Energy Saving Lights

[Paul Dolzalll]

I am shooting at a location that has what I believe to be energy saving bulbs installed in the cieling. I have attached a picture of the closest example I can find.

 

Does anyone have any idea what these look like in terms of color temperature or if this type of bulb is a problem with flicker? Specifically shooting at 24 fps with a normal shutter angle. I realize the color temp probably differs depending on model, but I have no idea how these lights work whatsoever. Thanks allot.

[Phil Rhodes]

Hi,

 

I built some lights using clusters of these a while ago. The ones I have are high frequency, but other types aren't - you'll have to put a flicker meter on each one of them individually.

 

Phil

[Paul Dolzalll]

Is there any color temperature or frequency that is generally associated with this type of light or is it all over the place depending on the model?

 

Also, the bulbs in this room are able to be dimmed, I don't know if that is usefull information.

Edited February 7, 2005 by Paul Dolzalll

[Phil Rhodes]

Hi,

 

Mine read as about 2800K, a standard for lighting that's intended to be used in people's homes, but they have the standard green issue on film.

 

You can get daylight balanced types, but thety're rather expensive and I don't know if the CRI is any better - they might just be bluer. On the other hand, since the blue phosphor used in triphosphor lamps has a wider band emission spectrum than the red, the cooler a fluorescent tube is, the better the CRI tends to be.

 

Phil

[Paul Dolzalll]

Hello Again,

Thanks for the help so far on the issue, these are my last questions :-)

I do not have a flicker meter available to me, but I was able to take a 24p camera and take a look at the lights. Color temp wise they seem to be about halfway between daylight and tungsten, and the green spike on them seems to be extremely small.

Anyhow, using the 24p camera I took a look at the lights using every shutter speed I could think of including 1/24 1/48 1/60 1/120 etc. and I was never able to get them to "flicker" per se, and I had to go all the way to a 1/250 shutter speed before I saw what would normally be considered obnoxious pulsating. I think I may have seen some very minor pulsating at 1/120 but I wasn't sure. Does this mean these lights are probably safe for film at 24fps and normal shutter angle?

 

Unfortunatley I wasn't able to get in the actual room just look at some lights of the same type in another room. When this type of light is dimmed would flicker problems be any different?

[Alvin Pingol]

I was able to take a 24p camera and take a look at the lights... the green spike on them seems to be extremely small.

<{POST_SNAPBACK}>

 

I'm unaware as to which format, film or video, you plan to shoot on (not sure whether the 24P test was using the camera intended for the project, or simply as color rendering tester), but it is important to take into account video's rendering of the green spike - it is not nearly as noticeable as is on film.

[Mark Sasahara]

I don't think that these can be dimmed, they are compact fluorescent.

 

Was your test shot with the camera that you will be using for that actual shoot? It's best to do your tests with the gear you'll be using. Play it back on a good, color correct production monitor. Digitize a small bit and run it through whatever post effects, if any, that you plan to apply and see how it looks on playback/DVD/tape. Also if you are planning for something like a film out, I'm not sure how this will transfer.

 

It's best to have a color chart, gray card, white card and black to see what the colors are doing. The gray card will help you see if there is a color cast or green spike.

 

Try doing an online search and see if there is a color correct lamp that will fit whatever the base is on those fixtures. That way you can swap out the old ones with new ones with correct colors. Practical if it's one room and not too many lamps need replacing. Lamps with a CRI of 90 or higher should be used. And test those too.

 

Adequate results can also be achieved by white balancing under the lights in the shooting area and then cleaned up further in post producton.

[Rik Andino]

Energy-Saving Bulbs--->aren't they just small flourescent lights

And they can fit incandsent sockets...so they save more enegry

Than the standard incandescent bulb...? :huh:

 

Anyways They tend to be somewhat green

And like most other flourescents their color temp. is unstable

Especially depending on the life of the bulb.

 

I'd just buy your standard tungsten balanced photo-flos

And swap those energy-saving bulbs with those.

In the long run it'll look much better

And you'll not have to worry about where the color-temp is off.

 

Good luck