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-   -   Follow focus for the Sony Z1 (https://www.dvinfo.net/forum/sony-hvr-z1-hdr-fx1/86924-follow-focus-sony-z1.html)

Carlos E. Martinez February 19th, 2007 01:47 PM

Follow focus for the Sony Z1
 
Any chance to get or build a follow focus system for the Sony Z1?

I haven't seen any for the Z1 or FX1.

Scott Vystrcil February 20th, 2007 10:56 AM

Check out our sponsors
 
16x9 (one of our sponsors) has a follow focus kit (as well as mattebox kits) for the Z1U.

http://www.16x9inc.com/cgibin/eDatCa...&link=mainpage

Chris Barcellos February 20th, 2007 11:00 AM

Also, check out Redrocks follow focus:

http://www.redrockmicro.com/mff_product.htm

They are showing it on a Z1 without the 35mm adapter.

Carlos E. Martinez February 20th, 2007 04:13 PM

Quote:

Originally Posted by Chris Barcellos
Also, check out Redrocks follow focus:

http://www.redrockmicro.com/mff_product.htm

They are showing it on a Z1 without the 35mm adapter.

Yes, that's very interesting. Much more affordable than 16 x 9's.

Though you will need the base and rods, so the whole package should be close to $1,000.

John Hewat February 21st, 2007 05:24 PM

How do these things work on the Z1? The Z1's focus ring doesn't have a constant relationship between its rotation and the servos. If that makes any sense...

Once you've reached the full extent in one direction, you can continue rotating the wheel.

So how does a follow focus work?


And a sub-question:

Are there any follow focus units that can be used on the Z1 and on the smaller V1? Or do you need two separate machines?

Douglas Spotted Eagle February 21st, 2007 05:58 PM

The RedRock Micro system works on either camcorder, because they have various ring sizes.
As far as the Z1, since it is continual, it is continual in both directions, so the follow focus behaves exactly the same as it does on a non-continuous lens.

Robin Davies-Rollinson February 22nd, 2007 05:29 AM

The problem with using a follow-focus device on any lens with a continuous focussing ring is being able to return to the same focus point time and again.
The whole point of the FF is to be able to make focus point marks on the white dial so that you can get accurate focussing to pre-determined points. If you move the ring too far either way, then all of the marks will be lost. You really need to keep within the extreme points and then the system will work and you can get accurate near and distant focus (and any other intermediate marks you may have made).
It's certainly not an exact science as with a proper manual lens...


Robin

Carlos E. Martinez February 22nd, 2007 06:14 AM

Quote:

Originally Posted by Robin Davies-Rollinson
The problem with using a follow-focus device on any lens with a continuous focussing ring is being able to return to the same focus point time and again.
The whole point of the FF is to be able to make focus point marks on the white dial so that you can get accurate focussing to pre-determined points. If you move the ring too far either way, then all of the marks will be lost. You really need to keep within the extreme points and then the system will work and you can get accurate near and distant focus (and any other intermediate marks you may have made).
It's certainly not an exact science as with a proper manual lens...

Things are what they are. It's not much use to think on how they should be.

The Z1 has a continuous focus ring: OK. How and when will that affect things?

What I just did was the following:

1) Sticked two tapes, selected a focus point and made a mark on both tapes.

2) Then picked another focus point and made another mark on the static tape.

3) This focus adjustment was repeatable.

4) Then switched the camera off and on again. Those two points did not change. The mark on the rotating ring could repeat the focus points above.

That is the way focus adjustment is done on all lenses. Except we have no stopping ends at close and infinity, as other lenses have.

So what is the problem then? Is there something that I am missing here?

What other test should I do to find the problem? I am not doubting there might be one: just want to know which is it.



Carlos

Chris Barcellos February 22nd, 2007 11:29 AM

Carlos:

I think if you switch the autofocus on, and turn off again, then it will be out of sync....

Boyd Ostroff February 22nd, 2007 11:57 AM

I also think that if you inadvertently turn the focus ring while the camera is switched off, then your marks will be wrong.

Carlos E. Martinez February 22nd, 2007 12:19 PM

OK. I am getting to know a bit more then.

1) The servo/autofocus mechanism it's not connected to the focus rings

2) If you move the ring out of position, with the camera off, the focus will remain but the ring will be in another position.

So it is really a matter of re-thinking what Sony designed and work around it.

To start with, a FF should be mostly used with a camera assistant, as in other situations it would be a matter of adjusting things as usual. But when using a CA, what might be the routines?

For case 1: do not use autofocus AFTER you put the tapes or made your marks. If you use AF remake your markings.

For case 2: Try not to move the focus rings when the camera is off. If you do, remake your markings.

What I miss, now that I think of it, is some kind of stick to make manual FF with an AC. Sony could have put a threaded hole to use as such.

Heath McKnight March 18th, 2007 05:27 PM

FYI, we've used the Red Rock Micro and the 16x9 follow focus with the Z1, but unfortunately, it's never the same that you set it as with this camera and the FX1. For example, if we're focused on an actor talking and we want to rack focus to the one in the back, whatever we've pre-determined was the focus setting/number for the second actor, it was never the same.

That's my only real issue with the Z1/FX1.

heath

Kurth Bousman March 20th, 2007 09:41 PM

Carlos - you might find this interesting , and budget forgiving-

http://www.indifocus.com/

Chris Leong April 17th, 2007 12:46 PM

Servo focus and infinity stops
 
Hi all -

Check out the redrock site for more on this - apparently when you set your focus and mark it on a servo ring, all is indeed well and the mark is repeatable - until you rotate past the infinity mark and the ring servo resets itself.

Redrock's solution is to supply a lens gear with a hard (settable) infinity stop on it. - therefore the zoom ring will not go past infinity, the servo will not reset and therefore you will get repeatable focus (and zoom, apparently) settings.

Not having a servo ring camera handy to test this out, I can't say from personal experience if this works or not, but they are charging over $100 per ring and they're still in business and presumably not inundated with returns and emails or nasty threads on forum posts about truth in advertising...

Actually the solution seems to be rather simple and very elegant. At first sight, anyway.

Now why didn't the manufacturer just include a set screw stop to limit the focus travel?

John Hewat April 18th, 2007 04:23 AM

Quote:

Originally Posted by Heath McKnight (Post 643824)
FYI, we've used the Red Rock Micro and the 16x9 follow focus with the Z1, but unfortunately, it's never the same that you set it as with this camera and the FX1...

Quote:

Originally Posted by Chris Leong (Post 662020)
Redrock's solution is to supply a lens gear with a hard (settable) infinity stop on it. - therefore the zoom ring will not go past infinity, the servo will not reset and therefore you will get repeatable focus (and zoom, apparently) settings.

Heath, did you have one of these hard stop points on your follow focus when you used it?


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