Little Question

[DanGeRoUs98]

Hey, I just ordered another laser pointer from an eBay chinese seller

Link to the product here: High Power 5mW Zoom Focus Adjustable Green Laser Pointer 18650 Battery Chgr | eBay

164 units have been sold, so I'm guessing it's good and reasonable.
Hope I'm lucky.

On the product description it clearly says it can light matches within a short distance by adjusting the focus when battery is fully powered.

It comes with 18650 battery, a charger, and safety keys.

How much output power do you estimate this laser to be?

 

[Leodahsan]

Its hard to tell. It may be the IR leak (if it has some) that actually lights the matches. 5mW of green + 50mW of IR will light the matches like you said :beer:

 

[Livinloud]

164 buyers could also not have LPMs to tell if they were ripped off. just because 164 people jump off a bridge and you dont hear back that any of them die, does that mean you should jump too?

 

[Leodahsan]

If 164 units had been sold, you can't assume its good and reasonable. You can assume it will probably arrive @ your house (if customs don't have it first).

 

[Eudaimonium]

Its hard to tell. It may be the IR leak (if it has some) that actually lights the matches. 5mW of green + 50mW of IR will light the matches like you said :beer:

Not true actually, the IR component in DPSS output is not collimated, it's as wide as aperture cap allows right at the start, with insane divergence - it basically stops to be dangerous under a dozen meters.

50mW alone, perfectly focus, would struggle to ignite some matches. 10mm wide beam, accompanies by low power green beam (even if focused normally) won't light absolutely anything.

Also, normally accepted IR margin is some 20-30% of output. So if you got 50mW greenie, maybe some 15 mW of that is IR, even if that much. It varies of course, but just a general "rule of thumb", it won't be that bad.

 

[DanGeRoUs98]

Well, the seller itself has received good feedback from many members buying his/her lasers. The laser output is still a doubt because I haven't received it yet. nor I have a Laser Power Meter to measure the output power. I would test it by doing some usual burning tests like cutting electrical tape or popping black ballons,so I could estimate how much I will get from this. If I can't do any of these, I would assume it is underspec.

If I get ripped off, This purchase is covered by eBay/Paypal Buyer Protection so I can get my money back by opening a case if I decide to return this item back from not being totally as described. The seller also promises 30 days money back guarantee if I am not satisfied with the item within that period of time.

eBay Buyer Protection really works, I have been refunded within a day by eBay Customer Support with some items that didn't arrive to its destination.

I'm just expecting it to be a good laser for the price, not to be WAY overpowered, which is very unusual from eBay.

 

[Leodahsan]

Not true actually, the IR component in DPSS output is not collimated, it's as wide as aperture cap allows right at the start, with insane divergence - it basically stops to be dangerous under a dozen meters.

50mW alone, perfectly focus, would struggle to ignite some matches. 10mm wide beam, accompanies by low power green beam (even if focused normally) won't light absolutely anything.

Also, normally accepted IR margin is some 20-30% of output. So if you got 50mW greenie, maybe some 15 mW of that is IR, even if that much. It varies of course, but just a general "rule of thumb", it won't be that bad.

Thanks for the headsup bro. Anyways the output would not be collimated even after lens, as this laser has focusing optics?

 

[Livinloud]

Lasers I dont think are covered by ebays protection since anything over 5mW is prohibited by fleabay. FYI burning tests wont tell you anything other than how well you can focus a laser. A 50mW 532 well focused can pop a balloon and light a match but a 200mW poorly focused or with a poor lens wont do anything. Only way to ever tell a lasers power is with a LPM.

I am not sure why every member thinks that burning tests tell a lasers power (its not just you, ive literally have said this like 10 times today in different threads). A LPM IS THE ONLY WAY TO TELL POWER OUTPUT.

 

[Leodahsan]

Anyways, the LPM being a calorimeter, it does indicate the laser power in heat (miliwatts), and, when you concentrate heat, you can burn.

So IMO you can have an estimative of a laser power by its burning capabilities, depending on target.

:beer:

Obviously, you can't say "its x mW because it can burn 'y' material".

 

[Kookapeli]

Most people who buy these lasers don't know anything about lasers so they're going to be happy with them regardless, quite a few people on here probably started off with a cheap Chinese Fleabay laser and look back on them now as a not very good, but they are a good introduction to the laser hobby