Tilting with Telephoto lenses?greenspun.com : LUSENET : Large format photography : One Thread
I've read that telephoto lenses behave unusually when you tilt them. As a practical consequence, what does this mean? Can you still tilt telephotos to increase depth of field? What kind of unusual effects will result? For instance, what would be the effect of tilting the Fuji 300T or Nikon 270T?
-- Howard Slavitt (email@example.com), October 27, 1998
In this focal length you are better off with the 300mm f/9 M-Nikkor as its far larger image circle (it will cover 8x10 film easily) will let you make camera movements to your hearts desire, to say nothing of saving you lots of $$. It is sharper too.
-- Ellis (firstname.lastname@example.org), October 27, 1998.
If the lens has the coverage, you can certainly use tilts.
-- Ron Shaw (email@example.com), October 27, 1998.
Tilting any lens about the rear node will tilt the plane of focus without moving the image. An ordinary lens has this point in the lens, so a physical tilt on the camera has this effect. A telephoto lens has the rear node somewhat in front of the lens, so to tilt about the rear node will involve a tilt and a shift and a bellows movement.
-- Alan Gibson (firstname.lastname@example.org), October 28, 1998.
With respect to Alan Gibson's answer, that when you tilt a telephoto lens it will also involve a shift and bellows movement, what is the practical effect? In other words, one you get used to it, is it still difficult and very cumbersome to tilt a telephoto lens, or is it a merely a minor inconvenience that you essentially forget about once you've done it a few times? Also, assuming that the optical quality of the telephoto image and the normal image (i.e. 300 M f/9 Nikkor) are the same (which I understand they won't be), does tilting a telephoto lens somehow degrade the optical quality of the image? Thanks.
-- Howard Slavitt (email@example.com), October 28, 1998.
In responce to your last post "With respect to Alan Gibson's answer, ...what is the practical effect? In other words, one you get used to it, is it still difficult and very cumbersome to tilt a telephoto lens, or is it a merely a minor inconvenience that you essentially forget about once you've done it a few times?"
Physically tilting the lens plane ain't hard, finding the focal plane again will slow you down. I don't think it is worth the hassle for this short of lens; but for longer lenses, yes.
"Also, assuming that the optical quality of the telephoto image and the normal image (i.e. 300 M f/9 Nikkor) are the same (which I understand they won't be), does tilting a telephoto lens somehow degrade the optical quality of the image? Thanks"
If you are under the impression that either of these telephotos are sharper than the 300 M Nikkor, I think you are mistaken but I'd like to see a good argument for that point.
I vote for the 300mm M-Nikkor for several reasons: versatility of movements (rise/fall and lateral shift as well as tilt) due to far larger image circle (the Nikkor 270T lens has an image circle of 160mm, the Nikkor 360T has an i.c. of 210mm, the 300M has an i.c of 325mm; sharpness (the 300mm M Nikkor is very sharp); price (according to the 1998 B&H sourcebook. a 270mm T costs US$1470; a 300mm M lists at US$690. For comparison: a 300mm f/5.6 Nikkor W lists at $1560 and has a i.c. of 420mm). Finally if you are goingto be in the field the 300mm M Nikkor is both smaller and lighter than an equivalent focal length telephoto.
I own a 300mm M nikkor and also have used the 500mm Nikkor T lens for architectural applications. Both are very sharp, but operationally the non telephoto is easier (for me) to use.
I am honestly very curious as to your source of info. Alan Gibson's answer was beautifully clear as to the pratical problems of movements with telephoto lenses.
-- Ellis (firstname.lastname@example.org), October 29, 1998.
I can't comment on the ease of tilting telephotos, nor on relative qualities, because I don't use such long lenses.
Howard: what format are you using? Ellis comments that the i.c. of the 270T is only 160mm, which means you wouldn't be able to tilt it at all on 5x4! Even on 2.25 sq, it would only give you about 8 degrees, which is hardly enough to get the ground in Scheimpflug.
-- Alan Gibson (email@example.com), October 29, 1998.
Sorry for any confusion my most recent post created. First, I am using 6 x9 format, on a Horseman VH. Therefore, the maximum bellows draw is about 11". A lens longer than 180 mm in a nontelephoto format is not very practical. The Fuji 300 T, or Nikkor 270 telephoto would both be fine, however, and would provide enough i.c. to allow tilting movements. Second, I did not mean to suggest that I understood telephotos to be sharper than non telephotos, in particular the Nikkor 300 M. To the contrary, I assumed that what Ellis told me was correct (absent anyh experience of my own) and that the 300 M is sharper. However, because of limited bellows draw, if I want to use a lens of that focal length, I will need to use a telephoto design.
-- Howard Slavitt (firstname.lastname@example.org), October 29, 1998.
I own the Fuji 400 F9 telephoto lens. I haven't found it to be significantly more difficlt to use than a normal lens. I think that the things you read about the nodal point being in front of the lens and the effect of this in operating a camera with the lens sometimes make it seem to be more of a problem than it is in practice. Certainly tilting it doesn't degrade the image.
-- Brian Ellis (email@example.com), November 02, 1998.