17 and 24mm TS-E lens profile?

Steve BB wrote:

Rodger in Edmonton wrote:

VignettingThe Canon lens has an immense image circle so it's no surprise that its vignetting figures are about as good as it gets today. Technically the vignetting is naturally still fairly pronounced at f/4 (@ ~1.3EV) but this is very acceptable for an ultra-wide lens - the Canon EF 16-35mm f/2.8 is worse @ f/4 for instance.

Thanks this is all super fascinating. The lack of distortion without any correction is super impressive. But the vignetting is really noticeable even when not shifted probably because with a lens like the EF 15-35 (which I have also) has a correction profile applied.

Im shooting artworks in a gallery against a white wall, and got the tilt shift so i could keep the camera at a height so the centre line of the paintings is at 'eye level' but then be able to shift down, to get more floor in shot, and less ceiling. Especially useful if there is also a sculpture on the floor and you dont want to tilt the camera. So as I'm shooting against a white wall, the vignetting is super noticeable.

The easiest way to correct the vignetting for a shifted lens is to enlarge the canvas of the image so that you can put the centre of the lens' image circle at the centre of the canvas. (Easier said than done as you'll have to work out where that is and you probably won't have recorded the actual amount of shift.)

Once you've done that, you can then use your editing program's vignetting correction manually and then crop to taste. There's no easy way of doing that automatically without the camera recording the amount of shift in the EXIF data though.

The alternative would similar to astrophotography processing. Plut a diffuser over the lens and take a flat exposure (same aperture and focus setting) to use for subtracting the gradients.  Using a tripod, the flat exposure could also compensate for any unevenness in the lighting, but that's not practical unless you've got a private session to record the exhibits.