Author Topic: 5D mk2 Rack Focus Help  (Read 2836 times)

mapompei

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5D mk2 Rack Focus Help
« on: September 16, 2012, 07:06:25 PM »
5D mk2 and 24-70 mm. f 2.8 L:
I fixed end and start points and I get the correct footage: all is ok but I have some questions:
1) How can i control the focus movement SPEED?
2) How can I AVOID the recording TO STOP soon after the end point is reached?
3) With the 24-70 lens i get a "soft limit reached" when I try to set a far away start point (after the "here" end point):
with this lens, can I work in the full range from macro position to infinite or not?

ScarySquirrel

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Re: 5D mk2 Rack Focus Help
« Reply #1 on: November 09, 2012, 10:29:27 AM »
Hi mapompei,

Did you ever find an answer to these questions as I have exactly the same questions, same camera and lens as well.

Thanks

a1ex

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Re: 5D mk2 Rack Focus Help
« Reply #2 on: November 09, 2012, 12:28:35 PM »
1) adjust step size and step delay
2) first start recording, then start rack focus (not viceversa)
3) probably the lens has poor mechanical condition.

oterpoter

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Re: 5D mk2 Rack Focus Help
« Reply #3 on: November 26, 2012, 04:46:53 PM »
I have the same lens, same issues.
Probably NOT a lens issue.. Pretty expensive piece of glass....
My lousy tamron macro lens works...

Francis

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Re: 5D mk2 Rack Focus Help
« Reply #4 on: November 26, 2012, 07:33:04 PM »
I have the same lens, same issues.
Probably NOT a lens issue.. Pretty expensive piece of glass....
My lousy tamron macro lens works...

Expensive glass does not necessarily mean an AF drive system that takes commands for small precise steps very well.

Depends on the travel of the focus ring as well it seems as well as the lens design. The same speedy AF motor that gets moves that big heavy element from one focal distance to another extreme very quickly is probably not as efficient at moving that big heavy element a very small amount. And if that Canon 24-70 2.8 is anything like my Sigma 24-70 2.8, there is some big heavy glass in there.