Center Filter for 47mm XL

[xiaubauu]

I am new to this lens and would like to know if I need Centre filter for Schneider SA 47mm XL on a 4x5 format? I notice that it has a 4x (2stop) Centre filter so it might have some pretty pronounce vignette. From your learned experience, is it very pronounce? or it helps if I stop down to f22 or less?

sorry for the noob question.

Thanks in Advance.

[xkaes]

See my test result thread. I tested light fall-off for this lens.

[Corran]

It has pronounced fall-off due to optical characteristics of an ultrawide lens. Whether or not you "need" the CF depends on your personal taste/aesthetic. Issues will be most apparent with high-contrast, low dynamic range film like chromes, especially with scans that can't handle deep shadow. I use a CF almost always with my Schneider XL lenses (38mm through 90mm), though occasionally I get away with not doing so on the 58mm (and only on 617 when using the 72 and 90). I use it even for black and white - see my latest images on the medium format thread as an example of the 38mm XL on 6x9, with the 2-stop filter.

If you are shooting black and white or maybe even color negative* film I would try it out first and decide if you want the filter to even the exposure out. You can always burn down the edges but bringing them up is harder if they go to deep shadow.

*In my experience color negative film will be okay in terms of density but color shift may occur due to the fall-off characteristics when pulling up the shadows, so YMMV.

[EdSawyer]

Yes, you pretty much need it, heavy vignetting in the corners on 4x5 without it.

[Jac@stafford.net]

From your learned experience, is it very pronounce? or it helps if I stop down to f22 or less?

In my experience, a center filter will have no significant effect unless it is stopped down to at least f/16, so f/22 is a good start.

[Dan Fromm]

Jac, FWIW, Rodenstock and Schneider both recommend stopping down two stops from wide open. More won't hurt.

[xkaes]

In my experience, a center filter will have no significant effect unless it is stopped down to at least f/16, so f/22 is a good start.

Maybe you mean "no significant effect UNTIL it is stopped down to at least f/16". My test results on the lens -- see my LIGHT FALL-OFF post -- shows a TWO stop fall-off at f5.6, which diminishes to a ONE stop fall-off at f16. In other words, the wider the f-stop, the more important a center filter is.

[Bob Salomon]

Maybe you mean "no significant effect UNTIL it is stopped down to at least f/16". My test results on the lens -- see my LIGHT FALL-OFF post -- shows a TWO stop fall-off at f5.6, which diminishes to a ONE stop fall-off at f16. In other words, the wider the f-stop, the more important a center filter is.

The instructions from Heliopolis, Rodenstock and Schneider for their center filters is that the lens must be stopped down at least two stops from wide open for the center filter to have an effect on the exposure.

[Martin Aislabie]

I have a friend who bought a 47XL and within a few weeks had to do and buy himself the CF for the lens.

You could try without it for fun but the fall is pretty extreme and you'll probably end up buying one.

Martin

[Jac@stafford.net]

Maybe you mean "no significant effect UNTIL it is stopped down to at least f/16". [.../]

I read your post in the voice of a former Oxford England girlfriend. It was not amusing. Thank gosh I have lived now for eighteen years with an entirely literate professional English editor who is Irish.
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