Paul C. Buff, Inc. Technical Forum

Hello,

I'm coming from continuous lights and have a couple questions regarding copywork use:

1. Is there any technical specs for the approximate CRI of the flash tube used in the Einstein, and or spectral charts? To be fair I can't really find this data for other makers online, but since I can find this data on the continuous lights I use it would be good to compare.

2. If using multiple heads, how much variance could I expect from each unit if they were all firing at the same power level? How about flash to flash?

3. How even is the illumination (within the main circle of light before it tapers off) coming from the UMF reflector? What would give me the most even light - bare bulb? - maybe a custom mod similar to Visatek's Sunlite fitted to the base mounting plate? I don't need "soft", and prefer hard linear light (though broad) like what I get from Totas, using barndoors to control spill.

Thanks!

-John

I think there are some specs on the einstein posted on the product page. Color temp is pretty tight from shot to shot, and over the output range.

You might look at the silver or white PLMs. The silver may be what you need--a fairly linear beam of light, not as soft as white umbrella, but focused and pretty even. Three different sizes to choose from.

There is actually not a lot of spill from the silver PLM when you put the light dome at the focus point--very parallel light. I put an 86" silver plm up in my living room when I first got it. The upper rim was probably 2-3 inches away from the ceiling, and it didn't spill onto the ceiling at all.

I don't know how practical the various sizes of the plms might be for your application, though.

Thank you for the suggestions. I did look at the Einstein specs, and the constant color mode on the Einstein is one of the main reasons I'm looking at the units. But I need more then two, probably 6, and am curious how much variation would I get from soo many units at the same power level - for both whitebalance, and flash to flash exposure differences. Maybe it would be nil or very little I hope. CRI is also important and seperate from whitebalance.

The PLM looks like fun, but is way too big for copywork - you would not be able to properly polarize it since most sheets are maxed at 17" wide.

I am working on getting the spectral information. However the UMF is very even in coverage. With the textured surface, there is no visible break up of the light pattern.

Thank you, I look forward to seeing it.

Also, as I search for light modifiers I ran across the photogenic Linear Reflector (PL12RGBK). I realize this takes an additional linear tube, but the concept is closer to what I want than a round reflector. Perhaps there is a way to replicate it with the UMF, or even flag the sides of the beauty dish to get a similar result?

How far back would I need to get the UMF away from the wall to eliminate any hot spotting? Most of the time my lights are about 8 feet from the artwork, sometimes I can get them further back but not always. If you have a photo or link of a wall shot with that reflector (and or the beauty dish) could you send it to me.?

Thanks!