Scheimpflug Calculations

[Dave Schneidr]

Has anyone written a simple calculation program that could operate on a palm pil ot or similar machine that does all the calculations? Can you point me to an onl ine resource that has all the necessary formulae? It seems like it would be usef ul to be able to enter lens focal length, distance to subject and relative angll e of desired focus plane and have a program caluclate the angles to preset into the camera. I'm sure there would have to be adjustments made but this would be a useful tool to get "in the ballpark" before putting your eye to the glass.

[Ron Shaw]

Well...since all 3 planes need to converge at the same point (such as ground, film plane, and lensboard), just eyeballing it seems to get you into the ballpark.

[tim atherton]

You might want to check out:

http://www.darkroom-innovations.com/Software/ExpoDev/expodev.html

http://www.darkroom-innovations.com/Software/FX-795P/fx-795p.html

I have no experience of them though.

Tim A

[Ben Diss]

I checked out the Darkroom Innovations software in detail. Its purpose is to control emulsion density on B&W film. Pretty sophisticated stuff and very impressive if thats what you want. It does not, however work as a general purpose exposure calculator.

I have considered writing such a program for PalmOS. Input would be:

1. Film (including reciprocity data) 2. Lens (available/preferred apertures) 3. Filters (filter factor) 4. Distance of nearest object to be in focus (actual or extension) 5. Distance of farthest object to be in focus (actual or extension) 6. Several meter readings with desired zones

It supplies:

1. Aperture (for depth of field) 2. Distance to focus (hyperfocal for aperture) 3. Shutter speed, accounting for: a. aperture b. bellows extension c. filter factor d. film expansion/contraction to achieve desired zone placement e. reciprocity correction

I suppose there ought to be a way to calculate Scheimpflug movements, I just haven't figured out how yet.

Anybody interested in a program like this?

-Ben

P.S. Thank you Quang-Tuan Luong for teaching me how to spell "aperture".

[Alan Gibson]

http://fox.nstn.ca/~hmmerk/ (by Harold M. Merklinger) has all the formulae.

With your surname, Dave, don't you have it all already in the family?!

[Dan Smith]

Way before you figure out all the math, do the proofs & double check I will have set up the camera, composed, focused, shot & backed up with an in camera dupe and am away for the next image. Why make it harder than it needs to be. Focus on the ground glass & watch your focus as you swing & tilt & rise & fall to your hearts content. When the batteries die in the field you will have to do so anyway.

[Lukas Werth]

Try Harold Merklinger's book "focusing the view camera" or his website (forgot the address, but you should find it through the search engines Lukas Werth

[QT Luong]

Check out Bob Wheeler's free software, just installed on the LF page.

[Ellis Vener]

Just to be precise about things, I must correct Ron. You want the three planes he mentioned to intersect in a line, not a point.

[al]

www.zonevi.com

look for exposure calculator