Any CPF standard testing procedures?

[kosPap]

well this might have come up again in a earlier date but I will have to ask nevertheless.

Has CPF established any flashlight test procedures, methods, distances, targets etc that are often used by members?

For example I did notice that some members take beamshots at -2 camera stops also. Flashlightreviews uses a target wiht rings that show the beam hotspot size, and I have made my own (http://groups.msn.com/clenchedteetharticles/flashlightbeamshots.msnw)

I intend on making some beamshots of my new flashlights so I would like to know and follow these tips/practices if they exist.

Else, how about establishing - unofficialy- some?

enjoy, kostas

 

[Lobo]

I've noticed the same thing as you did.
Another good practice is the luxreadings at 1m and the home made "integral sphere". Quickbeam has a description how to make one on his site.
http://www.flashlightreviews.com/features/lightbox_output.htm

And something that IMHO is even better than beamshots on a white wall is practical beamshots, like a large area indoors or outdoors with reference picture with no light/ambient light. But I guess those are harder to do.

I like your idea of establishing some "official" guidelines.
Cheers.

 

[cratz2]

Well, once you've done enough of your own beamshots to get a useful comparison, I think the standardized settings become less useful. I mean, when I used to post a lot of beamshots, I usually did a series of the same lights on the same night and posted them all in a thread. Even with manual camera settings, it would be difficult to directly compare what my camera got in a certain night vs what your camera would get on a different night.

It is very important to use manual camera settings. Automatic settings really are about worthless for comparing brightness because the camera will try to compensate for the difference in brightness of two lights. And a tripod is almost a neccessity.

I used to always use f2.8, 1 second, 28mm though my new camera defaults to f2.6 @ 28mm.

As for targets, it would be pretty useful if we all came up with a single target for beam pattern and shape but again, once you've done maybe 10 different lights, the target you used becomes less important. I do an interior shot at ~17 feet of a painting. The hotspot lights up the painting and the spill beam lights up the surrounding area. For outdoors, I shoot at a minibarn that is ~52 feet from the our backdoor.

I've seen a member using the same settings I use, except set for 2 seconds. This gives a better idea of the relative brightness of the spillbeam.

 

[DUQ]

The under exposure helps to define the "hotspot" of the beam.

 

[kosPap]

My camera settings are almost the same, though I can not vouch for the 28mm setting, maybe it is 50mm.

but I do believe a standard target will help for reviewing beamshots taken at different sessions by different users

it is LATe here in greece, got ot go an catch some ZZZ, kostas