Sigma 50mm f/1.4 DG HSM Art

[kaihp]

I trust sigma will sort it out
I'd be interested to find out what specifically was wrong with your copy though

I doubt its software otherwise everyone would have these problems

I'm beginning to suspect internal connections like (flex)cables, connectors etc. This could very easily give erratic behaviour. Hmmm; come to think of it, ESD damage can sometimes also give very odd behaviour.

I would also be interested in knowing the root cause of these problems that Viggo and Eldar has.

 

[Dylan777]

I trust sigma will sort it out
I'd be interested to find out what specifically was wrong with your copy though

I doubt its software otherwise everyone would have these problems

I'm beginning to suspect internal connections like (flex)cables, connectors etc. This could very easily give erratic behaviour. Hmmm; come to think of it, ESD damage can sometimes also give very odd behaviour.
I would also be interested in knowing the root cause of these problems that Viggo and Eldar has.

Could be....wickidwombat is located in China, less static and his lens is still solid.

 

[JustMeOregon]

I've been hanging-on every word of this thread as I sweat-over my own pre-ordered 50A... I really appreciate the way that all you guys have told of your experiences, good and bad, it is truly helpful. When I saw the posted FoCal results & graphs I had an idea...

Do you guys think that I could rely on testing a new 50A with FoCal as a way to insure that I get a good-focusing copy?

 

[Eldar]

I've been hanging-on every word of this thread as I sweat-over my own pre-ordered 50A... I really appreciate the way that all you guys have told of your experiences, good and bad, it is truly helpful. When I saw the posted FoCal results & graphs I had an idea...

Do you guys think that I could rely on testing a new 50A with FoCal as a way to insure that I get a good-focusing copy?

As far as I can see, it is the fastest way to determine if the AF is consistent. If you get a nice gaussian curve, with all the shots close to it, you do at least have a good starting point.

The problem though, in my case, has been that it started out spectacular. but now it´s gone totally bananas. I will return it next week. I wonder what Sigma will do ...

 

[JustMeOregon]

Eldar, thanks for the reply. When your 50A (that started out to be "spectacular") decided to go "bananas," was it an easily observable change in behavior (maybe even visible on the camera's lcd)? I'm just wondering if I'm going to have to run a FoCal test every 2-days-or-whtever just to be sure that my copy is stable. I'm hoping that if it "passes" an initial test, and later starts to exhibit some banana-like tendencies that it will be obvious and won't require FoCal-testing or pixel-peeping...

 

[Viggo]

Eldar, thanks for the reply. When your 50A (that started out to be "spectacular") decided to go "bananas," was it an easily observable change in behavior (maybe even visible on the camera's lcd)? I'm just wondering if I'm going to have to run a FoCal test every 2-days-or-whtever just to be sure that my copy is stable. I'm hoping that if it "passes" an initial test, and later starts to exhibit some banana-like tendencies that it will be obvious and won't require FoCal-testing or pixel-peeping...

My copy was a 99,4% hit rate with FoCal with a 30 shot test (same as my 24-70 mk2), it calibrated easier than any of my other lenses, no troubles whatsoever. And it simply worked.

But when it starts to go nuts you will absolutely know it. It's no way a camera/lens can miss a black and white traffic sign 15 times in a row, it should be 19 out of 20 sharp. And when it misses it still locks on the focus point you use, so you don't know until you review the image on the screen that it missed. It doesn't hunt at all, it locks fast, just in the way wrong spot.

 

[Eldar]

Eldar, thanks for the reply. When your 50A (that started out to be "spectacular") decided to go "bananas," was it an easily observable change in behavior (maybe even visible on the camera's lcd)? I'm just wondering if I'm going to have to run a FoCal test every 2-days-or-whtever just to be sure that my copy is stable. I'm hoping that if it "passes" an initial test, and later starts to exhibit some banana-like tendencies that it will be obvious and won't require FoCal-testing or pixel-peeping...

My copy was a 99,4% hit rate with FoCal with a 30 shot test (same as my 24-70 mk2), it calibrated easier than any of my other lenses, no troubles whatsoever. And it simply worked.

But when it starts to go nuts you will absolutely know it. It's no way a camera/lens can miss a black and white traffic sign 15 times in a row, it should be 19 out of 20 sharp. And when it misses it still locks on the focus point you use, so you don't know until you review the image on the screen that it missed. It doesn't hunt at all, it locks fast, just in the way wrong spot.

+1
My experience is the same. In your case, provided it starts off OK, I would just check in with FoCal after a while, to see if things have changed. But if you get the same problem as me (and Viggo) you will easily see it in the Camera LCD.

 

[JustMeOregon]

Thanks guys, it looks like I'm going to keep my pre-order and be able to relax a bit after all...

 

[wickidwombat]

i'm wondering if these copies have had a physical part failure internally
to me the sudden and dramatic change indicates its not software related
as the software tweeking is also having no effect now

so if its a part failure is it
a) a few random samples failing
b) a bad batch (in this case we should all worry)
c) design fault

I hope sigma let us know what was wrong with viggo's copy
my bet is on physical internal part failure

 

[Viggo]

i'm wondering if these copies have had a physical part failure internally
to me the sudden and dramatic change indicates its not software related
as the software tweeking is also having no effect now

so if its a part failure is it
a) a few random samples failing
b) a bad batch (in this case we should all worry)
c) design fault

I hope sigma let us know what was wrong with viggo's copy
my bet is on physical internal part failure

I sincerely hope so. That way it's fixed when it's fixed and not just "it's within specs" "no fault noted".

 

[razeac]

Just tested the sigma today (quite extensively) during Norway's Independence Day.

