Author Topic: Rack Focus Test: not so happy  (Read 5269 times)


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Rack Focus Test: not so happy
« on: June 16, 2012, 04:26:48 PM »
Hi everybody!
I've just upgraded my new 60d with the great Magic Lantern, everything it's fine and there are a lot of superuseful stuff!
But, yes, there's a but.
I've just been tring to get a good result with the Rack Focus feature but it has always been a little less smooth as I expected. I've seen a lot of tests on the web before tring and I'm not happy with my result, 'cause the others look way smoother then mine.
This is my test:
I've used these settings:
Focus StepSize: 1
Focus StepDelay: Wait + 80ms
With a Canon 50mm f/1.8 at f/2.2
Is it because of the delay? Should I try with a Wait+10ms?
Thanks a lot!


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Re: Rack Focus Test: not so happy
« Reply #1 on: June 16, 2012, 04:46:57 PM »
I did another test.
This time I decreased the StepDelay until 10ms (the min I think).
Well, as you can see by yourselves it's already better then the previous one:
But I'm not compltitely happy yet.
Does it depend on the lens's autufocus capabilities?
I'm using one of the most used Canon lens, so if anyone has achieved better results with this lens maybe it could be helpful!

Malcolm Debono

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Re: Rack Focus Test: not so happy
« Reply #2 on: June 16, 2012, 08:42:58 PM »
As you guessed, it does depend on the lens' autofocus capability. From what I've tried, I think USM lenses are better. The 50 1.8's results were quite choppy and not accurate. The 70-200 f/4L IS was much better.
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Re: Rack Focus Test: not so happy
« Reply #3 on: June 16, 2012, 11:14:56 PM »
Rackfocus uses the focus steps like the EOS Utility uses. And these steps are not exactly the same in both directions. Some lenses perform better than others. My 100mm 2.8 USM does ok if the distance is not very large. My Tokina 400mm does terrible and goes way beyond the end point. I think in 2.3 you can start and stop the rack focus manually with sensor remote. Like on the 550d. You put your hand near the sensor to start and away to stop. Choose the right end point by following the focus peaking.
I have to check that first.