Fluorescent WB hell

Heya,

What's the proper procedure to work with fluorescent lights? Did a couple of shoots this past week and on both I ended up with people looking like mutants courtesy of the greenish tint, even though I used a different approach for each shoot. In the first one I put a full plusgreen over the flash head which was aimed into a shoot-through brolly: the camera was set to daylight WB. This is what I got in LR later:

'As Shot' WB
'Fluorescent' WB

I don't know, but I think I can still see a slight greenish tint in the corrected photo (the uncorrected is just plain dreadful!)

Then comes yesterday's shoot. Trying to get the WB right, this time I used a 1/2 plusgreen gel and set the WB in the camera to Fluorescent. These are the results:

'As Shot' WB
'Fluorescent'
'Custom', as defined by a reading from the SpyderCube's grey, neutral area.

All shots seem greenish to me; even the last one which does look quite warm (too warm for my liking) has a slight greenish cast, especially to the left of the frame (where the brolly was located: again, shoot-through).

Any ideas?

TIA

Personally, I like use a fast enough shutter speed to kill the ambient light and rely on my own lighting whenever possible when florescent are in play.

Also, keep in mind that most fluorescent tubes don't have very good color accuracy so you may never get things looking just how you like if they're contributing too much to the overall exposure.

Sounds reasonable. Can this be done with only one flashgun? I was indeed 'dragging the shutter', trying to use the available light as fill.

If fluorescent lights (or any other gas-discharge lighting) are driven at the power-line frequency, you'll have to use one of several very specific shutter speeds to get uniform brightness and color across the image - especially when using a camera which has a focal plane shutter. The problem is that the color and intensity of the light changes 120 times per second when powered by 60Hz power. Thus, the only shutter speeds that would work properly are 1/120, 1/60, 1/30, 1/15, etc. The requirement is to have the shutter open for whole multiples of the half-cycle time for the power source.

You cannot blend flash or daylight with fluorescent light and expect good results. Of course, the same could be said for mixing incandescent light with flash or daylight.

Fluorescent lights that are driven by a high-speed electronic ballast do not have the same shutter speed limitations as those driven by magnetic ballasts (at power line frequency). This would include compact fluorescent lights (CFLs). However, these lights still have a very poor color spectrum and may not be worth a hoot for photography.

Alveric wrote in post #15122373
Sounds reasonable. Can this be done with only one flashgun? I was indeed 'dragging the shutter', trying to use the available light as fill.

It depends on the ambient light. I do it all the time indoors under household lighting. Brighter conditions will be more challenging.

Fluorescent lights produce a discontinuous light spectrum. In other words, certain wavelengths within the visual spectrum simply aren't there, and other wavelengths will be especially prominent. With a custom white balance you can make grey look grey, but some colors just can't be rendered properly. Reds are generally dull, and since red is an important component of most skin tones it can be impossible to make people look healthy.

The best approach, as recommended by Mike D, is to bring your own light and obliterate the fluorescent. It's usually not too hard if you have a white ceiling to bounce off. Keep your shutter speed at X-sync and let your flash do the talking.

Part of the fluorescent hell is the fact that most places use several different brands and models of bulbs, and each has its own peculiarilies...there is no such thing as a single, universal correction! In the days of film you would use a different set of color correction filters (and there were seven commonly used filter packs) to try to balance the source to the daylight rating of film.

Daylight fluorescent: 40R
+ 2/3 stop

White fluorescent: 20C + 30M
+ 1 stop

Warm White fluorescent: 40B
+ 1 stop

Warm White Deluxe fluorescent: 30B + 30C
+ 1 1/3 stops

Cool White fluorescent: 30M
+ 2/3 stop

Cool White Deluxe fluorescent: 20C + 10M
+ 2/3 stop

Note: When you don't know the type of fluorescent lamps, try a 10C + 20M filter combination and increase exposure by 2/3 stop; color rendition may be less than optimum.

Today, in the case of filters applied over daylight flashheads (which is intended to make your supplemental lighting similar to the ambient fluorescent) that correction filter is just like buying socks...one size, fits none well!

