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Kino
Flo Divas Published : 19th April 2004
Light
it up last and just dial it in. I find I like daylight Kinos
with eighth minus green as a base gel. Never had any colour
shift problems, but I don’t remember running it very
low, either. In short, a terrifically flexible and useful
unit.
>...have you metered these with new tubes?... No. One of the units I had was brand new so I assume the tube was new... I've rented these on several occasions and have always found the dimming to cause very suspicious colour shifts to the magenta. Sure, you can add gel. I just don't think it's worth the hassle most of the time compared to a 2'X4 Kino. So... I tape the dimmer so it stays at full. David Perrault, csc I can't say I dim the Diva's very far down, but I've had zero problems with color shifts. I typically use the Diva's as a soft kick. My new favourite is the Mole Richardson Biax 8; fabulous key light with about a 2 x 2 aperture, larger with a piece of diffusion over the barn doors. The Biax 8 seems robust, has switches for each pair of the eight tubes, is dimmable, and compact. With the 8 tubes it has enough punch to work pretty well with windows in the shot. Best regards, Leo Ticheli Director/Cinematographer Birmingham/Atlanta George Hupka wrote: >Interesting... I own 2 Divas myself, and other than old tubes, I've found >them to be largely free of that problem. I agree. I don't own these but have worked on location w/ cameramen who do. Most of these were video jobs and to my eye there was no shift when dimmed or at least none apparent on the video monitor- and we had them dimmed to about 40-50 percent. I don't consider an 1/8 correction of magenta a big deal and sometimes need to do this w/ regular Kinos depending on vintage of units and/or bulbs etc. I did not put a meter to the Divas, but I don't always trust a color temp w/ fluoro anyway. The Diva's I've encountered have been relatively new, probably purchased within the last year or so. Maybe earlier models had more color shift problems when dimming??? When others are talking about locking down the dimmer and big horrible color shifts when dimmed...I've never seen this. I don't doubt others observations so can only assume there must be different model years or some such. John Roche, Gaffer NYC Hi, I just heard, that this whole magenta shift problem with dimmed Kino-tubes comes from the inner-tube-temperature. ie when dimmed, the temperature in the tube gets lower and causes the phosphors to glow more in the magenta side of things. Has anybody noticed any differences in the colour shift when dimmed outside (where it’s often colder - at least here in Germany) and in an inside environment (stabile temperatures) ? Best regards, Daniel Pauselius Electrician, Leipzig/Germany John, You may be right. I have not seen the significant color shifts described by others on this list. I really like Divas but I check the color temps regularly (with both my color meters) and I keep the tubes warm before I bring the fixture to set. I find that the 55w bulbs require some time to come up to temp before using them. I do see strange color shifts while the bulbs warm up. I was interested in purchasing a couple of these fixtures in 2001 but when I asked to order them, I was told that production had halted for a short time to correct a design flaw. It seems there was a problem with the auto 120v/240v switching inside the fixture. I wonder if this has anything to do with others experience with color shift? Andrew Gordon Gaffer Regina, Saskatchewan Canada >I wonder if this has anything to do with others experience with color >shift? As I understand it, the phosphor color output is relatively stable - what happens with temperature change is that the mercury gas in the tube increases pressure as temperature rises and as the pressure goes up, the mercury arc running down the tube (which is what excites the phosphors and gets them to spit out light) gets proportionally brighter. Since mercury has a strong emission line in green (the dreaded green spike), at higher temps, the tubes give off a little more green from the mercury than the phosphor recipe was designed to balance with. This is a general reminder that if you swaddle your Kinos in gel with no room for the hot air to escape, you can get them to overheat and go a little bit green. Mark Weingartner LA based |
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