 Posted: Sat May 02, 2009 3:48 pm Post subject: Emulating a 35mm PC lens with a Flek 4/20 |
 |
|
vilva wrote:
I've often thought of getting a 35mm PC lens, but let's be realistic, a good PC lens doesn't come cheap, and I wouldn't be doing much shooting with it anyway. My pinhole snapshot experiment got me thinking: if I can get a decent shot for web use with a pinhole, I can certainly take a shot with a lens, do some cropping and still retain usable IQ.
Cropping to 35mm FOV from 20mm FOV means that a 35mm landscape frame fits comfortably inside a 20mm portrait frame. Here we have a down-sampled center crop at 35mm FOV (i.e. 56mm FF equivalent on a 350D. It seems the camera wasn't quite horizontal, but this was the best shot I found in my archives.):
Now, let's shift down:
and then up:
Portrait orientation gives us somewhat less shift, of course. First a center crop, left of center:
Then the lower limit:
and the upper limit:
As you can see, a single frame shot with the 4/20 can give quite many different views with correct vertical lines (within the limits dictated by the original shot, of course.) The IQ is quite adequate for typical web use at least, and you can do the shifting during PP, any of the variants, ad lib.
Here is the original frame (I should have aimed somewhat lower in order to retain correct verticals. Here the horizon is below the frame midpoint.):
Mounting the Flek on a 5D would give either a better IQ at the same crop factor (at the real 35mm FOV) or a wider shift range at the same number of pixels before down-sampling (at an about 44mm FOV). A 5D2 would fare even better, except perhaps at the extreme off-center areas of the full frame.
Veijo
_________________
Mainly Schneider-Kreuznach Radionar (1938), VPK Meniscus Achromat (1915), TTH Cooke Anastigmat (1917), TTH Cooke Aviar (1937), Goerz Dopp-Anastigmat III Dagor (1912), Voigländer Heliar (1928) or Aldis Uno Series III (1903 design) mounted on EOS 5D or EOS 350D |
Search
Memberlist
Register
Profile
Log in to check your private messages
Log in
