Focus issue or a possible user error?

[ooztuncer]

Do you think should I pursue more testing or spend my limited time on more useful things :p

shot with 40d (raw) on tripod (2 sec) with built in flash; no post processing; image opened in breeze browser pro and snagged it; exif info is on the right hand side.

Left hand side of the focus test:
http://img508.imageshack.us/img508/3073/leftsidejo9.jpg



Right hand side of the focus test:
http://img508.imageshack.us/img508/6691/rightsiderf3.jpg

[Mike]

Do a better test if you want consistent results - the paper is not straight or the camera is not - it will give inconsistent results unless you get everything in the right place to start with. Tripod? It's a must for these tests.

[Shutterbug Doug]

Tripod and a level playing field. If you leveled your tripod, good. Now level the camera and your chart. From what I see your side focus points are skewed and the chart looks twisted to the left(not squared in the photo). Try again!
Oh, and if you're pleased with the sharpness of your photos, more useful things may be in order....lol

[ooztuncer]

hehe, tripod and the camera was level but not the paper - wasted time, again! :)

[aram535]

You also need a much smaller DOF. So you can tell what exactly is in focus and what is not.

[freebird]

What lens are you trying to test?

[ooztuncer]

You also need a much smaller DOF. So you can tell what exactly is in focus and what is not.

Physically, I couldn't set the camera and the paper at 45 degrees and at the same time get a shallow DOF with 10-22 (even at the 22mm side). Any suggestions?



What lens are you trying to test?

It is written under the exif info (first post, right hand side of the images) - Canon 10-22mm.
And above photo is taken on the longer end (22mm) with min aperture value (f4.5).

[Mike]

Physically, I couldn't set the camera and the paper at 45 degrees and at the same time get a shallow DOF with 10-22 (even at the 22mm side). Any suggestions?

Well, the 10-22 isn't really a lens that is used for close-up work so I wouldn't be too worried. These lenses are often used with narrower apertures - between f8-f16 which give greater depths of field. The test you displayed showed that the lens is at least sharp, even if you didn't get the angles right.

My advice? Stop worrying and get out shooting in the real world! This lens is fine. :D

[aram535]

Physically, I couldn't set the camera and the paper at 45 degrees and at the same time get a shallow DOF with 10-22 (even at the 22mm side). Any suggestions?

It is written under the exif info (first post, right hand side of the images) - Canon 10-22mm.
And above photo is taken on the longer end (22mm) with min aperture value (f4.5).

Sounds like you're using the incorrect lens for this test. You need something a little narrower and a low f/stop for this test.

50mm 1.8 or something like that would work.

When you say you couldn't get 45 degrees, the best way to do it is put your camera on a tripod. Take any large paper (8x11 works) and fold it far corner to edge so that the two adjacent sides line up. That's a 45 degree angle.

i.e.
|_ <-- Fold the bottom right corner to the left side until the bottom and left sides line up. Don't go corner to corner.

Hope that helps.

[argyle]

Well, the 10-22 isn't really a lens that is used for close-up work so I wouldn't be too worried. These lenses are often used with narrower apertures - between f8-f16 which give greater depths of field. The test you displayed showed that the lens is at least sharp, even if you didn't get the angles right.

My advice? Stop worrying and get out shooting in the real world! This lens is fine. :D

+1 Skip the home-testing nonsense...too many variables to control in order to do a proper test. Get out and do some real-world shooting and review the pictures. If they look good to you, keep the lens.

[freebird]

Yep , what he said ^^^^