Have you repaired your 50 Art?

Just wanted to update this thread. Be aware of your 50 Art, it has suddenly started to hit perfect again. No new values no new calibration, and yet the last couple of days and a few hundred pictures in all kinds of horrid light and every single shot is DEAD ON... How? Why? And wtf? I don't know. But I will keep using it and do some controlled shots to keep for later so I can check if it starts to act up again.

Padded cell next...
 
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It is funny how all the fantastic new products seem to break the early adopters' hearts within the first 6 months of use. The miraculous Sigmas do not focus and the best ever Nikon lets the sunshine in like hippies in the musical Hair back in the sixties.
Even refurbished you cannot trust and all the second hand stuff is probably for sale for a Reason.

There are magicians who turn out beautiful stuff with the 50mm L as their only lens.
Here, for example: http://trash-russia.com/photos-by-russian-photographer-katerina-plotnikova-part-2/
 
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Viggo said:
Hi guys!

Just wondering if anyone here have had AF issues with the Sigma 50 Art and had it successfully repaired, not swapped for a new?

Mine is getting worse and I'm at the very last of my patience with it, so last chance is to perhaps send it for repair.

Thanks! :)

Mine has been perfect since day one. Got it fairly early. Have shot a lot with 50mm f/1.2 L before.

When you use such a shallow depth of field you have count on some misses no matter what if you are shooting something tight such as a portrait. I take 3 shots to be fairly sure I have at least one spot on. I'd say 2 of 3 in average are good in focus shots.

Also, we tend to use such extreme f-stops when the light is bad (and when the lens is most useful). Try testing the lens at good light and see if it makes a difference. Maybe also rent a Canon before you decide the Sigma that'is broken?

Good luck.
 
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Viggo said:
Padded cell next...

Intermittent faults drive me nuts too. I've been following the Sigma 50 saga in this and other threads, and I really sympathize with the frustration of it all. I take it there's no discernible pattern to the misbehavior at all? I'm thinking if there's some kind of mechanical or electrical fault things like temperature, carriage (bumpy roads? particular way of carrying the camera?) could play a role in determining what makes for a good day versus a nightmare.

FWIW I still haven't had the guts to try the 50 Art, but I did get a second hand Sigma 50 EX (yep, the older one) which is actually pretty dependable on my 5D3. It is at the same time dependably awful on my 5D2 despite numerous attempts at AFMA. Go figure, as they say.
 
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Maiaibing said:
Viggo said:
Hi guys!

Just wondering if anyone here have had AF issues with the Sigma 50 Art and had it successfully repaired, not swapped for a new?

Mine is getting worse and I'm at the very last of my patience with it, so last chance is to perhaps send it for repair.

Thanks! :)

Mine has been perfect since day one. Got it fairly early. Have shot a lot with 50mm f/1.2 L before.

When you use such a shallow depth of field you have count on some misses no matter what if you are shooting something tight such as a portrait. I take 3 shots to be fairly sure I have at least one spot on. I'd say 2 of 3 in average are good in focus shots.

Also, we tend to use such extreme f-stops when the light is bad (and when the lens is most useful). Try testing the lens at good light and see if it makes a difference. Maybe also rent a Canon before you decide the Sigma that'is broken?

Good luck.

I'm not gonna list all the copies of all the different super fast lenses I have owned and/or used, but it FAR outnumbers the 2.8 and slower lenses I have used. And I shoot wide open 99% of the time. Let's just say we can rule out user error with this specific issue. I'm a strobist so I also use the large apertures in bright sunlight a lot also. You are right in what you say about thin dof and that it requires a bit more focus to nail 8) but it's not the issue here.
 
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Eldar said:
Viggo, FYI, I just read some posts on a Facebook group concerning AF with the 50 Art in low temperatures. Apparently a number of owners have AF problems from about -5C. This just adds to the issues with the Sigma AF system.

