Question about "Warm White" vs "Daylight" Fluorescent Lighting Filters
I already did a search about this topic, and the threads I found did not really answer my question.
I know that there are 2 types of filters to compensate for fluorescent lighting when you are using a daylight balanced film. Fluorescent Daylight (FLD) and Fluorescent White (FLW). Okay, but none of the sources I found explains what the difference between the sources are. I guess they assume I'm smart enough to know
Is there a way to tell the difference with the naked eye? Or is one type more likely in certain situations or areas? Since I won't see the results until I develop the film, it would be nice to get it right the first time.
If nothing else, what are "household" fluorescent lights (compact fluorescent bulbs, bathroom lights, etc.) likely to be... daylight or warm? How about office (white collar jobs) lighting? I am guessing that growlights used in greenhouses would probably be daylight.
Any help would be appreciated.
I think cool tubes are the most common. Daylight used to be more expensive and even now seem to be less common. I don't know if anybody makes warm tubes. Yes plant tubes will be daylight balanced most likely. Certainly if the plants are flowering.
Older style t12 Daylight fluorescent bulbs when lit will have a markedly bluish cast to them - warm white bulbs will have a yellow-red cast and cool white bulbs will look white with a greenish tint. The newer t8 energy efficient lamps are all marked with an indicator as to their color temperature 3000k being warm - 3500k in between warm and cool and 4100k being cool and the closest equivalent to the old "cool white" - there are also 5000k - which is the most neutral color and the approximate color temperature of the sun at midday. Then there are also 6500k lamps which approximate the old "daylight color" which is very cool(bluish in color). Concerning household compact fluorescents - most of them are 2700k which is warm and intended to approximate the color temperature of a household 100w light bulb - the color temp is usually marked on these bulbs as 27k or 2700k as part of the catalog number - these bulbs can also be occasionally found in 3000k and 4100k as well - the higher the number, the cooler the color. Hope this helps. I've worked in the electrical and lighting business my whole life - so I hope I didn't ramble on too much.
Originally Posted by AgX+hv
The common FL tubes hardly give good colour exposures on colour film. Even when exposures are made with the so-called FL filters. What is termed as daylight often is not so in the sense that would be significant for colour film. Warm and Daylight designations used by the manufacturers are often loosely used. Warm just indicates that the FL glows with a yellowish tone. As such, there could be a range of what colour these tubes actually emit.
If your intent is just to get colours 'almost' right, then the typical FL corrective filters may just work. But don't expect the colour of your photos to be totally right.
If your intent is to make studio lighting fixtures with flourescent lighting, that's another issue. The common FLs don't only emit the wrong type of light, but also they lack colour rendering. There are FLs which are marked as "daylight" and may even carry a 5500 or 6000K rating, but this does not guarantee satisfactory lighting if its colour rendering is low. Colour rendering refers to the illumination source's ability to light the object's hues- for instance, reds may be rendered as pink or dull red by sources with low CR.
Another concern is the ballast used to power the tubes. Magnetic ballasts make the lamps flicker. This flicker produces colour shifts noticeable in exposures. Electronic ballasts should be used instead to avoid this flicker.
Some specialty FLs do have high Colour Rendering Indexes which allow them to be used for colour photography. Those used for plants or aquaria may be suitable. You would have to ask the lamp maker what the CRI, aside from the colour temperature, of the FL tubes you may want to use.
just to add some humor to a subject that astro-physisists might be able to discuss with some minor difficulty...why not use b&w film!?
sorry, but Jack Boucher (NPS Photog) once asked me "wouldn't you rather be an astro-physisist than mess with that kind of lighting?" He uses b&w exclusively.
I've used the F-DL filter under mixed flourencent lighting and used 120 positive film and still had to do some tweaking w/PS. So, good luck...
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I rigged a flourescent skylight which works fine for BW exposures. I haven't used it for colour film. Shot colour with it on d*g**l. Despite the built-in white balance and customised colour settings, plenty of tweaking still had to be done in PS to achieve the quality so easily obtained with daylight, flash or even tungsten light:
Originally Posted by Drew B.
Made it primarily so that I can use my non-synched cameras
in the studio.
There's no easy way to get 100% match with flourescent tubes. Fld, Flb, work as well as a CC30M 35,25, etc.
Some of the Fuji films use what they call a 4th layer technology that allow use in mixed lighting situations with tolerably good results
Some might say I have a bad attitude! Too bad.
You never know if the tubes are warm white, daylight or a mixture of the two, unless you can measure the actual colour temperature with a colour temperature meter to calculate the exact filtration its very difficult to be exact. If I am using slide film I usual shoot a few shots with both FLD and FLW to hedge my bets
As John Koehrer says some Fuji colour negative films have a fourth emulsion layer that is supposed to help compensate for florescent lighting ( Fuji Pro 160S, Fuji Pro 160 C, Fuji Reala )there are probably others too.
I can't say from personal experience how these films perform in flourescent illumination, I have only used them in daylight you would need to try them yourself.
ya, thats right! I do use NPS for mixed lighting..and it works great..but haven't tried it with flourescent lights thrown in. I think I'll try it soon.
Originally Posted by John Koehrer
yes I agree with him,,,,,cool tubes are the most common.Tubular skylights have several advantages over traditional sky lights. Traditional skylights can be fairly complicated to install, as they require a fairly sizable area to be cut out of your roof and ceiling, and then replaced with a special type of window. These skylights allow the full spectrum of light to enter your space, which can cause fading and discoloration of your carpeting and furniture. Traditional skylights add light in a very direct line, illuminating the area immediately below the window and nowhere else. As mentioned before, they can also create additional heat in your home. Solar tubes do not suffer any of these complications.
Originally Posted by Nick Zentena