Has any one tried using a coloured gel over a flash? If so, what are the effects?

[waltex]

I have been reading a lot recently about creating your own homemade flash diffuser, like the following

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It makes me wonder what would happen if I put a coloured gel onto a flash? Even a lightly coloured one.

As you would know, Lee has a variety of gels

http://www.leefilters.com/lighting/p...46C9C0C1B557F/

Some of them are for colour correction (correction of colour temperature) and some are for straight-out colour


Has anyone tried putting a coloured gel onto their flash, and what have been the effects? I am perhaps thinking of using a coloured gel with a homemade flash diffuser.

thanks for your help everyone

[ricktas]

Coloured gels do just what the name implies, it colours the flash output, usually for effect, to create say a nightclub feel in a shot taken in a non nightclub environment.

Colour cast can be corrected by using the correct white balance setting in your camera, or in post processing (as long as you shoot RAW).

I have a set of colour filters for one of my flash units (they came with it). I played with them for about 20 minutes, decided they were gimmicky and haven't used them since.

Using coloured filters over studio lights etc is a whole different ball game, and can create some really wonderful studio shots. Where you can colour the background, or use a hair spot, with a blue filter to give the hair a slight blue outline (or halo) around the subject. Used well coloured filters over studio lights can be very effective.

[arthurking83]

I have an SB800 and it came with two coloured gel filters.

I've used the orangey coloured filter once! .. and even then only as a curiosity.

What I have done tho is to use coloured cups instead. The coloured cups are of an opaque material and do lose a lot of ultimate light power.
I've also used this coloured cup method over a high powered LED torch too:

Normal:


Red:


Blue:


Red and Blue:

(ie. I didn't have a purple cup! )

The 'filters' (and set up):


gels will work better of course because they don't inhibit the light power as much.

One thing to note too, just in case. pre set WB on the camera, as if you use AWB, they may be a tendency for the camera to counter the strong filter effect.
What I did with these images was to shoot them in AWB, but with the intent of setting WB to whatever worked best on the natural light image.
That is, on the red image, the image on camera is a lot more blue/purple and nowhere near as vivid in the red. I set the white image to WB daylight(5200) and with that the rest of the images at the same WB setting and they 'all came good'. The camera naturally tried to balance WB as best as it could given the lighting circumstances.

[N*A*M]

for event photography, i use both the green and/or orange gels to match flash colour temperature to the other light sources (fluoro and tungsten respectively). it simplifies the white balance of the scene and can help keep your skin tones in check. it prevents your ambient background from becoming overly green or orange. when balancing, you have to realise that that the green gel prevents the background from going green, rather than making the scene more green because you will set the right white balance to suit. it's just backwards to common thought.

another backwards truth is that if you are using gels for effect, less is more. for more colour intensity, you actually want to reduce the power of the flash. too much flash power will wash out your colours and turn them closer to white. dial down the power, drag the shutter, and the colour saturation will increase dramatically.

both of these shots were lit the same way (Full CTO gel on SB900 through very tight DIY gridspot camera left; and a Clear SB600 camera right).
the second one has a tungsten white balance, set in post processing.



in conclusion, gels are both useful and fun. play with them! some of the concepts are initially backwards, but do make sense once you experiment.

cool examples AK.

[98kellrs]

for event photography, i use both the green and/or orange gels to match flash colour temperature to the other light sources (fluoro and tungsten respectively). it simplifies the white balance of the scene and can help keep your skin tones in check. it prevents your ambient background from becoming overly green or orange. when balancing, you have to realise that that the green gel prevents the background from going green, rather than making the scene more green because you will set the right white balance to suit.

+1 on this. Arguably the most common use for a gel is to correct your flash's colour temp. See here: http://strobist.blogspot.com/2006/03...o-correct.html. The part about sine waves and using your shutter speed to ensure an entire wave is captured to keep a consistent colour temp is quite an interesting concept, I wonder if Australia uses the same 60Hz sine wave?

[waltex]

Wow thanks everyone for your comprehensive answers and even photo examples!

I will try some coloured gels over a flash in the future!

[dredi1975]

i tried few times colour bottles of beer or wine....just for fun

[KLi]

There is colour gel or correction gel, colour gel is obviously for having different colour light, correction gels are used to colour balance. E.g Using flash on portrait shoot during sunset, light from sun is much warmer then your daylight balanced flash, so throw on a colour temp orange filter on your flash to match the light on your subject to the background sunset.

[srowlandson]

a coloured gel on a speedlite fired at the background can add an interesting backdrop to a portrait too.