300D Back focusing! - DPChallenge Forums

Canon EF-S 17-85mm f/4-5.6 IS USM

08/02/2005 12:21:30 AM · #1

I know the EFS18-55mm lens isn't the worlds most outstanding lens but I find more times than not that my pics aren't as sharp as they should be! They are fairly soft (quite noticeable). Though, even trying some of my other lenses I don't seem to be getting images as sharp as I expect! I'm getting some new lenses in a few weeks but I am wondering if maybe I should get my camera checked out or what's the best way to test for back focussing myself?

ty_roni

Canon EOS-350D Rebel XT

08/02/2005 12:27:49 AM · #2

Try taking a picture of a ruler from an angle, place the camera on a tripod and autofocus on a number with the lense wide open. See where it focuses coresponding to the focus point. Hope this is clear and helpful.

Ty

TooCool

Canon EOS-300D Rebel

Canon EF 50mm f/1.8 II

08/02/2005 12:41:28 AM · #3

Have you used dSLR style cameras before this one? Are you shooting in raw format? The makers of digital SLR style camera's assume that you want to do most of the sharpening and color adjustments yourself. Therefore the image will tend to come out of camera softer looking and duller...

Canon EF 24-105mm f/4.0L IS

08/02/2005 12:44:01 AM · #4

Originally posted by TooCool:

I've had this camera for over a year now and it gradually seems to worse! Maybe it's just me! I've just spoken to Canon and they told me here in Perth they've had a few with a similar problem which they can easily fix so....it might be worth getting checked out! Up to 3 weeks without my camera though! :(

I don't like to use a huge amount of sharpening in the camera...I tend to have it set flat...and I do shoot in RAW 99% of the time!

ShutterPug

Canon EOS-6D

08/02/2005 01:00:26 AM · #5

Makka - have been having the same problem here. I have owned this camera for about 10 months now and it seems the focus is getting softer and softer. If I send mine in, I'll only have a PowerShot G1 to shoot with - YIKES!!!!

08/02/2005 01:03:36 AM · #6

Originally posted by ShutterPug:

Yes, I still have my G2 here so I'm one up on ya! ;)

brianlh

Canon EOS-450D Rebel XSi

08/02/2005 01:21:14 AM · #7

I always thought back/front focusing were lens-only issues - can anyone verify whether or not this is true?

Canon EF 24-105mm f/4.0L IS

08/02/2005 01:39:56 AM · #8

Originally posted by brianlh:

I always thought back/front focusing were lens-only issues - can anyone verify whether or not this is true?

Hmmmm....I can't! I figured it was the body cause I get same with all my lenses!

ShutterPug

Canon EOS-6D

08/02/2005 01:53:09 AM · #9

Makka - will you be sending your in soon? If so, I think I'll hold off until you get yours back and tell me if it focuses better.
After just finding out about my daughter's car getting totalled, I'll be holding back any extra funds in case she needs some help - not that I have extra funds. Am going to pick up and extra day of work to try and get some.

08/02/2005 03:56:56 AM · #10

Well, I just tried these tests! I spoke to Canon and it's a 2 - 3 week turn around but they said they are easy to fix up! See what you think of these!

EFS 18-55mm f/22 at 55mm

EFS 18-55mm f3.5 at 18mm

EF 135mm f2.8

EF 135mm f22

These were all with auto focus! Please let me know what your opinion is!

Message edited by author 2005-08-02 04:56:42.

brianlh

Canon EOS-450D Rebel XSi

08/02/2005 05:02:47 AM · #11

I think most of your tests should be at wide apertures (such as your 3.5 and 2.8 shots) to test for back/front focus. It seems to be fine on the 135, while the kit lens seems a bit back focused. Try taking some shots with manual focus - autofocus isn't always the best against white pieces of paper. Or try several times with autofocus - you may even get some that show "front focus" if the AF is off.

Canon EF 70-200mm f/2.8L USM

08/02/2005 06:23:35 AM · #12

Originally posted by brianlh:

I took about 4 - 5 shots at each setting and they were all the same! I didn't try it with manual focus though! Maybe it's pointing more towards that dodgy lens?? It really shows to be back focused at f3.5!

I'm getting my EF50mm f/1.8 next week and a Tamron SP AF17-35mm in about 3 weeks so maybe I should wait and try again with those before I throw it at Canon to have a look for me?

Message edited by author 2005-08-02 06:25:13.

PaulMdx

Canon EOS-1D

08/02/2005 07:04:11 AM · #13

I don't think the 50/1.8 will tell you anything the 135/2.8 hasn't already. The 17-35 Tamron certainly isn't a great lens to compare against.