concerned Optical stabilisation isnt working on lens

413x

413x

413x

Caporegime
Joined
13 Jan 2010
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Llaneirwg
I have been trying out a new (but used) lens today and cant help but feel the OS on it isnt working

its the sigma 120-300mm f2.8

if i take a series of shots hand held of a static target almost always it seems the static ones are overall better. sometimes there is a near perfect one sometimes a very blurred one
with OS on they all seem somewhat blurred and some are bad

i can see the lens flicking with the OS on

this is at
f2.8
150mm
2m to target
1/60 shutter

have i got a dud?
 
^how do i test stabilisation.. its not that i expect hand held shots to be sharp, but the concern is the stabilization seems to make things worse
 
thats kind of what im doing indoors as its night and at best i see no difference,
i will try tomorrow on my lunch break.

i do hear noise from the lens
 
i think i might ..good job i bought it from a retailer!

i will give it a good go tomorrow but i really cant see an improvement with it on,
like i said the non OS is what i expect..4 shots in a row and some are sharp some not with it i see it as worse/same

I really cant see any stability increase with it on. Im guessing this isnt an easy thing to check for
 
I'll check the video tomorrow

I have os1 and os2
Os1 is fit panning
Os2 Normal

I've tried both
 
I think I'm sending this back
I took 14 shots with os on and 14 off at slow speed shooting
Shutter 1/30
250mm
100 iso
F 13 due to shutter priority

Subject was just a car number plate at about 15m ish
Obviously hand held

The 14 without os include a few fairly good ones and a lot of bad ones..
The os ones are all somewhat worse than the beat non os ones

Just watched the link
Mine to me looks like there is no difference between on and off except with on the picture through viewfinder sometimes almost jolts

From what I have seen this isn't right
 
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V-Spec said:
To be honest, if you're sure there's no difference at all between it being on and off then it's certainly possible it could be broken, the video I linked was pretty much exactly how I remember IS (on Canon anyway) and I don't think there's that much difference between them,

But tbh - 1/30th, handheld with a 3KG telephoto, I'd be impressed if one in ten shots were acceptably sharp, even with the best IS.
Click to expand...

I'm finding it hard to be sure about it

I was trying to find a shutter speed where I could see improvement. I can't see the difference like in the video you linked holding down the shutter release half way.
I'm fairly sure I'm right in thinking that if I press the shutter release half way that disregarding settings I should see roughly what that video shows.

Again, to me I don't see this, and if it is working I may as well send the lens back anyway as it's not improving my pictures. Handily I don't need to prove it's not working to get a refund.

I'm going to try my canon 100mm Macro IS lens with this as well (which I haven't tested as it was new but I'm fairly sure it's working as I get a lot of decent pics with it, more than I expected)
 
V-Spec said:
To be totally honest, a 120-300 is a nice piece of glass, but these things are not easy to use, they're heavy, unwieldy and because of their sharpness/focal-length you need good technique to get the best out of them,

It's easy to think that something so modern and precise will just give you great images, but the reality is it takes a great deal of practice to use them properly.

Before I moved down to London I was doing a lot of wildlife photography, and I used to spend ages at the side of the road practicing on cars (hours on end) practicing on anything I could to get my technique as good as possible - you can't point and shoot with long glass.

TLDR: Have a think about what you're trying to achieve - if you think long glass is not for you or your sure it's broken, then return it I guess, but make no mistake - that is a nice lens, it'll just take some getting used too...
Click to expand...

I wish I was sure. I haven't enough experience to make the call IIt's not that I am expecting great images at slow shutter speeds it's that I have that feeling I'm paying for stabilisation and it may not be working. Someone else may be able to look at it and go 'yep broke' or 'it's you, the lens is fine'

I guess I was expecting at least some improvement with stabilisation on hand held at non ideal shutter speeds I wasn't expecting all shots with stabilisation on to look worse than the best with it off
 
I'll check this with my 100mm IS tonight.. If I can clearly see the 100mm lens working and not working like described but the sigma not I don't think I will be able to be any more certain

I'm more sure it's broken from the lack of stability through the viewfinder with IS on
 
I'm now almost 100% sure stabilisation isn't working

I set my canon 100mm up on 5x live view and could absolutely see the difference as clear as the video working (quite amazing actually)
Set sigma to 120mm and saw no difference on or off. The on position was actual worse as the definitive flick I had thought I had seen occurred occasionally
-edit.. this would explain possibly why my non IS shots are better than IS - if the IS is attempting to work but correctly that would make things worse

If it is working it isn't good but I strongly suspect it's broke.

Now I can really see how I was getting more shots good from my macro and why i love it so much

Sigma is going back this week. I'm guessing it's faulty more than bad stabilisation as I haven't seen people say it's bad, hit and miss but not bad
 
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^ it was clear as day when i compared to the canon i could disregard focal length and shutter speed using that method.

I didnt appreciate how much difference IS made and it has really made me think about lenses in the future.
I was a bit taken back tell the truth at its corrective ability
Fine if shutter speed is high or tripod but hand held at moderate shutter speeds is another matter.
 
The lens is going for repair of the IS unit by sigma. Then I'm getting the same one back.
 
so do i. At least this way the unit will be tested and working. Hoping to see an obvious difference.
Annoying as it has to make 4 courier trips

to the shop
to sigma
back to shop
to me

im going to do a back/forward focus test before it goes as well. I think its ok
 
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