Paul C. Buff, Inc. Technical Forum

For fun, we spent some time comparing the output of the new crop of Paul Buff reflectors.

We compared:

- 7" Standard Reflector
- 8.5" High Output Reflector
- 11" Long Throw Reflector
- 22" High Output Beauty Dish (silver)
- 64" Silver PLM
- The Retro Laser Reflector
- and a salad bowl (yes, an actual salad bowl)

You can see the raw data here.

You can read our whole discussion here.

The reason for this post? To share the data and see what folks think we should do in our next round of testing. Let me know!

Thanks!

BUD THORPE
Studio Manager
theSOPHA.com
Manchester, NH

AWESOME WORK MAN!

Awesome work Bud! Thank you so much!

Great work!

Hmm...can anyone explain the non-linearity of these results? I can understand close-up non-linearity (within 10 feet), but going from 20 feet to 40 feet should always be two stops less, shouldn't it?

Granted, we need better user instructions, but you should be getting about 1f more output from the Retro Laser when focused to minimum beamwidth than from the 220HOBD.

We found the bright dipping on the first batch was not as bright as our approved sample and are about 4/10 f low, so we are returning 2000 for rework. They are making some new ones now and they are due to ship from China in 12 days or so.

Also, I assume there is a typo on your 20' HOBD measurement . . .do you mean f11 +0/10 rather than f11.8.0?

On Einstein at 640WS at 20' we got f16 + 4/10 from the 22HOBD Silver and f22 + 5/10 from the tightly focused Retro Laser from the approved sample (GN = 540), and f22 +1/10 from the versions that have been shipped.

You really have to look at the beam patterns to really compare reflector . . . the 22HOBD has a very hot center and rapid falloff while the Retro Laser is very even across it pattern, with a rapid grid-like falloff.

I'm trying to get picture of all the beam patterns against a mid grey wall and outputs together and on the web.

Paul -

First, nice catch on the typo. I have corrected the jpeg file, the blog post, and the link in the original post.

I also agree that seeing the beam pattern is integral to a complete assessment of this and any reflector. As we weren't testing against a wall, we couldn't see the resulting beam pattern for any one particular reflector. I think that the focusing factor in using the Retro Laser Reflector requires more evaluation on my end to make a proper conclusion.

That said, today I have a SOPHA Member's Only photoshoot - one "station" is out in our alleyway competing with the sun. For that shot we will be using the 22" HOBD with a grid, and not the Laser. Reason? I am following my observed data.

As an aside - when I was performing the tests, it turns out that I was illuminating a building hundreds of yards away (our local library) - it appears that I was lighting up a room on the third floor of the library. Funny.

Paul - keep up the great work. I have three studios full of your gear that gets HARD daily use. Profoto couldn't pay me to switch. Seriously.

This sort of testing is really difficult. The light produced against a flat wall is the only accurate way to see what the different reflectors are doing . . . and it mighty hard for most (including myself) to find a nice gigantic flat wall that you can shoot at 20'+. You also have to consider the ambient that creeps into the measurements and the all important effects of spill light that accentuates the readings and apparent pattern when it bounces off peripheral objects .- especially in an alley like setting. This really affect the 22HOBD because its shallow shape produces tons of spill light that bounces off side objects and adds to the meter readings, while the Retro Laser and silver PLM have essentially no spill light at all.

We've had to paint the wall, floor and ceiling of our modest test studio dark grey to accurately see patterns and color response. On large modifiers, we've found it takes 20' to 30' to determine the real Guide Numbers and that they can be extrapolated linearly with little error for greater distances. But on wide angle reflectors with a lot of spill, you have to test at 10' unless you have a gigantic room with dark surfaces and 30' square wall or the spill effect don't allow seeing the patterns and true output.

Evaluating and quantifying this stuff is really difficult so we all really appreciate your efforts.