coverage questiongreenspun.com : LUSENET : Large format photography : One Thread
Hi, I'll buy my first LF lens but confused a little bit about the coverage. I know a image circle of 161 degree is minimum for 4x5. I was wondering how much movements are available with a 180 coverage. I'll be shooting mostly landscapes and portraits, not detailed architectural shots. Thanks.
-- Tolga Yayalar (firstname.lastname@example.org), August 29, 1999
Not much, only about 10mm in any direction, or less than half an inch. My experience is that I generally want a minimum image circle of about 210mm, for most lenses, the exception being the ultra extreme wide angles like the 47mm XL.
-- Ellis Vener (email@example.com), August 29, 1999.
A couple of things you might keep in mind: First, how much coverage you'll need is dependent on what kind of photography you'll be doing. With portraiture and and most kinds of landscape work, you're not apt to need to use a lot of shift or rise/fall. When you're focused on a subject that is considerably closer than infinity, the image circle will be a bit larger than specified for that lens (generally calculated at infinity except for macro lenses!). For landscape work, you're most likely going to want to do some tilting. If you tilt the front, you'll need to be mindful of running out of coverage. Think of front tilts and swings as waving a flashlight. Just a little movement of the flashlight results in the beam moving quite a bit at the target. If you tilt from the rear, you'll actually reduce the target size and gain coverage. It would be like setting the flashlight down on a table, walking over to the beam it shines on the wall and rotating your hand in the beam. Same goes for swinging. Work at the rear of the camera and you won't have a problem. There are subtle differences in the effects of tilting and swinging at the front vs. the rear. In some instances, you might want to use a little of each. I'm curious as to what focal length of lens you're considering?
-- Robert A. Zeichner (firstname.lastname@example.org), August 29, 1999.