Matching PD170 and VX2100 at DVinfo.net

Ray Saavedra · May 3rd, 2005, 10:58 PM

I posted this at the Sony VX2100/PD170 but did not really get any good answer. So here it is again since it's deals with wedding events.

For those that own both these cams and do wedding events. How do you guys match these two cams before shooting the reception?

I usually WB both of them with the same card at the same distance. Sometime I set it to auto WB. Both cams has the same setting. On the PD170 I use to have the ire setting to 7.5 but recently change it to 0. The VX2100 seems to have blacker black than the PD170. Does anyone know what the ire setting on a VX2100.

My problem is during the reception when the house lights dims and I have to use manual gain and exposure. The PD170 has independent control and sometime set it to F1.6 and 12dB as an example. But as everyone knows, you can't set the VX2100 the same way. It's OPEN and 12dB. So it is much brighter than the PD. How do you guys deal with these? How do you guys set your PD and VX.

Also, as a test I put both on auto mode and the VX has blacker black. Is it just the LCD?

TIA,
JR
__________________
junray@yahoo.com

Glenn Chan · May 3rd, 2005, 11:26 PM

The IRE setup refers to what happens when you go from digital to analog. 16 16 16 in RGB (digital) values are *supposed* to translate to 7.5IRE. Consumer gear like the VX2100 translate 16 16 16 to 0IRE.

It may be that the PD170's setting toggles between translating 16 16 16 to 7.5IRE or 0IRE
OR
that it records blacks at 32 32 32 to compensate for it translating 16 16 16 to 0IRE (thus, blacks are recorded at 32 32 32 in RGB values and translate to 7.5IRE from the PD170).

To match the cameras, the setting should be 0IRE.

To double-check (because I haven't touched either camera):
Capture footage from both cameras and check on the same monitor. If your editing program supports waveform monitor or histogram, you can check if black levels match between both cameras. Or take a screenshot and use photoshop. Put the lens cap on and eyedropper that footage in Photoshop- hopefully it reads 16 16 16 for both cameras.

Boyd Ostroff · May 4th, 2005, 06:59 AM

Sounds like your main problem is the IRE setting. From everything I've read, plus personal experience, you should always leave that at 0. If you set it to 7.5 then you will never get a true black in your recording. If you need to add setup to your video then it should be done at playback, not during recording.

But clearly this is the reason you aren't matching the VX-2100 which is permanently set to 0 IRE. Regarding the iris/gain, it shouldn't really be a problem as long as you understand what's going on with the 2100. When it says "open" it means it's at the maximum iris opening for the current focal length. This will vary depending on how far you've zoomed in. At max wide it will be f1.6. At max telephoto it will be f2.4. As you know, turning the exposure wheel past this point will add gain in 3dB increments.

To match this on the PD-170, just make sure that the iris is completely open (showing the smallest possible f number for your current zoom setting) before you add gain. This will then behave the same as your 2100.

But it sounds like most of your problems are actually related to the 7.5 IRE setting on the PD-170 which you shouldn't be using...

May 3rd, 2005, 10:58 PM	#1
Ray Saavedra Regular Crew Join Date: Jul 2002 Location: San Francisco Posts: 127	Matching PD170 and VX2100 I posted this at the Sony VX2100/PD170 but did not really get any good answer. So here it is again since it's deals with wedding events. For those that own both these cams and do wedding events. How do you guys match these two cams before shooting the reception? I usually WB both of them with the same card at the same distance. Sometime I set it to auto WB. Both cams has the same setting. On the PD170 I use to have the ire setting to 7.5 but recently change it to 0. The VX2100 seems to have blacker black than the PD170. Does anyone know what the ire setting on a VX2100. My problem is during the reception when the house lights dims and I have to use manual gain and exposure. The PD170 has independent control and sometime set it to F1.6 and 12dB as an example. But as everyone knows, you can't set the VX2100 the same way. It's OPEN and 12dB. So it is much brighter than the PD. How do you guys deal with these? How do you guys set your PD and VX. Also, as a test I put both on auto mode and the VX has blacker black. Is it just the LCD? TIA, JR __________________ junray@yahoo.com __________________ junray@yahoo.com

May 3rd, 2005, 11:26 PM	#2
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	The IRE setup refers to what happens when you go from digital to analog. 16 16 16 in RGB (digital) values are supposed to translate to 7.5IRE. Consumer gear like the VX2100 translate 16 16 16 to 0IRE. It may be that the PD170's setting toggles between translating 16 16 16 to 7.5IRE or 0IRE OR that it records blacks at 32 32 32 to compensate for it translating 16 16 16 to 0IRE (thus, blacks are recorded at 32 32 32 in RGB values and translate to 7.5IRE from the PD170). To match the cameras, the setting should be 0IRE. To double-check (because I haven't touched either camera): Capture footage from both cameras and check on the same monitor. If your editing program supports waveform monitor or histogram, you can check if black levels match between both cameras. Or take a screenshot and use photoshop. Put the lens cap on and eyedropper that footage in Photoshop- hopefully it reads 16 16 16 for both cameras.

May 4th, 2005, 06:59 AM	#3
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 11,802	Sounds like your main problem is the IRE setting. From everything I've read, plus personal experience, you should always leave that at 0. If you set it to 7.5 then you will never get a true black in your recording. If you need to add setup to your video then it should be done at playback, not during recording. But clearly this is the reason you aren't matching the VX-2100 which is permanently set to 0 IRE. Regarding the iris/gain, it shouldn't really be a problem as long as you understand what's going on with the 2100. When it says "open" it means it's at the maximum iris opening for the current focal length. This will vary depending on how far you've zoomed in. At max wide it will be f1.6. At max telephoto it will be f2.4. As you know, turning the exposure wheel past this point will add gain in 3dB increments. To match this on the PD-170, just make sure that the iris is completely open (showing the smallest possible f number for your current zoom setting) before you add gain. This will then behave the same as your 2100. But it sounds like most of your problems are actually related to the 7.5 IRE setting on the PD-170 which you shouldn't be using...