December 19, 2014, 08:03:36 PM

Author Topic: slow focusing on canon 300 mm 2,8 IS  (Read 681 times)

validus1978

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slow focusing on canon 300 mm 2,8 IS
« on: February 04, 2014, 08:18:15 AM »
Hello, I want to ask you. I have the option to buy a used Canon 300 mm 2.8 IS made ​​in 1999. On the surface has a few minor scratches but the optics are clean scratched. Test photos looked beautiful razor sharp. But my personal impression of him was such that the lens is quite professional too slow refocusing from minimum distance to infinity. If you focus so precisely but I still have too feel that this refocusing on longer distances is slow ... It also seemed to me that somehow sharpening ring goes harder, but it can be just my wrong impression because it's my first lens canon 300 mm 2.8 IS and I do not give it out to compare

May be the USM already worn?

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slow focusing on canon 300 mm 2,8 IS
« on: February 04, 2014, 08:18:15 AM »

neuroanatomist

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Re: slow focusing on canon 300 mm 2,8 IS
« Reply #1 on: February 04, 2014, 08:47:01 AM »
Slow compared to what?  Regardless, it's definitely not going to be instantaneous to go from MFD to infinity.  Canon knows this, which is why they put a focus limiter switch on the lens.
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privatebydesign

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Re: slow focusing on canon 300 mm 2,8 IS
« Reply #2 on: February 04, 2014, 09:35:06 AM »
The 300 f2.8 IS has a pretty long focus throw for a super tele, it will be "slow" from limit to limit, but as Neuro says there is a focus limiter, and also the set distance re focus capability specifically put there to limit hunting as an issue.

I don't think the focus would slow down if it was worn, I think it would just stop working.

validus1978

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Re: slow focusing on canon 300 mm 2,8 IS
« Reply #3 on: February 04, 2014, 01:04:21 PM »
Slow compared to what?  Regardless, it's definitely not going to be instantaneous to go from MFD to infinity.  Canon knows this, which is why they put a focus limiter switch on the lens.

Iam compared with canon 400 mm 5,6 L and this lens and this lens seems to me that it has a faster response when focusing from close to infinity...and and overall seems faster somehow, I am testen on 1D Mark IV and 7D body ...

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Re: slow focusing on canon 300 mm 2,8 IS
« Reply #3 on: February 04, 2014, 01:04:21 PM »