How much of a difference does IS make?

Grayman

Grayman

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Graeme
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Hello all,

Perhaps another naieve question...but how much difference does IS on a Canon lens really make? If I was to use a 70-200 f4 non IS lens in good light and quick shutter speed would I really see the difference? If I was going to use a slow shutter speed I would ivariably use a tripod which would compensate for the ack of IS..no??

Thanks
 
if you are using a quick (say 1/250 or less) shutter speed I wouldn't imagine that you would see much difference.
If you were using 1/60 then I think that you would start to see a higher % of keepers with IS (& bearing in mind that IS does nothing for subject movement).
 
Grayman said:
Hello all,

Perhaps another naieve question...but how much difference does IS on a Canon lens really make? If I was to use a 70-200 f4 non IS lens in good light and quick shutter speed would I really see the difference? If I was going to use a slow shutter speed I would ivariably use a tripod which would compensate for the ack of IS..no??

Thanks
Click to expand...

If you really do use fast shutter speeds or a tripod, then IS won't help you much.

You will also be the first person in the world to work like that.

I just paid an extra £400 over the non-IS to get a 70-200 4 L IS. All my other lenses are also IS, except the super-wide.
 
IS slows the AF down .. you can hear it clunking as it focuses. The only time I used IS at sports is in very low light for say a manager or crowd shot wheer I can take my time.. IS for when you ened a bit of extra shutter speed.. at high shutter as you emntion then no need ..
 
KIPAX said:
IS slows the AF down .. you can hear it clunking as it focuses. The only time I used IS at sports is in very low light for say a manager or crowd shot wheer I can take my time.. IS for when you ened a bit of extra shutter speed.. at high shutter as you emntion then no need ..
Click to expand...

Not on my lenses it doesn't. Completely independent function.
 
have i used the wrong terrminology? If I use IS on my 300 i can hear it clunking and it takes longer to focus IMHO
 
It's probably more justified on the f/4 version than the f/2.8 because of the stop reduction between the two. However it only reduces the effect of your (i.e. the photographers) movement and not the subject, so it's always worth considering and deciding whether the f/2.8 non-IS may be more beneficial to your needs - the f/4 IS is really the ultimate walkaround telezoom lens in terms of flexibility though.
 
KIPAX said:
have i used the wrong terrminology? If I use IS on my 300 i can hear it clunking and it takes longer to focus IMHO
Click to expand...

I've got to say I haven't actually noticed it myself, there is a substantial crunchy-click whether you hit the AElock/shutter button, and then about half a second before it completely stabilises the image, but AF was locked well before then.

ummmm interesting though, i need to go experiment now...

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KIPAX said:
have i used the wrong terrminology? If I use IS on my 300 i can hear it clunking and it takes longer to focus IMHO
Click to expand...

Terminology is fine, but it only slows down AF if you don't engage IS first with a half-press on the shutter release, then focus/re-focus.

IS takes a fraction of a second to get up and running, and sometimes makes a little noise, but once it's there the reactions are lightning quick, as they must be to correct vibration and movement. IS uses the same technolgy as loudspeaker coils and they can move thousands of times a second.

In theory, IS actually enhances AF (unlike in-camera stabilisation) as it gives the focsuing system a stabilised image to work on for better accuracy.

The only thing I can think of that might slow things down with a big lens like 300 2.8 is the aperture blades have a long way to close down at higher f/numbers. I have heard for example that the frame rate of a 1D3 is slighly compromised with a big aperture lens working at high f/numbers but I don't know if it's true. I would have thought the mirror would always be the slowest component but I dunno - would be interesting to check.
 
There was another thread on here about this recently and someone posted a link to Bob Atkins site and he showed a few examples of pictures taken with IS on and IS off and there was a big difference. He cropped the photo's too and it showed up even more. His conclusion was that it worked very well.
 
The newest generation of IS lenses will give you an extra 3 or 4 stops. This means that you'll be able to handhold your camera with a shutter speed 3 or 4 stops longer than you'd normally be comfortable handholding your camera with non-IS lens at. If you can handhold your non-IS lens and get sharp photos at 1/250s, with an IS lens you will be able to handhold and get a sharp image at 1/30s or less.

Of course it only works if your subject is stationary. It won't help at all with moving subjects.

George.
 
Canon 100-400 lens + Kenko 1.4X converter, handheld at 560mm (728mm equivalent) at 1/80. EXIF is intact....

20090808_105220_0149_LR.jpg


100% crop....
20090808_105220_0149_LR.jpg


A shot without IS might require a shutter speed of 1/800 (nearest available speed to 1/728) or faster.
1 stop IS might allow shooting at 1/400.
2 stop IS might allow shooting at 1/200.
3 stop IS might allow shooting at 1/100.
I shot this at 1/80, which is 3.3 stops below the recommended/guideline minimum shutter speed. The cracks show at 100% viewing but a normal sized print would look fine. Actually, I think the "cracks" are due to heat and wobbly air, since lots of the image is sharp and just some areas are wobbly/blurry. I'm sure the engine heat, exhaust and downdraught are stirring things up.

Here's a moving target at 450mm (585mm equivalent) handheld at 1/160. That's 2 stops slower than the recommended minimum....

20090808_112322_0272_LR.jpg


100% crop - sharpening at Lightroom defaults....
20090808_112322_0272_LR.jpg


IS works.
 
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