Problems with auto focus during zoom at DVinfo.net

Rita Hanson · November 17th, 2005, 10:02 AM

Hello,

I use my GL2 for sports coverage (primarily horses.) Since my target is moving I use the auto focus. I am having alot of problems with losing the focus while I am zooming (as subject is moving further away). I've noticed the problem since I got the camera in July, but it seems to be getting worse. I have to zoom is very slowly to not lose the focus. I have an Optura 30 as well and I have never had it lose the focus. Is this operator error or a camera problem?

Thank you for any insight you can give!

Rita

Robin Davies-Rollinson · November 17th, 2005, 10:53 AM

Rita,
The GL2 can't zoom and focus at the same time unfortunately - the lens just isn't designed that way. Even if you used manual focus, you can't control both the functions at the same time.

Robin

Rita Hanson · November 17th, 2005, 11:44 AM

Wow, really?!? That's bad news for me since I need to zoom in and out constantly and stay in focus at the same time. If this is true, then I am somewhat out of focus even when I am zooming slowly?

This seems unbeleivable to me -- it's a video camera! It's hard to imagine a situation where you would not need the camera to stay focused while you are zooming. Is this normal for most video cameras in this range?

Rita

Dale Guthormsen · November 17th, 2005, 10:23 PM

Rita,

I would zoom out to the distance where focus is needed at the furthest, then focus. Usually yhis is past the point where everything is in focus from that distance out. then bring them zoom back in as far as you can and still be in focus. This method gives me a broader range of focus which is better when you are not close to the subject. I film fast moving wildlife and have had some great footage. Shoot lots, edit lots, focus continually if needed.

gus

Rita Hanson · November 23rd, 2005, 08:17 PM

Thanks for the help -- would it help if I set the zoom speed to low or medium? I've been using it on variable.

Rita

Don Palomaki · November 24th, 2005, 06:05 AM

Try slow zoom speed, see if it works for you.
Try aperture priority shooting mode and stop down for greater depth of field. Add gain if that can be tollerated to allow smaller aperture.

The camcordrers focus ability depends in large part on the image content. Good contrast (like from vertical edges) is needed in the focus sensing zone. Zooming and camera moves can cause loss of these focus queues and inhibit accurate or fast focusing.

Chris Hurd · November 24th, 2005, 12:10 PM

All camcorders of this type from various manufacturers use one lens motor which has its duties constantly split between zoom and focus movements. No camera in this class can do both things at once, unfortunately.

Rita Hanson · November 25th, 2005, 01:52 PM

Thanks for the info. Don, I will try your suggestions. Chris, why have I not noticed this with my Optura?

Rita

November 17th, 2005, 10:02 AM	#1
Rita Hanson New Boot Join Date: Jul 2005 Posts: 6	Problems with auto focus during zoom Hello, I use my GL2 for sports coverage (primarily horses.) Since my target is moving I use the auto focus. I am having alot of problems with losing the focus while I am zooming (as subject is moving further away). I've noticed the problem since I got the camera in July, but it seems to be getting worse. I have to zoom is very slowly to not lose the focus. I have an Optura 30 as well and I have never had it lose the focus. Is this operator error or a camera problem? Thank you for any insight you can give! Rita

November 17th, 2005, 10:23 PM	#4
Dale Guthormsen Inner Circle Join Date: Jun 2005 Location: Saskatchewan Posts: 3,048	Zoom focus Rita, I would zoom out to the distance where focus is needed at the furthest, then focus. Usually yhis is past the point where everything is in focus from that distance out. then bring them zoom back in as far as you can and still be in focus. This method gives me a broader range of focus which is better when you are not close to the subject. I film fast moving wildlife and have had some great footage. Shoot lots, edit lots, focus continually if needed. gus

November 24th, 2005, 06:05 AM	#6
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,487	Try slow zoom speed, see if it works for you. Try aperture priority shooting mode and stop down for greater depth of field. Add gain if that can be tollerated to allow smaller aperture. The camcordrers focus ability depends in large part on the image content. Good contrast (like from vertical edges) is needed in the focus sensing zone. Zooming and camera moves can cause loss of these focus queues and inhibit accurate or fast focusing. __________________ dpalomaki@dspalomaki.com

November 24th, 2005, 12:10 PM	#7
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	All camcorders of this type from various manufacturers use one lens motor which has its duties constantly split between zoom and focus movements. No camera in this class can do both things at once, unfortunately. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

November 17th, 2005, 10:53 AM	#2
Robin Davies-Rollinson Trustee Join Date: Dec 2002 Location: Gwaelod-y-garth, Cardiff, CYMRU/WALES Posts: 1,215	Rita, The GL2 can't zoom and focus at the same time unfortunately - the lens just isn't designed that way. Even if you used manual focus, you can't control both the functions at the same time. Robin

November 17th, 2005, 11:44 AM	#3
Rita Hanson New Boot Join Date: Jul 2005 Posts: 6	Wow, really?!? That's bad news for me since I need to zoom in and out constantly and stay in focus at the same time. If this is true, then I am somewhat out of focus even when I am zooming slowly? This seems unbeleivable to me -- it's a video camera! It's hard to imagine a situation where you would not need the camera to stay focused while you are zooming. Is this normal for most video cameras in this range? Rita

November 23rd, 2005, 08:17 PM	#5
Rita Hanson New Boot Join Date: Jul 2005 Posts: 6	Thanks for the help -- would it help if I set the zoom speed to low or medium? I've been using it on variable. Rita

November 25th, 2005, 01:52 PM	#8
Rita Hanson New Boot Join Date: Jul 2005 Posts: 6	Thanks for the info. Don, I will try your suggestions. Chris, why have I not noticed this with my Optura? Rita