What are gels?

3rdPlanetPhotography

I have a home studio.. and I keep seeing post about gels. I missed that class. What are they and how do they work?:scratch

Art Scott

kc7dji wrote:

I have a home studio.. and I keep seeing post about gels. I missed that class. What are they and how do they work?

If you are refering to my suggestions for using Rosco Gels for coloring backgrounds, then I will try to explain better.

...with a gel over the front of your background light(s) it will change the color of the background to the color of the gel....that is of course if you are using a blk muslin or paper background.
These gels areesaily and cheaply bought at theatrical supply sores or from Rosco link to gel pages at Rosco...link:
http://www.rosco.com/us/promotions/roscolux.asp

.....This link shows a swatch book of Rosco gels

These are the same gels used by most all staging and lighting companies around the world....same that you see at concerts and such.

I'll see if I can get my scanner hooked back up and post some pics that were done with a blk background that I changed to a different color with gels.

I would tell my portrait clients that I paint my background with light not paint,,,,,,,,I started out with my studion in the front room of a 12 X 60 mobile home...so 1 background was my only option at the time and I just stumbled into this by accident....after placing one of my colored filters over a vivtar 285 and doing a test print of it (the Vivatar 285's used to come with 3 colored filters and 1 clear diffuser.....so I was curious as to what the colored filters would do...........

This method of coloring the background works best if you can have the subject 3 to 5 feet from background and lessen your main lights on your subject...the distance of the background lites are from the background determines the type or amopunt of wash (coverage) you get....lights up close creates colored hotspots...can be cool if you have access to 5 or more back lights ...using different colors on each side creates different effects as does 1 light high and 1 low the possibilities are pretty much endless........

JimM

I just picked up a couple of Rosco's here locally. They were $6.50 each for a 20x24" gel. I'll post some pictures when I set my studio up again.

Bodley

JimM wrote:

I just picked up a couple of Rosco's here locally. They were $6.50 each for a 20x24" gel. I'll post some pictures when I set my studio up again.

As I am severely "PHOTO" Gel challenged, other types , anyway, how do you use these with 580ex type flashes? How do they attach and how much light do they eat up?

JimM

I don't think they will come in much handy on an on camera flash, unless you want to change the color of the light hitting your subject. They are much more useful in a studio setup, to change the color, or color tint of your backdrop. You could rubber-band the gel over the 580 to iluminate a different shade, but i don't think you would use this very often, just for a special effect once in a while.

Bodley

JimM wrote:

I don't think they will come in much handy on an on camera flash, unless you want to change the color of the light hitting your subject. They are much more useful in a studio setup, to change the color, or color tint of your backdrop. You could rubber-band the gel over the 580 to iluminate a different shade, but i don't think you would use this very often, just for a special effect once in a while.

I have 3 off-camera 580's (actually 2-580 & 1-550) I use as a portable setup.

How many stops do you lose with a gel?

JimM

Here are some samples of me using gels:

No gel or rear strobe:


Rear strobe (no gel), very hot


with blue gel


with blue and grey gel


example of gel:


you can see I have not devised a way to mount the gels, but I wanted to try them so I just laid them over the light.

Hopefully this helps explain a little. I am still learning, and I really would like a darker backdrop to start with.

Shay Stephens

I use gels on my flash units, mostly I convert them to incandescent, but I do have some to convert to various types of fluorescent too.

Since they are basically just film, you can just tape, pin, or rubberband them to the lights. Depending on your light, you may be able to get special gel holders, or you could make something yourself. It's definitely not rocket science thankfully

The amount of light lost depends on the gel, and you should get that info on the page you buy them on. But usually it's around 1/3 to 2/3 of a stop. It can go higher, especially if you stack gels together.

ScottMcLeod

Don't forget LEE gels and GAM gels.

Rosco, as nice as they are, are lacking in blues with a red tint. (Most of their blues have a green tint)

If anyone has questions about colour theory or gels, fire them over here, because I've been doing colour theory for 3 years so far in school.

Bodley

[quote=Shay Stephens
Since they are basically just film, [/quote]

As the old saying goes "Tis better keep your mouth shut and be thought of as an idiot than to open your mouth and remove all doubt".

Here's to removing some doubt on my part - I had envisioned gels as being somewhat comparable to what colored breast implants might look like (before they are implanted of course).

Maybe colored with lights in them - Sorry, I digress :

colourbox

JimM wrote:

I don't think they will come in much handy on an on camera flash, unless you want to change the color of the light hitting your subject.

Years ago I read an article about how to use gels outdoors or in a very large space, to change the color of everything except the subject! What you do is put, for example, a green gel on the lens and a red gel on the flash. When you take the photo, the flash gel (red) reddens everything lit by the flash, such as the subject. But when the flash gel is an exact complementary color (green), it cancels out the lens gel for all areas lit by the flash. So if you used this technique to take a picture of a person in a field, the person would appear normally balanced but the entire background, which is outside flash range, would be as red as the gel. The sample photos in the magazine were extremely cool, but I never tried it.

JimM

This would be interesting to try... has anyone done this?

colourbox wrote:

Years ago I read an article about how to use gels outdoors or in a very large space, to change the color of everything except the subject! What you do is put, for example, a green gel on the lens and a red gel on the flash. When you take the photo, the flash gel (red) reddens everything lit by the flash, such as the subject. But when the flash gel is an exact complementary color (green), it cancels out the lens gel for all areas lit by the flash. So if you used this technique to take a picture of a person in a field, the person would appear normally balanced but the entire background, which is outside flash range, would be as red as the gel. The sample photos in the magazine were extremely cool, but I never tried it.