Jump to content

Kino Tubes in Regular Fixtures


Recommended Posts

Hi, I come here a lot for all the great information you guys dish out! But this is my first post, It's one that has been asked before, but I'm looking for a more up to date specific answer, so any help is appreciated.

 

I'm shooting a class room scene, in the classroom there are over head fluro lights already. Our gaffer is coming with kinos, and has said, with no real confidence, "they should work".

 

So I've been told about needing older 40w globes rather than newer 75w, and this:

"a standard fluorescent fixture they will be under driven resulting in less light output and incorrect color balance. It should be about the same as running a 4ft tube in 2ft mode in a kino fixture. When under driving the bulbs they will appear more magenta than normal. "

 

Should I be hiring some different type of bulbs for those scenes, rather than using the standard kino blubs?

Will I need to balance out the color across all the blubs with gels?

Will the light be diminished (I know this may be impossible to answer without actually being on set)?

 

Would love any help or more information before we head out onto set!

Link to comment
Share on other sites

  • Premium Member

A better option may - and you should test - be something from the Philips TL-D 90 Graphica range, which come in either tungsten or daylight. The daylight have somewhat better colour rendering, but both are adequate for background work and even for noncritical keying. The four-foot tubes are 36W and will be correctly driven in conventional fittings.

 

P

  • Upvote 1
Link to comment
Share on other sites

A better option may - and you should test - be something from the Philips TL-D 90 Graphica range, which come in either tungsten or daylight. The daylight have somewhat better colour rendering, but both are adequate for background work and even for noncritical keying. The four-foot tubes are 36W and will be correctly driven in conventional fittings.

 

P

 

Great thanks Phil, will look into that! Ideally not having to gel each bulb (18+ in all) would be good.

Link to comment
Share on other sites

  • Premium Member

I would first check to see exactly what kind of globes are in the existing fixtures. You don't want to assume that they are T12 and have them turn out to be T8 when you get there. Can you do a tech scout of the location with your gaffer?

Link to comment
Share on other sites

 

"a standard fluorescent fixture they will be under driven resulting in less light output and incorrect color balance. It should be about the same as running a 4ft tube in 2ft mode in a kino fixture. When under driving the bulbs they will appear more magenta than normal. "

 

Should I be hiring some different type of bulbs for those scenes, rather than using the standard kino blubs?

 

 

I've never had a problem with Kino tubes being under driven, but as Satsuki says, you'll also need to check that the fittings are T12 and not T8. Another potential source of trouble will be the ballasts on the overheads. If they are relatively new, they'll have high frequency ballasts, but there are a lot of older fluorescents still out there, and they may cause visible flicker.

 

If you have the budget, replace all the tubes so at least you have consistency. even if your replacements have a green cast it's easier to correct when they all look the same. If budget won't allow that, then check the existing tubes to see if they are cool white or warm white. If they are mostly cool or mostly warm, then remove the odd ones out and correct for the rest.

  • Upvote 1
Link to comment
Share on other sites

  • Premium Member

If the fluorescent tubes are mounted in enclosed "luminaires" with a sheet of glass on the bottom, you might be better off fitting sheets of colour correction gel on top of the glass. That way you can get them to more closely match any other light sources in the scene. Failing that, you can tape strips of gel around the individual tubes, but this is a bit fiddly as you have to make sure the seam is at the top,

 

As far as I am aware, Kino Flos are just ordinary fluorescent tubes with more care taken with the colour temperature of the phosphors used.

 

If at all possible, whatever you use, I would suggest you change all the tubes at once because unless the school has a regular lighting maintenance contract, you're going to find that the tubes have been fitted at different times, and will be different brands and have different colour temperatures, which is not obvious to the naked eye but is painfully obvious when photographed. Also , if the fluorescent fittings use old-fashioned iron core ballasts (most likely in a school) you're likely to have strobing problems, and these are likely to be worse as the tubes age.

 

Depending on budget, you might be better off buying a carton of tubes from a hardware store and basically just donating them to the school when you're finished. As Phil has suggested, ideally you should get "Tri-Phosphor" tubes which are similar to Kino Flos but they are somewhat more expensive.

 

If strobing is too much of a problem, another approach is to use LED-based replacements for the fluorescent tubes. These are normally just a drop-in replacement, but you have to change the starter unit at the same time.

The good thing about those is that they are independent of the power rating of the ballast, and they do not strobe.

They are a lot more more expensive of course. It's the sort of thing a lighting gaffer might consider having in his truck, perhaps with a range of slide-on correction filters.

  • Upvote 1
Link to comment
Share on other sites

I would first check to see exactly what kind of globes are in the existing fixtures. You don't want to assume that they are T12 and have them turn out to be T8 when you get there. Can you do a tech scout of the location with your gaffer?

 

Yes we're heading back out there soon (though the gaffer has not come out yet, nor do i know if he'll be able to!) it's over an hour and half drive, plus it's a school so we're pretty restricted with when we can go by, can't pop in unfortunately, but I'll be checking them.

 

 

 

Depending on budget, you might be better off buying a carton of tubes from a hardware store and basically just donating them to the school when you're finished. As Phil has suggested, ideally you should get "Tri-Phosphor" tubes which are similar to Kino Flos but they are somewhat more expensive.

 

 

We're going to hire what we need at this stage, it's a bit cheaper than buying, they have what we need in the Philips range. And unfortunately we wouldn't have the budget for LED. The good news is I've managed to get us on location the day before to fit the tubes, so we'll find out before if there's any issues.

 

Thanks heaps for the information, this will be very valuable!

Link to comment
Share on other sites

Consider... Turning off all the overhead lamps and mostly lighting through the windows. You may like that much more!

 

This would certainly be ideal! We're shooting in winter now (Australia) and the room gets very little natural light even during the day. If I had the budget I would be lighting form outside only for sure.

 

Actually, perhaps this is off topic, we're shooting a couple of night scenes in a remote area and it's meant to be overcast winter feel, in reality it will probably be close to pitch black since the moon's hidden and there's no city lights, or even an house porch lamp or something, any suggestions? In the back of my head I keep think perhaps we'll have to introduce a house in the distance, or a bit of moon light.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...