timothy_pastore Posted August 8, 2003 Share Posted August 8, 2003 I just posted a question about a canon 85mm, but on top of this, I just got the canon 24-70 2.8L. I bought it used 10 from BHphoto, and they had several, so I think it was a refurbished one, (just to give some preliminary info) I tested it against the said sigma and the sigma was sharper everywhere but at the 70 end (ok the sigma has no 24, so the canon blew it away there :)) Some tests at 50 and 35 were close a couple times, but at 28 and almost always at 35 the sigma is even kickin the canons ass. The canon is a $1300 lens. The sigma $300. This CAN'T be right, can it? I tell ya, I'm getting more and more impressed with the sigma optics by the test. I'm starting to wonder how much of it is name. Link to comment Share on other sites More sharing options...
timothy_pastore Posted August 8, 2003 Author Share Posted August 8, 2003 Look at this crap ... this sigma is the better one and this is 28mm, both shot wide open, both at 1/125th. Man I'm getting some bad luck with these canon lenses.<div></div> Link to comment Share on other sites More sharing options...
bobatkins Posted August 8, 2003 Share Posted August 8, 2003 You seem to be having bad luck, but I have to ask again, what happens when you use manual focus? Is this a focus issue again? I guess it's POSSIBLE that whatever body you are using has a focus problem. Why it doesn't show on the Sigma lenses I don't know, but maybe if it were adjusted right it would be the Sigma lenses that didn't look sharp! Link to comment Share on other sites More sharing options...
carl smith Posted August 8, 2003 Share Posted August 8, 2003 Either you're pulling our chains or its somethign other than your 85mm 1.8 thats busted. Granted buying used, even a 10 can sometimes run you in to trouble. Why was it turned in for example... I agree with Bob, there's something amiss with your camera most likely. Link to comment Share on other sites More sharing options...
chuck_dowling Posted August 9, 2003 Share Posted August 9, 2003 Yes, Timothy, please shoot this test again using MF. That cannot be the best the Canon L glass can do! Who refurbished this lens, Canon? Are you shooting these with the (now famous for having focus issues)10D? Link to comment Share on other sites More sharing options...
keith_van_hulle1 Posted August 9, 2003 Share Posted August 9, 2003 Logic dictates that there's nothing wrong with the body. If so, it would affect ALL lenses. Or are we saying this fault is just selective of Canon glass? I don't think so. Maybe possible but no one on the forum has ever heard of this? You know how we're always telling people "if it's too good to be true". Well I have a feeling here. Fool me once, shame on me, fool me twice . . . Link to comment Share on other sites More sharing options...
bobatkins Posted August 9, 2003 Share Posted August 9, 2003 Not correct. Foucus on EOS bodies isn't a 100% mechanical action (though mechanical aligment is required). It's certainly possible for there to be some electrical miscommunication. The AF process involves the prediction of the focus point from the defocused image, then driving the lens towards that focus point. Some Canon lenses (the long telephotos for sure) actually have a focus adjustment in the lens itself - which obviously couldn't be true if focus were a purely mechanical process and the body simply moved the lens motor back and forth until it found the best focus! The other option (far fetched, but possible) is that the camera does have a mechanical focus offset which is being compensated for by the Sigma lenses not focusing at the right point and the two effects cancelling out. As I said, far fetched, but possible. I'm not suggesting Sigma lenses aren't sharp, I'm suggesting that Canon lenses really should be better than what Timothy is seeing. Since we're getting a lot of shots from Timothy, I'm guessing he must be using a 10D. Though mine has tested fine, there are certainly enough reports out there of focus problems to make that something high on the list of possible explanations. Maybe everyone with 10Ds showing a focus problem should go out and buy Sigma lenses! Link to comment Share on other sites More sharing options...
timothy_pastore Posted August 9, 2003 Author Share Posted August 9, 2003 Guys - I assure you I am not pulling your chains! I sound like I work for Sigma I know - LOL. I don't I swear :) I'm doing the tests again, and I think it may be a focus issue. I did some manual focus tests and the canon did seem to get quite sharp, BUT - I am doing the same things to both of them. PIcking a focus point - focus shoot. Shouldn't the canon have a better AF as well?? what's the point if the glass is great and AF won't focus? I'll let you know what else I find, but THis is pissin me off Link to comment Share on other sites More sharing options...