Haven't really tried it in the cold yet, but we live in Norway so the odds of -5 is prettttttty high, was outside Oslo for Christmas and it was -21, and I came from +1 down south, lol.. So the AF is dependent on using f11 in bright sun and +20 degrees then, fantastic.
 
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Ah, temperature dependency could be a factor. I haven't tried mine outside in the cold, the weather has sucked big time from about the beginning of November. Now that we get -20C in the following days, sun light should be available instead of the continuous overcast (yay November and December in Northern Finland, but we get the compensation in March) for the last two months.

Perhaps there is indeed something related to thermal expansion and the build material. It really does not take a lot of thermal expansion to throw the autofocus off, and makes me wonder whether some amount of complaints of the 50EX or 50L are caused by that too.

Given the Sigma's new Thermally Stable Composite, it is indeed possible that therein lies part of the problem. Could you provide a link to the Facebook group? The most burning question from my part is whether there is hysteresis with respect to the temperature involved. That would mean that taking the lens (calibrated at +20C) from +20C to -20C and using it there, then bringing it back to +20C indoors does not return the lens to the earlier calibrated position.
 
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Northstar said:
Sorry to see this discussion...it seems we are still waiting for a really good all around 50mm.

Both yes and no, mine worked for 6 months and it's been extremely consistent and so perfect it makes most other lenses look like you won them on a vending machine. And the AF and tracking have been as good as the 2470 II. But if it only lasts a few months, that is quite a big issue, I agree. If I had known the working copy would also stop functioning I would have given up on it way back in April.

This is the last chance it gets ..
 
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Crazy autofocus

Autofocus problems will make you crazy, especially when you know the lens/camera combination is capable of extreme sharpness!

I have had a Sigma 50 classic for about four years. I was very happy with the sharpness, not that different from the 50 Art I rented. Unfortunately the autofocus performance varies a lot. Sometimes when I would get very frustrated, I would put it away and just use other lenses. Then, 2 or 3 months later I would try it again and find it worked very well for a while. (I did send it in for calibration before the 3 year warranty ran out, but could detect no difference when I got it back.)

I'm hoping that my recently purchased, used Canon 50 1.2 will at least have consistent focus errors. That way I can learn to compensate. It's in for calibration right now as I've reported in another thread.

Viggo, thanks for sharing your experience. All this would be even more frustrating if we were not able to learn from each other.
 
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Viggo said:
Northstar said:
Sorry to see this discussion...it seems we are still waiting for a really good all around 50mm.

Both yes and no, mine worked for 6 months and it's been extremely consistent and so perfect it makes most other lenses look like you won them on a vending machine. And the AF and tracking have been as good as the 2470 II. But if it only lasts a few months, that is quite a big issue, I agree. If I had known the working copy would also stop functioning I would have given up on it way back in April.

This is the last chance it gets ..

I just wish canon made a great 50 or 85 1.4....it's really a shame that it has to come down to this.
 
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Hmmm....that reminds me of the Miele® repairman I called to fix a howling waterpump on my dishwasher.
He asked me what the problem was and I told him that it must be the bearing of the waterpump that is making the noise as it only appeared when the machine is emptying.
"The Miele® water pumps do not fail!"
On the bill he had written: 'Program selector calibrated'. He only charged for the mileage.

So the focusing motor was dirty...Sigma® focusing motors do not fail?
 
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Rudeofus said:
martti said:
So the focusing motor was dirty...Sigma® focusing motors do not fail?

If you know and understand how USM/HSM/USD works, you will quickly agree that mechanical failure is quite unlikely, whereas a grain of dust, or sticky lubricant can cause a lot of grief.

You might be surprised but I really do understand how the HSM works.
I also understand how image building and afermarketing functions.
For some reason, some of the brands just want to stick to the lies they started out with instead of going like "hmmm this is something we have not seen, must be the bearing"...

Yeah, never let the truth surface if you can help it.
Maybe I am becoming paranoid because I am living in France.
 
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