Green Lacewing And "Presents" - Update Friday

Images taken in a controlled environment or with a posed subject. All subject types.

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Guppy
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Re: Green Lacewing And "Presents" - Update Monday

Post by Guppy »

Hi
An interesting article with informative and also very beautiful pictures.
Many thanks
Kurt

AlP
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Re: Green Lacewing And "Presents" - Update Monday

Post by AlP »

I got a little sidetracked today. I found a second parasitized aphid. When I looked at it yesterday the underside had a nice soft webbing on it and somewhat more transparent than now. Today it looks like hardened crazy glue. I could see a black thing moving about inside. Single image at 5x and beautiful diffraction of f16 (effective aperture f85?). I used f16 because Canon claims a depth of field of 1/4 of 1mm at 5x and f16 and I don't have a vertical stand (as of yet).
paratisized aphid ventral 5x f16 1024.jpg
Dorsal view. Nice thing about this parasitized aphid is you don't have to chase it around.
paratisized aphid dorsal 5x f16 1024.jpg

rjlittlefield
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Re: Green Lacewing And "Presents" - Update Monday

Post by rjlittlefield »

AlP wrote:
Tue Sep 06, 2022 11:40 am
Single image at 5x and beautiful diffraction of f16 (effective aperture f85?). I used f16 because Canon claims a depth of field of 1/4 of 1mm at 5x and f16 and I don't have a vertical stand (as of yet).paratisized aphid ventral 5x f16 1024.jpg
The standard model for effective aperture would say f/96 = 16*(5+1). I think that's pretty close for the MP-E 65.

In this regime, Canon's DOF table is too conservative because it does not give "credit" for the large diffraction blur. That is, their table calculates with a constant value for circle of confusion, but at effective f/96 the best achievable blur is much wider than the circle they've used. Once we've decided that the diffraction blur is acceptable, then the acceptable circle of confusion should grow to match, and a better estimate is 0.8 mm (HERE, table 2-A.)

I look forward to seeing what comes out of the aphid shell.

--Rik

AlP
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Re: Green Lacewing And "Presents" - Update Monday

Post by AlP »

rjlittlefield wrote:
Tue Sep 06, 2022 1:31 pm
and a better estimate is 0.8 mm (HERE, table 2-A.)

I look forward to seeing what comes out of the aphid shell.

--Rik
Thanx for the info. A company (Canon) under estimating, that has got to be a first in my lifetime. I too hope whatever is coming out, comes out in the next couple of days. I am heading out to your side of North America but a little further up in British Columbia's rain forest. I did more snaps after the above pix with a little more patience and hand stacking that did produce a little better quality but I'll leave well alone.

AlP
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Re: Green Lacewing And "Presents" - Update Tuesday

Post by AlP »

Hi, all. Ooops, someone (me) took a stoopid pill. It just dawned on me the reason the fuzzy is gone is that I used a dampened tip of a toothpick to pick up the aphid to move it. Mystery solved.

AlP
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Re: Green Lacewing And "Presents" - Update Tuesday

Post by AlP »

Dang, missed it. Sometime between 8'ish and 11 am this morning the wasp came out of the parasitized aphid.
parasitized aphid 5x 39 steps copy 1024.jpg

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