Follow Focus for Canon XH

[Zack Birlew]

Well, I was just wondering, based on the images we've seen with the added iris ring, will current follow focus systems be able to take advantage of it?

I don't know the exact usefulness of it, I just thought that would be neat. Maybe someone could come up with a dual follow focus-like system?

[Chris Hurd]

Hi Jack, how's Vegas. It's been awhile.

So far the best follow focus solution I've seen for these particular lenses comes from my friend Karl Horn out in L.A. -- basically it's just a geared ring that fits snugly over the lens control ring. No reason why you can't have one for focus and one for iris. I hope this pic from NAB does justice to the concept. It's showing an XL1 but the same idea applies to these cams.

[Zack Birlew]

Thanks Chris, that's reassuring to know there's something out there already for this.

Vegas has been pretty darn hot lately actually, but I haven't had much time for the strip or anything, too busy with summer school at the moment. =)

[Chris Hurd]

Oops -- boy did I goof up big time.

Sorry guys, but the solution I talked about above will *not* work.

I was thinking about this and realized there's a physical limitation on the XH camcorders that will prevent the slip-on geared ring idea from working. If you look at the photos included below, it's pretty clear that the Instant AF sensor and the XLR audio input module over on the right side of the camera body are going to prevent you from slipping anything over those lens control rings. I don't know why I didn't think about this before responding to Jack's post.

If you can't see the attached images, just go to http://www.dvinfo.net/canonxh/articles/images2.php and look at the fourth photo down from the top and you'll see what I mean.

[Matthew Kent]

I suppose if you were really desperate, the instant af could be removed, and maybe left dangling?

[Cole McDonald]

I've seen a follow focus that uses a rubber wheel and no gear on the boards here somewhere, can't remember where, but I think they were developped by a board member.

These should work for this camera.

[Matthew Kent]

I forgot about that... It's called the indiFocus, click here for the site. I've heard it works fairly well except for fast racks, which can sometimes cause it to skip.

[Evan C. King]

Can't all those things just then be mounted on the opposite side?

[Chris Hurd]

Matthew, thanks for that link, I remember seeing it before and thought I had it bookmarked, but couldn't find it recently. I've been looking for that thing.

Evan, the type of FF we're talking about that won't work at all with the XH is the kind that involves slipping a geared ring over the lens focus control ring... it's not a question of which side the FF control is on... but a matter of not being able to slip the geared ring over the lens. The photos above should show what I mean.

[Tim Le]

The Instant Focus module does look like it's just screwed onto the lens with two small screws. So maybe it will be possible to remove the entire module? If it is, hopefuly the IR emitter isn't hard wired to the rest of the camera and there is some standard connector there. A connector would be awesome because then we could remove the module and disconnect the connector.

The IR sensor is also blocked if you put a matte box on the lens so being able to remove and relocate the module would be even more important if you still wanted to use Instant Focus. I wonder if the exact position of the IR sensor is important to the Instant Focus system and if moving it around will mess up the algorithms.

[Chris Hurd]

Removing it might void your warranty though. Also, just about any lens attachment (not filters, but things like teleconverters, wide angle adapters etc.) will probably block that sensor too.

[Matthew Kent]

Originally Posted by Chris Hurd

Removing it might void your warranty though. Also, just about any lens attachment (not filters, but things like teleconverters, wide angle adapters etc.) will probably block that sensor too.

No problem with the link Chris, I wouldn't be surprised if I originally got it from you on some other post somewhere. As for the instant AF, is this the only AF mechanism on this camera? It seems to be a poorly thought out device if it is, since these models are clearly intended for professionals, and Canon had to know many would be using support gear that would get in the way.

[James Collinson]

Has anyone successfully adapted or been able to use a follow focus on the A1/G1 with the focus sensor being in the way?

[Bill Pryor]

I'm finding that I can follow focus myself in most cases because of the distance readouts on the screen, something impossible with manual lenses. When an assistant is available, I can flip out the LCD screen into a position where he can read it, and he does the focus shift. The external sensor is irrelevant for that.

[Matthew Nayman]

James,

I've got an arriflex follow focus over here (rented) and am using it with Nikon lenses on my M@ adapter.. however, you cannot use a follow focus on most video cams (HVX and DVX excluded) because the lenses are electronic, not manual. The lens marlks would be inconcistent because focus distances changes if you spin the focus wheel faster or slower.


Shame