focusing with EX1

Jason Bodnar · July 15th, 2008, 12:46 PM

Steven, yes we are on the same page.

Tom Roper · July 15th, 2008, 01:49 PM

Quote:

Originally Posted by Steven Thomas

I'm not sure about starting wide than checking focus on the tele end.
It's to subjective too where you leave focus at the wide end. A hardly noticeable difference of focus on the wide end yields a large change on the tele end.

I agree Steven but the "hardly noticeable difference" is exactly what the backfocus issue is about. If you can't see it, you can't judge it. But if you can judge it, you should be able to accurately set it at the wide end using the peaking or expanded focus. If the backfocus is correct then it should remain in focus when you zoom to the target.

The point is that some people could be saying they have the backfocus set properly when they are unable to judge focus at the wide end independently.

If perfect focus can be established at the wide end using an external monitor for example, it should remain focused when you zoom to the target. If it doesn't , there either isn't good backfocus or you haven't established what perfect focus is at the wide end.

I don't think it should be argued that perfect wide angle focus can't be achieved if we are going to accept the backflange calibration, since it uses the exact same contrasts as the peaking that you would use to judge focus with.

Steven Thomas · July 15th, 2008, 02:30 PM

Tom,
I have to disagree. The DOF of the wide end of the lens is huge. Peaking on or not, it would be impossible to nail a focus target on the wide end and have that target in perfect focus when zoomed in on it. How do you judge this when everything's in focus on the wide end..

I can't do this on any camera. I can't imagine why the EX1 would be any better.

Tom Roper · July 15th, 2008, 04:33 PM

Quote:

Originally Posted by Steven Thomas

How do you judge this when everything's in focus on the wide end.. .

Open the iris to f1.9, use the expanded focus, turn detail on. If on some level it was not possible to nail focus at wide angle, the backflange calibration adjustment could not work, which actually is how I feel about it, that getting the correct data stored into the lookup table by that procedure is hit or miss. But if you are successful getting the right data into that table, it should be repeatable so I will try it some more as you did, and hopefully it will stumble onto it. But as it stands, I can focus more precisely now at the actual wide angle I am shooting, but it would of course be hugely convenient to be able to rack the focus.

Tom Roper · July 15th, 2008, 06:36 PM

The backflange calibration worked perfectly, exactly as it should now on a rack focus.

Thanks guys. You don't get to be a doubting Tom without having some doubts.

Actually, I just pointed the cam at a white textured wall about 6.5 feet away. I could see it snapping into focus, finished in seconds.

Tested it outside, seems perfect. Thanks for the confidence.

George Kroonder · July 16th, 2008, 03:15 AM

Good to hear it solved your issues Tom.

George/

Paul Curtis · July 16th, 2008, 03:30 AM

A bit late to the thread but isn't this a known issue with the cameras internal ND filters? The back focus wanders off if you have them on, where as no ND works fine. So you can zoom in focus then zoom out without NDs.

There was some discussion previously about whether the internal back focus adjustment would fix this or whether new firmware was required.

I'd be interested to know if the internal adjustments work to cure this as i don't have the time to send the cam off for focus adjustments.

Also does anyone find the fully manual option more restrictive than the auto/manual - you can focus closer on auto manual then you can on fully manual.

cheers
paul

George Kroonder · July 16th, 2008, 04:02 AM

Paul,

You are correct there was a problem with the (fixed) correction for the ND filters in the EX1 that was fixed somewhere between FW 1.03 and 1.05.

I've heard that some dealers/resellers can do the FW upgrade for you (on appointment I'd say). I'm hoping, fingers crossed, a new FW release will be user installable and move the FB Adj. out of the service menu. However, I have no indication that that will actually happen.

George/

Tom Roper · July 16th, 2008, 11:35 AM

My cam was not a particularly high serial number but was delivered with 1.05.

I sort of expected if it had a backfocus issue, Sony would have calibrated it before delivery.

I only did the flangeback calibration with ND off. The backfocus seems perfect now with ND off or ND2, although I have not tried ND1.

Perhaps the ND issue was fixed in 1.05, or perhaps it never was. I don't know. What I do know, and this may be appalling and shocking, but I did the calibration on nothing more that a white textured wall from 6.5 ft...handheld. That's right. It didn't seem to care.

Not saying you should try that, but it seemed rather forgiving. It's possible the star charts aren't necessary, but with the textured plaster wall, nothing else was in the field of view.

So suddenly I've gone from being the doubting tom to the apostle tom. Sorry...but hallelujah it's nice being able to rack the focus.

George Kroonder · July 16th, 2008, 11:43 AM

You da man Tom!

Handheld backfocus adjustments without any sort of specific target, thats edgy stuff ;-]

George/

P.S. I feel like a wuss now for following the Siemens Star gospel.

Perrone Ford · July 16th, 2008, 11:51 AM

How do we find out what version of the firmware we have?

George Kroonder · July 16th, 2008, 11:57 AM

It is listed in the service menu.

George/

Steven Thomas · July 16th, 2008, 12:15 PM

Yes it is.

Francois Dormoy · July 19th, 2008, 09:15 PM

I just got my PMW-EX1 yesterday and one of the problems I found is that it takes several seconds to focus on the subject, unlike my previous camera (Sony VX2000).
Is that because of an incorrect setting ? Or it it fact of like with the EX1?

