Fotoguy20d
3-Aug-2011, 11:40
I'd like to understand how the diffusion feature works on these lenses. Is it changing the gap between the front pair? between the front pair and the rear doublet? Both? Presumably, when I'm trying to change the diffusion, I'll be shooting wide open?
Reason I ask is I have a 7" which of course lacks that feature. I was able to rig it so the rear glass of the front pair is linked to the nut which retains it. So, I can dial in the separation between the front pair. The front/rear can be controlled easily enough just by varying how far on the front element is threaded to the shutter. Just looking on the ground glass, it seemed like there was only a little softness achieved by changing the spacing within the front pair. I'd rather have a better understanding before I start blowing through film experimenting.
Thanks,
Dan
Reason I ask is I have a 7" which of course lacks that feature. I was able to rig it so the rear glass of the front pair is linked to the nut which retains it. So, I can dial in the separation between the front pair. The front/rear can be controlled easily enough just by varying how far on the front element is threaded to the shutter. Just looking on the ground glass, it seemed like there was only a little softness achieved by changing the spacing within the front pair. I'd rather have a better understanding before I start blowing through film experimenting.
Thanks,
Dan