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2900k Kinos and Video

Published : 31st August 2005

I've been using 2900k Kinoflos for the first time on a video shoot and they are coming up VERY magenta. They become less magenta as they warm up but we're still adding 1/4 plus green to make them look normally warm and suck out some red. Is this typical?

I'm shooting with a D35.

Art Adams, DP [film|hdtv|sdtv]
Mountain View, California - "Silicon Valley"
http://www.artadams.net/


Art Adams writes :

>I've been using 2900k Kinoflos for the first time on a video shoot and >they are coming up VERY magenta.

You are using Keno ballasts aren't you? the only time I have seen the effect you are describing is when you use Kino tubes in normal domestic fittings, as they do not drive the tubes hard enough.

The only other thing that effects color is the age of the tube or running a4ft tube on a 2ft ballast.

Keith Jakins
Australia


Hey Art

>I've been using 2900k Kinoflos for the first time on a video shoot and >they are coming up VERY magenta…Is this typical?

No, not typical at all.

Are you using the 12v kit, 2', 4'? Have you tried putting on the spare 2900k bulb and seeing if that makes a difference ? Have you switched ballasts (they can sometimes be a problem).

Is it somewhat magenta to the eye as well as on video ?

I've found that the 2900k can be more pleasing to the eye than using warming gels on the Kino.

Remember one thing - keep the ends of the Kino's well ventilated. I've seen sparks overly tape the gels to the ends, then wonder why there is such a green bias on the bulbs. Supposedly if the Kino’s heat up too much they will shift more to the green, and the overall life of the Kino is down.

Best,

Duraid Munajim
DP, Toronto


We're using a Kino Diva 200 and a Diva 400, with all the appropriate tubes, and we've now used them with both tungsten and HMI's. The 29's needed minus green because they were too green; the 56's needed plus green because they were too magenta.

It's not a ballast issue because the Divas come with built-in ballasts. My gaffer thinks they changed the formulation for the new tubes they've had to built to fit these units.

Art Adams, DP [film|hdtv|sdtv]
Mountain View, California - "Silicon Valley"


I've noticed the same magenta shift when using Diva 400's in the past (only remember it happening with tungsten lamps). It always seems to occur later in the day, hinting at some sort of temp. related issue. The lamps were not gelled or on any funky angles so airflow shouldn't have been an problem.

I recall reading a post a month or so ago about this very issue and someone I think suggested only using the Diva's in a vertical position... though there's nothing about that in the
user manual.

Matt Gorrie
Sydney, Oz


Art Adams wrote :

>The 29's needed minus green because they were too green; the 56's >needed plus green because they were too magenta.

It's the tubes. The "U" bend tubes always have color issues. Straight T5 tubes are much, much better as can be seen in the Softlights units. Softlights were the first to use the "U" bend tubes and the first to abandon them many years ago because of color issues.

Disclaimer: I sell (and use) Softlights for that and other reasons.

Anders Uhl
Cinematographer, NY
The DoP Shop


>The (new?) Diva manual does mention magenta shifts when dimmed >down more than a stop as well as if the tubes are not vertical or slanted >up (ie keep the connection end of the tubes up).

Hmmm. More often than not I always use Kinos horizontally so the light wraps around noses better. I guess I'll just have to carry minus green with me when I use them.

Art Adams, DP [film|hdtv|sdtv]
Mountain View, California - "Silicon Valley"


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