AE Shift Compensation at DVinfo.net

John Locke · February 8th, 2002, 01:52 PM

I've heard that the AE Shift on the XL-1 needs to be set at +.05 to +.1 and basically left there. Is that true? Wondering why that would be the case.

Adrian Douglas · February 8th, 2002, 08:50 PM

I guess it would depend on the subject your shooting John. Have you heard something about the camera underexposing this much from the factory?

John Locke · February 8th, 2002, 11:24 PM

Never got the lowdown of "why", Adrian. Just heard that something in the factory settings was off and that this would compensate.

Just wondered if anyone else had heard that.

Chris Hurd · February 8th, 2002, 11:37 PM

I have heard of that. Frankly I think it's a judgement call because I've heard it both ways. More than a few pro shooters I've talked to claim the XL1 is a little hot out of the box and needs to be stopped down. Others think it's cool and needs to be opened up. Your mileage may vary... I think you should do what's right to your eye. Probably not much help,

Ken Tanaka · February 9th, 2002, 12:02 AM

I've seen the -3dB gain setting recommendation but never the AE setting. On the XL1 the -3dB looks pretty good for thick blacks under well-lit scenes but the XL1s' ability to let you adjust black might negate the need for that (haven't tried it yet). Turning down the AE setting might also look good for certain scenes. I suppose that as Chris said let your eyes be the judge with your cam. Take it for a drive; tape is cheap, eh? (And somewhat reusable, contrary to assertions in another hread <g>.)

Bob Zimmerman · February 9th, 2002, 10:10 PM

I just got my XL1s a couple of weeks ago and the AE shift came out of the box set at +.50. I was wondering about that. Did the factory set it higher? I put it back at 0

John Locke · February 9th, 2002, 10:18 PM

Ken,

Seems everyone concurs that -3 db gain is the way to go. You mention "well-lit" scenes. I found it interesting in another thread that someone says -3 db is great for low-light situations especially. I'm planning on testing that out soon.

As for the AE shift setting, I plan to do just what you recommend...I'm going to do some pretty extensive bracket testing to get to know this camera inside and out (instead of using only the few settings that I know work).

Zimvg304...that's interesting that yours came out of the box already set at +.50. I'm pretty sure mine came with all the settings at "0." Probably wouldn't put much stock in that, though. More than likely just someone at the factory left it at that setting.

What about others who've just bought their cameras?

Ken Tanaka · February 9th, 2002, 11:10 PM

I have a new XL1s that will be arriving Mon or Tues so I'll take particular note of the "factory" settings for y'all. (Don't ask how many cams I've got now...enough to start a substantial production shop. Tonight I found myself drooling over the new Sony 750 HD cam...but the tape stocks will set me back $2/min.)

I think I'll have some time to test out some of these tweaker settings (ex: -3dB gain, +0.5 AE, etc.) with both the XL1 and the XL1s. Perhaps I can grab some good stills and put them up somewhere. I don't have access to a web site...maybe Chris can find a spot on the Watchdog if others would find it worthwhile. (I can try the same adjustments with my GL1, too, for that matter.)

Chris Hurd · February 11th, 2002, 12:17 AM

Ken, there's *always* room on the Watchdog site. That's what it's for. I'm not the fastest with getting stuff online, but the space is definitely available and at your service.

Nathan Gifford · February 11th, 2002, 10:13 AM

Does using AE shift give you some advantages over gain? Is the AE acting like an offset control?

I guess, I will have to go through the manual again or go shoot some ships up on the levee here.

Nathan Gifford

Bill Ravens · February 11th, 2002, 03:13 PM

AE shift changes the setting that the camera thinks is the "right exposure". Gain will shift the amount of current the CCD amplifier relates to the amount of light it "sees". Too much gain and the CCD will generate noise that will be seen on the image. So, an AE shift will change the exposure of the image, gain will change the amplification of the image. In electronic terms, a +1 db of gain will double the output current(logarithmically) and reduce the signal to noise (s/n) by some amount). Two different parameters with very different results.

Ken Tanaka · February 11th, 2002, 09:24 PM

Zimvg304,

I just received a new XL1s today and, for the record, both the AE and gain were set to zero. So your AE setting of +0.50 was probably a mistaken remnant of Canon's quality assurance tester at the factory as zchildress conjectured earlier.

Bob Zimmerman · February 12th, 2002, 02:12 PM

Thanks Ken. Did you leave it at zero?

Ken Tanaka · February 12th, 2002, 03:07 PM

Doing some experimentation later this week with the various settings on my XL1, XL1s and GL1. I plan to have Chris put up some results on the Watchdog.

Bob Zimmerman · February 13th, 2002, 03:47 AM

I'll check that out ken. Ken I live down by Champaign, IL,,great winter weather this year in ILLinois, unless you like snow!

