Do you work mainly with speedlights? Then at some point you’ve bumped into the idea of gelling your flash. For lots of starting photographers that may be a confusing process. The first challenge is to figure out precisely what do you get and where do you get it from?
Then comes the oh dear moment. How do you put those cute color cut-outs on your flash head without them falling off?
Good news. Gelling your flash is fast, simple and inexpensive. One point in your favor is that the fresnel lens on your flash is merely a few square inches in size; and that is the sum total you’re ever going to need to gel.
What is a fresnel?
This is it:
It’s basically where the light emerges from on your flash head.
How do you get your gel to stick to your flash?
Some speedlights have integrated clips for mounting one or more pre-cut gels to the front of the speedlight. Problem solved.
If your flash doesn’t have that special clip then it’s time to make a pilgrimage to e-bay where you can buy add-on clips.
If you want to save a few bucks then you can gaffer tape or elastic band the gels to your flash. Take the money you’ve saved and spend it on other cool photo equipment.
There are a few issues to keep an eye on, unless you think permanently heat-welded gels on your speedlights look cute.
For one, you’ll want total coverage of your flash head except for the edges. It’s preferable to have gaps at the edges.
You see there is a minor issue of heat dissipation. You don’t want a great deal of warmth to build up between the speedlight head and the gel. Gels are created to soak up all this heat, but most people underestimate how much heat is being soaked up.
It’s truly easy to cook the plastic fresnel lens. This can happens if:
a) You’re utilizing an external high-voltage battery
b) You’re firing a lot of high-power pops in quick succession
c) You’re photographing at high-power settings
Basically quicker recycle times can lead to a lot of heat, which can lead to this:
Lucky for us, modern flashes have built in thermal safeguards, but cheap flashes and flashes older than a decade don’t.
Be careful or you’ll fry those babies.
This problem appears more frequently when photographers are using dense gels that absorb a lot of light. This is true for dark blues and deep reds.
It’s a vicious cycle, because they’re so dense that you’ll need to crank up your power levels on the flash to get the job done.
Be on the safe side and leave an air gap and mind your shooting momentum at even moderate power settings.
If you really want that gel married to your flash head till death do us apart then at least use a very mild gel like Rosco 08 warming gel. This way you’ll be safe when you’re in a heavy photo session shooting at full-power.
This practically sums it up for all you flash photographers. Big lights, using their distinctive tube/bulb design, high power levels and various light modifiers, are a different animal entirely.