Question regarding Sigma 18-35 Art Lens

Hey everyone! I have been reading a lot about this USB dock for certain Sigma lenses and can't seem to find an answer to my question, so I thought I would ask here. Does the USB dock enhance my lens quality in some way? On B&H, it mentions that the USB dock allows you to adjust the focus settings and such. I just don't want to feel like I NEED this lens if it isn't going to do anything for me. I am probably misunderstanding what this dock really does, but it doesn't hurt to ask

ShadowKingpin wrote in post #16897486
Hey everyone! I have been reading a lot about this USB dock for certain Sigma lenses and can't seem to find an answer to my question, so I thought I would ask here. Does the USB dock enhance my lens quality in some way? On B&H, it mentions that the USB dock allows you to adjust the focus settings and such. I just don't want to feel like I NEED this lens if it isn't going to do anything for me. I am probably misunderstanding what this dock really does, but it doesn't hurt to ask

The dock does not improve the optical quality in any way but if you find that your lens is front/back focusing, you can calibrate the lens with the dock to get accurate AF. It's a very useful tool in my opinion. My S18-35 had some severe front focusing and after fiddling with the dock for half an hour, the AF is spot on.

nguyedt wrote in post #16897538
The dock does not improve the optical quality in any way but if you find that your lens is front/back focusing, you can calibrate the lens with the dock to get accurate AF. It's a very useful tool in my opinion. My S18-35 had some severe front focusing and after fiddling with the dock for half an hour, the AF is spot on.

I might just pick it up then. Is it pretty difficult to do in the program, or extremely simple?

ShadowKingpin wrote in post #16897603
I might just pick it up then. Is it pretty difficult to do in the program, or extremely simple?

Very simple. You can adjust the lens at different focal lengths for various distances. It's a bit of trial and error. This is what I ended up with for my copy.

it also lets you set the focus limiter on some lenses and on others tweak the focus to be fast or slower and more accurate

nguyedt wrote in post #16897658
Very simple. You can adjust the lens at different focal lengths for various distances. It's a bit of trial and error. This is what I ended up with for my copy.

I'm going to probably be laughed at for asking this, but what did all of that represent? I'm looking at the picture and trying to find out what you were doing on there (Please don't hate me!). I still have a lot of learning to do in the realm of Photography. xD

ShadowKingpin wrote in post #16897719
I'm going to probably be laughed at for ask this, but what did all of that represent? I'm looking at the picture and trying to find out what you were doing on there (Please don't hate me!). I still have a lot of learning to do in the realm of Photography. xD

the verticle scale is MM, so each row represents a set focal length.(18mm 24 mm 28mm 35mm) For these focal lengths you can adjust front/rear focusing. negative values move the focus closer to the user, positive further. The columns represent distance. So you can adjust the selected focal lengths at the distances shown across the top of the chart. (listed in both feet and meters)

hope that helps

Jerobean wrote in post #16897797
the verticle scale is MM, so each row represents a set focal length.(18mm 24 mm 28mm 35mm) For these focal lengths you can adjust front/rear focusing. negative values move the focus closer to the user, positive further. The columns represent distance. So you can adjust the selected focal lengths at the distances shown across the top of the chart. (listed in both feet and meters)

hope that helps

That helped out A LOT. Thanks a ton for the explanation

nguyedt wrote in post #16897538
The dock does not improve the optical quality in any way but if you find that your lens is front/back focusing, you can calibrate the lens with the dock to get accurate AF. It's a very useful tool in my opinion. My S18-35 had some severe front focusing and after fiddling with the dock for half an hour, the AF is spot on.

If the lens misfocuses, the first line of defense is to return it for a specimen that does not. The USB dock is a palliative. I should know, for my specimen exhibits no focusing problems even on a lowly 650D.

Abu Mahendra wrote in post #16898134
If the lens misfocuses, the first line of defense is to return it for a specimen that does not. The USB dock is a palliative. I should know, for my specimen exhibits no focusing problems even on a lowly 650D.

This.

I've returned more Sigma lenses than any other. I tried to use the dock to fix a front/rear focus issue on an ART lens, and it just still wasn't perfect. I'd rather get a different copy, or a different lens completely. I just won't tolerate a lens that is that off, for the cost we pay.

Very best,

MalVeauX wrote in post #16898567
This.

I've returned more Sigma lenses than any other. I tried to use the dock to fix a front/rear focus issue on an ART lens, and it just still wasn't perfect. I'd rather get a different copy, or a different lens completely. I just won't tolerate a lens that is that off, for the cost we pay.

Very best,

This was my first Sigma lens and I enjoy it so far. If something did happen with it, I would definitely just get a new one.