I think my 28-105 may be front focusing a tad (pics inside)

A good many of the shots I've taken with my Canon 28-105 have seemed to come out...well...less than sharp. So, I did some focus tests on both of my lenses tonight.

On the 50mm f/1.8, the first shot looked a tad suspicious. But, I believe it was slightly off center when the shutter opened. But, the second shot (which I believe I lined up correctly) looked spot on to me...at least enough to say that it was in the range of acceptable sharp focus even at f/1.8.

The 28-105 seems to be a bit of a different story though. Here's the test picture I took. 1/3, f/4.5, 105mm. It looks as though the center line (where the focus point was focused) is a bit off. Now, I did have to touch the camera to start the countdown on the timer. But, it was on a tripod and the timer fired the shutter.

Tell me what you think. Is this "acceptible" by Canon standards? Or does it need to be sent back to Canon for a warranty repair? I honestly don't think it's the camera as my 50 f/1.8 and Kit 18-55 seemed to be either spot on or w/in a range that seemed acceptible.

Click here to view test shot

FlipsidE

The focus looks pretty good to me. I really doubt Canon would perform any adjustments.

Instead of a visit to Canon, why not visit the optometrist?

Haven't you had fears about just about every Canon item you have in the last few weeks?

---Bob Gross---

- After five bad Digital Rebels...yes, I have fears about everything Canon. Seriously. I am paranoid about everything because of the two weeks of horrible problems I had getting a camera that actually was to my satisfaction out of the box. Now, I dunno who actually caused those issues, but I find it hard to believe that all of them were caused by Best Buy. So, I think some things (like the LCD in horrible shape on the DReb before my last) just slipped through QA/QC. So, I get nervous every single time something comes in that has the Canon name on it.

Yeah, I'm sure one of these days I'll get over it after these current canon products hold up well enough for a few months. But, not right now...not after the issues I've had so far.

FlipsidE

I'm not sure, but I think that the Digital Rebel is manufactured in a different plant and different country from the higher end Canon products. That isn't an excuse, but it might be one explanation if there is a quality problem.

Another issue is that I don't think we know if the Canon products that you saw at Best Buy were "factory sealed". In some stores, the camera department employees regularly "sort through" bodies and lenses, even though they are not supposed to. Their justification is for customers just like you. Somebody feels like they got some Canon product that is not perfect, so the employees sort through the remaining stock, sort of looking for a good one so that they can shut off the customer complaint. There may be exceptions, but the average camera department employee at Best Buy does not know anything about camera equipment as compared to the experienced staff at the high-end (and full price) camera store downtown.

Suppose that you had a Canon product, and then judged it imperfect, so you returned it to Best Buy and got a replacement. Suppose you went through that several times. What do you suppose happens to those reject products? If there is some obvious, catastrophic failure in the product, then that is one thing. But if there is some subtle irregularity, then where do you think those go, and who do you think pays for it?

---Bob Gross---

I actually think that shot is front focussed a little but if you had to touch the camera to trigger the countdown that may have been enough so I think you would need to do a few repeats. Unless you were shooting very narrow DOF shots I doubt it would lead to noticably out of focus results.

Screw the ruler-shots. Go out and take some real-world shots. In reading your posts you're obsessed with pixel-peeping your equipment. Just get out and shoot and judge the performance that way. You're supposed to be enjoying this, not worrying about it.

Amen!

I second that.

Still, I looked carefully at your image - first, if you're really going to do this, you might consider using a separate object for your point of focus - the camera can easily grab focus on any contrast point that is within the focus sensor's area of coverage. And, that area of coverage is larger than the little squares in the viewfinder portray.

Second, your focus looks fine despite using a somewhat less-accurate method. The center mark is well within what would be considered the DOF area. Your lens is fine.