> "Daniel Flather" <[EMAIL PROTECTED]>
> AHH... I see now, I shoot most of my IR with my 15/2.8 &
> 24/2.8 so DOF and/or focus is not a big issue.
> With a tele the opposite would apply of course. I
> learned to expose HIE properly as not to waste to
> much of it at $12 a roll.
Hi Dan,
You bring up an interesting point.
On my EF 100-400, the amount of IR correct is greatest at shorter
focal lengths.
How large is the IR correction required for the EF 15mm f/2.8?
Is it larger or smaller than IR correction for the EF 24mm f/2.8?
Is it possible that the greater DOF (which is proportional to
the square of the focal length) can be overcome by a greater
amount of IR correction required at longer focal lengths?
Is there a formula to calculate the focus shift required?
Cheers
Julian Loke
*
****
*******
***********************************************************
* For list instructions, including unsubscribe, see:
* http://www.a1.nl/phomepag/markerink/eos_list.htm
***********************************************************
