concerned Optical stabilisation isnt working on lens

As previous posters have said, you should easily be able to see the stabilisation working through the viewfinder. Put it to 300mm and focus on something at infinity. If the image is as shaky with you holding OS/VR on as it is without then i would say something is up. My long range holding techniques are pretty poor and i can tell instantly when the VR on my 200mm lens is active, just by looking through the viewfinder with it on.
 
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
 
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...

This, your effective focal length is 400mm (250mm x 1.6 canon crop). Hand the rough rule of thumb would be 1/400th. Personally I would aim for 1/500th second as baseline, especially with a 3kg piece of glass.

IS/OS will give about 2 stops most of the time, so that is about 1/125th of second. With good technique and a very well working stabilization system you might get to 1/60th.
1/30th is still another whole stop away and even with good technique and excellent OS that is too much. One thing about OS is that is can actually make things worse when you are not in the correct operating range. Shutter speeds too high or shutter speeds to low will likely increase blur.


I would take some shots at 1/125th second at 250mm with OS on and off and see where you are (or at 300mm and 1/250th second).

OS/IS/VR is not some kind or miracle, as I told you before if you want high acuity then you need to use a decent tripod.

Also if you are not used to long lenses then thee is lot of technique to learn and with such a big lens you need to build up strength. Quite a few of the wildlife pros do marathon training and do weights several times a week because they might have to trek 10-20miles into the wilderness ad hold 4Kg camera setups for extending periods.
And it is not just about strength, it is mostly technique. A lot to do with breathing, half holding shutter etc. When I first started using my 300mm f/4.0 with 1.4xTC (so 630mm FF equivalent) I rarely got good shots. With time, practice and getting high shutter speeds (1/600th second) I managed to get the results I wanted.
 
al4x said:
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
Click to expand...

The thing is the 100mm lens is so much easier to use.


If you really see no difference then probably the OS is broken. If you purchased from a shop just go back and ask if you can try a different copy.

Try at a more reasonable shutter speed. E.g. at 250mm try shooting at 1/25th or 1/250th of second. The OS should work well at those settings. If it doesn't help then you might have something broken.
 
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
 
Last edited:
al4x said:
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
Click to expand...


send it back and get it exchanged, Sounds like their is a fault.
 
^ 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
 
You must log in or register to reply here.
Back
Top Bottom