I read a previous post where someone had tested a Heliopan Center Filter on a Rodenstock and Nikkor lens and had identical results as with the Rodenstock center filter. Has anyone tried a Heliopan Center Filter as a replacement for Schneiders Center Filters for the SuperAngulons?

I just got a 58 mm XL and am noticing some vignetting shooting in the 6 x 9 format when I use tilts (I was shooting at f11 on color chromes.) The price of the Heliopan center filter is about a $100 cheaper than the Schneider. Both have identical specs, 67 mm front filter on the lens, 86 mm thread on the outside of the center filter, 1 1/2 stops exposure compensation. Will they give nearly identical results?

Also, is it possible to use color correction filters on top of Center Filters? I would suspect that because you've now added two pieces of glass over the lens you are degrading image quality. Any advice?

-- Howard Slavitt (nverdesoto@earthlink.net), February 02, 1999

Answers

vignetting or fall off? I defiune vignetting as running out of image circle (dark corners) and fall off as a gradual darkening towards the edges.

As far as the results go, my impression is that Schneider is tuning the size and intensity of each CWF for each focal length. Heliopan doesn't (but works fine with my 90mm f/4.5 Grandagon).

It is probably better to put your cc filters taped across the back of your rear cell.

-- Ellis Vener (evphoto@insync.net), February 02, 1999.

Yes the Heliopan Center filters work on Schneider lenses but our rims are too fat for the 47mm Schneider aand the 45 and 35mm Rodenstocks

-- bob salomon (bobsalomon@mindspring.com), February 02, 1999.

Center filters won't help too much with this type of vignetting. You need to re-center the camera and start your correction moves with either the front or rear standard moved slightly in the direction of the vignette (remember..image is reversed) OR switch to a lens with a larger image circle..either a different design, or a longer focal length..OR convince your client that this is very cool and they are lucky to be getting it

-- C Matter (cmatter@riag.com), February 05, 1999.