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-   -   Multiple preset zoom and focus (https://www.dvinfo.net/forum/canon-xh-series-hdv-camcorders/101019-multiple-preset-zoom-focus.html)

Mats Frendahl August 10th, 2007 05:28 AM

Multiple preset zoom and focus
 
Via Lanc there exist a range of remote controls to control zoom and focus, like the VariZoom series.

Have anyone seen similar controls where, e.g., one could preset 16 focuses and 16 zoom levels? It must be a "simpel" task for any E-engineer with knowledge in the Lanc Protocol to make such a unit.

Would be great to have.

Richard Hunter August 14th, 2007 03:27 AM

Hi Mats. Do you know which varizoom model can control focus on an XH-A1?

Richard

Mats Frendahl August 14th, 2007 05:27 AM

Hi Richard,

I'm thinking of buying the

http://www.varizoom.com/products/controls/vzpgl.html

or

http://www.varizoom.com/products/controls/vzprol.html

They both seem good. I don't know what differs them in technology, other than one is "pistol grip". Some 30 USD more also.

What I can see from their page all their models have a Focus control.

I think I'm leaning towards the "VZ Pro-L", the focus buttons are under the casing on that one, above on the other. Could be better to have away from the zoom lever so no "focus accidents" can happen...

That one along a 100ft cable will have it remotely controlled (not pan and tilt). Neat.

Their "VZ CS1LK Dual System" is cool, but the price...

Richard Hunter August 14th, 2007 07:59 AM

Thanks Mats for the info. I'm not really keen on adjusting focus with buttons. I always seem to overshoot and then have to hunt back and forth. What I'd like to see is a controller with a rotary focus knob but so far I haven't come across one for the A1.

Richard

Mats Frendahl August 14th, 2007 08:30 AM

Richard, aha, you mean a remote focus wheel? Nope, haven't seen any, it would be great though. I've seen such on old film cameras where a designated "focus man" took care of the focus while the "camera man" took care of the framing. It was a big mechanical thing where they wrote markers and stuff on the dials to quickly go to correct focus. This was 20 years ago. Today they are prob. digital and with very high price. Strange there is no 3rd party comp. doing more Lanc controllers.

Richard Hunter August 15th, 2007 04:30 AM

Yes, something like that. The A1 focus ring action is very strange, because the angle of travel required to shift focus varies greatly with the zoom setting. At the tele end the focus control is quite fine, but at the wider end you go from zero to infinity just by thinking about touching the ring. It would be great to have a LANC controller focus wheel that had a scale showing metres and worked repeatably. I expect there's a technical reason with the A1 lens design why you can't seem to get one of these, cos I doubt if the electronics required would cost that much.

Richard

Rene Roslev August 15th, 2007 05:23 AM

Quote:

Originally Posted by Richard Hunter (Post 729219)
The A1 focus ring action is very strange, because the angle of travel required to shift focus varies greatly with the zoom setting.

Don't think there is anything strange about that as depth of field depends on focal length. Wide-angle coupled with a small image sensor means minimal shift from close to infinity - you get as much control as you need.

Richard Hunter August 15th, 2007 07:10 AM

Hi Rene. I'm not talking about depth of field, just the focus distance setting. It's possible I don't understand the relationship between focal length and the angle of rotation required to change the focus distance - actually it's not just possible, it's a fact - but I don't see why the lens focus behaviour needs to be this way, seems to be just how the servo designer decided to do it.

As for getting as much control as I need, I wish it were so! I would really love to have a calibrated dial with distance markings that was repeatable and dependable at any zoom setting.

Richard

Glenn French August 15th, 2007 08:41 AM

I also think the focus wheel is far too sensitive ( I've told Canon this ). It is better at zoom, naturally - but ten or 20 times more movement would be far more useful at both ends.

Mats Frendahl August 15th, 2007 04:20 PM

Quote:

Originally Posted by Glenn French (Post 729309)
I also think the focus wheel is far too sensitive ( I've told Canon this ). It is better at zoom, naturally - but ten or 20 times more movement would be far more useful at both ends.

Yes, the ratio with which the ring works is kind of odd, but perhaps one learns... in time for "XH A2" where Canon changes it again... ;)

Perhaps the Lanc protocol is a uni-directional protocol that only can receive commands and not transmit values such as focus, zoom etc. It would be nice if it were a real bi-directional protocol, then an E-engineer could easily make all kinds of gadgets for us. Is this the reason why the available Lanc products are fairly limited in control? The Console works over FW and I guess have much better protocol support.

I'm going to order the VariZoom Pro control - that will be interesting to work with as I need to control the A1 from a distance.

Bill Pryor August 15th, 2007 05:05 PM

You can go into the menu and change the focus speed of the ring. But, as you say, it's still way too fast at wide angles.

Richard Hunter August 16th, 2007 09:06 AM

Quote:

Originally Posted by Mats Frendahl (Post 729574)
Yes, the ratio with which the ring works is kind of odd, but perhaps one learns... in time for "XH A2" where Canon changes it again... ;)

Perhaps the Lanc protocol is a uni-directional protocol that only can receive commands and not transmit values such as focus, zoom etc. It would be nice if it were a real bi-directional protocol, then an E-engineer could easily make all kinds of gadgets for us. Is this the reason why the available Lanc products are fairly limited in control? The Console works over FW and I guess have much better protocol support.

I'm going to order the VariZoom Pro control - that will be interesting to work with as I need to control the A1 from a distance.

Or maybe a firmware update for the A1? (Not that I am optimistic about that possibility).

Do let us know how you get on with the Varizoom. It is good to get feedback from a user with the same camera.

Richard

Mats Frendahl August 16th, 2007 02:58 PM

Quote:

Originally Posted by Richard Hunter (Post 729868)
Or maybe a firmware update for the A1? (Not that I am optimistic about that possibility).

Do let us know how you get on with the Varizoom. It is good to get feedback from a user with the same camera.

Richard

Richard, sure will. I'm ordering it this or next week.

OT: it says "You may not post attachments" - how do one add images to posts?

Richard Hunter August 17th, 2007 04:15 AM

Quote:

Originally Posted by Mats Frendahl (Post 730053)
Richard, sure will. I'm ordering it this or next week.

OT: it says "You may not post attachments" - how do one add images to posts?

You just need to remain an active forum member a while longer, and then MAY NOT will change to MAY. (Don't know the exact time this takes though.)

Richard


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