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mfrissen · Joined: 10 Jun 2004 Posts: 25

Hi,

I'm contemplating a RH-10 back for my CG45. I'm using an excel sheet to calculate/print the DOF for different ranges. However, I'm always confused with the following:
- if I use a RH-10 back, which is in effect a 6x7 format, should I use the 6x7 CoC (0.06mm) or keep using the 4x5 CoC (0.1mm) to calculate the DOF?

since the distance to film doesn't change.. I think the latter.. but as I said.. I'm always confused with this "CoC" thing (hence the name probably...)

Dan Fromm · Joined: 14 May 2001 Posts: 2165

Quote:

On 2004-12-06 05:25, mfrissen wrote:
Hi,

I'm contemplating a RH-10 back for my CG45. I'm using an excel sheet to calculate/print the DOF for different ranges. However, I'm always confused with the following:
- if I use a RH-10 back, which is in effect a 6x7 format, should I use the 6x7 CoC (0.06mm) or keep using the 4x5 CoC (0.1mm) to calculate the DOF?

since the distance to film doesn't change.. I think the latter.. but as I said.. I'm always confused with this "CoC" thing (hence the name probably...)

Use the 6x7 CoC because you'll enlarge 6x7 more than 4x5 to get the same final print size.

glennfromwy · Joined: 29 Nov 2001 Posts: 903

Yep, circle of confusion. That's me.