Heliopan Center Filters on SuperAngulons?

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

I just got a 58 mm XL and am noticing some vignetting shooting in the 6 x 9 form at 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 id entical specs, 67 mm front filter on the lens, 86 mm thread on the outside of th e center filter, 1 1/2 stops exposure compensation. Will they give nearly ident ical 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?

vignetting or fall off? I defiune vignetting as running out of image circle (dar k 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 w ith my 90mm f/4.5 Grandagon).

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

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

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