Measuring of Bellows for Exposure

[chris_4622]

It's been so long I can't remember who posted the .pdf, maybe Doremus but I printed the disc and ruler out on heavy card stock. Recently working with a model up close I had her hold the disc, I focused and measure on the ground glass with the ruler and voila, bellows compensation figured. All in 15 seconds.

[Mark Sawyer]

I simply made a chart that has all the lenses I commonly use on it with bellows extension factors and time/f-stop adjustments up to the longest bellows I own...

Why not make a little chart for each lens translating each marked f/stop to its actual diameter? Then just measure the bellows extension and divide.

[Jerry Bodine]

I do exactly as the same as Doremus. I don’t trust myself doing any multiplication or division quickly in the field, but I’m comfortable with ADDING corrections to the nearest 1/3 stop; a filter correction (in f-stops) is then added to the bellows extension correction. So my chart shows corrections as f-stops. Then after selecting the exposure time, if the situation calls for reciprocity correction, I have curves in my field notebook (pre-tested with my workflow for each of my films). These curves also note when N-minus development times are required to reduce the inevitable contrast increase. FWIW, for dim field conditions that make reading the charts difficult, I use a Fenix flashlight (3 different power levels) that is smaller than a partially burned cigarette (for size description only) that can be held in my teeth; it’s also handy for seeing the lens controls.
https://www.fenix-store.com/fenix-e0...ight-2014-edt/

[snommisbor]

Thanks for the answers. If you are an iPhone user and I would imagine android as well, Reciprocity Timer is great. You put the particular film you are shooting, add your filters, put the bellow length you are at, and then where you want your meter reading. So if you read 1 second at zone 7 then put 1 second in move it up to compensate for +2 stops and it will calculate the correct exposure with filters, bellows and any reciprocity. Plus once you shoot the timer will save the info you just did and you can snap a photo as well to show what you just shot.

[Emmanuel BIGLER]

Hi!

Another way to compute bellows extension factors is to estimate the image magnification ratio.
Using Philipp Salzgeber's Quick Disc, no computation is required, no electricity, no smart phone, no chart ...

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

This target and analogue ruler system computes bellows factors accurately for many view camera lenses, namely all quasi-symmetrical lenses.
The exception being telephoto lenses for which bellows extension factors are given by a more complex formula, but I am not aware of many LF photographers using telephoto lenses for macro work!

[Cor]

Hi!

Another way to compute bellows extension factors is to estimate the image magnification ratio.
Using Philipp Salzgeber's Quick Disc, no computation is required, no electricity, no smart phone, no chart ...

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

This target and analogue ruler system computes bellows factors accurately for many view camera lenses, namely all quasi-symmetrical lenses.
The exception being telephoto lenses for which bellows extension factors are given by a more complex formula, but I am not aware of many LF photographers using telephoto lenses for macro work!

Great tool..it is worthwhile to repeat the warning on the disc.....do not forget to remove the disc from the scene before exposure !...

Best,

Cor

[erie patsellis]

Visual departures used to make a tool the was in every commercial studio I knew of. The quick stick is basically a half meter ruler with a sliding marker that has bellows correction factors from 30mm to 500mm. Pretty simple to use, line up the arrow on the ruler with the lens plane and slide the moving indicator to the approximate film plan and read off correction for the focal length. They crop up used from time to time, mine will probably be buried with me when I go.