Purchasing Sigma 35 f/1.4: how to know it is a good copy?

I think it looks right.
This one is ISO 800, F 1.8, 1/20 sec

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light_pilgrim wrote in post #16483821
community - THANK YOU for suggestions. Everything is exactly what I needed. Got the lens...just did 5 shots...low light...some books and coffee mugs. Looks OK for what I was able to test. Will give it a proper run during the weekend.

I think Sigma did a very-very good job with this lens. Feels great...this lens.

FYI mine worked fine at home in near pitch dark. But I went on a trip and it never shot the same every time I moved to a new location

Best way to test is to take it everywhere with u. And always shoot at 1.4 to exaggerate the problem

As for the comment that there are just a couple users with af problems in lightning conditions I highly suggest u to read the big thread. You'd change your mind. Some people even reported they thought the af was good initially but months later realized the lens is broke

Best lens-test subject ever. Going out and making images > shooting test charts. Not only have you confirmed the lens is working great (in real-world conditions), but you have some beautiful images as well, all from the same test. Well done!

Not to hijack this thread.....

I also take the plunge yesterday, and brought this lens home. Wasn't my intended purchase, but I came home with it anyway

Few questions....as I have been following this sigma lens for a while.

1. what does it mean exactly when its front focus vs back focusing? Doesn't it depend on where you want the focus to be? Do you mean you want to focus back object and its focusing on the front instead? or vice versa?

2. how do you find out the firmware on the lens itself? Does 012 mean anything? Somewhere I read the lens is upgraded to 1.2?

Thanks for your input

so I don't have a friend posing at the moment here's couple of shots focus on different items. how does this look?

bacchanal wrote in post #16483391
I've been testing a Sigma 35 1.4 against my 35L for the last couple of weeks. I'm actually thinking of replacing the L with the Sigma.

The Sigma is awesome optically, but (imo) it is not quite on par with the Canon for low light AF. It's hard to accurately describe light levels on a forum, but (with the 5D3) the Sigma starts to struggle in the ISO3200 f/1.4 1/80 and below range...basically dim indoor lighting with no AF assist beam. The hit rate drops significantly and the AF seems to hesitate...it seems to get close to being in focus and then there is a little delay before you get an AF confirmation light. The Canon is relatively fast and accurate down to around the ISO3200 f/1.4 1/40 range, and below that they both struggle (which probably says more about the 5D3 than either of the lenses). To put it in other words, I would probably give the Canon a 1 stop advantage for AF performance, if that makes any sense. This is going more on feel than formal testing...but I shoot a lot with fast primes in dim lighting, ymmv.

So, if you think dim indoor lighting with no AF assist beam is a situation you'll be shooting in often, I would try to get a feel for how the Sigma performs there. In brighter, more contrasty light or with an AF assist, in my experience it's been hard to distinguish the AF performance from the Canon.

Somethingw rong with 5dmk3 IMHO. I test and both 6d and 5dmk3 AF fine at ISO25600, f1.4, 1/30. Now AF is not as quick as in day time but still AF that one can easily take a shot. This with 35L as well as Sigma 35mm f1.4.

Agree that AF on 35L is better than Sigma Art.

For now it works OK. It is hard to believe that Sigma released a product that just cannot be good no matter what. I still see a lot of happy users...actually majority are happy. You know how it is with internet....some folks come to report a problem and we mostly hear about problems. Those who are happy....just keep shooting We shall see....so far so good. I compare it to the Zeiss I had: Sigma is better with AF for sure And also very close if not identical when it comes to IQ. I do not see as much of this green fringing as I used to see with Zeiss at f/1.4

Xyclopx wrote in post #16491095
FYI mine worked fine at home in near pitch dark. But I went on a trip and it never shot the same every time I moved to a new location

Best way to test is to take it everywhere with u. And always shoot at 1.4 to exaggerate the problem

As for the comment that there are just a couple users with af problems in lightning conditions I highly suggest u to read the big thread. You'd change your mind. Some people even reported they thought the af was good initially but months later realized the lens is broke

light_pilgrim wrote in post #16491989
For now it works OK. It is hard to believe that Sigma released a product that just cannot be good no matter what. I still see a lot of happy users...actually majority are happy. You know how it is with internet....some folks come to report a problem and we mostly hear about problems. Those who are happy....just keep shooting We shall see....so far so good. I compare it to the Zeiss I had: Sigma is better with AF for sure And also very close if not identical when it comes to IQ. I do not see as much of this green fringing as I used to see with Zeiss at f/1.4

Not saying all of those lenses are bad. I think at least more than half are fine it seems like. Though you have to be aware that many people with af problems don't even know it. So it goes both ways. Just cause you don't hear complaints doesn't mean there are no problems. I have experiences with people like that quite often. As you know most lenses need some kind of micro adjustment. At least most of my canons do. Yet how is it that anyone could use the lower end cameras without ma? Think about it.

Anyway I'm not here to argue that. It's a great lens. Just saying you should use it in a variety of situations before being sure yours is good.

I fully understand it and definitely this is why I purchased it - to actually use it in all conditions I do not collect lenses
But I also do not want to seek for a problems deliberately....I will just keep using it the normal way and if it works as good as now...I am happy.

Xyclopx wrote in post #16491995
Not saying all of those lenses are bad. I think at least more than half are fine it seems like. Though you have to be aware that many people with af problems don't even know it. So it goes both ways. Just cause you don't hear complaints doesn't mean there are no problems. I have experiences with people like that quite often. As you know most lenses need some kind of micro adjustment. At least most of my canons do. Yet how is it that anyone could use the lower end cameras without ma? Think about it.

Anyway I'm not here to argue that. It's a great lens. Just saying you should use it in a variety of situations before being sure yours is good.

light_pilgrim wrote in post #16491998
I fully understand it and definitely this is why I purchased it - to actually use it in all conditions I do not collect lenses
But I also do not want to seek for a problems deliberately....I will just keep using it the normal way and if it works as good as now...I am happy.

sounds good to me.

By the way, i read that there is the new firmware for this lens. I will need to get a dock. Why will this firmware bring...improve the af?

I have this lens for a couple of days as well. Yesterday I shot a pretty big part of wedding with it. The IQ is amazing, but yes, I had some pretty bad missfocused shots.

Is the dock capable of correcting everything to prevent missfocus almost all the time?

Job511 wrote in post #16491397
so I don't have a friend posing at the moment here's couple of shots focus on different items. how does this look?

it would be easier if you could precise where was the focus point on each picture

FF/BF issues occur when you focus on a specific point and get blur / sharp image instead of what you aim to shoot

Just tested mine in the garden. Not really happy about the results.

1m. = +12MA but sometimes +3 is better
1.5m. = +12MA
2.5m. = +8MA
5m. = 0MA

But there where some missfocussed shots.

My previous experience was with MF Zeiss 35 F/1.4 lens and so I know it is very hard to nail the focus with the 35 mm lens wide open. Tiny movement and it is oof. It might be that in some cases the oof results is down to the user error. Not saying it is, but just saying it is easy for it to be the case. In the next couple of weeks I will use mine a lot more and so i shall see how it behaves. I do not see anything worrying right now.