February 8th, 2002, 01:52 PM	#1
John Locke Retired DV Info Net Almunus Join Date: Sep 2001 Location: Austin, TX USA Posts: 2,882	AE Shift Compensation I've heard that the AE Shift on the XL-1 needs to be set at +.05 to +.1 and basically left there. Is that true? Wondering why that would be the case. __________________ John Locke SursumFilms.com

February 8th, 2002, 08:50 PM	#2
Adrian Douglas Trustee Join Date: Oct 2001 Location: Chigasaki, Japan. Posts: 1,660	I guess it would depend on the subject your shooting John. Have you heard something about the camera underexposing this much from the factory? __________________ Adrian DVInfo.net Search for quick answers Where to buy? From the best in the business...DVInfo.net sponsors

February 8th, 2002, 11:24 PM	#3
John Locke Retired DV Info Net Almunus Join Date: Sep 2001 Location: Austin, TX USA Posts: 2,882	Never got the lowdown of "why", Adrian. Just heard that something in the factory settings was off and that this would compensate. Just wondered if anyone else had heard that. __________________ John Locke SursumFilms.com

February 8th, 2002, 11:37 PM	#4
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,369 Images: 513	I have heard of that. Frankly I think it's a judgement call because I've heard it both ways. More than a few pro shooters I've talked to claim the XL1 is a little hot out of the box and needs to be stopped down. Others think it's cool and needs to be opened up. Your mileage may vary... I think you should do what's right to your eye. Probably not much help, __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

February 9th, 2002, 12:02 AM	#5
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	I've seen the -3dB gain setting recommendation but never the AE setting. On the XL1 the -3dB looks pretty good for thick blacks under well-lit scenes but the XL1s' ability to let you adjust black might negate the need for that (haven't tried it yet). Turning down the AE setting might also look good for certain scenes. I suppose that as Chris said let your eyes be the judge with your cam. Take it for a drive; tape is cheap, eh? (And somewhat reusable, contrary to assertions in another hread <g>.) __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

February 9th, 2002, 10:10 PM	#6
Bob Zimmerman Major Player Join Date: Nov 2001 Location: Illinois Posts: 888	I just got my XL1s a couple of weeks ago and the AE shift came out of the box set at +.50. I was wondering about that. Did the factory set it higher? I put it back at 0

February 9th, 2002, 10:18 PM	#7
John Locke Retired DV Info Net Almunus Join Date: Sep 2001 Location: Austin, TX USA Posts: 2,882	Ken, Seems everyone concurs that -3 db gain is the way to go. You mention "well-lit" scenes. I found it interesting in another thread that someone says -3 db is great for low-light situations especially. I'm planning on testing that out soon. As for the AE shift setting, I plan to do just what you recommend...I'm going to do some pretty extensive bracket testing to get to know this camera inside and out (instead of using only the few settings that I know work). Zimvg304...that's interesting that yours came out of the box already set at +.50. I'm pretty sure mine came with all the settings at "0." Probably wouldn't put much stock in that, though. More than likely just someone at the factory left it at that setting. What about others who've just bought their cameras? __________________ John Locke SursumFilms.com

February 9th, 2002, 11:10 PM	#8
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	I have a new XL1s that will be arriving Mon or Tues so I'll take particular note of the "factory" settings for y'all. (Don't ask how many cams I've got now...enough to start a substantial production shop. Tonight I found myself drooling over the new Sony 750 HD cam...but the tape stocks will set me back $2/min.) I think I'll have some time to test out some of these tweaker settings (ex: -3dB gain, +0.5 AE, etc.) with both the XL1 and the XL1s. Perhaps I can grab some good stills and put them up somewhere. I don't have access to a web site...maybe Chris can find a spot on the Watchdog if others would find it worthwhile. (I can try the same adjustments with my GL1, too, for that matter.) __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

February 11th, 2002, 12:17 AM	#9
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,369 Images: 513	Ken, there's always room on the Watchdog site. That's what it's for. I'm not the fastest with getting stuff online, but the space is definitely available and at your service. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

February 11th, 2002, 10:13 AM	#10
Nathan Gifford Wrangler Join Date: Sep 2001 Location: Tickfaw, LA Posts: 1,217	Is there an advantage to using AE shift over gain? Does using AE shift give you some advantages over gain? Is the AE acting like an offset control? I guess, I will have to go through the manual again or go shoot some ships up on the levee here. Nathan Gifford

February 11th, 2002, 03:13 PM	#11
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	AE shift changes the setting that the camera thinks is the "right exposure". Gain will shift the amount of current the CCD amplifier relates to the amount of light it "sees". Too much gain and the CCD will generate noise that will be seen on the image. So, an AE shift will change the exposure of the image, gain will change the amplification of the image. In electronic terms, a +1 db of gain will double the output current(logarithmically) and reduce the signal to noise (s/n) by some amount). Two different parameters with very different results. Last edited by Bill Ravens; February 11th, 2002 at 06:49 PM.

February 11th, 2002, 09:24 PM	#12
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Zimvg304, I just received a new XL1s today and, for the record, both the AE and gain were set to zero. So your AE setting of +0.50 was probably a mistaken remnant of Canon's quality assurance tester at the factory as zchildress conjectured earlier. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

February 12th, 2002, 02:12 PM	#13
Bob Zimmerman Major Player Join Date: Nov 2001 Location: Illinois Posts: 888	Thanks Ken. Did you leave it at zero?

February 12th, 2002, 03:07 PM	#14
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Doing some experimentation later this week with the various settings on my XL1, XL1s and GL1. I plan to have Chris put up some results on the Watchdog. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

February 13th, 2002, 03:47 AM	#15
Bob Zimmerman Major Player Join Date: Nov 2001 Location: Illinois Posts: 888	I'll check that out ken. Ken I live down by Champaign, IL,,great winter weather this year in ILLinois, unless you like snow!