Sigma 35 vs Canon 35L - QC Issues

Just got my 3 copies of Sigma 35. 2 of them has the focus squeaky issue that sounds like a 15 year old car's belt in cold weather (1 of them did not focus probably with any MA, the other one I did not even bother). I already sent them back. The other one just does not focus properly. I can MA to get it to focus fine when the camera is static. But the minute I move the focus chart by 5 or 6 feet, the lens requires a different MA in the opposite direction! Unbelievable, how hard is it for these guys to get this right. This in total makes 12 Sigma copies I tried over the course of 3 years and every single one of them (not kidding here) had similar issues.

That being said, the lens IS sharper than 35L, significantly. Especially in the corners, wide open, it destroys 35L. But unfortunately that accomplishment is utterly useless because there is no way I can reliably use this lens.

One other thing to note is Sigma has significantly more vignetting than 35L. Most pictures taken wide open will require post processing.

I will post some pictures tomorrow and do a deeper analysis as I think it might be useful to other people who might be in my shoes.

Edit : I know I said I'll post some pictures tomorrow but I could not help myself and decided to post 2 pictures to show how bad vignetting is, I think this is ridiculous.

Vignetting

Canon:

http://img593.imagesha​ck.us/img593/3933/gipi​.jpg

Sigma:

http://img822.imagesha​ck.us/img822/2037/6ich​.jpg

Sharpness

Canon:

http://img69.imageshac​k.us/img69/9821/u1wh.j​pg

Sigma:

http://img203.imagesha​ck.us/img203/8032/6txl​.jpg

Charlie wrote in post #16032197

[GIFS ARE NOT RENDERED IN QUOTES]

Ah come on That's not why I posted this

I think the squeaky sound issue is very common with this lens. 3 out of 2 lenses having this issue is really bad. The MA not working in different focus distances is something I have experienced in all of my Sigma lenses (on 3 bodies). My theory is this is a lot more common than people think. Most people don't take the time to properly focus test their lenses.

Instead of writing an essay, I'll just say it in one sentence - return it and get 35L.

kin2son wrote in post #16032215
Instead of writing an essay, I'll just say it in one sentence - return it and get 35L.

I already have 35L. I will just return the 3rd lens and be done with it. I was just trying to help others who might be in the same situation. Sigma is NOT a replacement for 35L. There might be 10 out of 100 cases that are not like mine, maybe more, more, maybe less, I would say those are exception. There is a reason Canon is "L" and that's consistency, accuracy, and reliability. I would never be able to trust the Sigma the way I trust Canon. Not so sharp is better than out of focus.

Not to mention, the vignetting, is probably the WORST in any lens I have ever seen.

Here's my experience.

Straight out the box, it clearly front focused on my 5D3, so I MA'ed it (+5).

It seems to do the trick for MFD -> my normal shooting distance (don't ask me how many feet as I have no idea).

Now for longer distance -> infinity, it clearly back focused @ f1.4 when I test it. BUT I never ever shoot far subject at large aperture anyway. Why? Because my main subject is my daughter and long distance to infinity on 35mm is so wide that my daughter is too small within the frame anyway. Also by f2 you probably won't notice it anymore. Therefore it doesn't bother me at all.

Consider getting the dock? It's only $60 and that's still way cheaper than 35L.

Vignette? Pft that's a one click fix in Lightroom. Why would anyone care about that really?

To sum up I'm very happy with the lens under REAL LIFE SHOOTING. I've learnt not to shoot charts and based my judgement in situation that really matters.

kin2son wrote in post #16032275
Vignette? Pft that's a one click fix in Lightroom. Why would anyone care about that really?

Vignette fix in PP is pushing the exposure in the corners. If you are at high ISO, this can be a noise problem.

Overall, sometimes vignette is a problem and sometimes it is not. I mean, sometimes I even like a shot with vignette.

But for some folks and some shots a heavy vignette is a problem, and pushing the exposure in the corners 3 stops is not acceptable. Think about it....a 'corrected' shot at ISO 3200 could be seeing ISO 25600 in the corners.

Charlie wrote in post #16032197

[GIFS ARE NOT RENDERED IN QUOTES]

Oh yeah, this is about to get real interesting. And that's all the more I'll say in this thread.

JeffreyG wrote in post #16032291
Vignette fix in PP is pushing the exposure in the corners. If you are at high ISO, this can be a noise problem.

For pixel peeper, yea sure

And no vignette requires 3 stops push, at least not for the Sigma 35 in question (max is 1 stop).

If you hate vignette that much, shoot @ f1.8 then, big deal...

Oh and here's a fact - if you're going to shoot wide open, 99.99% of people don't really care about corners.

kin2son wrote in post #16032331
For pixel peeper, yea sure

And no vignette requires 3 stops push, at least not for the Sigma 35 in question (max is 1 stop).

If you hate vignette that much, shoot @ f1.8 then, big deal...

Oh and if you're going to shoot wide open, 99.99% of people don't really care about corners.

Well let's not forget that the Sigma is still decently sharp (not tack sharp mind you) in the corners. Pushed exposure in the corners from fixing vignetting in post or not, at least you get detail there which is a big thing in my book.

TheLensGuy wrote in post #16032252
There might be 10 out of 100 cases that are not like mine, maybe more, more, maybe less, I would say those are exception.

How silly.

There were several polls on these forums which, by their very nature are biased against the Sigma (naysayers being the louder voice on the internet, Canon forum, yada yada. Afterall, what normal person with a perfectly working lens actively searches for information about that lens? People with faulty lenses are going to be typing into their search bar "Sigma 35 problem" and the polls will pop up, hence their bias), yet none of them returned more than about 20% of people having a faulty S35.

This is yet another prime example of: I had bad luck, therefore it is the rule, anyone who has a normal copy is incredibly lucky.

I've tried 1 less Sigma lens than you, 11 total, and all of them worked perfectly.

Also in the same dilemma right now, I dont know which to get as if I get the Sigma, I have extra 500 to buy the 100 2.8 macro -.- alsmost*

no problems with mine. Very happy here!

Well i do love the Canon lenses. However, I am in transition to dump two canon primes and keep two sigmas.

TheLensGuy wrote in post #16032252
I already have 35L. I will just return the 3rd lens and be done with it. I was just trying to help others who might be in the same situation. Sigma is NOT a replacement for 35L. There might be 10 out of 100 cases that are not like mine, maybe more, more, maybe less, I would say those are exception. There is a reason Canon is "L" and that's consistency, accuracy, and reliability. I would never be able to trust the Sigma the way I trust Canon. Not so sharp is better than out of focus.

Not to mention, the vignetting, is probably the WORST in any lens I have ever seen.

Or ... you spend the $10 or so, send the lens to Sigma, have them adjust it, and have a great lens for far less than the 35L. Alternately get the USB dock and calibrate it yourself.

I agree that you should not have to do this, but I don't get why so many people are adamant about not sending the lens to Sigma for calibration (or now doing it themselves). In the case of the 35mm it seems well worth it. I recently bought the 30mm "A" crop lens, which front focused only at longer distances. After a one week trip to Sigma, the focus is now excellent.

BTW, according to Photozone, the Sigma 35mm vignettes 2.05 EV wide open, the 35L vignettes 2.41 EV wide open. Lenstip also agrees that light falloff of the 35L (70%) is worse than the Sigma 35 (66%). I don't know why your pictures don't confirm this, but I would call both test results pretty reliable.