bobatkins Posted August 9, 2003 Share Posted August 9, 2003 If it won't focus right, it's broken! It's certainly not a intrinsic characteristic of Canon lenses or bodies that they don't focus properly. I don't know why the Sigma lenses seem to work better on a broken camera though. That is a mystery. Lets just hope that after you get it fixed and it works perfectly with Canon lenses that your next set of tests don't show that all your Sigma lenses now have focus issues.... Link to comment Share on other sites More sharing options...
timothy_pastore Posted August 9, 2003 Author Share Posted August 9, 2003 Ok, Well I went to the local camera shop here and asked if I could do a side by side with one of thier 24-70's. I didn't tell them I didn't buy it from them - but it was in the name of science :) Mine tested better when looking at the focusing spot on every shot!! BUT it seemed they were pretty close and the other just happend to focus a little more poorly. I'll attach a sample at the wide end. There was a difference in test in 1) obviously the subject, and 2) I was shooting from about 4 feet away from subject. Before I was shooting at about 2 feet. Is it possible the canon does not do well close up in terms of AF? It has a close focus of 1.25 ft I belive and I was well away from that. I'm going to compare it again to the sigma at a greater distance and if the sigma still wins - I guess this means for some reason sigma lenses grab focus better on my 10d than canon glass. This would really piss me off - lol<div></div> Link to comment Share on other sites More sharing options...
timothy_pastore Posted August 9, 2003 Author Share Posted August 9, 2003 Ok - I did some more testing, and this is what i've basically found The sigma is every bit as sharp as the canon at the wide end (28- 35) and on my camera - the great majority of the time - locks focus better. At 50-70 the canon is quite a bit sharper, and they both lock focus fine. The canon is right on at 50 up, but is not locking on my point at 24-30. The canon is $1000 more, and has got me wondering about if it's worth the difference. Has anyone else tested these lenses or other "higher quality" sigmas against their brand counterparts. I'm starting to think that I and most photographers have really been buying into manufacturer hype. Both canon 24-70's I tested had issues focusing at the wide end, so what are the chances it's both those lenses only? I hate how noisy the sigma is when it focuses - but for the difference in money, maybe I can live with it Link to comment Share on other sites More sharing options...
bobatkins Posted August 9, 2003 Share Posted August 9, 2003 You can't just conclude it's the lens or it's the camera, it may be both. There may be some issue with that particular lens model focusing on that particular camera. The same lens model on a different camera may be perfect. The same lens on a different MODEL of Canon camera may be perfect. This isn't like the old days when focusing was a purely mechanical process. On the EOS system it's as much of a function of software and electronics as it is meachanics. If you really want to get to the bottom of this you're going to have to send BOTH your camera and your lens to Canon, along with a DETAILED letter of explanation and a set of sample images. I'd go to Canon, not an "authorized repair shop" with this and I'd try to speak with a real technical repair person before sending anything to them. The receptionist on the desk isn't going to understand what you're saying, and just sending it in blind without talking to someone is asking for trouble. You might also try borrowing another 10D and see if it behaves the same. Maybe your freindly local camera shop can help there too? I've moving this to the EOS forum, since it will be interesting to find out what happens if you do contact Canon. If you are using a 10D then it may well all be covered under the camera warranty, and since the 10D hasn't been out for a year yet, you're OK there. Link to comment Share on other sites More sharing options...
keith_van_hulle1 Posted August 9, 2003 Share Posted August 9, 2003 OK. I know what Bob is saying and I guess this would have to be a really unique interface situation where Sigma's pin out's to the body makes the difference. I mean REALLY unique. What you need is a control. Your best bet would be to "acquire" a second body and test the same lenses under the same conditions. I just can't buy the equality issue. I tested my 28-70L against the 2.8 version from Tokina and Sigma (on two bodies) before purchasing and found the Canon kicked butt big time. I wasn't aware the 24-70 would be that much worse than the 28-70. Right now you have too many variables to be able to say it's the lens or the body. Isolating potential issues thru some more testing would be in order. Link to comment Share on other sites More sharing options...
gerry_szarek Posted August 9, 2003 Share Posted August 9, 2003 Timothy Post where you live, maybe someone lives close by with 10D, we have a joint science experiment. To eliminate any autofocus issues, I would focus manually. GS Link to comment Share on other sites More sharing options...
