Intentional Vignetting.

[JeffWA]

If I wanted to purposley cause Vignetting how would I go about this? Would I need to use a filter or is there some kind of lighting I can setup?

I understand I can do it in photoshop post, but would like to see if I could do it with the camera first.

[macropod]

Hi Jeff,

There may be a problem with terminology here - light fall off vs vignetting.

Light fall-off is a function of the lens design and is usually more severe when the lens is designed with elements that are a bit on the small side. You see this most often when images taken with lenses deisigned for FF cameras are compared against those for cropped sensors. Because the FF lenses are designed for a wider coverage, they don't suffer as much from light fall-off. See the lens tests at http://www.slrgear.com/reviews/index.php for some comparisons. You may be able to buy filters to enhance the light fall-off.

Vignetting describes what happens when the image circle delivered by the lens isn't big enough to cover the sensor area. As a result, part of the image is blacked out. You can cause this by using a lens designed for cropped-sensor DSLRs on a FF body (but be careful, because some of these lenses either won't fit onto the FF body or, if they do, they'll foul the mirror). Aternatively, all you need to do is to place whatever vignette shape you want in front of the lens, so that it obscures just those bits of the image you want blocked out. A common (usually unintentional) way of doing this is to stack too many filters on the front of the lens.

Cheers

[JeffWA]

Ryto, my bad. Yes light fall of sounds like what I'm after. Is there a way in a portrait situation where I could intentionally cause this without expensive/complex lighting setups? Or is that really the only way?

[macropod]

Hi Jeff,

It seems to me your options are to use:
. lenses known to suffer from significant light fall-off (this is usually only so when wide-open),
. filters designed for this,
. a flash that illuminates only part of the scene, or
. post-processing.

Cheers

[phantom_oz]

Jeff

I have done it one using 2 stacked filters on the Tokina 12-24 on a Canon 40D, not intentionally though :-)

Cheers
Rick