JohnJ Offline Upload & Sell: Off
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jcolwell wrote:
Here's a few photos that I took to try and replicate the problem on (1) a Mirex adapter, and (2) a Fotodiox Pro adapter, with images at f/4 and f/32 for both cases. I used the A 120/4 Macro on my 5DII, with three indirect flash units (600EX, 2x580EX). The f/4 photos are at ISO 100 (Mirex), ISO 800 (Fotodiox, doh), and both f/32 are at ISO 3200. You can see an overall slight increase in reflected light for both f/32 examples, but there is no evidence of the central bright spot. Of course, there are so many variables that this is certainly not conclusive. I also tried some direct reflection images off the shiny inside surface of an EF lens cap, but saw no difference between apertures.
I'm pretty sure the increase in light for the example images at f/32 relatove to f/4 is because the flash units were firing at relatively high output for the f/32 photos. I could probably get more consistent illumination and use constant ISO with my strobes & softboxes, but most of that stuff is packed up right now.
For me, the largest apparent difference between f/4 and f/32 is the softening effect of diffraction at f/32....Show more →
Interesting. I agree that if there is a flare spot in your examples it's much less obvious. There is a highlight right in the centre of the images which might mask it some what, but still there's very little sense of a flare spot there.
jcolwell wrote:
JJ, what's the inside of your Mirex look like?
Mine's shown below, on the right, with the FotodioxPro on the left. You can see some reflection from the internal grooves on the Mirex, but it's not too bad considering the 600EX-RT is pointing straight at the Mirex.
Gotta go watch some football. Probably missed the kickoff, as usual.
My Mirex is the same.
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