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Old Sep 15, 2011, 9:50 AM   #31
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Quote:
Originally Posted by THAIPHUKET View Post
Why is that not doable ...
That is doable.

Quote:
Originally Posted by THAIPHUKET View Post
... across board?
That is the problem.

Let's say that Canon's IS (in a particular camera/lens combination) provides a 4 stop benefit over not using IS.

Let's say that Nikon's VR (in a particular camera/lens combination) provides a 3 stop benefit over not using VR.

It would seem that the Canon outperforms the Nikon, with regard to their ability to produce blur free photos.

Let's say that, with IS off, at a 35mm equivalent focal length of 300mm, the Canon can't reliably take blur free photos unless the shutter speed is at least 1/500 second.

Let's say that, with VR off, at the same 35mm equivalent focal length , the Nikon can reliably take blur free photos with a shutter speed as slow as 1/200 second.

That means that the Canon, with IS on, can take blur free photos with shutter speeds as slow as 1/30 second, and the Nikon, with VR on, can take blur free photos with shutter speeds as slow as 1/25 second.

Therefore, in this comparison, if you want blur free photos, the Nikon outperforms the Canon.
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Last edited by TCav; Sep 15, 2011 at 10:34 AM.
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Old Sep 15, 2011, 12:28 PM   #32
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What you're looking at is how much it's improved. That's all the manufacturers give you. That's what SLRGear.com is checking.

That doesn't matter. What matters is the end result.


For instance, using SLRGear's results, at 70mm, with image stabilization on, the majority of the photos are "Good":
  • at 1/15 second for the Canon 40D with the Canon EF 70-200mm f/2.8L IS II USM
  • at 1/8 second for the Canon 40D with the Sigma 70-200mm f/2.8 EX DG OS HSM APO
  • at 1/15 second for the Sony A55 with the Sony 70-200mm f/2.8 G
Additionally, at 200mm, with image stabilization on, the majority of the photos are "Good":
  • at 1/10 second for the Canon 40D with the Canon EF 70-200mm f/2.8L IS II USM
  • at 1/30 second for the Canon 40D with the Sigma 70-200mm f/2.8 EX DG OS HSM APO
  • at 1/125 second for the Sony A55 with the Sony 70-200mm f/2.8 G
Which is better, in the same environment, is what matters, not how much it has improved over previous versions.

The environment is what we'd need to control in a meaningful test, and it's the environment that will short circuit any attempt at standardizing this metric.
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Last edited by TCav; Sep 16, 2011 at 8:29 AM.
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Old Sep 15, 2011, 11:42 PM   #33
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TCav, I played with your signature, because this applies to you, really

A good photographer helps a photographer; he doesn't make one.

Come the the North of Thailand, you will love it.

Cheers Pico
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Old Sep 16, 2011, 8:32 AM   #34
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You are very kind.

Actually, most of this comes from my years of experience in the field of Metrology.
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Old Sep 26, 2011, 4:40 PM   #35
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Not sure about yardsticks- but I personally find lens based systems far superior to body based ones. Not only do they stabilise what you're looking at(prior to shooting) but they avoid the "wonky" horizon syndrome also...!!
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