Colour temperature readout? at DVinfo.net

Mark Harmer · June 12th, 2009, 06:10 AM

Hi all,

Just a quickie: I know how to adjust the colour temperature in K on the XHA1 (you can dial in direct values) but I'm trying to find the right correction gel for a lamp to match it to my existing ones.

I've been able to store a white balance using my existing light and also the new ones, and they're definitely a bit different.

Is there any way I can get an actual readout of the colour temperature that the XHA1 is seeing / storing so I can get hold of the appropriate lighting gel so I can correct my new lights to be the same colour temp as the existing ones?

If I had unlimited Gels I could experiment, but sadly I have no gels so I hope to order the right one - hence I need to find out what I have to get.

Hope I've explained that OK - and hope an XHA1 afficionado out there can help me with this!

Bill Pryor · June 12th, 2009, 09:48 AM

The camera does not provide a color temperature readout, which is dumb. It should be easy to display it, since the camera knows what it is, but they didn't give us that. No hour meter either. I have an old Gossen color temperature meter left over from my film days.

If I'm clear, you're trying to match two different types of lights? If they're all that much different, then one is probably daylight and the other tungsten, so you can either gel the tungsten with CTB for use with the daylight, or gel the daylight with CTO. If you can't tell by looking, set the camera to the tungsten preset and turn on your lights. The one that looks too blue will be the daylight.

Mark Harmer · June 13th, 2009, 01:14 PM

Bill,

Hi - I found a swatchbook of Arri gels and it does appear (from looking through the filter - they're really small!) that the soft lights when corrected by full CTO match the uncorrected spots, so they probably are daylight. I've now ordered a few gels - full CTO to convert the soft lights to match the old spots I have, and full CTB for those situations where I have some daylight coming into the room so I can just blue up the spots and keep the soft lights uncorrected.

But yes - really bonkers that the XHA1 doesn't give any readout since it "knows" what colour you're looking at. I suppose I could take some footage and step through the k values on the dial, transfer the whole lot to a NLE and then sample the various frames to see which K value on the soft lights matches my spots, which I know are 3200K - and maybe I'll do that, but I've bitten the bullet and just decided to order various gels including CTO and CTB and I'm sure they'll work fine.

Looking forward to trying some experiments with lighting!!

Thanks for the reply.

June 12th, 2009, 06:10 AM	#1
Mark Harmer Regular Crew Join Date: Nov 2006 Location: Moreton in Marsh, United Kingdom Posts: 96	Colour temperature readout? Hi all, Just a quickie: I know how to adjust the colour temperature in K on the XHA1 (you can dial in direct values) but I'm trying to find the right correction gel for a lamp to match it to my existing ones. I've been able to store a white balance using my existing light and also the new ones, and they're definitely a bit different. Is there any way I can get an actual readout of the colour temperature that the XHA1 is seeing / storing so I can get hold of the appropriate lighting gel so I can correct my new lights to be the same colour temp as the existing ones? If I had unlimited Gels I could experiment, but sadly I have no gels so I hope to order the right one - hence I need to find out what I have to get. Hope I've explained that OK - and hope an XHA1 afficionado out there can help me with this!

June 12th, 2009, 09:48 AM	#2
Bill Pryor Contributor Join Date: Jan 2003 Location: Kansas City, MO Posts: 4,449	The camera does not provide a color temperature readout, which is dumb. It should be easy to display it, since the camera knows what it is, but they didn't give us that. No hour meter either. I have an old Gossen color temperature meter left over from my film days. If I'm clear, you're trying to match two different types of lights? If they're all that much different, then one is probably daylight and the other tungsten, so you can either gel the tungsten with CTB for use with the daylight, or gel the daylight with CTO. If you can't tell by looking, set the camera to the tungsten preset and turn on your lights. The one that looks too blue will be the daylight.

June 13th, 2009, 01:14 PM	#3
Mark Harmer Regular Crew Join Date: Nov 2006 Location: Moreton in Marsh, United Kingdom Posts: 96	Bill, Hi - I found a swatchbook of Arri gels and it does appear (from looking through the filter - they're really small!) that the soft lights when corrected by full CTO match the uncorrected spots, so they probably are daylight. I've now ordered a few gels - full CTO to convert the soft lights to match the old spots I have, and full CTB for those situations where I have some daylight coming into the room so I can just blue up the spots and keep the soft lights uncorrected. But yes - really bonkers that the XHA1 doesn't give any readout since it "knows" what colour you're looking at. I suppose I could take some footage and step through the k values on the dial, transfer the whole lot to a NLE and then sample the various frames to see which K value on the soft lights matches my spots, which I know are 3200K - and maybe I'll do that, but I've bitten the bullet and just decided to order various gels including CTO and CTB and I'm sure they'll work fine. Looking forward to trying some experiments with lighting!! Thanks for the reply.