PMW-EX1 Auto Focus Slow? at DVinfo.net

Steven Thomas · November 30th, 2007, 01:33 PM

Please check your camera's AF response time.

Even under good light with good contrast and aiming at objects with vertical line structures, my camera is reponding real slow in AF mode?

Sometimes it may take as long as 6 seconds or more to focus. Sometimes it does not. Also looking at the DOF LCD indicator, it appears to hunt around even though it's locked on the subject.

Any thoughts on this and what you all are seeing?

You would not be able to use this in a run-and-gun situation, well unless you don't mind your shots out of focus. ;)

Dave Elston · November 30th, 2007, 01:47 PM

Quote:

Originally Posted by Steven Thomas

Also looking at the DOF LCD indicator, it appears to hunt around even though it's locked on the subject.

I believe the DOF LCD indicator could well show varying values when focus is locked as it is governed/determined by the aperature and zoom position, not by the point of focus itself. That's my understanding of this feature as described in the manual. In conditions where iris or FOV(zoom) is varied the DOF will also vary.

I can't comment on AF response though, waiting until January before I make the purchase.

Craig Seeman · November 30th, 2007, 02:05 PM

Steven, I could have sworn there is a speed control for autofocus in the menus. I remember seeing that for sure for ATW (auto white balance).

Piotr Wozniacki · November 30th, 2007, 02:53 PM

ATW is sompletely different in that you actually might not want it to react to any fast or accidental light tempererate changes; autofocus shhould alwayd perform as quick as possible.

Eric Pascarelli · November 30th, 2007, 03:00 PM

I'll check my camera. It certainly seems faster than the HVX!

Craig Seeman · November 30th, 2007, 03:07 PM

Maybe turning on/off MF Assist impacts speed?

Steven Thomas · November 30th, 2007, 03:33 PM

Quote:

Originally Posted by Craig Seeman

Maybe turning on/off MF Assist impacts speed?

It defaults OFF, I can try on. You never know, although this feature is for
using AF to get you closer after you make a manual focus adjustment.

I will try turning it on.

Steven Thomas · November 30th, 2007, 07:23 PM

There's no control parameter for AF speed.

Also, even when mine finds focus it continues to hunt.
Once it finds focus, it modulates just slightly in and out.
It happens from wide through various ranges through the zoom travel.

Yes, there's decent light and objects that can grab focus. I even tried it outside in the daylight.
As suggested by Craig, I've tried to see if the MF assist impacts it.
No difference.

You can even display the focus distance/DOF display item and watch
it slightly move around from left to right on the focus distance line.

Very strange.

Has everyone got a chance to determine if their camera has this problem, or am I just "bad luck to a hunting dog?" LOL

Actually, this is no laughing matter....
Also, again the AF is running real slow. Usually takes 3 to 6 seconds, or not at all.

Craig Seeman · November 30th, 2007, 07:35 PM

I tested AF at my dealer yesterday. Had about 3 hours hands on with the camera. While it wasn't as fast as my PD170, it seemed ok. It did seem a bit slower when I was zoomed in and moved it to a neighboring object vs wide though.

Steven Thomas · November 30th, 2007, 07:38 PM

Thanks Craig.
When you say a bit, are we talking 3 to 6 seconds?

Also, I was real surprised how slow it was even at wide where DOF is huge.

Craig Seeman · November 30th, 2007, 07:44 PM

3 seconds seems right when I was zoomed in and moving from one object to a an next to it but further away. It didn't concern me because in those situations I'd using Push Auto when doing "run and gun" and that worked fast (it seemed to me). When I was wide I didn't notice the issue.

The only time I resort to auto is when I'm tracking an object with changing focus so Push Auto would be awkward. That's a bit different than changing the "point of interest" from one object to another.

Actually a good test would have been someone walking towards me/the camera but I didn't try that.

To test auto having two people standing at different focal points might have worked (moving from near face to far face for example).

Steven Thomas · November 30th, 2007, 07:57 PM

Hmmm.
Maybe mine's the same.
Does yours hunt.

You will probably need a monitor hooked up to see it.

Also, if you turn on the focus/dof display item (Lens Info), you can actually see the focus point wandering around on the line.

You can turn this on by first setting your camera to manual AF operation, then push the USER 1 button. By hitting that but again it changes from meters to feet. This is aasuming you have not reconfigured the switch fro the "Len Info" setting. Now switch back to AF mode and check it.

Kevin Shaw · December 1st, 2007, 01:55 AM

I got my first hands-on look at the EX1 tonight, and both myself and a friend felt the AF response was unsatisfactory. Bummer. :-(

Steven Thomas · December 1st, 2007, 09:23 AM

Once it locked focus, did you look to see it there was still a small amount of "hunting"?

Mine finds focus, then slightly moves back and forth trying to readjust.
This happens even under good light and objects with good contrast.