jorge_ituarte3 Posted August 9, 2003 Share Posted August 9, 2003 This is very interesting. I also have a 10D and I seem to be having same trouble with my Canon 24mm 2.8. I can only use it accurately in manual focus. I recently bought a Canon 14mm 2.8 L and had to send it back to B&H. I bought the Sigma 14mm 2.8 and it seems to focus dead on. All my other Canon glass from 50mm up is dead on with AF. This is very interesting to me because I have had nothing but disappointing results from third party glass in the past. I only bought the Sigma 14mm to try it out and I'm keeping it. Link to comment Share on other sites More sharing options...
anthony_thornborough1 Posted August 9, 2003 Share Posted August 9, 2003 I've used Canon L and Sigma EX/Apo lenses and have found the latter just as good in every respect except noise levels when AF'ing, and significantly better in the price department!!! Glad to learn some cobwebs have been blown out of the myth corner here. Link to comment Share on other sites More sharing options...
jim_larson1 Posted August 9, 2003 Share Posted August 9, 2003 And Bob published an article showing Canon the canon 28-105/28-135 to be as sharp as the 50/1.8 on a 10D. Huh. I think the all of the old rules of thumb are heading out the window. . . Link to comment Share on other sites More sharing options...
joseph_coalter Posted August 10, 2003 Share Posted August 10, 2003 I'm not into formal testing, but I have a 10D and a 24-70 2.8, and together they make tack sharp photos. I think you are try to prove a point about the Sigma, but who cares. The Canon is probably more durable, and will hold its resale value much better. If you keep trying, you might find a situation where the Sigma is equal or better, but for all around use, my quess is the Canon is hard to beat. As for the image making ability of the 10D, I have used it with my 35-350L where I can easily read 2 inch high letters on a sign at 150 yards. Maybe not scientific, but impressive to me. Link to comment Share on other sites More sharing options...
jay_. Posted August 10, 2003 Share Posted August 10, 2003 I owned the Sigma 28-70/2.8 EX in Nikon mount back in my F5 days. I could only compare it to the then-new 28-70/2.8 AFS Nikkor, and the Sigma was every bit as sharp and contrasty, BUT: it had significantly more barrel/pincushion distortion at the ends of the zoom range, and much more propensity to flare at the wide end outdoors if the sun was anywhere in front of me. Link to comment Share on other sites More sharing options...
jorge_ituarte3 Posted August 10, 2003 Share Posted August 10, 2003 I was not trying to start a Canon/Sigma thingie. I just found a common issue with the original poster. I would be interested in seeing if others have similar experiences with AF on the 10d with Canon glass at the wide end. I think that it is important that I clarify my comments about my purchase of a Sigma 14mm 2.8. The only other third party lens that in the last 10 years that I thought was optically superb was a Tamron 90 2.8 macro I won in some contest a long time ago. However it was the flimsiest looking thing I ever held in my hands and ended up selling it and (at that time) purchasing the Pentax version. So, 99% percent of the time I have had better performance with the manufacturers high end glass. The Sigma 14mm 2.8 is one of those rare exemptions. It really is optically better and mechanically (seems) equal the Canon 14mm L. The Sigma is also $1300.00 less. I may change my tune if I tried this lens on full 35mm frame. Link to comment Share on other sites More sharing options...
yakim_peled1 Posted August 10, 2003 Share Posted August 10, 2003 It may be a particular case but I think that "This CAN'T be right", as a general rule. If it is so, it means that all those photographers who bought the 24-70 were best off saving a 1000$ and getting better quality. In these days where internet news spread around so fast, I guess "This CAN'T be" the case. Happy shooting , Yakim. Link to comment Share on other sites More sharing options...
gareth_harper Posted August 10, 2003 Share Posted August 10, 2003 "If it is so, it means that all those photographers who bought the 24-70 were best off saving a 1000$ and getting better quality. " Probably correct. Lets face it most of that 1000 dollars goes on the Canon label and the little red ring. Me? I use a Tokina 28-80 f2.8 ATX Link to comment Share on other sites More sharing options...
ben_rubinstein___mancheste Posted August 10, 2003 Share Posted August 10, 2003 I kinow that my sigma 28-70ex is blown out of the water by the Nikon equivelent at f2.8, and maybe f3.5, after that (accepting distortion) the only difference I can see is the $1000. Link to comment Share on other sites More sharing options...
gareth_harper Posted August 10, 2003 Share Posted August 10, 2003 "the only difference I can see is the $1000." That's the price you pay if you are a lens snob! Link to comment Share on other sites More sharing options...
chuck_dowling Posted August 10, 2003 Share Posted August 10, 2003 Focus Pocus! Link to comment Share on other sites More sharing options...
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