A very brief look at the Sylvania site, comparing three types of tubes identical in voltage, wattage, length and all other physical attributes gives three totally different colour temperatures of tube. We can choose from Cool white deluxe (3000°K), Warm white deluxe (4000°K) and Daylite deluxe (6000°K) [amusingly, they only sell 'deluxe' and not standard grades - the power of association, eh] - none of which directly match photographic standards. Without physically checking every tube in use, we have no way of knowing what each one is and colour temperature isn't usually a factor in janitorial resupply. If it fits & it's bright enough then it's OK tend to be the only considerations.

Factor in ageing of the tubes (they almost certainly won't all be the same age), the cleanliness of the tubes, any discolouration of the reflectors above the tubes and yellowing/dust/flies on diffusers if fitted - basically you haven't got a hope in h*ll of colour balancing. In theory, yes - you could invest substantially in a colour temperature meter, measure each tube individually, filter-sleeve each tube individually and the theory is that you could correct. In practice, just forget it!

Matching old, incandescent bulbs isn't as difficult as the colour temperature only ranges from about 2500°K to maybe 3200°K as the wattage increases (2500-2900°K is about the normal range). The range isn't nearly as great; there aren't the shutter speed/cycle factor considerations and anyway the human eye will happily accept off-colour rendition which is a little warmer than neutral. The same can't be said for fluorescents; despite manufacturer's claims, the very nature of the beast pretty much kills any chance of acceptable rendition because there are whole wavelengths of colour which are totally absent. That's in addition to the preceding considerations.

Wilt: Thanks for the memory jog - I've still got Wratten filters foils for this sort of work. Somewhere. Long time no see! The 20M was also nice for removing green casts on skin under the shade of foliage using Ektacolor/Vericolor, if I remember correctly.

Incidentally, harking back to Curtis N's mention of the discontinuous spectrum, this is exactly why fluorescents are so tiring to work under for long periods.

I shoot in fluorescent light all the time. I gel for it when I need to use flash and use the flash as fill with a fluorescent gel to match the lights and I shoot (as Wilt pointed out) at 1/125, 1/60, 1/30, 1/15, 1/8 etc but not faster than 1/125.

Fluorescent and tungsten in the background no flash.

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Great shots, airfrogusmc!

Cant remember where I read or saw this, but when shooting in this kind of light,
try to run at 1/60 or slower, only changing the apeture and or iso in manual mode, or,
try shooting in TV mode with the 1/60 or lower speed, and let the camera select the
iso and apeture.

Thanks but I shoot often at 1/125 but the key is to shoot at 1/125, 1/60, 1/30. 1/15, 1/8, 1/4. Those even speeds are important as Skip pointed out in #4.

I only shoot manual.

A half cycle (1/125) goes thru the exact same color cycling as a full cycle of color cycling (assuming 60 Hz cycle AC)

Do the 5500k compact florescent bulbs sold for video lighting fix the discontinuous spectrum problem?

SkipD wrote in post #15122454
If fluorescent lights (or any other gas-discharge lighting) are driven at the power-line frequency [...]

Fluorescent lights that are driven by a high-speed electronic ballast do not have the same shutter speed limitations as those driven by magnetic ballasts (at power line frequency). This would include compact fluorescent lights (CFLs). However, these lights still have a very poor color spectrum and may not be worth a hoot for photography.

How can you tell the difference 'twixt electronic and magnetic ballasts?

Alveric wrote in post #15128435
How can you tell the difference 'twixt electronic and magnetic ballasts?

In the "olden days", I could have used my stereo system's turntable (which has been stored and out of service for many years). The turntable had a set of lines around it that appeared to stand still if they were lit with fluorescent light and the turntable was turning at exactly 33RPM (or other standard speeds).

Quite honestly, at this time of the morning I cannot think of a way to observe the frequency of the light. However, if you tried making a series of photographs with the light from the fluorescent lamp being the dominant illumination of the scene and using shutter speeds significantly faster than 1/120 second, you will see significant variations in color and brightness from shot to shot.