What's the Opposite of a Center Filter???

[Scott Rosenberg]

hey guys,

center filters are used to even-out the illumination and reduce fall-off towards the edges... is there a filter out there that is the inverse? that is to say when fall-off is desired, is there a filter out there that will subtly darken the edges? i realize this can to be done in PS, but was wondering if there was a way to get it on the film.

thanks,

[Ash]

A long/narrow lenshood may cause light fall-off

[Nick]

Scott,

Shoot wide open. :)

Why would you want this on the film? It seems as if it is an effect you could accomplish easily in both traditional and digital post-processing.

[Struan Gray]

It's called a 'vignetter', which is French for 'piece of cardboard with a hole in it'. Old portrait studios (and some modern ones) had a wide selection to place in front of their lenses.

It's easy enought to rig something on the front of a compendium or in a filter holder. Perhaps the simplest option would be, as others have said, an over-long lens hood. Make one out of paper.

[Scott Rosenberg]

would not a long lens hood, stacking filters, or a vignetter, result in a pretty sharp fall-off? i was more thinking about something with a gradual transition out towards the edges... like a center filter softly and gradually darkens the center of an image.

[Ash]

No, because as you know, it isn't in focus. Just like placing a finger over the lens, it darkens the area, but it's too close for you to see the shape of your grubby mitt :)

[Ron Marshall]

would not a long lens hood, stacking filters, or a vignetter, result in a pretty sharp fall-off? i was more thinking about something with a gradual transition out towards the edges... like a center filter softly and gradually darkens the center of an image.

Some vignetters have scalloped or serrated edges so the falloff is less abrupt.

[C. D. Keth]

I made a few to fit in the mattebox of a motion picture camera by exposing a sheet of 4x5 neg to a black spot I drew on a piece of white paper. I just left it very out of focus so it would have soft edges. Since 4x5 is a standard MP filter size, it worked out nicely. Depending on which mattebox slot I use it vignettes either very slightly or more heavily. I made one for each focal length I needed to use it with.

Edit- I remembered something that might be useful. Remember those things for giving enlargements soft edges? I can't find a photo of one, but it looks soft of like a big aperture with clear plastic blades, but the blades close into a solid circle as you turn it rather than smaller and smaller apertures. You could spray the blades on one of those black and probably make a very effective vignetter.

[David A. Goldfarb]

A mattebox is the usual thing for this--a compendium bellows shade with a slot on the front standard for vignette masks, which might be round or oval with straight or serrated edges, or if you want to get really hokey, it could be heart shaped or star shaped. You can also make masks that are inverted from the vignette mask so that you can shoot one thing as the background and something else in the center, or do a split-screen--all kinds of schmaltzy effects.

[Ash]

christopher - I came across one of those (enlarger doohickies) today!!!

Anyone want it? I can get it very cheap I should think

[Scott Rosenberg]

A HUGE thanks to Ash! he actually went down and bought the vignetter than offered to ship it to me gratis... wouldn't even let me cover the postage to get it back across the pond.

THANKS, Ash!