Jason Bodnar · July 19th, 2008, 10:08 PM

Francois, you must be talking when using AutoFocus becuase in Manual it is as fast as you can be... Love the EX1 manual mode... I have a VX2000 as well and the autofocus is very quick on it which makes it worse when you compare it to the EX1 autofocus becuase as you have noticed it is not as fast...

July 15th, 2008, 06:36 PM	#20
Tom Roper Trustee Join Date: Jun 2004 Location: Denver, Colorado Posts: 1,891	I Concede The backflange calibration worked perfectly, exactly as it should now on a rack focus. Thanks guys. You don't get to be a doubting Tom without having some doubts. Actually, I just pointed the cam at a white textured wall about 6.5 feet away. I could see it snapping into focus, finished in seconds. Tested it outside, seems perfect. Thanks for the confidence.

July 15th, 2008, 12:46 PM	#16
Jason Bodnar Major Player Join Date: Nov 2007 Location: Seattle WA Posts: 376	Steven, yes we are on the same page.

July 15th, 2008, 02:30 PM	#18
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Tom, I have to disagree. The DOF of the wide end of the lens is huge. Peaking on or not, it would be impossible to nail a focus target on the wide end and have that target in perfect focus when zoomed in on it. How do you judge this when everything's in focus on the wide end.. I can't do this on any camera. I can't imagine why the EX1 would be any better.

July 16th, 2008, 03:15 AM	#21
George Kroonder Major Player Join Date: Jan 2008 Location: Utrecht, NL \| Europe 3rd Rock from the Sun Posts: 612	Good to hear it solved your issues Tom. George/

July 16th, 2008, 03:30 AM	#22
Paul Curtis Major Player Join Date: Mar 2005 Location: canterbury Posts: 411	A bit late to the thread but isn't this a known issue with the cameras internal ND filters? The back focus wanders off if you have them on, where as no ND works fine. So you can zoom in focus then zoom out without NDs. There was some discussion previously about whether the internal back focus adjustment would fix this or whether new firmware was required. I'd be interested to know if the internal adjustments work to cure this as i don't have the time to send the cam off for focus adjustments. Also does anyone find the fully manual option more restrictive than the auto/manual - you can focus closer on auto manual then you can on fully manual. cheers paul

July 16th, 2008, 04:02 AM	#23
George Kroonder Major Player Join Date: Jan 2008 Location: Utrecht, NL \| Europe 3rd Rock from the Sun Posts: 612	Paul, You are correct there was a problem with the (fixed) correction for the ND filters in the EX1 that was fixed somewhere between FW 1.03 and 1.05. I've heard that some dealers/resellers can do the FW upgrade for you (on appointment I'd say). I'm hoping, fingers crossed, a new FW release will be user installable and move the FB Adj. out of the service menu. However, I have no indication that that will actually happen. George/

July 16th, 2008, 11:35 AM	#24
Tom Roper Trustee Join Date: Jun 2004 Location: Denver, Colorado Posts: 1,891	My cam was not a particularly high serial number but was delivered with 1.05. I sort of expected if it had a backfocus issue, Sony would have calibrated it before delivery. I only did the flangeback calibration with ND off. The backfocus seems perfect now with ND off or ND2, although I have not tried ND1. Perhaps the ND issue was fixed in 1.05, or perhaps it never was. I don't know. What I do know, and this may be appalling and shocking, but I did the calibration on nothing more that a white textured wall from 6.5 ft...handheld. That's right. It didn't seem to care. Not saying you should try that, but it seemed rather forgiving. It's possible the star charts aren't necessary, but with the textured plaster wall, nothing else was in the field of view. So suddenly I've gone from being the doubting tom to the apostle tom. Sorry...but hallelujah it's nice being able to rack the focus.

July 16th, 2008, 11:43 AM	#25
George Kroonder Major Player Join Date: Jan 2008 Location: Utrecht, NL \| Europe 3rd Rock from the Sun Posts: 612	You da man Tom! Handheld backfocus adjustments without any sort of specific target, thats edgy stuff ;-] George/ P.S. I feel like a wuss now for following the Siemens Star gospel.

July 16th, 2008, 11:51 AM	#26
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	How do we find out what version of the firmware we have?

July 16th, 2008, 11:57 AM	#27
George Kroonder Major Player Join Date: Jan 2008 Location: Utrecht, NL \| Europe 3rd Rock from the Sun Posts: 612	It is listed in the service menu. George/

July 16th, 2008, 12:15 PM	#28
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Yes it is.

July 19th, 2008, 09:15 PM	#29
Francois Dormoy Regular Crew Join Date: May 2008 Location: Montreal, Canada Posts: 81	I just got my PMW-EX1 yesterday and one of the problems I found is that it takes several seconds to focus on the subject, unlike my previous camera (Sony VX2000). Is that because of an incorrect setting ? Or it it fact of like with the EX1?

July 19th, 2008, 10:08 PM	#30
Jason Bodnar Major Player Join Date: Nov 2007 Location: Seattle WA Posts: 376	Francois, you must be talking when using AutoFocus becuase in Manual it is as fast as you can be... Love the EX1 manual mode... I have a VX2000 as well and the autofocus is very quick on it which makes it worse when you compare it to the EX1 autofocus becuase as you have noticed it is not as fast...