Eldar and Viggo - I'm keeping this lens. Just reviewed all of my shots from the 50A and I must say I'm satisfied. I was really anxious if most of shots are OOF.. AF issues are none if I do some of the methods the lens wants me to do ( af button spamming, use smaller apertures and not just 1.4 all the time lol) maybe use 1.4 only during steady portraits. AI servo seems better @ f2.0 and smaller apertures. I hope you guys will have your lenses back fixed.

 

[kaihp]

And when it misses it still locks on the focus point you use, so you don't know until you review the image on the screen that it missed. It doesn't hunt at all, it locks fast, just in the way wrong spot.

I know nothing about AF algorithms etc, but this seems odd. Wouldn't the camera do several Phase-Detect rounds to assure that focus is achieved? Initial PD-AF to determine focus direction and distance, and then at least a follow-up to confirm that focus is achieved? I recall Roger Cicala writing about this on his blog some time ago (a search reveals this was in July-August 2012).

Yeah, modern-style AF is closed-loop, so the camera should confirm the focus. And yet, it doesn't change away from the incorrect focus setting. This would indicate that the lens thinks it's in the position where it's supposed to be, and yet, it isn't. Wombat is probably right: some physical/electrical part failure seems likely.

Oh, and gratullerer med 200 års dagen til Norge (selvom det var i går) til alle Nordmenn her i tråden .

 

[Viggo]

Tusen takk i like måte KaiHP. If I get the time I'll post a few from the celebration over in the Anything shot with the 1dx-thread.

Btw, when you guys post a working it non working 50 Art, can you please share which body you are using it on, and what sorts of values you have your afma set too?

I have two buddies with 50 Art, one using 1dx and one using a 6d and the one using the 1dx has hm the same issues I and Eldar has, but the one with the 6d it seems to work fine.

First thing I will do when I get it back is to test it in the 5d2 for a while, I hope it's not a 1dx issue.

 

[wickidwombat]

Tusen takk i like måte KaiHP. If I get the time I'll post a few from the celebration over in the Anything shot with the 1dx-thread.

Btw, when you guys post a working it non working 50 Art, can you please share which body you are using it on, and what sorts of values you have your afma set too?

I have two buddies with 50 Art, one using 1dx and one using a 6d and the one using the 1dx has hm the same issues I and Eldar has, but the one with the 6d it seems to work fine.

First thing I will do when I get it back is to test it in the 5d2 for a while, I hope it's not a 1dx issue.

tried the different lenses on the different bodies?

 

[kaihp]

Btw, when you guys post a working it non working 50 Art, can you please share which body you are using it on, and what sorts of values you have your afma set too?

I have two buddies with 50 Art, one using 1dx and one using a 6d and the one using the 1dx has hm the same issues I and Eldar has, but the one with the 6d it seems to work fine.

First thing I will do when I get it back is to test it in the 5d2 for a while, I hope it's not a 1dx issue.

Good point, Viggo.

If I recall correctly, wickedwombat is shooting with a 5D3 (his lens is OK), and Eldar has used both a 1Dx and a 5D3 (both have problems with his 50A, it seems).

 

[Viggo]

Tusen takk i like måte KaiHP. If I get the time I'll post a few from the celebration over in the Anything shot with the 1dx-thread.

Btw, when you guys post a working it non working 50 Art, can you please share which body you are using it on, and what sorts of values you have your afma set too?

I have two buddies with 50 Art, one using 1dx and one using a 6d and the one using the 1dx has hm the same issues I and Eldar has, but the one with the 6d it seems to work fine.

First thing I will do when I get it back is to test it in the 5d2 for a while, I hope it's not a 1dx issue.

tried the different lenses on the different bodies?

We live a while apart, but my wife has a 5d2 I will try mine on at least.

 

[Viggo]

Btw, when you guys post a working it non working 50 Art, can you please share which body you are using it on, and what sorts of values you have your afma set too?

I have two buddies with 50 Art, one using 1dx and one using a 6d and the one using the 1dx has hm the same issues I and Eldar has, but the one with the 6d it seems to work fine.

First thing I will do when I get it back is to test it in the 5d2 for a while, I hope it's not a 1dx issue.

Good point, Viggo.

If I recall correctly, wickedwombat is shooting with a 5D3 (his lens is OK), and Eldar has used both a 1Dx and a 5D3 (both have problems with his 50A, it seems).

Ah, didn't know he tested on both yet. I don't know if that's a good or a bad thing even, lol.

 

[Eldar]

Btw, when you guys post a working it non working 50 Art, can you please share which body you are using it on, and what sorts of values you have your afma set too?

I have two buddies with 50 Art, one using 1dx and one using a 6d and the one using the 1dx has hm the same issues I and Eldar has, but the one with the 6d it seems to work fine.

First thing I will do when I get it back is to test it in the 5d2 for a while, I hope it's not a 1dx issue.

I have. same results on both bodies.

Good point, Viggo.

If I recall correctly, wickedwombat is shooting with a 5D3 (his lens is OK), and Eldar has used both a 1Dx and a 5D3 (both have problems with his 50A, it seems).

Ah, didn't know he tested on both yet. I don't know if that's a good or a bad thing even, lol.

 

[candyman]

I checked my 50Art on my 6D and this time I used SpyderLenscal.
Now I am not a pixelpeeper but it seems no adjustment was needed. So I did not adjust it.
I added also two portraitphotos with centerspot focus on the right eye.
It seems that there is no focus to the left or right nor front or back. But I love to hear your opinion.

I did not check yet my 5D MKIII I am going to use Focal next Friday and start some outdoor shots as well.

 

[Viggo]

Thanks candyman! I seems there is still a small hope mine will work for me as well.