What the hell?

[Mike Lopez]

I have a Fuji 400-T lens I bought from Midwest last fall. I'm only saying where I bought it to indicate that it should be functioning well, since Midwest is such a reputable dealer. On at least two occasions where I've tried to use it near the limits of its coverage, I have composed with the lens wide open, and then I see some serious--no, HUGE--vignetting when I stop down. It's as if the lens' image circle is being cut in half or something when I stop down to about f22 or further. Can anyone explain what's going on here? Is it something in the design of a telephoto? Do I have a lemon? I should probably stipulate that, at least as I recall, the vignetting occurred at the bottom of the ground glass, and occurred in situations where I used a combination of front tilt and rise. I know that there are issues with tilt in telephoto lenses, but I've never seen anything about this sort of problem. Thanks for any help.

[John Kasaian]

Mike,

Are you using front movements? I've heard they'll drive a telephoto user crazy.

[Gem Singer]

Hi Mike,

Sounds normal to me. I assume you are using a 4X5 format camera. The lens is a true telephoto design, with a 220mm. image circle. Think of it as a long tube, like a telescope. When you apply front rise, then tilt it downwards, you are cutting off part of the image. Closing down the lens only serves to increase the problem.

When I used a Fuji 400T on my 4X5 camera, I seldom found the need to use front rise and never front tilt. Those movements were used mostly with shorter (non-tele) lenses for architectural subjects or for near/far relationships.

[Bill_1856]

I have two Wollensak and one Rodenstock telephotos, and they all behave that way to some extent.

[Mike Lopez]

Thanks for the input. Yes, this is happening when I use front rise and front tilt. Eugene, oddly enough, I used these movements for architectural subjects. I used them to photograph elevated portions of buildings a few blocks away from street level. So I would use the combination of movement to shoot over the top of the tree across the street but under the power line overhead, etc. It sounds like maybe I shouldn't worry about this based on the input I've received. Thanks.

[Ken Lee]

http://www.kenleegallery.com/images/buckland.jpg
Here is an example where the vignetting on the 400T blended into the darkness of some passing clouds. It's a good lens for what it does: allows you to get a long reach with much less bellows draw.