Sigma 18-35 f/1.8 - is "sticky" focus ring normal?

Coven · 02-22-2021, 03:10 PM

Hello!

I've recently bought a used Sigma 18-35 in very good condition and there is one thing that is bothering me.

The zoom ring is very smooth and easy to turn. The focus ring on the other hand is noticeably more stuff, but still smooth when moving fast and decidedly.

The issue appears when I try to critically adjust the focus moving very slowly and gently, without the "brute force" - the feedback I get is... It feels "choppy", I feel delicate steps, as if it was stuck for a brief moment. It's very subtle but annoying.

Is it normal? Thanks in advance for answear.

swanlefitte · 02-22-2021, 06:29 PM

Just checked mine. If I move 1 minute every second as a clock it is fine. Even slower with smaller increments is pretty smooth. I can't really imagine that critical of focus being much smoother without giving the lens a longer focus throw which is 120°

Imp · 02-22-2021, 08:44 PM - **1 Like**

Originally posted by Coven

Hello!

I've recently bought a used Sigma 18-35 in very good condition and there is one thing that is bothering me.

The zoom ring is very smooth and easy to turn. The focus ring on the other hand is noticeably more stuff, but still smooth when moving fast and decidedly.

The issue appears when I try to critically adjust the focus moving very slowly and gently, without the "brute force" - the feedback I get is... It feels "choppy", I feel delicate steps, as if it was stuck for a brief moment. It's very subtle but annoying.

Is it normal? Thanks in advance for answear.

same on my copy, feedback feels 'choppy' as you put it.

gatorguy · 02-23-2021, 06:33 AM

Both the zoom and focus rings are smooth on my copy. The focus in particular is well damped, a bit less tight than the zoom, and very easy to use manually when needed.

Coven · 02-23-2021, 10:14 PM

Really strange... Well, at least one of you has this "issue". Do I have to worry - that is the question...

Imp · 02-24-2021, 06:05 AM

I mean it's really really subtle. I wouldn't notice it under normal photographic conditions, I've only noticed it because I've been using it adapted to a GH3 for video and I'm using manual focus a lot more with more precision, and there's a very slight choppiness. But I don't think it's anything to worry about, for me after the initial resistance is overcome it moves smoothly.

FreeSpirit9 · 02-26-2021, 03:11 PM

Mine is smooth for both focus and zoom.

02-22-2021, 03:10 PM	#1
Coven New Member Join Date: Sep 2019 Posts: 22	Sigma 18-35 f/1.8 - is "sticky" focus ring normal? Hello! I've recently bought a used Sigma 18-35 in very good condition and there is one thing that is bothering me. The zoom ring is very smooth and easy to turn. The focus ring on the other hand is noticeably more stuff, but still smooth when moving fast and decidedly. The issue appears when I try to critically adjust the focus moving very slowly and gently, without the "brute force" - the feedback I get is... It feels "choppy", I feel delicate steps, as if it was stuck for a brief moment. It's very subtle but annoying. Is it normal? Thanks in advance for answear.

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02-22-2021, 06:29 PM	#2
swanlefitte Pentaxian Join Date: May 2015 Location: Minneapolis Photos: Gallery Posts: 4,068	Just checked mine. If I move 1 minute every second as a clock it is fine. Even slower with smaller increments is pretty smooth. I can't really imagine that critical of focus being much smoother without giving the lens a longer focus throw which is 120°

02-22-2021, 08:44 PM - 1 Like	#3
Imp Pentaxian Join Date: Nov 2014 Location: Washington, DC Photos: Gallery \| Albums Posts: 1,749	Originally posted by Coven Hello! I've recently bought a used Sigma 18-35 in very good condition and there is one thing that is bothering me. The zoom ring is very smooth and easy to turn. The focus ring on the other hand is noticeably more stuff, but still smooth when moving fast and decidedly. The issue appears when I try to critically adjust the focus moving very slowly and gently, without the "brute force" - the feedback I get is... It feels "choppy", I feel delicate steps, as if it was stuck for a brief moment. It's very subtle but annoying. Is it normal? Thanks in advance for answear. same on my copy, feedback feels 'choppy' as you put it.

02-23-2021, 06:33 AM	#4
gatorguy Moderator Join Date: Feb 2015 Location: Central Florida Photos: Gallery Posts: 6,092	Both the zoom and focus rings are smooth on my copy. The focus in particular is well damped, a bit less tight than the zoom, and very easy to use manually when needed.

02-23-2021, 10:14 PM	#5
Coven New Member Join Date: Sep 2019 Posts: 22 Original Poster	Really strange... Well, at least one of you has this "issue". Do I have to worry - that is the question...

02-24-2021, 06:05 AM	#6
Imp Pentaxian Join Date: Nov 2014 Location: Washington, DC Photos: Gallery \| Albums Posts: 1,749	I mean it's really really subtle. I wouldn't notice it under normal photographic conditions, I've only noticed it because I've been using it adapted to a GH3 for video and I'm using manual focus a lot more with more precision, and there's a very slight choppiness. But I don't think it's anything to worry about, for me after the initial resistance is overcome it moves smoothly.

02-26-2021, 03:11 PM	#7
FreeSpirit9 Veteran Member Join Date: Aug 2013 Location: Queensland, Australia Photos: Gallery Posts: 557	Mine is smooth for both focus and zoom.