I'm trying to compare some lights here and I'm wondering what the best way to capture them is. I have a DSLR so I can control anything I want, but should I let it pick the shutter speed for the brighter one, then use the same setting for the dimmer one or vice versa?
1. Set to manual mode to ensure consistent exposure and base it on your medium powered light if comparing others
2. Set white balance to daylight and lock it in. No AWB here.
3. Use a tripod
4. Use a control flashlight everyone knows for reference (i,e. m@glight?)
5. Use common object(s) to illuminate for reference
Bracketing one over and under the target exposure may be helpful in showing spill and flood.
I usually manually set ISO to 400 and set aperture to 5.6 and shutter to yield average exposure based on my middle powered light. A daytime control shot may be useful for seeing the ovrall terrain fo the are which one my not see at night.
So it's been more than a year, and now I have another light I want to compare... I'm still not sure if I should shoot the brightest one first so it's exposed more correctly, or shoot the dimmer one first and have the brighter one be overexposed... The first way, the dimmer light is going to look even dimmer in comparison, and the second way the brighter one is going to look brighter than normal. Which do you guys do?
Well, I haven't done any beamshots yet as I'm just now waiting for my first serious order of flashlights to arrive, but, based on my 45 plus years as a professional photographer I would shoot the dimmer light first and bias the exposure to show that light as somewhat underexposed but still showing some dim detail. Then, if there is a very great difference in brightness between the lights, the brightest one would probably appear overexposed and washed out. That way would probably give the viewer more information that he/she could relate to.
The problem we run into when photographing scenes that have a great brightness range is that the human eye is capable of discerning details in a much wider range of brightness than any film or digital imager can.
Actually, you could also expose for the brightest light with just a little bit of overexposure washout on that picture and then use the same settings to shoot the dimmer lights and let them go as dark as they need to then post both sets of pictures so the viewers can see the brightness range from both directions. Making these decisions is so much easier with the instant feedback of digital than it was in the film days.
EV_007 gives real good suggestions above too. I'll look forward to seeing your results.