At wich apertures does 17-40L perform best ?

By coincidence I took some pics at the max f22, but normally lenses don't perform well too much stopped down.
Technically, out of reviews, between wich apertures does the 17-40L perform best at it's sharpest?
It's my latest lens, didn't test it thoroughly yet.

f22 is in the defraction zone. If you really need that small of an aperture, you probably need some kind of ND filter.

I can only speak for my copy, but 5.6 - 11 are razor sharp, with a little falloff of sharpness at the edges on full frame. f4 is perfectly usable if you're not a psycho pixel-peeper.

I used mine most from f/8 to f/16. On a 5D2, diffraction is barely visible in any channel at f/11. Beyond f/11 I was trading a little sharpness in the center for improved sharpness in the corners.

At f/22, you loose about half the camera's resolution in the red channel, about a third in the green and very little in the blue.

F8 is the aperture i use most on my 17-40, and its the sharpest area after what i have read on the net.

noisejammer wrote in post #14730308
I used mine most from f/8 to f/16. On a 5D2, diffraction is barely visible in any channel at f/11. Beyond f/11 I was trading a little sharpness in the center for improved sharpness in the corners.

x2 on this.

From f8 on I'm trading center sharpness for corner sharpness. The center may even be sharpest below f8.

I tend to hover around f8-11, seems to work well

f/8 and f/11 for me.

In fact, I never use it below f/5.6 but almost always set it to f/8 first and then expose around that aperture.

btdvox wrote in post #14731303
f/8 and f/11 for me.

In fact, I never use it below f/5.6 but almost always set it to f/8 first and then expose around that aperture.

+1
I love my 17-40 on both FF and 1.3 crop. It is not the sharpest lens going but in this apeture range it is sharp enough and gives the best (IMO) colour rendition of any of my L lenses.

According to Photozone, the 17-40 performs best (in the center and borders) at f/5.6... But the corners improve up through f/11.

If you need more depth of field than f/8 or f/11 so will give you, learn about hyperfocal focusing to maximize your depth of field. Anything beyond will just get soft due to diffraction.

I use my 14mm at f/5.6 or f/8 and focus at something like 3' or 5' in front of the camera. Everything from 1.5' to infinity is in focus this way without having to stop down too far and get to use the lens in the sweet spot.

Depends on what you're doing with it. I'm a photojournalist, and I shoot wide open most of the time. When I had a 17-40, I shot it almost exclusively at f/4. With the 5D, 5D2, and 1D4, it was always tack sharp.

When I had the 17-40, I found it very sharp wide open in the center. Edges got mushy, but in a way it did not bother me really. Stopped down to f/5.6 or f/8 and the image quality was good around I thought.

My 17-40 was sharp at 5.6 - 8.0


Kr,
Ashvin Ghisyawan
www.totaalfotografie.n​l

Thanks, that I wanted to know as I mostly photograph in darker conditions, and sometimes i'm lazy to use a tripod as we do fast visits
Then I know I can go to the minimum edge of f5.6-f8 to get sharper pics than f4 and still handholdable with 5D MKII at f3200 (don't like to go to 6400).