Studio Flash filter gels

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gary900r

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Can anyone recommend a good place to buy a good selection of colours of gels for studio flash heads.

Thanks
 
I bought these on Ebay. At 24" x 24" they are far from being full sized sheets, but big enough for most purposes.
These primary colours can be used together to produce other colours, and the intensity/saturation is controlled by the amount of power used, so there is in fact no real point in having anything other than primary colours, unless you want to colour correct
 
I've just looked on ebay and someone does custom selections of 6 for less than £20. So you can get the primary colours, a CTO and 2 NDs (or a 1/2cto and only 1 ND)
 
sk66 said:
Why ND's? To use like a graduated?
I think I would want polarizers instead if that is an option.
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Studio lights can be a little powerful when you want to limit the DoF, an ND is a godsend at that point.
It depends what you're shooting but a polariser is a good call too, can be used simply as a ND or to control reflections.
 
A polariser on the camera lens can have some effect, if the angles are right, but to be truly effective the light source needs to be polarised too - and that involves a polarising sheet that's very expensive and which dies if it gets hot. And it's a linear, not a circular polariser, which needs a matching linear polariser on the camera lens - which creates its own problem with autofocus. Me? I just get the light at the right angle to avoid the problem:)
ND filters though, can be irreplaceable for studio work.
 
Phil V said:
Studio lights can be a little powerful when you want to limit the DoF, an ND is a godsend at that point.
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I get it; big strobes, smaller working space, minimum power... I didn't think about shooting wide for shallow DOF (it's never my first thought). I would just use an ND on camera since I already have them.

Phil V said:
It depends what you're shooting but a polariser is a good call too, can be used simply as a ND or to control reflections.
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That was my thinking... controlling reflection on products when combined w/ a CPL.
 
Garry Edwards said:
ND filters though, can be irreplaceable for studio work.
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I guess if your strobes are already at min pwr and you still need to create a ratio?

Garry Edwards said:
And it's a linear, not a circular polariser, which needs a matching linear polariser on the camera lens - which creates its own problem with autofocus.
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I've never heard that... why wouldn't a CPL work? Maybe not entirely as effectively?
 
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sk66 said:
I guess if your strobes are already at min pwr and you still need to create a ratio?
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What's a ratio? :)

sk66 said:
I've never heard that... why wouldn't a CPL work? Maybe not entirely as effectively?
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I'm not sure that my understanding of physics is deep enough to answer that question but I SUSPECT that the likely reason is purely commercial - the market for a circular sheet of polarising filter is too small, and the cost would be too high.
 
Garry Edwards said:
What's a ratio? :)
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Lighting ratio between two strobes already at minimum power...

Garry Edwards said:
I'm not sure that my understanding of physics is deep enough to answer that question but I SUSPECT that the likely reason is purely commercial - the market for a circular sheet of polarising filter is too small, and the cost would be too high.
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I meant a CPL on camera combined with LPL filter sheet on the light. I don't think a CPL on the light is technically feasible; I'm pretty sure the net result would be the same as with an LPL.
 
We only use circular polarisers on the camera lens to prevent exposure and AF problems with some of the camera's systems can that can be polar sensitive. A circular polariser is a linear polariser with a 1/4 wave plate stuck on the back, and works just the same as a bare linear in this circumstance - and in every other circumstance for that matter, provided it's not used back-to-front. In theory I guess a sheet circular polariser is possible, but it would be completely pointless.
 
HoppyUK said:
We only use circular polarisers on the camera lens to prevent exposure and AF problems with some of the camera's systems can that can be polar sensitive. A circular polariser is a linear polariser with a 1/4 wave plate stuck on the back, and works just the same as a bare linear in this circumstance - and in every other circumstance for that matter, provided it's not used back-to-front. In theory I guess a sheet circular polariser is possible, but it would be completely pointless.
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I think you're agreeing with me?
 
sk66 said:
Did I misunderstand you when you said ND's can be irreplaceable?
I thought you were still referring to sheet filters for the strobes.... but I can see where you might have meant on the camera since I had mentioned it.
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What I mean is that it can be very difficult to manage without ND filters.
I use both approaches - typically a 0.9 one on the camera when all that I want to do is to use a large aperture, and I also use ND gels over individual lights when I need to reduce the power of a specific light more than can be achieved simply by reducing the power.
 
