What is your minimum and maximum working distance, lens-to-subject?
What is your minimum and maximum working distance, lens-to-subject?
For small and medium format my rule-of-thumb for head-and-shoulders portraits is 2-3x normal focal length and 3-4x for full-face. Twelve feet is barely enough distance for the shorter of those focal lengths. Large format is a bit different but only due to practicality. In that work space I would probably just use double normal FL for any format... 300mm for 4x5, 450mm for 5x7, 600mm for 8x10. Normal FL for full-length portraits... 150mm for 4x5, 210mm for 5x7, 300mm for 8x10.
This is only my opinion... you'll read many differing opinions.
My Chamonix 45N has 400mm extension plus another 150mm with the extension rail, plus another 100mm with a top hat board. That's 650mm total extension. A 300mm lens can easily be used at portrait distances... even without the top hat board. There are plenty of 4x5, 5x7 and 8x10 cameras with enough extension to use lenses of appropriate FL for portraits. Of course if one prefers a little perspective distortion then shorter lenses are a better choice for them.
240-300-360mm is the sweet spot for portrait lenses on 8x10 in my mind.
180-250-300mm is the sweet spot for portrait lenses on 4x5 in my mind.
... and for 5x4, the sweet spot is 12, 10, and 7-1/4 inch.
One of my assumptions is a monorail camera with a long(ish) rail.
Bookmarks