View Full Version : Exposure compensation for 8x10

29-Dec-2009, 16:47
This is a very basic question, but I'll ask any way just to make sure:

Should I be exposing 8x10 film differently than I expose 4x5? Should I add any time because the size of the film is larger? (Aside from bellows factor, assume I am shooting at around infinity).



J D Clark
29-Dec-2009, 16:49
No, you can expose 8x10 film the same as 4x5 -- adding bellows factor compensation (and others, like for reciprocity failure) as necessary. At infinity, no bellows factor should be necessary.

John Clark

Len Middleton
29-Dec-2009, 16:59

Just consider your 4x5 sheet a smaller piece of the big roll that they cut the bigger piece for the 8x10 from.

As John said above, any differences should only come from how you are using it (e.g. shutter accuracy on different lenses).

Differences in processing (developer used, tray versus drum) could affect highlight density, but should not affect exposure.

Hope that helps,


29-Dec-2009, 17:00
cool, thats what I thought, I just needed some confirmation before I went out this weekend and started shooting.

29-Dec-2009, 18:36
They answered your question, but there is also failure of reciprocity to consider.
So, since you likely will be using a smaller aperture in 8x10, in some cases you may be outside of the range of reciprocity for you film, when you would have been OK with the 4x5.

30-Dec-2009, 04:13
Also consider that when shooting a portrait, you might be approaching 1:1 (macro) photography if the head fills the sheet - or in any case you get closer to 1:1 more easily than with smaller formats. Remember to compensate for that (bellows), and add any reciprocity failure compensation after you calculate the bellows draw compensation… (and don't ask why I know that you easily can forget about this…) :)

MIke Sherck
30-Dec-2009, 07:56
Considering that "infinity" for a camera lens is usually considered to be 200x focal length of the lens, since you're usually using longer focal length lenses for 8x10 (and larger!) you're more often at less than "infinity" for your lens, so you more often need to compensate for it. Not difficult but you do need to keep it in mind -- that tree over there may have been at "infinity" when you were photographing it with the 6" lens on your 4x5, but now that you've put a 12" lens on your 8x10 it may not be! :)