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Lachlan 717
7-Jan-2010, 14:52
Has anyone tried one of these (see eBay listing 220535479121) digital white balance lens caps for pre-exposure?

I'm not sure how light tight the seal would be, but it might be worth a sheet or 2 to test.

D. Bryant
7-Jan-2010, 19:30
Has anyone tried one of these (see eBay listing 220535479121) digital white balance lens caps for pre-exposure?

I'm not sure how light tight the seal would be, but it might be worth a sheet or 2 to test.

I've not used one myself but have considered it also. I think it has interesting possibilities.

Don Bryant

Lachlan 717
7-Jan-2010, 20:00
I've not used one myself but have considered it also. I think it has interesting possibilities.

Don Bryant

I think that the seal could be a problem, but a strip of 3mm neoprene and some adhesive could make a light-tight sleave.

Also, I don't know if the circle of white is big enough to cover the whole image. No good if it vignettes.

Maybe kill 2 birds and glue one to a step-up ring, and then attach the neoprene?

Lynn Jones
11-Jan-2010, 12:43
I've tried several of these that didn't work including a couple that I made. The light source muse be very even. I finally ended up exposing out of focus grey cards in the studio and marking the holders. For certain applications I sometimes pre-expose wit colored filters, but that is another story.

Lynn

Lachlan 717
11-Jan-2010, 14:54
I've tried several of these that didn't work including a couple that I made. The light source muse be very even. I finally ended up exposing out of focus grey cards in the studio and marking the holders. For certain applications I sometimes pre-expose wit colored filters, but that is another story.

Lynn

Thanks for the info, Lynn.

What caused the lack of uniformity? Was it a light leak?