I have a Sinar with asymmetric movements, and I've gotten used to the tilt/swing on rear standard, then transfer to front standard routine. I've also recently gotten an old Petzval that comes mounted on a tophat board, and I'm curious if this will work exactly the same as with other lenses on flat boards. Does it matter if the nodal point is in line with the axis of the tilt/swing? Or does the movement get exaggerated if the lens is mounted forward or back from the standard?
Yes, as the front movements will move the lens on an arc...
Even more refocusing will be required for even a small tilt/swing...
Steve K
Yup. What Steve said. However, it has not ever really changed the way I work. Movements for me are always a "look at the ground glass and watch" kind of thing. That using a top-hat lens board makes it look a little weird at first, didn't make it any harder to do. And after the first couple of times, I just forgot about it.Originally Posted by LabRat
Just remember -- the ground glass never lies. You remember that, you'll be fine.
Bruce Watson
Also, with SF and Petzval lenses, behave differently off-axis, so as Bruce said, you have to watch the GG to get an idea of what's happening and film test to see if you like it...
It is ideal for the rear nodal point to be on the FS axis, as you can just tilt the lens without refocusing and see the effect in real time (on an axis tilt design), but tophat boards will sometimes even cause changing the top/bottom edges as you are trying to refocus and tilt (as the lens moves on that arc)... But you do get used to it...
Even just using a true tele takes some getting used to, esp up close... ;-)
Steve K
The only time a tilt/shift can be done without distorting the image is if the axis of rotation goes through the rear nodal point. That will sometimes happen with lenses close to "normal" focal length, but never for wide-angle or telephoto designs, and sometimes not for lenses close to normal focal length.
- Leigh
If you believe you can, or you believe you can't... you're right.
A top Hat bounted lens may vignette with movement.
Drew Bedo
www.quietlightphoto.com
http://www.artsyhome.com/author/drew-bedo
There are only three types of mounting flanges; too big, too small and wrong thread!
Why would you use one on a Sinar?
I've got an old Petzval that came with a tophat version of a mounting flange already attached to a Linhof board
Doesn't mean you have to use it that way does it?
Could be better to remount the lens on to a Sinar lens board without the top hat. Top hat extenders are often required for cameras that do not have enough bellows or extension. This is NOT the case for a Sinar where bellows, rail and shutter are not going to be limitations.
Bernice
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