Bellows Exposure calculation

**BrianShaw** · 7-Nov-2013, 08:50

Originally Posted by Kirk Gittings

I use this simple tool. It works fine and I don't have to use my math challenged brain.

et tu Brute?

**Kirk Gittings** · 7-Nov-2013, 09:43

Originally Posted by BrianShaw

et tu Brute?

**smithdoor** · 7-Nov-2013, 12:23

I have upload a APERTURE / SHUTTER SPEED Exposure Factor Chart and if you are use just a 135mm lens a Bellows exposur factor

Dave

**Jim Becia** · 7-Nov-2013, 13:17

Originally Posted by Kirk Gittings

http://www.salzgeber.at/disc/disc.pdf

I use this simple tool. It works fine and I don't have to use my math challenged brain.

I use this also and have about 3 or 4 sets of the disc in every large format camera bag I own. They have been washed away and blown way, so having a few extras on hand works out well. Have also given a number of them away to LF guys who were not aware of bellows extension calculations. Seeing that I don't carry any other type of measuring device, this has worked perfectly for all formats when it comes to close focusing and bellows extension.

**Mark Sawyer** · 7-Nov-2013, 13:45

I never figure bellows extension. I just figure out what the f/stop is. Focal length divided by aperture. No discs, no apps, no conversions...

Come on, guys, it's just a ratio...

**smithdoor** · 7-Nov-2013, 13:59

The basic on Bellows Exposure calculations is if you more than 6' for lens under 100mm no change if you lens is 150mm then more 12' no change only if you are working close will make change in exposure setting. Most of the time I working over 12' with a 135mm and do not make changes

Dave

Originally Posted by Mark Sawyer

I never figure bellows extension. I just figure out what the f/stop is. Focal length divided by aperture. No discs, no apps, no conversions...

Come on, guys, it's just a ratio...