Have searched "Clear Scan" at DVinfo.net

Jay Gladwell · December 27th, 2002, 11:29 AM

I've done a search here regarding the "Clear Scan" feature on the XL1s and not found what I'm looking for.

On the old XL1, through adjusting the monitor's refresh rate and the camera's shutter speed, I was able to completely get rid of the scan bars on computer monitors and televisions. I can't get rid of the scan bar *totally* with the XL1s.

I've tried using the "Clear Scan" feature and I've tried every possible combination of fresh rate and shutter speed, but to no avail. In the best case scenairo I still get a single faint white scan line that rolls down the screen.

Is anyone else having this problem, or I am the only one?

The problem that I see is: Monitors adjust their refresh rate in whole numbers, i.e., 60, 65, 70, 75, 80, 85, etc., but the cotton-pickin' Clear Scan uses fractions and NEVER settles on a whole number, like 75, for example. It gives me 74.9 then jumps to 75.6! This is the first and only complaint I've had with the XL1s and I'm crushed.

I don't use After Effects and I can't get any more equipment--even rentals. Must I live with the little white scan line?

Ken Tanaka · December 27th, 2002, 12:40 PM

Jay,
The reason that Clear Scan uses fractional numbers is precisely because monitor refresh rates are whole numbers. Remember what those Clear Scan "numbers" stand for: they're shutter speeds expressed in fractions of a second. Monitor refresh rates are expressed as refreshes per second. In order to eliminate the rolling bar or line when shooting a monitor the camera must be shooting at a shutter speed that's slightly out of synchronization with the monitor's refresh rate.

Keep experimenting and practicing with Clear Scan, but leave your monitor's refresh rate alone. I suspect you may be defeating your own purpose. The design goal of Clear Scan is to avoid having to alter the monitor's characteristics.

Jay Gladwell · December 27th, 2002, 12:49 PM

Ken--

That's what I did in the beginning. The refresh rate was set at 75 Hertz. I set CLEAR SCAN at 74.9 and got the thin white scan line rolling down the screen. I tried other settings in CS above and below the 74.9--the bar just thicker and blacker.

Then I tried adjusting both, what I've already described is the best I can get (and I tried it on two different monitors!). Are you telling me you can completely get grid of all indications of scanning? If so, what are your settings--both monitor and camera?

Andre De Clercq · December 28th, 2002, 03:15 AM

I am not familiar with XL1(/S), but I happen to know what "clearscan is. If it is true that you only can set for those rough exposure increments like 1/74.9 sec jumps to 1/74.6 sec then you will have to live with this artifact. Do you see only one horizontal bar? To me this feature is worthless in this case.

Jeff Donald · December 28th, 2002, 07:15 AM

The XL1S adjusts from 61.9Hz to 201.9Hz in 117 steps. I've used this feature many times and have never had a problem. Most of the monitors were in the 75Hz to 100Hz range. I would talk to Canon service on this matter. I believe you should be able to eliminate all traces of the scans on the computer monitor.

Jeff

Jay Gladwell · December 28th, 2002, 07:22 AM

Thanks, Jeff, I never thought of the most obvious answer!

December 27th, 2002, 11:29 AM	#1
Jay Gladwell Join Date: Jul 2002 Posts: 1,244	Have searched "Clear Scan" I've done a search here regarding the "Clear Scan" feature on the XL1s and not found what I'm looking for. On the old XL1, through adjusting the monitor's refresh rate and the camera's shutter speed, I was able to completely get rid of the scan bars on computer monitors and televisions. I can't get rid of the scan bar totally with the XL1s. I've tried using the "Clear Scan" feature and I've tried every possible combination of fresh rate and shutter speed, but to no avail. In the best case scenairo I still get a single faint white scan line that rolls down the screen. Is anyone else having this problem, or I am the only one? The problem that I see is: Monitors adjust their refresh rate in whole numbers, i.e., 60, 65, 70, 75, 80, 85, etc., but the cotton-pickin' Clear Scan uses fractions and NEVER settles on a whole number, like 75, for example. It gives me 74.9 then jumps to 75.6! This is the first and only complaint I've had with the XL1s and I'm crushed. I don't use After Effects and I can't get any more equipment--even rentals. Must I live with the little white scan line?

December 27th, 2002, 12:40 PM	#2
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Jay, The reason that Clear Scan uses fractional numbers is precisely because monitor refresh rates are whole numbers. Remember what those Clear Scan "numbers" stand for: they're shutter speeds expressed in fractions of a second. Monitor refresh rates are expressed as refreshes per second. In order to eliminate the rolling bar or line when shooting a monitor the camera must be shooting at a shutter speed that's slightly out of synchronization with the monitor's refresh rate. Keep experimenting and practicing with Clear Scan, but leave your monitor's refresh rate alone. I suspect you may be defeating your own purpose. The design goal of Clear Scan is to avoid having to alter the monitor's characteristics. __________________ 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

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December 27th, 2002, 12:49 PM	#3
Jay Gladwell Join Date: Jul 2002 Posts: 1,244	Ken-- That's what I did in the beginning. The refresh rate was set at 75 Hertz. I set CLEAR SCAN at 74.9 and got the thin white scan line rolling down the screen. I tried other settings in CS above and below the 74.9--the bar just thicker and blacker. Then I tried adjusting both, what I've already described is the best I can get (and I tried it on two different monitors!). Are you telling me you can completely get grid of all indications of scanning? If so, what are your settings--both monitor and camera?

December 28th, 2002, 03:15 AM	#4
Andre De Clercq Major Player Join Date: Sep 2002 Location: Belgium Posts: 804	I am not familiar with XL1(/S), but I happen to know what "clearscan is. If it is true that you only can set for those rough exposure increments like 1/74.9 sec jumps to 1/74.6 sec then you will have to live with this artifact. Do you see only one horizontal bar? To me this feature is worthless in this case.

December 28th, 2002, 07:15 AM	#5
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	The XL1S adjusts from 61.9Hz to 201.9Hz in 117 steps. I've used this feature many times and have never had a problem. Most of the monitors were in the 75Hz to 100Hz range. I would talk to Canon service on this matter. I believe you should be able to eliminate all traces of the scans on the computer monitor. Jeff

December 28th, 2002, 07:22 AM	#6
Jay Gladwell Join Date: Jul 2002 Posts: 1,244	Thanks, Jeff, I never thought of the most obvious answer!