Is my lens/camera back focus? here is my focus test picture

highroller · 8th of January 2008 (Tue)

Here are the focus test pictures I took from my new 30D with 28-135 IS. They seem out of focus. How do I know if it is the lens or the camera? What do I do now? Thanks for the help.

135mm f5.6

70mm f5.0

28mm f3.5

vincewchan · 8th of January 2008 (Tue)

Did you take these with a tripod? Try it again with a 45 degree angle.

highroller · 8th of January 2008 (Tue)

Quote:

Originally Posted by vincewchan

Did you take these with a tripod? Try it again with a 45 degree angle.

They are taken with tripod and 45 degree angle, with mirror lockup and self timer. Here are the enlarged one. Looks like at 28mm, the focus is around 20~30mm in the back. At 70mm, it is around 2~6mm front. Then at 135mm, the focus is around 6~10mm front.

135mm

70mm

28mm

MikeI · 8th of January 2008 (Tue)

Take it out for some real world shooting. Focus charts can drive you crazy.

wimg · 8th of January 2008 (Tue)

There is nothing wrong with your lens, from what I can see. There is always a spread of DoF over the different focal lengths of a zoom, and nearby, like with a test chart, the focus is always different to the focus at middle or far distances.

Furthermore, DoF is normally not evenly distributed front and back. Just try any DoF calculator to see what I mean; do also try different distances to see the changes with distance.

Finally, Canon only guarantees focus to be within 1 stop of DoF with a lens slower than F/2.8.

Kind regards, Wim

Ray2006 · 8th of January 2008 (Tue)

Is your (is) on or off

gravy graffix · 8th of January 2008 (Tue)

why does everyone post pics and they take em down?

hard to get opinions like that.

8th of January 2008 (Tue)	#1
highroller Junior Member Join Date: Dec 2007 Posts: 23	Is my lens/camera back focus? here is my focus test picture Here are the focus test pictures I took from my new 30D with 28-135 IS. They seem out of focus. How do I know if it is the lens or the camera? What do I do now? Thanks for the help. 135mm f5.6 70mm f5.0 28mm f3.5

8th of January 2008 (Tue)	#2
vincewchan Member Join Date: Oct 2007 Location: SoCal, USA Posts: 613 IMAGE EDITING OK	Re: Is my lens/camera back focus? here is my focus test picture Did you take these with a tripod? Try it again with a 45 degree angle. __________________ 5D

8th of January 2008 (Tue)	#4
MikeI Goldmember Join Date: Dec 2006 Location: NorCal Posts: 2,072	Re: Is my lens/camera back focus? here is my focus test picture Take it out for some real world shooting. Focus charts can drive you crazy. __________________ Doubleshot Photography ~~~~~ My Gear ~~~~~ Personal Gallery

8th of January 2008 (Tue)	#5
wimg Cream of the Crop Join Date: Jan 2007 Location: Netherlands, EU Posts: 6,578	Re: Is my lens/camera back focus? here is my focus test picture There is nothing wrong with your lens, from what I can see. There is always a spread of DoF over the different focal lengths of a zoom, and nearby, like with a test chart, the focus is always different to the focus at middle or far distances. Furthermore, DoF is normally not evenly distributed front and back. Just try any DoF calculator to see what I mean; do also try different distances to see the changes with distance. Finally, Canon only guarantees focus to be within 1 stop of DoF with a lens slower than F/2.8. Kind regards, Wim __________________ 5D Mk II, 1D Mk III, with a solitary zoom and a gaggle of primes, GF-2 with 3 primes and 3 zooms, G10, an accessory plague, and some analog stuff

8th of January 2008 (Tue)	#6
Ray2006 Member Join Date: Nov 2007 Posts: 32	Re: Is my lens/camera back focus? here is my focus test picture Is your (is) on or off

8th of January 2008 (Tue)	#7
gravy graffix Senior Member Join Date: Jun 2007 Location: Logan Square and Joliet IL Posts: 1,134 IMAGE EDITING OK	Re: Is my lens/camera back focus? here is my focus test picture why does everyone post pics and they take em down? hard to get opinions like that. __________________ Peoria IL Wedding Photographer Chicago Wedding Photographers

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