Focus on a stedicam:auto? at DVinfo.net

Marcus Martell · January 3rd, 2010, 04:13 PM

Hi guys i met a DOP that suggested to use alway the auto settings on the focus when using the steadicam.
What are your opinions?

Charles Papert · January 3rd, 2010, 05:21 PM

If a camera has autofocus, it's going to have 1/2" chips or smaller. In this instance, you are better off setting it at the hyperfocal for a given shot and working within those parameters. The smaller the chip, the easier this is as there is greater depth of field. Autofocus might work for specific shots, but I would be wary of it searching/hunting and making things worse. Best to try a take and play it back on a good sized monitor to ensure that it is doing the right thing.

The fact of the matter is that so many people are using DSLR's and 35mm adaptors these days that the in-and-out of focus look is becoming "sexy", lord help us. So a little momentary buzz doesn't seem to have the stigma that it once had. One must be careful with autofocus that unexpected things don't derail your efforts, like walls and doorways and foreground elements. The last thing you want is to discover in the edit suite that the focus is in the wrong place and no-one knew it.

Dave Gish · January 3rd, 2010, 09:50 PM

Quote:

Originally Posted by Charles Papert

If a camera has auto focus, it's going to have 1/2" chips or smaller.

Right. When I fly these types of cameras, I:
• Never use Auto Focus.
• Frequently use Auto Iris.
• Never use Image Stabilization (OIS).

Jon Fairhurst · January 3rd, 2010, 10:17 PM

I hear rumor that there will be some nice electronic focus tools for the Canon DvSLRs before long. That's part of why I've started a home built steady rig project. If the rumors are true (I have no inside info), it could be less expensive to buy an electronic focus control than a good quality mechanical follow focus. Could be sweet!

Mark Schlicher · January 4th, 2010, 09:34 PM

I'd add that some cameras' autofocus are particularly slow...the HVX200 is notoriously laggy in the 720P modes. This can absolutely clobber your attempts to keep focus with that technique. I've seen that concept fail spectacularly on a jib. The 200 can hunt for focus for a second or more sometimes!

But even if it were snappy, you'd still have the problem of always having to keep your main subject in the center of frame, lest the autofocus find something else it wants to place in focus. Recipe for boring composition...a classic tail wagging the dog.

The advice Charles gives is the technique I generally use. I light to a fairly fat stop, and either set the lens to the hyperfocal distance, or center the focus on the range of distances in which the talent will be working during the shot (2/3 of the DOF behind the subject, 1/3 in front.)

Marcus Martell · January 22nd, 2010, 10:02 AM

Hola , in my case the camera is a Sony Z1....so what are your recomendations?

thx

January 3rd, 2010, 04:13 PM	#1
Marcus Martell Trustee Join Date: Nov 2008 Location: spain Posts: 1,202	Focus on a stedicam:auto? Hi guys i met a DOP that suggested to use alway the auto settings on the focus when using the steadicam. What are your opinions?

January 3rd, 2010, 05:21 PM	#2
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	If a camera has autofocus, it's going to have 1/2" chips or smaller. In this instance, you are better off setting it at the hyperfocal for a given shot and working within those parameters. The smaller the chip, the easier this is as there is greater depth of field. Autofocus might work for specific shots, but I would be wary of it searching/hunting and making things worse. Best to try a take and play it back on a good sized monitor to ensure that it is doing the right thing. The fact of the matter is that so many people are using DSLR's and 35mm adaptors these days that the in-and-out of focus look is becoming "sexy", lord help us. So a little momentary buzz doesn't seem to have the stigma that it once had. One must be careful with autofocus that unexpected things don't derail your efforts, like walls and doorways and foreground elements. The last thing you want is to discover in the edit suite that the focus is in the wrong place and no-one knew it. __________________ Charles Papert www.charlespapert.com

January 3rd, 2010, 10:17 PM	#4
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	I hear rumor that there will be some nice electronic focus tools for the Canon DvSLRs before long. That's part of why I've started a home built steady rig project. If the rumors are true (I have no inside info), it could be less expensive to buy an electronic focus control than a good quality mechanical follow focus. Could be sweet! __________________ Jon Fairhurst

January 4th, 2010, 09:34 PM	#5
Mark Schlicher Regular Crew Join Date: Apr 2009 Location: Nashville, TN Posts: 189	I'd add that some cameras' autofocus are particularly slow...the HVX200 is notoriously laggy in the 720P modes. This can absolutely clobber your attempts to keep focus with that technique. I've seen that concept fail spectacularly on a jib. The 200 can hunt for focus for a second or more sometimes! But even if it were snappy, you'd still have the problem of always having to keep your main subject in the center of frame, lest the autofocus find something else it wants to place in focus. Recipe for boring composition...a classic tail wagging the dog. The advice Charles gives is the technique I generally use. I light to a fairly fat stop, and either set the lens to the hyperfocal distance, or center the focus on the range of distances in which the talent will be working during the shot (2/3 of the DOF behind the subject, 1/3 in front.)

January 22nd, 2010, 10:02 AM	#6
Marcus Martell Trustee Join Date: Nov 2008 Location: spain Posts: 1,202	Hola , in my case the camera is a Sony Z1....so what are your recomendations? thx