I wanted to give everyone on here an update about this.
I didn’t get any feedback about the Sofirn IF25A, so I bought a 4,000K version and I’ve used it for a couple of nights now.
The 4,000K light is nice, with a high CRI, but it doesn’t feel bright compared to 6,500K lights if that’s what you’re used to. The high CRI does illuminate things in a very natural way though, and that’s nice.
Turbo mode is fun, but it doesn’t last for very long because of heat. I had to calibrate the temp sensor out of the box, and I’ve set the limit to 65 currently. Turbo works, but it’s pretty pointless for my application because I care more about a sustained high luminance flood of light than a temporary shot.
The beam shape is fine. I’ve read that there is no hot-spot and it’s a flood, but that’s not true. It is a fairly broad hot-spot though, and the spill is weak to the point of being irrelevant. Overall I’m happy with the beam shape; any wider and it would need more lumens output to be useful, and any narrower would not light up enough of the surface ahead.
A good test of the performance is if I feel confident to ride at the same speed as in the day, and I cannot say that it’s the same… but it’s close, and that’s a win I think.
I’m finding myself running the light at ~60% of the ramp, and at that point it gets warm to the touch, but not hot. Run time would probably be about 2 hours at this output.
Another finding, which is to be expected, is that if the ambient lighting is higher (due to street lights etc.), you need a higher light output from the flashlight. This is because the human visual system is adapting to the brightest objects in your field of view, and we can only see so much range. The flashlight needs to bring the foreground in to this visible range and more light is required to do that. I’m confident that if I were riding on a non-street-lit trail, this flashlight as way more than enough output to be effective.
Finally, the ergonomics… I’m hand holding this flashlight, and that’s proving to be very good; far better than a headlamp, for many reasons I’ve covered in earlier posts. The problem I have with the IF25A is that it is quite short. I wear wrist guards which are slippery plastic on the outside, and the short build of the IF25A makes it feel slightly insecure in my hand.
Given the ergonomics, I would love to have something that takes two 21700 cells in series, with a similar light output (beam shape, colour and lumens), and has a buck converter for continuous steady drive as the battery drains. I don’t think such a flashlight exists… but we can dream.
Short summary is that I’m reasonably happy with the IF25A for my application. It’s not perfect, but it’s a very good solution…. I’ll keep looking for something with better ergonomics, but I’m liking it so far.