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To start with, you just need an instrumnet to measure illuminance (lx). I'm shure you can get this for some $50 or less on hamfeasts (or even new). Make something you can turn around where you can attach your light, so that it's lens (or whatever corresponds to it) is at it's axis. Having your lightmeter at a defined distance (not too close, maybe 2m or more would be fine). You also have to take care that spilled light does not influence your measurement too much. Several apertures, which are very black, will do it. The you turn your light and get your readings for every few degrees (depending on what is, flood or spotlight). You can easily draw an polar diagram with this data and probably get an rough estimation about the luminous flux (lm). And be shure to have the light fed by a 'standardized' power source (a regulated power supply should alse be eay to get on hamfeasts). <HR></BLOCKQUOTE>
I'm sure forum members would be delighted to see how you measure lightbeams from 2 different flashlight with many rings of various number and intensity around a hotspot with that instrument?
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Yes, but you get only an idea, and pretty often it is misleading. Like in the case where you overexpose your photo (I mentioned already). Keep that in mind. <HR></BLOCKQUOTE>
May not be perfect but I strive to be fair and close to true by selecting the one setup from series of samplers, sometimes 10 to 20 photos using different camera settings, without software retouch to be as close to true, and photographing Lightbeams at one time with one camera setup and setting for all of them.
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Actually you are measuring numerical data, but your measurements output is a diagram, which says more than 1000 photos. Reading a diagram is easy to learn and I'm shure you guys could do it very fast. Just compare the first few diagrams with you actual lights. For a row of numbers, you are very correct. This is only for people who are working daily with it and are number-addicted .-) <HR></BLOCKQUOTE>
I'd like to see diagram of TEC-40 or SL4AA lightbeam.
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Not necesarly: I hope to get access to a technical's school equipment, as I'm not working (commercially) in the electronics industry now for decades .-) <HR></BLOCKQUOTE>
That's good news! Eagerly awaiting lightbeam test results from that.
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The problem is, that your camera's perception is so much different from your eye's. And, BTW, it's pretty easy to make misleading photos. <HR></BLOCKQUOTE>
I agree. My eyes have wider scale in recognizing wide range of different tones of bright and dark parts of lightbeam. I'm still in the process of learning and developing how to do this right and I hope I'm getting better. Btw, do you know pro photog who shoots flashlight lightbeams whom CPF members who photograph lightbeams can learn from?
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Again: What's your camera's dynamic range? <HR></BLOCKQUOTE>
According to the manual my Kodak DC290 can be adjusted from -2.0 to +2.0 exposure value (EV) in 0.5 EV increments.
If you're referring to this
http://www.dpreview.com/news/0011/00111608dynamicrange.asp, as I said above still learning and hope to get better.
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This text was written when it looked like the other models will come out soon. As we all know, all the former available models (one and two piece) are not really good to hold in your hand. <HR></BLOCKQUOTE>
The webpage
http://www.hdssystems.com/ActionLight.htm shows pictures of the 1 and 2-piece models on top and Action Light Feature Comparison at the bottom, so I don't think HDS is telling viewers that they have other flashlight models in mind page for those performance claims other than Action Lights shown on the that page.
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