I'm not trying to be rude,just bringing up a point that a lot of people might not be thinking about if they are also packing a camera along.
Because I'm probably going to be packing a digital camera that takes AA batteries,I'll probably be using a light source that takes the same ones.I don't really see a way around packing 4 AA on three day hikes so I might as well use the same cells for both.I can understand a really lightweight light if I WASN'T using the digital..but for my purposes I don't think it makes sense for me to carry more different types of batteries than I already am packing.
More than likely I will be making a smaller animal also... for when I don't carry the camera,but using the same rechargables because of the constant cost of replacing batteries.I deal with selling a lot of older cameras and the battery costs can be astronomical to maintain just the different ones for testing cameras!I'm pretty sick of buying more and ones that aren't dual purpose.If they are rechargable,it's a different story.A lot of batteries these days run $5-15(OUCH!) and don't last forever.
If a setup uses a 76 series,I use a lot of those in testing cameras but am wondering about the longevity of the battery(or two).Replacing those at about $5 apiece gets pricey,even though the weight factor is nothing.
It's one thing to make miniscule light setups but it's another when they eat up dollars by the handfuls!Ideally would be a lightweight solar setup that could clip on your pack and recharge the batteris as you hike..or motion activated to recharge those batteries or both if you hang around a camp for a few days..I think if a person figures the costs of the batteries it may be equivalent of a good solar system that would work better and longer,let alone,not have to be replaced in the middle of NOWHERE on a longer hike
An ideal light setup FOR ME would probably be one that uses 2 rechargable AAs in a lightweight watertight battery case or tube with a small LED head on the end..that I can store my additional digital camera batteries in.When I need them for the camera,I have them.At the moment,I do have a lightweight aluminum tube one that weighs 80 grams using three AAs and three LEDS that is super bright,more than what I really need for light.I'll probably be revamping it down to 2 cells and less lights to decrease weight and carry ONLY what I need for extra cells.Like I said,I need to carry the extra cells anyway..might as well have a light they function with....just a thought...