A Photography forum. PhotoBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » PhotoBanter.com forum » Photo Techniques » Photographing People
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

color temp for halogens



 
 
Thread Tools Display Modes
  #1  
Old March 9th 04, 02:31 AM
Doug
external usenet poster
 
Posts: n/a
Default color temp for halogens

I have a few halogen shop lights that I am thinking about using for some
portrait work (background, hairlight) and I am curious if this is a good
idea. I am using 35mm negative, not digital.

In one case I want to use them in my studio, which would be a combination of
those two halogens, plus my Canon 420ex for fill. Are these all the same
temp?

In the second instance, I want to drag them to some location work that I am
doing and using them in daylight.

Am I looking for trouble? Has anyone ever done this??

thanks


  #2  
Old March 9th 04, 08:20 AM
zeitgeist
external usenet poster
 
Posts: n/a
Default color temp for halogens



I have a few halogen shop lights that I am thinking about using for some
portrait work (background, hairlight) and I am curious if this is a good
idea. I am using 35mm negative, not digital.

In one case I want to use them in my studio, which would be a combination

of
those two halogens, plus my Canon 420ex for fill. Are these all the same
temp?

In the second instance, I want to drag them to some location work that I

am
doing and using them in daylight.

Am I looking for trouble? Has anyone ever done this??



halogen is basically the same as tungsten, and would give you a very warm
yellow orange color cast.

however, the juxtabosition of the two can be interesting.

shoot vertically, aim your flash to bounce off a sidewall. Use the halogens
for background and hair light. You'll need a tripod for this.

set your f/stop for as minimal as you can, shoot wide open if needed, and
you'll need a very slow shutter speed, 1/15th would be lucky, you could end
up 1/8th 1/4th. If you have a hand held meter, you want to get the
background to be one stop under what your subject exposure will be.

keep in mind, 100 watt seconds, a rating of a flash power, is the equivelent
to a 100 watt incandescent bulb for one full second. So do the math to get
a decent exposure at 1/15th, that's four stops and each stop doubles the
required out put, 2, 4, 8, 16 100 watt bulbs.


  #3  
Old March 9th 04, 10:57 AM
Mxsmanic
external usenet poster
 
Posts: n/a
Default color temp for halogens

Doug writes:

I have a few halogen shop lights that I am thinking about using for some
portrait work (background, hairlight) and I am curious if this is a good
idea. I am using 35mm negative, not digital.


If you filter for it and/or use tungsten film, it's not much of a
problem. Color casts can also be corrected after principal photography
in Photoshop, but that's an inferior solution to filtering or otherwise
compensating at the time of exposure.

Halogen lamps have a higher color temperature than ordinary light bulbs,
since their filament temperatures are higher. But they are still quite
orangish-red compared to daylight.

In one case I want to use them in my studio, which would be a combination of
those two halogens, plus my Canon 420ex for fill. Are these all the same
temp?


Flash units typically produce daylight color temps until you put filters
over them. Mixing them unfiltered with halogen light will make proper
balance impossible, although the effects may or may not be acceptable.

In the second instance, I want to drag them to some location work that I am
doing and using them in daylight.


Not a problem in daylight, as flash units are already balanced for that.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.
  #4  
Old March 11th 04, 04:10 AM
KBob
external usenet poster
 
Posts: n/a
Default color temp for halogens

On Tue, 09 Mar 2004 01:31:53 GMT, "Doug" wrote:

I have a few halogen shop lights that I am thinking about using for some
portrait work (background, hairlight) and I am curious if this is a good
idea. I am using 35mm negative, not digital.

In one case I want to use them in my studio, which would be a combination of
those two halogens, plus my Canon 420ex for fill. Are these all the same
temp?

In the second instance, I want to drag them to some location work that I am
doing and using them in daylight.

Am I looking for trouble? Has anyone ever done this??

thanks


Color temp of the usual halogen 120V non-photo lamps is about
2800-2900K. Visit any of the websites of the leading lamp suppliers
for details.
  #5  
Old March 12th 04, 01:59 AM
Stefan Patric
external usenet poster
 
Posts: n/a
Default color temp for halogens

On Wednesday 10 March 2004 07:10 pm, KBob wrote:

On Tue, 09 Mar 2004 01:31:53 GMT, "Doug" wrote:

I have a few halogen shop lights that I am thinking about using for
some portrait work (background, hairlight) and I am curious if this is
a good
idea. I am using 35mm negative, not digital.

In one case I want to use them in my studio, which would be a
combination of
those two halogens, plus my Canon 420ex for fill. Are these all the
same temp?


No! Halogen shop lights are around 2800K, while your flash is around
5500 to 6000K. Mixing them or the halogens with normal daylight is not
a good idea -- colorwise. Won't make any difference with black and
white.

Mixing flash and daylight is okay.

In the second instance, I want to drag them to some location work that
I am doing and using them in daylight.


You're going to have color problems. See if you can buy some Rosco
Industries "Booster Blue" filters (www.rosco.com) to balance the
halogens to around 5000 to 5500K. You're shooting daylight balanced
film, so all light(s) has to be balanced, more or less, to "Standard
Daylight" to get acceptable results.

Theatrical lighting and movie supply houses have all kinds of filtration
media for all kinds of light sources.

Am I looking for trouble? Has anyone ever done this??


Yes. And Yes. I shot architectural interiors for years,
professionally, and had to deal constantly with "mixed" light sources.
For the most part, you can compensate, you just have to know what
you're doing. The Rosco website's Technotes area is a good place to
start learning. Also, find and read as many books as you can find on
photographic lighting techniques.

thanks


Color temp of the usual halogen 120V non-photo lamps is about
2800-2900K. Visit any of the websites of the leading lamp suppliers
for details.


--
Stefan Patric

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 02:20 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 PhotoBanter.com.
The comments are property of their posters.