georgeretired Loc: Manitoba Canada

Last summer I found myself in a shoot where the room was not deep enough to get a good shot of 24 people. I recently purchased the Sigma 10-20mm f/4-5.6 over a Canon 10-20mm lens as the sales person said I wouldn't notice the difference and the cost was 40% lower. Problem - I do use the AF on the lens but it doesn't always register on the finished RAW product and worse, the pictures are not sharp focus - both inside and outside pictures. I've changed my lens back to a canon 17-85 and the AF works fine on all shots. I've done the check through on the camera and checked the Sigma lens AF control but can't find any physical problems. My question is would the Canon product been better as I only have Canon lens and no experience to go by. When I have read many of the forums, the Sigma does get good reviews and many have used them on Canon Camera. Technically, was this "mm" the best choice of lens. Much appreciated for any advice you can give me.

infocus Loc: Australia

I can't answer your specific questions other than to say I have a Canon 7D and a canon 10-20mm lens and I love them both. I have often contimplated buying Sigma or tamron but honestly have never been game

infocus Loc: Australia

Oops! clicked on post twicw. sorry

MagicFad Loc: Clermont, FL

All things being equal I would say there is a problem with that particular lens. Reviews say the lens is right on with no mention of the problem you are having.

Cotondog Loc: Saskatchewan, Canada

I agree with MagicFad. I use the Sigma 10-20 mm on my Canon 50D. Love it, and have no problem.

Al FR-153 Loc: Chicago Suburbs

Excuse my ignorance but doesn't the 50D have a 'lens focus adjustment' on it? The 60D does not, but the 7D does and I thought the 50D had one. Thereby, you could adjust the camera for that particular lens to obtain the sharpness.

MagicFad Loc: Clermont, FL

I don't think it is a lens focus adjustment but it does have a "profile" for some lenses that does the same thing

picsbywayne Loc: Toronto, Ontario, Canada

When I was in the market for my 10-22mm, the feedback I received was that the Canon was rock solid but the Sigma could either be "just as good" or "so-so" depending on the build quality of the particular lens you recevied.
The general feedback was that the Sigmas didn't have the same consistency.

I went with the Canon and it has performed wonderfully for 2 years now.

Bill Emmett Loc: Bow, New Hampshire

I shoot with a Canon 50D. My usual walk around lens is a Tamron 18-270mm. This lens started to give "soft" images over the last few months of shooting. Actually I could not tell the images were "soft", but a UHH member pointed out the problem to me. I took the lens back to the shop I bought it at, and they all agreed the the lens had a problem and should be sent back to Tamron. I looked in the manual, and in my book "Canon EOS 50D Digital Field Guide" and read the part about the adjustment for front, or back focus. It seems the adjustment will work on Canon lenses, in fact it will memorize the lens, and make the new adjustment when the lens is installed. But, for some reason it will not do it on second market lenses. Or, it only mentions Canon lenses. I will send the Tamron back to Tamron Land without trying the adjustment, only because the lens is only 6 months old. Tamrons warranty is for 6 years on this lens. In the book there is a procedure to revert the original settings if you are not happy with how the problem was solved. I checked the actual Canon manual it stated that the information to make the fine lens adjustments have been purposely omitted. To see the section about focus checks look on page 183, about focus grids.

georgeretired Loc: Manitoba Canada

Thanks to everyone who replied. I went for another walk today in a flower conservatory and took several pictures. I used a tripod, upped my AP to about 13-16, went AWB, upped my ISO to about 640 and used a delay with my shutter. Also did a few 3-shot HDR pictures. All enclosed with very little if any adjustments.
Would appreciate your comment about "in focus or not". Guess my decision is whether I should pop the extra $400 to get a Canon 10-20 F3.5 over the Sigma F4.

Single shot


Single shot


HDR shot

Al FR-153 Loc: Chicago Suburbs

George (Retired), could you please repost and click on the (store original) tick box. This allows for better viewing than just a thumbnail view. Thanks

georgeretired Loc: Manitoba Canada

as requested.......

All pictures taken at the Assiniboine Park Zoo that has a Conservatory. This is in Winnipeg Manitoba Canada.

HDR