Well, I've finally managed to get some decent comparison pictures. I copied Doyler 78's camera settings-
f2.8
speed 1/4
ISO 400
And here are the results. Firstly, this is the Cateye EL-530-
The centre spot isn't too bad, and there's a general circle of light which isn't very bright but does help you with a bit of peripheral vision. You can also see the lenses on the sides, which gives a
slight bit of side-on light.
This is the BLT Ozone 21ne-
You can't really see much difference, but the central spot is a fair bit brighter than the EL530. It shines further if you point it up a bit. A combination of these two will light up a dark towpath enough to cycle at 10-12mph, but it can be slightly unsettling, and I find that you have to constantly swing the bars from side to side to get a wide throw.
Now this is the Ayup-
There's really no competition between this and the first two, nor the first two together. It's a wide beam, and it's massively brighter. I've not tried a Dinotte, but I suppose that the Ayup has the advantage, having two independently directional beams, that you can aim one above the other and get a longer stretch lit in front of you.
I did the towpath again tonight in total darkness, and the Ayup is great. I had none of the dodgy moments that I had with the other two lights. People approaching from the other direction were screwing their eyes up with the brightness.
So if you were to ask me how much you need to spend to be able to ride at daytime speeds on unlit paths, I'd say £116, which is the cost of these Ayups including postage from Australia.
The only disadvantage I can see is that you can only see where the bike is pointing. If you want to see where your head turns then you need something on your helmet as well.