They list lens as 3 3/16" (80mm) so I'm sure a 75-80mm aspheric can be made to work. I've been eyeing this up for some time but hate to waste $20 on junk if it's no good to modify. I'm mainly worried about having enough focal length for the lens to work with an XM-L but it looks pretty similar to what Zizo used.
$17.95 is the sale price. I've looked at that light many times but haven't been convinced to buy it yet. The one item I want them to put on sale, they never do! Technically it is on sale now, but only $2 off... I think it's a good candidate for a 20%-off coupon.
Yes, almost! There was about .2mm gap between the C2 and 109 LED bezel, but you can push it hard and it will fit. I epoxy glued mine and it looks like one solid piece. The focal length is about 1-2mm long for dx aspheric. I didn't like raising the LED so I just trimmed the top of bezel where the lens seats, and the lens looks more protected with the bezel now.
The left light is in the wrong focal length just for comparison.
Can you measure the back focal length of Optolife 80mm? If it's around 50mm it should work. The quality of dx lenses are getting worse everyday. I ordered 5x75mm lenses and only 2 were usable. 50mm lenses are just junk and 66mm are the best but no good host to use it for.
HA! Yes, I have some experience with that host LoL. I bought it when it was on sale and then used a coupon on it. It looked cool so I figured I would see what it looked like. About 3 minutes into using it, it shut off, so I opened it to see why...
The top of the battery carrier spring melted into the plastic from the current flow and shorted out inside the head :)
As I recall the metal of the light felt like cheap pot-metal. You might want to give it a shot though since you wont be using the factory battery carrier anyway. You can always return it if you don't like it.
Lux@ 1meter = Measured Lux x Square of measuring distance in meters
3 meters
Lux@1 meter = measured lux@ 3 meters x9
5 Meters
Lux@1 meter = measured lux@5meters x25
10 meters
Lux@1 meter = measured lux @10 meters x100
Most flashlight light beams coming out of flashlight first converge & then diverge, the point of this converge/diverge junction gives extremely high lux but it's not accurate indication of throw.
The longer the throw capability of a flashlight, the smaller the beam spread angle will be, thus the converge/diverge junction will be further away from the flashlight, thus the measurement needs to be taken further away from flashlight to be more accurate.
Typically, I measure at 10 meters for lights ~100 Klux or higher & 100 meters for lights with 1 million lux or higher. If questionable, then increase the measuring distance & try again.
10 meters is not always enough, I have a light that measured ~2Million cps (CP=lux@1meter) at 10 meters,
but only 800,000 cps when measured out at 100 meter distance.
Perfect, this is exactly what I needed to know. I'll try to take some readings tonight when I get home. I'll have to convert feet to meters first though since I'll be using a tape measure to see what the furthest distance in my basement is :)
Is there a variable I can throw in for cat dander in the air? LoL
There is indeed a difference if air is not clean or humidity is high, but that's not nearly as big of an error impact as measuring at too short a distance & end up measuring at the convergence/divergence junction. Worrying about air quality is like splitting hairs now for typical flashlight lux measurements.
Unless, one is going for world record, then go up to the mountain where observatory is & measure it from a mile away :)
So it seems like aspheric lenses are if not statistically better, they are not doing worse at 6.74m than 3.17m, but C8 with a reflector is doing worse as expected. I guess it could be that the lens focuses at longer distance better.