Looking for a way to compare the relative illumination of my torches, LED & Luxeons, for example to compare torch with torch, or Alkaline with nimh batteries, I came up with the following:

Here in the UK you can buy 25 Aspirin or Paracetamol tablets in a small opaque container, (2.5 inch deep, 1.5 inch across diameter) 4 for £1, $1.75.

When empty (!) they make excellent illumination globes for light output comparison.

Best done at night (!) or darkened room.

Most of my torches fit into the aperture, place torch head just inside opening, and it diffuses the beam lovely.

Then you need a light measuring device, my digital camera is ideal, but any camera (35mm etc) which shows aperture and shutter speed will do.

Make sure the camera is set to fixed ASA, not Auto ASA, and the flash setting is off, so you don't get fixed 1/100 shutter speed(depends on camera)

Best if aperture is fixed, or doesn't alter on your camera, until a certain level is reached, then just compare shutter speed indicated by your various torches for comparisons, (or batteries) it can show up small differences not really visible to naked eye.

Of course it's all relative, no actual lux, lumens or whatever figures, and doesn't take into account beam angle, for example a focussed Luxeon beam will appear brighter for distance work than a non focussed many led torch, which may give higher illumination reading using above method.

I find this very usefull for comparing HK Luxeons, with UK and US Luxeons, where a HK Luxeon 3 (Clone) seems to give camparable output with UK and US 1w Luxeons.

Similarly, for emils, and others, one cell led pocket torches.

As I think has been mentioned before, emil's in order of illumination, AAA keychain light (60%), AA 8 led (125%), AAA 5 led (160%), AA 8 led "R" (200%) compared to my standard UK AA 5 led torch, all single cell.

Surprisingly 3w HK luxeon clone only give 320%, but of course much greater throw outside.