a critical means for me to identify insects, including various "little brown moths" that I come across. As long as I can get a candidate family, I can generally get an ID in BG from pictures that were no doubt taken from a light trap. That resource is simply incredible. Thank you for your help!
I am currently working on getting a UV light set up to attract insects as well. It would probably need to run on AC via extension cords for now. Maybe later on a car battery. I am reluctant to use a generator b/c of the noise.
Mark Sturtevant
Dept. of Still Waters

Posts: 174
Joined: Fri Oct 28, 2011 9:29 am
Location: Finland

Re: extreme f-stop

Post by JKT »

MarkSturtevant wrote:
Thu Jul 02, 2020 5:38 am
I am reluctant to use a generator b/c of the noise.
I don't know just how silent you'd want, but the quality units have pretty low noise levels. My Honda EU10 won't bother anyone 100 m away. Admittedly good battery and LEDs would be a very nice combination.

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