Home of Professional Cinematography since 1996
Published : 30th January 2004
I have a shoot coming up that requires about 20 single Kino tubes in a line. The idea is to create a look like neon that is very blue, kind of a steel blue or cobalt color. The question is do I do this with blue Kino tubes, which I have never seen, or simply using blue gel on daylight tubes? It might be nice to have some blue tubes for future blue screen work so I wouldn't be opposed to buying some if they are the better choice. I need to look at the tubes and see a deep rich blue.
Thanks for your help
Tom Burke wrote:
>The idea is to create a look like neon that is very blue, kind of a steel >blue or cobalt color.
The Kino bluescreen tubes (I'm sure someone will chime in with their proper name) are amazingly blue. Much purer color and far more efficient than using gels. I've used them for a 'neon blue' effect in a background, and they were awesome...incident exposure on them was down, (be wary of meters with 'spiky' sources like this anyway) like -2 or 3 stops, but what looked good to the eye was right.
Alan Thatcher writes :
>The Kino bluescreen tubes (I'm sure someone will chime in with their >proper name) are amazingly blue.
In Europe we can get 4ft fluo tubes in a variety of phosphor colours for special applications. One supplier is a company called Skytec who supply the low end club market with affordable gear. Maybe American DJ has something similar?
These tubes are coated with blue phosphor as opposed to having a filter, so they look very bright and pure. On the other hand, gelling up ordinary fluorescent tubes works pretty well too. It may help to get a gel swatch book and view several different colour temperatures of tube through selected colours to see which one has the most zing.
Another product that comes to mind was a roll on silicon sleeve by Colourcover. I think there may have been heat shrinkable coloured sleeves made too.
>The Kino bluescreen tubes (I'm sure someone will chime in with their >proper name) are amazingly blue. Much purer color and far more >efficient than using gels.
Wow, that is surprising. I was going to mention the gelling with blue routine.
My curiosity has me wondering what stop you shot at and how bright were the tubes in relationship to the T-stop and ASA? I've only used them in blue screen applications where they are, of course, wonderful as are the green tubes for green screen. But I always thought they would burn out white if shot too overexposed.
Super Blue Keno Tubes are amazing in their saturation. Always use a spot meter as they will foul your ambient readings. They make a wonderful glow that does look alot like neon. The disadvantage could be that it is very difficult if not impossible to match the color with hot light & gel. Make sure you have enough to fit the job. All other blue sources look pale or turquoise by compare.
I have also used the green, pink, & red lamps. The pink/blue combo is great for the neon thing. Shooting the tubes directly is a little risky...you can dim them on a magnetic dimmer to about 60% before they start to flicker. Even if the tube overexposes some the air around the tube still will have a saturated look.
Spike Simms wrote :
>Super Blue Keno Tubes are amazing in their saturation.
Just used these on a job and they are Very blue. Side by side with a green Kino the output seemed much less although I did not meter them. Used as a kind of uplight wash on background/curtains. As usual they appear different to eye than color rendered on video. Looked more lavender to eye but rendered very blue on video. Did not color temp them as it did not matter.
John Roche, Gaffer
Jim Sofranko wrote:
>My curiosity has me wondering what stop you shot at and how bright >were the tubes in relationship to the T-stop and ASA?
As I recall we used the tubes for the effect, and they were NOT visible in frame. They would probably burn out if shot directly, but then again they're such a pure source maybe they'd saturate one layer and leave the others alone?
(This would be an excellent subject for a test.)
In the spot I used them on they were significantly under in exposure but looked great, to the eye, and in dailies. I don't remember the stop, but it was at least -2 from exposure, probably -3.
I myself distinguish among three versions of blue made or rented by KinoFlo over the years -
KF55 : These are the standard 5500 kelvin version that most of us are familiar with, used for matching daylight.
Blue : These were/are made by Philips or perhaps some other manufacturer, and are a standard color. They appear to be the color blue to the eye. There are other colors as well, such as red, pink, gold (which looks yellow to me), and of course green. Kino Flo is calling these "Designer Lamps" or "Designer Colors".