Well, a linear is slightly more effective but I take your point, and you're probably right that they could be used together, although it isn't something that I've ever given any thought to or tried.

Back in the 80s/90s when I used polarising sheets over lights, I found them very useful - but leave the modelling lamp on for just a few seconds and the polariser was ruined.
I went through a phase of using them to discover and photograph stresses in plastics, just to photograph some interesting effects. But it's a bit like water drop photography, it's a bit of a novelty that wears off
 
There is no difference in polarising ability between linear and circular polarisers. After all, a circular one is only a linear polariser with the addition of a quarter-wave plate on the rear. What is perhaps more surprising is there's no difference in polarising effect between a £20 cheapie and a £200 B+W (for cameras) - I've tested both types to death looking for it, despite what some may claim. The main performance differences are in the overall density and colour of the polarising material, the glass and coatings.

I've only ever used sheet polarisers once, to photography oil paintings that were impossible to light without reflections off the shiny textured surface. Two polarising sheets over the lights at one orientation, and one on the lens at 90 degrees and they were gone like magic :)
 
Garry Edwards said:
Back in the 80s/90s when I used polarising sheets over lights, I found them very useful - but leave the modelling lamp on for just a few seconds and the polariser was ruined.
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Just melted I assume?

I went through a phase of using them to discover and photograph stresses in plastics, just to photograph some interesting effects. But it's a bit like water drop photography, it's a bit of a novelty that wears off
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I've seen those types of pictures. Interesteing, but yeah, a novelty...
 
HoppyUK said:
There is no difference in polarising ability between linear and circular polarisers. After all, a circular one is only a linear polariser with the addition of a quarter-wave plate on the rear.
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Yeah, the QWP adds polarization back to the light after the LPL has removed the reflections. The added polarization allows the AF system to work.

I've only ever used sheet polarisers once, to photography oil paintings that were impossible to light without reflections off the shiny textured surface. Two polarising sheets over the lights at one orientation, and one on the lens at 90 degrees and they were gone like magic :)
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There's not a lot of use for them if you have a lot of lighting options. But they're also good for metal surfaces where the reflections are not otherwise polarized.
 
sk66 said:
Just melted I assume?


I've seen those types of pictures. Interesteing, but yeah, a novelty...
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Well, if you leave them on long enough they will buckle, and eventually melt - but they stop working long before they get to that stage
 
sk66 said:
Yeah, the QWP adds polarization back to the light after the LPL has removed the reflections. The added polarization allows the AF system to work.

<snip>
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Not quite. The quarter-wave plate 'circularises' the polarisation - basically scrambles it. The light coming from the back of a CPL is not polarised. It's the polarisation that can upset AF and metering.

Garry Edwards said:
Well, if you leave them on long enough they will buckle, and eventually melt - but they stop working long before they get to that stage
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The polarised sheets I used were kinda thickish and semi-rigid about 12in square - just big enough to cover a small light. They'd been well used and badly buckled, but still worked fine. The idea was you only swung them into position for the actual exposure. They were being chucked out because of the buckling, so I gave them a home. Still got them somewhere I think :)
 
HoppyUK said:
Not quite. The quarter-wave plate 'circularises' the polarisation - basically scrambles it. The light coming from the back of a CPL is not polarised. It's the polarisation that can upset AF and metering.
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All light is polarized... most of it is "circularly polarized" (i.e. having two wavelengths at 90 degrees to each other). A QWP splits linearly polarized light (one wavelength direction) into two directions (@90*) of smaller amplitude.
The pellicle mirror and the beam splitter portions of the AF system have a liner polarization effect on the light (the translucent portion of the reflex mirror is a reflective LPL). So if the light hitting them has the opposite direction of linear polarization it would be blocked. And if the light hitting them had the same polarization it would all pass thru to the AF system and not go to the metering system/viewfinder (the light that hit's the pellicle portion). The QWP improves AF by ensuring that the light gets through "appropriately."

Are we far enough off topic yet?;)
 
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