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Irene Troy
BetterPhoto Member Since: 5/27/2004
 

Canon 28-135 Focus issue


Okay folks, I’m having focusing issues with my Canon 28-135 IS lens. Starting a few weeks back, every few frames seemed to be just a tad soft. At first I thought the issue was “user error” because I kept forgetting to shut off the IS when using a tripod (which I use most of the time). However, even with IS turned off, the focus remained softer than I find acceptable. Because this was not a constant issue, I kept blaming the problem on my mistakes or just pushing the reach of the lens, etc. Then, last night I was shooting just after sunset in a high contrast situation. [A lighthouse lit up with Xmas lights against a near black sky and breaking waves in the foreground] and switched to manual mode because the lens seemed not to be focusing correctly. Mid-way through, I suddenly could not move the focusing ring at all. Yet, when I switched back to auto-focus, the lens did focus, sort-of. I am disappointed with the results of this shoot. Out of nearly 20 frames (with this lens), there are only three or four that have acceptable sharpness and these are still not quite what I hoped to achieve. The frames shot with another lens are sharp throughout. I still cannot get the focusing ring to move manually, but the lens will focus in auto mode, although not as sharp as it should. So…is this lens toast or can this stopped focus ring be fixed? Any input will be greatly appreciated!


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11/29/2011 5:22:36 PM

 
Gregory LaGrange
BetterPhoto Member Since: 11/11/2003
gregorylagrange.org
  I have a 100mm that the focusing ring is hard to turn by hand. It developed gradually and I don't like using it that much because of that reason. Auto focus still works on it.
It also developed some mold on the inside. Photos and optics are still very good. The mold and the focusing ring may or may not be related. I think I actually ended up buying a gray market lens when I did buy it.
On some lenses, as far as I can tell it's the prime lenses and not zooms, when you switch to auto focus the focusing ring can still freely be turned but it doesn't move the barrel. On my 100mm, sometimes the ring will turn but the barrel won't move. Others it will, but not too smoothly. I only have one zoom lens so I'm assuming all Canon zooms are like it, and that one, switching to auto focus makes the focusing ring not able to be turned by hand.
So it might be related to the motor inside the lens. I don't know. And I bet it could be fixed, just how much compared to getting a new lens, or a good used lens, I don't know.


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11/30/2011 2:48:48 PM

 
Carlton Ward
BetterPhoto Member Since: 12/13/2005
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carltonwardphoto.com
  Hi Irene,
I have a Canon 50mm f/1.4 that is now a paperweight as it lost its ability to auto-focus and the same thing happened when I switched to manual focus, the ring would spin but do nothing. The 28-135mm lens is a better lens than the 50mm and I am surprised you are having this trouble as many of my photographer friends that have this lens think very highly of it. I have not owned this lens but used a friends on a recent shoot and I could see a bit of softness (I shoot w/all L lenses) though it did work with both manual & auto focus.
Your lens may be having a problem and would recommend taking it to a local shop and have them check it out if you can. If you are shooting several frames per second - it is not uncommon for a couple of frames to be tad sharper than others and I have seen this with several lenses. I think its partly due to the camera's ability to record the images quickly even though they have a buffer - ??? I was using a Canon 20D/tripod shooting this kid that was riding his bicycle up & down a tree shooting 7 frames each pass he made and every other image was sharp and the others were a tad soft. I haven't tried this with my 5D mk II as I rarely shoot more than 1 frame at a time.
Hope this helps,
Carlton


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11/30/2011 3:39:29 PM

 
Irene Troy
BetterPhoto Member Since: 5/27/2004
  Hi guys and thanks for the responses. The 28-135 is my “workhorse” lens, one I use probably 80% of the time. The focusing ring on this lens will not turn at all, although it continues to focus – sort-of - in auto-focus mode. Looking at images shot the other night, there are numerous frames where the result is very soft to completely blurred using auto-focus. This is very unusual for me and I have to assume it’s the lens and not the camera or even my error. [Not that I don’t make mistakes, but this is specific to this lens] I spoke to the folks at Canon and they seem to think something unusual has happened to the lens and suggest I send it in for repair. Sadly, we no longer have a camera shop near home. The nearest is Hunts and, frankly, I’m not a real fan of theirs. I’m trying to accept that I have to send the lens to Canon and trying to figure out how to work without it for whatever time it takes for the repair.


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11/30/2011 6:35:06 PM

 
Gregory LaGrange
BetterPhoto Member Since: 11/11/2003
gregorylagrange.org
  I think the local camera repair shop is done thing nowadays. Any camera store probably just sends it out to a regional tech certified for that particular brand anyway. So maybe better for you to deal with the packaging and shipping then to add the middle man's cut on the repair bill.


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12/1/2011 1:55:54 PM

 
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