Re: KODAK 4X5 IR

[WallyH501@xxxxxxx]

A couple of thoughts about focus using 4x5 IR film....


1) If you want to be very critical, (have the critical focus point as close
as possible), one can take a camera with a IR indicator on the lense (on most
35mm lenses this will be a red dot) and focus the 35mm on the same scene as
your 4x5.... then adjust the 35mm lense to the IR indicator.... look through
the 35mm and see which part of the scene is now in critical focus... then
focus the 4x5 on that point....

2) Another approach.... use the IR indicator on the 35mm lense that
approximates the 4x5 lense (an 85mm on a 35mm camera is pretty close to a
210mm lense on a 4x5, etc) and notice where the IR indicator is.... the IR
indicator on the 85mm lense / 35mm camera I have is about f8.... stop down
two or more stops than f8 on the 4x5s 210mm and focus (circle of confusion)
should be acceptable for most applications and print sizes.... So... for each
4x5 lense, keep a note as to which stop to be stopped down to at a minimum...
and then stop down to east Jesus anyway....

Regards,

Wally

------------------------------

Topic No. 23