Sigma 150-600 C focus ring

[J.davis]

I believe that my 160-600 c has a stiff focus ring. I compared it to my smaller Sigma lenses and they rotate freely.
I have also tried a friends tamron 150-600 and his turns as freely as my smaller Sigma lenses.
C.R.Kennedy said it was normal, but to get the focus ring to move, the lens is lifted/moved before the ring rotates.
So the initial force to move the focus ring will have to be heavier than the lens.
Anybody on the forum with a Sigma 150-600 C, can you test your focus rings for easy movement please and reply.

[Mark L]

I have the sports version of this lens. Moved up from the Sigma 120-400. The new lens has a stiffer focus ring than the smaller lens and I'd expect that given the bigger size of the lens. It is still not a problem to move with my thumb.
@Dazz1 any thoughts.
Reckon you both live close enough to each other to get together and compare (for John's sake :))

[arthurking83]

4 sigma lenses here:

* 10-20 /4-5.5; focus ring is so light you can easily move it with a broken little pinkie!(actually is a problem in that it's easy to defocus when you don't want too!

* 12-24 /4.5-5.6; a bit stiffer, but still easy to move with thumb. a little harder too with pinky, but doable.

* 50/1.4(old style, not Art!) stiffer again. easy to move with thumb but needs a converted effort to do with pinky(i.e. almost can't)

* 150-600 S, can't move with pinky at all, stiffest focus collar of the lot, definitely needs a stronger finger or thumb. But is consistent in it's movement. That is, it doesn't feel as though it's more difficult to start moving and then moves a bit smoother.

They all feel different, but the 50 and 12-24 feel the most similar(even tho they feel different if I try to use a pinky to move the focus(and no one really does that, that was simply to for a more accurate feel)
If I were to describe the focus feel in a review of all those lenses, I call the 150-600S stiff, but feels nice and tight.
The reason I use the expression nice and tight tho, is because if I compare it to the 10-20, the 10-20 feel crap!. It's loose, it feels grindy coarse and cheap. Very loose almost as tho the collar is worn(like a bearing) and it's like worn metal to worn metal or something.
The 12-24 and 50 also feel tight and stiff, but not as stiff(or hard to move) as the 150-600S.


...
C.R.Kennedy said it was normal, but to get the focus ring to move, the lens is lifted/moved before the ring rotates.
So the initial force to move the focus ring will have to be heavier than the lens.
.....

Gong by that description, it sounds like this lifting movement happens if you're using only one finger(ie. and not gripping it with a finger and thumb, which turns the action into a proper rotation motion).

Either way, I'd say(more likely) you have a problem, and CRK will almost always deny an issue, as it costs them to sort it out .. and of course they want to minimise their costs! :rolleyes:
There should never be any more requirement to start moving a focus collar than it requires to keep it moving. That's how you described the feel of the focus collar's movement ... hard to start moving, but then smooths out.

Has the lens been subjected to any knocks at all, no matter how minor?
Is it stored in a bag with other stuff? If so, does any of that other stuff put any pressure on the lens barrel .. etc.

[J.davis]

I keep my kit in good shape and stored in a backpack, snug fit but not squashed as to cause concern. 150-600 C lives on the body in the backpack ( its my 'go to' lens).
Mate just tried his Sigma 50-500 and it rotates freely with fingernail on the ring.
AK, I am not inducing rotation of the lens when trying to move the focus ring, it is just that initial effort to start the ring moving that moves the lens.
I am going to a camera shop soon to try some new models and then talk with C.R.Kennedy again.

[arthurking83]

.....
I am going to a camera shop soon to try some new models and then talk with C.R.Kennedy again.

:th3:

and try to be firm with them too.

Is it still under warranty?

[Mark L]

it is just that initial effort to start the ring moving that moves the lens.

Have to agree with you that that shouldn't happen. Smooth from the start is what should be expected I'd think.

[J.davis]

They are all stiff and that's about it.
Must admit that I didn't check that out before buying, was not high on the priority list.

[arthurking83]

They are all stiff and that's about it.
.....

So nothing wrong with your lens, specifically .. they're all like that?

[J.davis]

Pretty much so AK. Dodgy as, when you compare the opposition.

[arthurking83]

The Sport model focus feel is just fine.
As said earlier, much stiffer than all my other Sigma lenses .. in fact compared to all my other lenses. But it's feel is fine ... fluid and damped.
Probably expected to be so for such a large lens too.

Hopefully as it ages it will loosen up a little, which they usually all do.