O-like 400mw Crown Upgrade Review / Questions

[2100]

One update : I focused the beam on 2km target, with the help of a telescope at 32X mag, i managed to focus it to the smallest possible spot.

I measured ~ 1.6 mRad. One at 3.2m away the the other at 12.5m distance. So not exactly very accurate coz it's not like 10m away and second reference distance is 50m, but it's probably ard there.

In comparison, i got about 0.3mRad from the O-like 100mW with built in beam expander. That hit nearly 5km. With this one i could not see the spot, probably not even with 1W, because the beam is too think and the beam slicing through the air sort of blocks the spot.
I could probably set it up on a tripod and then walk about 10m away to view with the bino, but then that's too much work + it would overheat due to the longer time lapse.

So just a few more cents from me.

 

[stanzal]

Interesting. I figured the o-like with the built in beam expander would have fairly good divergence but 0.3mRad is fantastic. I plan on picking up a 10x beam expander for 400mw shortly and will definitely post an update once I get it mounted to the laser and test it out. Assuming my laser has similar specs to yours (1.6mRad divergence), I should end up with .16mRad which would be pretty ridiculous.

One update : I focused the beam on 2km target, with the help of a telescope at 32X mag, i managed to focus it to the smallest possible spot.

I measured ~ 1.6 mRad. One at 3.2m away the the other at 12.5m distance. So not exactly very accurate coz it's not like 10m away and second reference distance is 50m, but it's probably ard there.

In comparison, i got about 0.3mRad from the O-like 100mW with built in beam expander. That hit nearly 5km. With this one i could not see the spot, probably not even with 1W, because the beam is too think and the beam slicing through the air sort of blocks the spot.
I could probably set it up on a tripod and then walk about 10m away to view with the bino, but then that's too much work + it would overheat due to the longer time lapse.

So just a few more cents from me.

 

[2100]

Interesting. I figured the o-like with the built in beam expander would have fairly good divergence but 0.3mRad is fantastic. I plan on picking up a 10x beam expander for 400mw shortly and will definitely post an update once I get it mounted to the laser and test it out. Assuming my laser has similar specs to yours (1.6mRad divergence), I should end up with .16mRad which would be pretty ridiculous.

Yes, it is fantastic. Actually 405nm (single mode) is also fantastic. It is just that the eyes cannot focus on blue/violet properly. Through just a pair of 7 x 50 binoculars, you can see the dot (very small may i add, smaller than the size of a window pane) at 2km distance. Through 32X on my 6"/152mm aperture refractor telescope, it's tack sharp and you can even see that the shape/pattern/details of the dot. It's crazy if you are using optical aids.

Do be careful of traffic signs if using optical aids, through a 6" refractor, i reckon i could easily blind myself with the 405nm even when pointing at it 1km away. :drool:

Actually a 3X beam expander is nice enough. 10X probably fattens the beam too much and i figure one can't possibly make full use of that low divergence without lots of power to aid it. I mean if you are gonna be pointing it at a 10km object with a 10X expander, it could get there in a vacuum, but with 10km to there and cutting through another 10km back, there really is too many particles in the air to both scatter and attentuate. Of course with a few watts that'd really be fun.

BTW, check out this slight upgrade. It's not a difficult job, i used those small think precision screwdrivers to unscrew it, which i do so too with my flashlights to take out the tailcap switch.

http://laserpointerforums.com/f44/c...waterproofing-lens-70787.html?highlight=400mw

 

[2100]

Hmm...i used a cheap greenie (low powered) which is very very stable and measured that the waterproofing lens (AR coated) cut 3.3% on the light meter. I guess this is expected with my experience with flashlight lenses, with its 1mm thickness.

So stanzal, has your beam expander arrived?

 

[stanzal]

Nope, not yet. I'm ordering from Jetlasers and they're supposed to ship pretty fast, so hopefully I'll get it sometime in the next week or so. Will definitely post an update once it arrives - I might have to modify the adapter a little bit before I can use it though, as it's meant to screw on to a slightly bigger laser than the o-like.

Hmm...i used a cheap greenie (low powered) which is very very stable and measured that the waterproofing lens (AR coated) cut 3.3% on the light meter. I guess this is expected with my experience with flashlight lenses, with its 1mm thickness.

So stanzal, has your beam expander arrived?

 

[stanzal]

Just received the Jetlasers 10x beam expander. Although none of the adapters that it comes with fit the o-like, I've found that if you hold the expander straight onto the face of the laser it actually fits pretty well - you just have to hold it there whenever you want to use it, which can be a little bit of a pain. Anyway, the beam expander DRASTICALLY improves divergence (you can really tell that a far away dot is 10x smaller). It's a ton of fun to play with because it allows you to point the laser at objects very far away - km's and miles away at that. When pointed at the sky, the beam almost looks like it gets smaller (this is of course an illusion, but a neat visual nonetheless).

 

[2100]

Thanks for the update Stanzal.

Why wouldn't it fit? There are supposed to be 3 screws that'd screw onto the O-like. Not a very secure fit, but at least secure enough for some fun use.

You could get longer screws?

 

[stanzal]

Yep, I plan to get longer screws sometime in the next few days. The only problem is that there aren't really any places for them to screw into the O-like so the fit wouldn't be very secure, and with the substantial weight of the beam expander it might very well slide off.

Thanks for the update Stanzal.

Why wouldn't it fit? There are supposed to be 3 screws that'd screw onto the O-like. Not a very secure fit, but at least secure enough for some fun use.

You could get longer screws?

 

[2100]

I supposed you can stick some foam tape onto the host. A ring of tape round the host should suffice. That'd offer some additional grip.