What's the difference between these cards and holding a CT Blue gel in front of the lens (in front of some white sheet) to "trick" the white balance?

Nothing, except these cards are pre-measured, and you'll know what you are getting with the various degrees of cards. They're not rocket science, just pre-planned, consistent, laminated, and come in a very nice case with instructions on how to use them.

Have used em for awhile, but for the most part can't go more than the 1/2 or it just gets to saturated for my taste. Still worth the money IMHO and I would get them again. Perhaps it won't be as bad with my XL2 as it was with the other XL's, havent tried yet.

- Ray

www.undergroundplanet.com

Warm Cards are overpriced (read: anything more than free) for what they do.

See my article about achieving the same effect using what you already have on the set.

http://michael-morlan.net/pages/learning/learning_wb_with_cc_gels.htm

Michael

I find them EXTREMELY useful. I'll have to read Michael's article, though. But I use them on a regular basis.

Mine have arrived literally today...*grin*

Just two pieces of hardware here: CTB and CTO gels, four inches by four each and that's it.
You can now make two things:
1-get a *warmer* or *colder* image to the degree you want (read: total control up to the cam's possibilities).
2-replace the "$" sign by a "¢" sign on your costs.

With the $64.35 you save, you can buy tape... or place an order for Spot's upcoming book ; )

Futz: What are CTB & CTO gels. Where can I get them ?

Every place that sells/rents lighting or photo equipment.
It can be Roscolux, Lee filters (different brands).
CTB=CT Blue (Thungsten to daylight)
CTO=CT Orange (Daylight to thungsten)
These filters are used to correct light sources.
You put the blue one in the frame between lens and white surface to get warmer white balance and vice versa. The more blue you get into the frame, the warmer the result (and vice versa again with the CTO filter).
If caught in a rush, most of the guys I work with are able to get the correction they want with their *B&W* viewfinder just by the numbers (kelvins, that is).
A little practice with a color monitor to compare your results at first and after a while, there you go.
But they actually *have* these numbers in the viewfinder; with a consumer cam, it's a few more seconds of hit or miss but, again, you get used to it so you get better every time. And since you got color monitor, it can be more of an "instant" process.


If you don't wanna pay for a full sheet of gel for each color, just ask one of these sample booklets. Usually free and you got everything you need and more. It's usually around one inch by three inches but it's all you need and very convenient (small to carry) plus you get all the colors the brand has to offer if you want to buy more colors in the future.
And there's more with this option: you get correction filters for neons.
And like ND filters, everything is "scaled" (1/4, 1/2, etc...). Lots of latitude.

In fact, to correct a light source, you pick up the complementary color and put it on the lamp. So if you want to "trick/cheat" even more with your camera, you set your white balance with it. To sort of sum it up... : )

CTB = Colour Temperature Blue
Standard Tungsten to daylight correction.
Boosts 3200ºK to nominal 5500ºK daylight.

CTO = Colour Temperature Orange
Standard daylight to Tungsten correction.
Converts 5500ºK daylight to 2900ºK.

There are several variations of each ranging from 1/8 to 2x.

In simple terms, a gel is a piece of heat-resistant plastic that you put in front of a light to get a specific colour out of it. Think of all the rock&roll shows/theatre performances you've attended. Any colour you see on stage is the result of a piece of gel being placed in front of the (normally white) light fixture.
Gel is available in various sizes ranging from 12" x 12" sheets up to rolls 4' x 25' long to allow lighting designers to cut their own. Prices start around $7 U.S. for a 21" x 24" sheet.
There are literally hundreds of colors available.
Manufacturers include (but not limited to) Rosco & Lee Filters.
Lee Filters has a list of dealers across the U.S. A worldwide list is also availble on their site.
Rosco has some technotes that you might find interesting reading.

Mike

Oops, I exagerated a little with the prices... ; )

rs170 & Futz: Thanks for the techinfo. I am trying to explore all possibilities. Can I use blue or orange glass filters to achieve the desired results ? I am concerned for the ease/speed of handling these add-ons.

Can I use blue or orange glass filters

You could but then you're into a lot more money. Both Lee and Tiffen make them but now you're into what are called "warming" (or colour conversion orlight balancing). There's usually an 80 series number with it.
What I'd do is look on-line for specific filters for your needs (an 80A for example) and then go to your local photography store and see what they have for filters. All you need is the right filter diameter and most camcorders have a thread mount similar to 35mm cameras.
You may even be able to get a filter holder that clamps on to your lens. A buddy of mine did that with a Cokin mount and it worked quite well. Cheap too :-)

Mike Kujbida

Here is a quick and dirty that give a SLIGHT warming effect.

There are many grades of printer paper on the market. Some of them have an "Index" of whiteness of 92 or higher. Getting 92 or higher is tough, so they cheat. They add blue and various chemical brightners to the mix. Sort of like some laundry detergents.

The higher the "index" the bluer the paper for many brands. Just hold one of these VERY bright pages next to an ordinary page, and you will see the difference.

These very slightly blue pages make an excellent very slight warming card. Note, I said VERY slight. But, that is often all I want.

And you can print your own on card from Photoshop or whatever as long as you go easy with the blue. Not very "pro" but what works works.

I'll experiment with a pastel blue A4 matte printing paper mounted on a cardboard or foam core and see how that works out. I may to try different shades of blue to get the right effect.

PS: I still think the process of handling these cards or pointing at a white surface to get a proper white balance is cumbersome and archiac. Hopefully,in the future, cameras will be designed with a "magic button" to automate the process.

Thanks to all.

And by the time you've gone for the drive to get your gels, typed your photoshop and printed it, laminated the cards or protected the gels somehow, I submit that the 60.00 spent on the protected, familiar, cased, and washable WarmCards are a better value.
Cheaper is always good, and sometimes better. And sometimes more hassle than just buying the real deal.
JD55, there are already auto systems. But without holding up something that represents white, how is the camera going to know that it's looking at the white that YOU want it to see. In fact, what if there is no white in the shot?
Whte balance is here forever whether you use WarmCards, Expodisc, or just a white T-shirt worn by the props guy.