The dunes image is wonderful, but since I don't know the scene, what movement did you use and for what effect? Who knows, maybe I'll learn something.
Printable View
...backward base tilt on the back (similar to forward front tilt, except for little field displacement vs. front tilt) - pretty much essential as I was using a 90mm lens which is marginal for 5x7 with movements, and needed to preserve what coverage I had available (front tilts move available field relative to film, rear tilts not so much) . The price of course (for this back tilt) is a bit more perspective distortion, but not overtly distracting in this case. Other data...orange filter, PMK Pyro. Light was fading so fast that I was only able to obtain one image...glad it worked! Actually, there is a bit of blur in the extreme upper left (had to work quickly, also exhausted from having sprinted two miles with gear to get here in time)...unfortunate as this has, so far, limited me to printing this to 30x40 - whereas if it were sharp overall, I'd love to go to 40x60! Will likely do this (40x60) anyway...just because!
Gotta admit that my previous post was a bit political...in defense of staying true to ourselves and not ascribing to others generalizations. Just sayin! :)
"...backward base tilt on the back (similar to forward front tilt, except for little field displacement vs. front tilt)"
Nice dune image John Layton. Just curious if you would have preferred the benefit of front tilt vs rear backward tilt for this image? I ask because the backward rear tilt as you say distorts the image as if you were using a wider lens than 90MM. Moving the film plane away from the field of view would "elongate" the image away. In other words, did you view the image in advance with the "elongation" effect? I say that as for some, having the film plane perpendicular to the ground (assuming flat ground) is necessary to retain WYSWYG. Of course for base architecture imaging, this used to be the "standard" approach for many pros. (The didactic in me comes out again). I appreciate your insight.
PDM
I don't want to get into an argument over this again, but...
Rear movements along with a subsequent tilting of the whole camera forward are identical to front movements, in terms of "distortion." There is nothing about rear movements that inherently creates distortion, only the tilting of the image plane, which is just as possible with front movements along with tilting the whole camera backwards. Compositions will vary but some rise/fall of one of the standards corrects this (but it sounds like there was a lack of available image circle).
Corran,
I don't believe I asked you for your input on this, nor am I aware of any prior "argument". Obviously if the rear backward tilt brings the film plane perpendicular to the ground, than it's the same as front tilt. If the rear tilt goes beyond that, then distortion does come into play. So your comment is a "half truth" as such. Let's not put your popularity and number of images posted as the basis for elbowing others who have knowledge of this. Ok?
Excuse me pdm but I'll put some input in if I feel like it. No need to be a jerk. Ok?
It's simply a common misconception that rear movements inherently cause perspective distortion. Which is, as you say, a "half-truth" and a more refined understanding could help others who happen to be reading.
Call me what you want, but there is an intrinsic need for some subscribers to learn and I am simply trying to keep the dialogue clear, accurate and open minded. There is inherent distortion in rear tilt other than when the film plane is perpendicular, whether fore or aft. Go back to Adam's The Lens and his discussion points on the subject. If your and H20s attempts to dismiss dialogue of these basis skills in this thread smacks of a private club. I know of nothing that should limit discussion in this or any other forum. If there are new limitations that have been set forth, please advise.
I personally enjoy these discussions as I enjoy learning something new. OK?