using palm software Vade Mecum (by Wheeler)

pellicle

Member
Joined
May 25, 2006
Messages
1,175
Location
Finland
Format
4x5 Format
Folks

I've been using this software on and off for some time. I recently started to experiment with using one of its features, and suspect I might have found a bug (either that or simply its not behaving as I expect)

I'm using the DOFd2 calculation to try to find the f number needed to get the DoF for a particular focus spread. As I understand it, the software takes the distance between the closest and furthest subjects divided by two and computes the f number required (taking into account parmeters set elsewhere on desired CoC; Lens focal length; film format)

I decided to start with a simple calculation, I focused first on an object about 6 meters (guessing by eye) away and measured the 'extension' as being 190mm. Returning the standard to infinity measures 180 mm (no surprises).

So, the spread is 10mm, thus I enter 5 into the calculation input.

Here's where it goes south, and I get results I can't figure out:

Bellows Factor = 2.44
u = 0.5(m)
FrontDOF = 15.3 (mm)
BackDOF= 16.3 (mm)
Adjusted N = 16_7

can anyone suggest if this is user error, or software error.

thanks
 

donbga

Member
Joined
Nov 7, 2003
Messages
3,053
Format
Large Format Pan
I found Vade Mecum so difficult and irritating to use I deleted it and have never missed it.
 
Cookies are required to use this site. You must accept them to continue using the site. Learn more…