You have to look for it using a decent monitor, but you can visually see it "breathing" in and out of focus.

Craig Seeman · December 1st, 2007, 12:13 PM

That's why I mention the MF assist. It will try to "walk the focus in" and I can imagine in many circumstances that's not a good thing. Whenever you see it hunting, see if changing MF Assist impacts it.

Quote:

Originally Posted by Steven Thomas

Once it locked focus, did you look to see it there was still a small amount of "hunting"?

Mine finds focus, then slightly moves back and forth trying to readjust.
This happens even under good light and objects with good contrast.

You have to look for it using a decent monitor, but you can visually see it "breathing" in and out of focus.

November 30th, 2007, 01:33 PM	#1
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	PMW-EX1 Auto Focus Slow? Please check your camera's AF response time. Even under good light with good contrast and aiming at objects with vertical line structures, my camera is reponding real slow in AF mode? Sometimes it may take as long as 6 seconds or more to focus. Sometimes it does not. Also looking at the DOF LCD indicator, it appears to hunt around even though it's locked on the subject. Any thoughts on this and what you all are seeing? You would not be able to use this in a run-and-gun situation, well unless you don't mind your shots out of focus. ;)

November 30th, 2007, 02:53 PM	#4
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	ATW is sompletely different in that you actually might not want it to react to any fast or accidental light tempererate changes; autofocus shhould alwayd perform as quick as possible. __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

November 30th, 2007, 02:05 PM	#3
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	Steven, I could have sworn there is a speed control for autofocus in the menus. I remember seeing that for sure for ATW (auto white balance).

November 30th, 2007, 03:00 PM	#5
Eric Pascarelli Major Player Join Date: Nov 2007 Location: Los Angeles, CA Posts: 498	I'll check my camera. It certainly seems faster than the HVX!

November 30th, 2007, 03:07 PM	#6
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	Maybe turning on/off MF Assist impacts speed?

November 30th, 2007, 07:23 PM	#8
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	There's no control parameter for AF speed. Also, even when mine finds focus it continues to hunt. Once it finds focus, it modulates just slightly in and out. It happens from wide through various ranges through the zoom travel. Yes, there's decent light and objects that can grab focus. I even tried it outside in the daylight. As suggested by Craig, I've tried to see if the MF assist impacts it. No difference. You can even display the focus distance/DOF display item and watch it slightly move around from left to right on the focus distance line. Very strange. Has everyone got a chance to determine if their camera has this problem, or am I just "bad luck to a hunting dog?" LOL Actually, this is no laughing matter.... Also, again the AF is running real slow. Usually takes 3 to 6 seconds, or not at all.

November 30th, 2007, 07:35 PM	#9
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	I tested AF at my dealer yesterday. Had about 3 hours hands on with the camera. While it wasn't as fast as my PD170, it seemed ok. It did seem a bit slower when I was zoomed in and moved it to a neighboring object vs wide though.

November 30th, 2007, 07:38 PM	#10
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Thanks Craig. When you say a bit, are we talking 3 to 6 seconds? Also, I was real surprised how slow it was even at wide where DOF is huge.

November 30th, 2007, 07:44 PM	#11
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	3 seconds seems right when I was zoomed in and moving from one object to a an next to it but further away. It didn't concern me because in those situations I'd using Push Auto when doing "run and gun" and that worked fast (it seemed to me). When I was wide I didn't notice the issue. The only time I resort to auto is when I'm tracking an object with changing focus so Push Auto would be awkward. That's a bit different than changing the "point of interest" from one object to another. Actually a good test would have been someone walking towards me/the camera but I didn't try that. To test auto having two people standing at different focal points might have worked (moving from near face to far face for example).

November 30th, 2007, 07:57 PM	#12
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Hmmm. Maybe mine's the same. Does yours hunt. You will probably need a monitor hooked up to see it. Also, if you turn on the focus/dof display item (Lens Info), you can actually see the focus point wandering around on the line. You can turn this on by first setting your camera to manual AF operation, then push the USER 1 button. By hitting that but again it changes from meters to feet. This is aasuming you have not reconfigured the switch fro the "Len Info" setting. Now switch back to AF mode and check it.

December 1st, 2007, 01:55 AM	#13
Kevin Shaw Inner Circle Join Date: Sep 2004 Location: Sacramento, CA Posts: 2,488	I got my first hands-on look at the EX1 tonight, and both myself and a friend felt the AF response was unsatisfactory. Bummer. :-(

December 1st, 2007, 09:23 AM	#14
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Once it locked focus, did you look to see it there was still a small amount of "hunting"? Mine finds focus, then slightly moves back and forth trying to readjust. This happens even under good light and objects with good contrast. You have to look for it using a decent monitor, but you can visually see it "breathing" in and out of focus.