Super Blue : These are the tubes used for blue screen work, KinoFlo calls these "Visual Effects Lamps". They emit a very narrow portion of the spectrum, thus exposing only the blue layer of the film and allowing for a very clean, pure matt. There is a complimentary tube for green screen work.
For a music video, I once lined a 48' trailer with vertical rows of 8' and 4' KinoFlo tubes, using TransFlo ballasts, and chased them with a dimmer board to create the effect that the trailer was moving while the artist was rapping inside. We used the blue version of the tubes as opposed to the super blue. At least I think I did - it was a while ago. The gel thing works really well too, but it's not as handy as the tube because of the time and care that it takes to gel a fluorescent tube. If you need to match the color of the blue or super blue tubes on the talent or in other areas, just order extra tubes and put them in a Kino Flo fixture like a 4' 4-bank.
Los Angeles, CA
The Kino super blue tubes are a visual effects tube designed specifically for lighting blue screen.
They emit only in the blue region...and by eye look like a disco black light (UV) My Minolta colour Temp. meter goes crazy and just won't give me a degrees Kelvin reading.
They are the simplest way to get great results with bluescreen...using image 80 housings you can evenly light, shadowless, huge areas...hundreds of feet of studio, with virtually no reflected spill.
Put the 80's through a rack and turn off or on tubes via the DMX to control exposure...FANTASTIC. General Electric also make super blues...same plastic cover, 40 watt tube (just called 'BLUE'..I have used them) half the price of Kino here (mind you Kino had the market for so long and mark-ups probably higher than in the U.S.(An American D.O.P. told me Kino tubes were manufactured by Sylvania)
Ted Hayash writes :
>Super Blue : These are the tubes used for blue screen work, KinoFlo >calls these "Visual Effects Lamps".
It would be interesting to see the video interpretation of the cheap blue and green phosphored tubes. I've a slight suspicion they might be a bit more affordable for budget conscious projects.
Talking of flashing fluorescents...There was an interesting post on a show-control group recently that described an existing system that was chasing ordinary fluorescent tubes with 50/60Hz inductive ballast's.
Anyone who has dabbled technically with the dimming and flashing of fluorescents will know that the cathode heaters need to be kept hot while the tube is unlit to allow instant re-strike. This application achieved this in the most simplistic manner possible by simply putting a relay across the starter. When the relay is energised it shunts the starter and effectively turns off the tube by channelling all the current through the cathodes. When the relay opens again the tube lights instantly.
This is a rather simplistic novel approach and would probably be bad for the tubes if they were held in the cathode-energised state for long periods of time (like a welded starter), but for regular flashing this shouldn't affect lamp life too adversely.
Graham Rutherford writes :
>They emit only in the blue region....and by eye look like a disco black >light (UV)
It's probably worth mentioning that there are two types of disco style blacklight lamps. The raw blacklight-blue tube that looks bright blue (think insect-o-cutor), and the filtered blacklight that is the most common in discos that looks a dull purple. These two tubes use the same phosphors, but the dark one uses a woods glass type filter to enhance the fluorescing effect.
Yep thanks Clive…I meant the blue ones...but I have seen the purple ones… I bow to your Discoexpertise.
Have you ever come across a lamp?
It is the size and construction of a Dino. But instead of using twenty-four 1000 watt Par 64 globes it used the mini-brute 650 watt globes , which were a par, about four inches across...available in floods (DWE) or spot (FBO).
These were arranged six across and about twelve down...seventy -two in all.
Do you know what it was called?...I remembered it when everyone was talking about lights that could cook pizza.
Thanks for all the great advice! Due to a very tight budget we are going to have to go with gelling them. In fact since it's thanksgiving time and we are shooting on Tuesday I'm just going to have to go to a local house, that happens to have two flavours of blue gel on rolls, and choose between them.
We'll take whatever we can get. I am considering buying some green tubes for future green screen work since I do a lot more green than blue these days.