Originally posted by KDINDC It had been 'hit and miss' until I discovered a T/S app.
A T/S app......hmmm.
But it's straightforward, with only your phone and its calculator required:
sine angle of tilt = f/ / Dist.
e.g. photographing an engagement ring with a TS-E 24mm: 24/175 (
mm with target subject area or sharpness [peg] of
17.5cm from PPL [principal plane of lens]) then with the SCI calculator a resulting sine of ........ 8° (the same formula is used in large format work involving movements of the lens and/or focal plane, with some additional references involved). That small 24/175 example would be applicable only to 35mm; the same thing on 4x5 (f/ 100) would result in an angle of ......
35° (!), introducing vignetting and hobbling the image through aberration.
That (mathematical approach) has been one method I have used since training, but a visual cue of placement is also important.
I'm not keen on adding any more apps to my phone to keep the weight low...