Re: Your question

Brad is correct. "One way" of trying to chroma key is the use of Zebra stripes in the viewfinder.

In the "old days" I did that myself. HOWEVER, I couldn't GUARANTEE my keys, the way I do now. Zebra stripes set to 70 IRE tell the user that in this "area of the picture" there is a light level of "at least" 70% IRE... that might be 76%, 80%, who knows with the stripes... It's nearly IMPOSSIBLE to get uniform and even lighting by using that method. The right side of the picture may have stripes, and not the left side, by the time the whole viewfinder is showing stripes, you have no idea where your true IRE levels are across the frame. I know... We got "lucky" a few times and had some disasters with others.

It wasn't until someone showed me the TRUE measuring tool for light in an electronic video camera, a wave form monitor, that my chroma key work began to stand out from the others in my market.

WHO SAID ANYTHING ABOUT OWNING this gear? Heck, I RENTED a WFM for years! They are about $75 per day, in the SD world... a little more in the HD world. I bill that back to the client. I'm sure others do too. I tell clients that we may cost more "up front" in terms of equipment, but I GUARANTEE our keys on the first pass with minimal effort. That CAN NOT be done with out using a waveform monitor. Once clients give it a try, they are hooked! They see the benefit of the money they are paying.

By the way, the WFMs built into monitors really don't cut it, either... they are only a reference. Remember, the "monitor" is just that, a monitor and not a measuring tool. I've used these types of monitors "side by side" with the real reference gear, and they just don't compare. When performing a chroma key, you are shooting in an advanced state. This isn't a simple interview. There are so many things that can go wrong, it's better off to begin with the best of your ability.

I've actually keyed shots with Lowell lights! Not to say they aren't "good" lights, I just generally use different instruments these days. Again, it's more TECHNIQUE than fancy lights. If the principals are applied correctly, desirable results occur. I will only stress that a WFM makes the process not only easier, but provides a better outlook on the final result.

The bottom line is: the choice is YOURS! Do what you want. I've just been really fortunate with folks sharing knowledge and wanted to "pay it forward..." When adjustments were made to our process, our results were noticeably better. Thus, we became "first calls" and experts in this area. Thus, we've made more money. We don't guess any longer, we KNOW!

Curt Pair
Picture This Productions
Sony ICE Team
F900/F800/F350/PDW700/EX1/EX3/D790/D600
Adobe Premiere Pro CS3 HD/Matrox
Phoenix, AZ