Fleurescent light and filtrationgreenspun.com : LUSENET : Large format photography : One Thread
I have to photograph a large store interior on 5x4, using tranny. The problem is that the store is lit with strip lighting, (so called daylight) and I have 2 questions. First, does anyone know what is needed in the way of filtration? Second, the front of the store (nearest to camera in the main shop will be partly lit by daylight coming in through the window. Any ideas on the filtration for this mixed lighting?
-- Paul Roberts (email@example.com), August 23, 2000
A couple of approaches...
1) Shoot at night or block-out the windows so you eliminate the daylight.
2) Gel the lights to daylight
3) Gel the windows to FL & shoot w/ FL filter correction
4) Shoot NPS which does a good job with mixed lighting and have a transparency made from the negative. This approach has the least labor cost, but a much higher lab cost. I've heard of some very well known architectural photographers who are using this approach routinely.
-- Larry Huppert (Larry.Huppert@mail.com), August 23, 2000.
In theory, daylight tubes (when new) burn at about 5,700K, so no correction is needed on their colour, but because of their discontinuous spectrum (which will always produce a green cast, you will need magenta CC filtration. In theory again, you need a CC27M - either a 25 or a 30 should do fine. Your mixed light shot at the front of the building is more difficult. 1 exclude all daylight and use entirely strip lighting 2 exclude all daylight and use green gels over flash heads 3. cover window with green lighting gel 4. compromise by measuring effect of daylight and using reduced filtration on the lens, say CC15M
Or, if you're really desperate, scan into photoshop and correct there.
Hope this helps,
Garry Edwards, acclaimedimages.co.uk
-- Garry Edwards (firstname.lastname@example.org), August 24, 2000.
If the windows are not in the photograph, shoot at night using only the fluorescent lights as illumination.
If the windows are part of the photo, shoot prior to sunrise or after sunset so that the light from outdoors is 1 to 1-1/2 stops less than the interior. There should be little if any effect from the daylight on the interior color balance and you will still get some detail outdoors through the windows.
My cinematographer's manual shows a 40M + 30Y CC filter correction plus 1 stop more exposure for daylight fluorescent lights using daylight balanced film.
-- steve (email@example.com), August 24, 2000.
Here is a good site that is Fuji-specific for filtering.
-- Wayne DeWitt (firstname.lastname@example.org), August 26, 2000.
Fuji NPS is the way to go- absolutely an incredible film for this mix of lighting. Fluorescent lighting is a huge headache otherwise, filtration requirements differ depending on type of bulb, manufacturer, age, ballast type and condition, voltage, fixture lens type/age, etc. Filtration recommendations from Kodak may get you close if you are lucky and try several different combinations, but testing is required for really good color fidelity. Just use NPS and have chromes made. In case you are wondering, I shoot Architecture professionally.
-- David Rose (DERose1@email.msn.com), September 15, 2000.