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Old November 27th, 2003, 11:19 AM   #1
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Follow Focus

just wondering, why is a follow focus so expensive?

looks like a few peices of alluminum and plastic.

and exactly how is it so much better than regular focus?

how does it even work?

thx

-arthur
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Old December 2nd, 2003, 04:21 PM   #2
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Follow Focus is probably so expensive because it isn't a high
volume product and probably needs to be made according to
strict guidelines for the gears to work properly I can imagine.

A follow focus system basically makes it easier to change the
focus with a lens. This is just primarely on 35mm lenses. Why?
Because of two things:

1) Shallow depth of field (DOF) which requires precise focussing

2) On a motion picture shoot the camera operator DOES NOT do the focus himself. That is the job of the focus puller which can either do it by turning the knobs (with an extension if needed)
or doing it by remote control.
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Old December 2nd, 2003, 04:22 PM   #3
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The term follow focus comes from the fact that if you have
a shallow DOF and a subject is moving you will need to alter
the focus so that it "follows" the subject.

Follow focus or (correct) focus pulling can only be done on a
manual lens that isn't using servo's (ie you can turn the ring
around and around forever instead of it having a fixed beginning
and ending point). Almost no DV camera has such a lens
available (optionally).
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Old December 2nd, 2003, 05:22 PM   #4
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Are you sure about that?

Surely you could make some sort of blockers on your follow focus turning knob, so that you could only turn it within the focus range of the lens, then you could probably mark off lengths two..

Kieran
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Old December 2nd, 2003, 05:24 PM   #5
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You could make stoppers indeed. But how do you know where
the lens would be? Almost all servo controlled lenses turn at a
*different* speed depending on how fast you dial the ring. This
is one of the major problems why this won't work.
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Old December 2nd, 2003, 06:48 PM   #6
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Kieran, believe Rob. The camera op on our LadyX episode, who was more used to pro cameras and film cameras and not the XM2 we were using was scratching her head, going "I just can't seem to pull focus on this thing"...I chuckled, telling her she was shit out of luck, and she kept trying. After about 5 takes, she finally believed me and gave up ;) She had even marked the barrel and everything.

On the DVX100 you can apparently pull accurate focus though.

Aaron
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Old December 3rd, 2003, 12:32 AM   #7
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focus pulling

Get the Canon 16x manual lens. You can pull beautiful focus as well as rack focus till your little heart in content. I don't even use my 16X auto focus lens anymore. Just shoot like the big kids do. Figure out your depth of field. let your actors wander. piece of cake.

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Old December 3rd, 2003, 05:18 AM   #8
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David is correct that the 16x manual lens is full manual and
can be outfitted with a follow focus system. BUT, since it is all
still basic DV you'll still have a lot of DOF so you won't barely
need to focus much anyway (unless you have the lens wide
open and zoomed in). That's why those cameras don't come
with a follow focus system orginally.

If you want a controllable DOF with Follow Focus system most
people get a Mini35 or build one themselves. Do a search on
Mini35 (expensive!) here and you'll find plenty of threads.
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Old December 3rd, 2003, 11:24 AM   #9
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You CAN pull focus on sandard XL1s lens

Hi,

OK, that's not quite true but in most lighting situations I find a couple of techniques work.

1. Switch to autofocus; start the shot just before you really need to; turn the focusing ring far enough to get the amount of blur you want then let go. Sometimes you'll get a bit of "seeking" but this can add an extra dynamic to the shot.

2. Switch to manual then use the push focus button. The effect is similar to the above but sometimes works better. Haven't worked out why yet.

That's MHO FWIW. I even manage pull zoom with variations of these techniques. I agree that a fully manual lense would be better if you were an octopus but for regular people with two arms and one brain, the standard SL1 lense works for me. Not perfect but pretty bloody good!

As always, please feel free to tell me I'm talking b***ocks.

Roger
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Old December 3rd, 2003, 01:46 PM   #10
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I've never had too many focus problems with the stock XL1s lens, not to the extent where I'd want to do rack focus using the auto focus features anyway.. Yes, a fully manual lens would be lovely but I decided to splash out on a new tripod instead this year.

I'll upload a clip of a smooth rack focus tomorrow that I shot at the weekend for a 48hr film thingy..

Kieran
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