Luminous Landscape Forum

Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: X-Re on January 21, 2007, 05:31:52 pm

Title: 30D back focusing
Post by: X-Re on January 21, 2007, 05:31:52 pm
It took me a little while to catch on - but my 30D back focuses consistently, sometimes more than others. In most situations, its fairly mild - and examining the resulting files just led me to believe that the 30D naturally produced slightly softer images than my previous 10D did... Then I stuck a polarizer on it for the first time on my 17-40... and the camera massively back focused. Tried the same filter on my 70-200/2.8, same problem but not as severe. I then noticed that, without the filter, both lenses were still backfocusing, but not quite as much as w/ the polarizer on them. A slight tweak on the focus ring to set the focus closer made them noticeably sharper in the viewfinder (the difference between getting that "cruncy/gritty" in focus look in the viewfinder and not getting it). It also does the same thing w/ my 50/1.4.

The 10D didn't have this problem at all. It should be noted that I rented a 70-200/2.8 for an event so that my wife could drive a camera for me, as well - the 30D wouldn't focus at all w/ the rental lens, but the 10D had no issues at all.

I have checked the position of the focus sensors - this doesn't appear to be that issue. And... yes, I know how to use the focus on the camera

So, is there a consensus on which Canon service center is the right one to send the camera to? The camera is still under warranty, luckily - hopefully this can get corrected w/o incurring a cost... I remember reading stories of differing levels of skill in fixing focus issues at different service centers, etc. I can't seem to find good info on this, right now - can't find where'd I'd read what in the past. The 10D I've got is so solid, I just stopped thinking about those sorts of issues...

Any hints on navigating the warranty service maze, etc, or info on what to expect? This is the first time I've had to make a warranty claim on a piece of photo gear...


Title: 30D back focusing
Post by: situgrrl on January 28, 2007, 05:50:51 pm
Can I bump this only I seem to be having a similar it a lens issue or a camera one?  I'm not sure how to identify it specifically but it seems to affect 3 of my 4 lenses under certain conditions (eg stage lighting so wide open or thereabouts).
Title: 30D back focusing
Post by: DarkPenguin on January 28, 2007, 07:32:56 pm
Keep in mind that the AF sensors are not exactly in the little rectangles.  So sometimes it can look like it is focusing on what you want but is actually focusing on something in front or behind.  But if you are sure it is focusing incorrectly just contact canon and they will tell you where to send the camera.
Title: 30D back focusing
Post by: X-Re on May 08, 2007, 01:10:51 am
Final report.... Called Canon and was told to ship it to Irvine. Irvine determined it was backfocusing and adjusted it under warranty. I did not send any of my lenses with the camera - the only adjustment was to the camera...

The whole experience was quite easy, in fact...

I finally got to run a good number of pictures through it this past weekend (was mostly playing with the D2X I'd been evaluating in between) - wow, what a difference. I was able to work with what it produced before, and get what I thought were decent shots, but this is a lot better... Looks nice and crispy with all three lenses, etc...

(this post was slightly prompted by me feeling insecure while reading Michael's first impressions report on the 1DMkIII    .... )  I can't tell you the sigh of relief I breathed to have it confirmed that the problem wasn't just me being an idiot behind the camera