Like aijii said it's a 20mw laser. It's right on the label. 75mw is because of IR leak I think. The guys who sold you the laser remeasured with IR leak. So here we go 75mw.....but really it gives you about 25-30mw of real blue.
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Like aijii said it's a 20mw laser. It's right on the label. 75mw is because of IR leak I think. The guys who sold you the laser remeasured with IR leak. So here we go 75mw.....but really it gives you about 25-30mw of real blue.
Doc please, give me at least *some* credit... I'm not completely clueless.Quote:
Originally Posted by Dr Laser
*I* measured the power. Multiple times, with a calibrated Lasercheck wand. I also checked it at several different distances. Most of the power measurements were taken at a distance of 3 feet from the head. But I also measured the power some 22 feet away from the head. The power readings were within 1 mw of each other. If I was reading IR leakage, then the added distance would have caused the power to drop drastically.
The 75 mw is *not* from leaking IR - it's all blue at 473 nm. If you look at the master test image in the main post you can see the spot at 105 feet is almost exactly as bright as the one from my 100 mw Lasever blue unit.
Now, it may be that the laser is in fact only rated at 20 mw from CNI and has been cranked up to 75 mw + by Dragon Lasers. However, it may *also* be that the sticker is incorrect. Or there could be some other explanation.
I've e-mailed Frank at Dragon Lasers and asked him to clarify. When he answers I'll be sure to post his explanation here.
Adam
No no... It's not about you knowledge it's just me throwing ideas.;)
I usually measure visually. I have top spec 40mw blue and 300mw green all are with perfect beams filtered and collimated. I put them side by side with a new laser and see how brighter they are compare to top spec ones. I have a sheet of blackened aluminum just for this purpose.
Good idea to call them up and find out whats going on. If they increased the power.... find out how!!.....if they warranty their make over....any why the hell a 20mw sticker is on.
Ok then - my bad... Sorry for getting defensive.:oQuote:
Originally Posted by Dr Laser
Actually, if they increased the power, then I'm more than a little concerned. I mean, sure, you can crank up the power, but what does that do to the expected lifetime? I know folks that have cranked 5 mw green pointers up to 50 mw, but they also died after 300-400 hours. I sincerely hope that's not what they're doing. (Unless they've found a way to improve the cavity optics, but I doubt that... To get a 4-fold power increase you've just about *got* to increase the output of the pump diode.)Quote:
If they increased the power.... find out how!!.....if they warranty their make over....any why the hell a 20mw sticker is on.
Granted, Dragon Lasers does offer a warranty and all, but that's not the point. I don't want to be the one that has to tear apart a projector to get at the laser that crapped out after 9 months of use, just so I can send it back to China for a replacement. I've already been down that road once before. (And Astroguy has been down that road multiple times, right Fred?) No, I don't want to have to rely on a warranty. I want the laser to last. And *if* they're cranking up the power by more than a factor of 4, then I want to know how they can be sure it will still last 10,000 hours.
Like I said though, I'm not exactly sure what is happening here. Maybe they're installing larger pump diodes? Or maybe the sticker is wrong. Hopefully Frank will post directly to the forums here and explain the controversy surrounding that label.
Adam
Don't forget there are two sources of IR. I think you're probably right that this isn't IR, as there's enough difference between 20 and 75 mW of a visible colour for your experience to alert you if there's that much difference, but even so it could be worth checking. The 808 nm IR will diverge and fall of fast with distance but the 946 nm IR wouldn't, it might travel with similar divergence to the main beam. and while at tens of metres it's deviated off the main beam path enough to let you measure the blue beam, the blue beam might be too wide to catch with a Lasercheck.
A prism or diffraction grating can split them for testing. Also, some dark plastic that passes IR will help. Given the wide difference in wavelength, any good translucent red stuff might work.
Some time I want a blue laser but it's still not tempting me yet. This review comes as close as any yet, but there are still too many gotchas, it has to look a lot less like a lottery before I'll get one. DPSS makers and sellers need to think about this because it might not be long before we can forget about it and use actual blue diodes and not use DPSS at all.
guys,
we've sold LOTS of CNI. As an example, a couple of 200mw greens we bought for ourselves arrived in Melbourne doing in excess of 300mw, ALL GREEN. If the laser is only barely making power, then we know something's up.
Doctor: It is absolutely not out of hte ordinary for a CNI 20mw to be doing 75mw. CNI normally ship their lasers way over spec'd power. ITs just that some resellers take advantage of this to make more money.
The times we've bought CNI through other local resellers to save money, we've found the lasers arrived barely exceeding spec'd poewr, if not just barely under it. In these instances, we checked serial numbers with CNI and found that the items were actually lower power lasers that were being sold as higher powered lasers.
The end result is the reseller appears to have REALLY cheap prices, cheaper than buying from CNI themselves, but the loser is the buyer.
Be wary.
See - we are more than just a "drop shipper". We actually add value, by guaranteeing our customers will receive what they paid for. We don't "remove value".. like some of the others do.
Sorry, just damn sick of seeing dodgy Chinese outfits screwing customers for money and getting away with it. Dragon Lasers may have made an honest mistake, but I doubt it.
I'd be interested to hear what their story is, but we've seen this enough with other resellers that i'd put money on it that its just another case of the same thing.
The fact that they left the sticker on is just stupidity on their behalf. The ones we bought had the stickers removed or replaced with reseller stickers, with no mention of CNI anywhere on the box.
Hey Adam, awesome review! Much more info than I thought would go in one but all very informative and good to know. As usuall you go above and beyond. I wanted to "Smile" a lot about it but am at work and can't get more than these two seconds to state... "Remember, my 50mW CNI is delivering a good 75mW consistantly." I think someone suggested I put mine on eBay as a 75mW to help me get an analog blue. :rolleyes: :D To be honest, if... when I get an upgrade for my blue I plan on going CNI and am sure I will be going to dave and aijii for it. ;)
I'll be back with... >:)
Sounds good, Aijii. I haven't got money spare yet, but I'll be up for one of your blue lasers at some point. I looked at the prices for 20 to 50 mW and I liked what I saw. 100 mW would be nice but I don't know if I'll find enough money. I haven't tried very hard recently though.
A some what hasty post to answer some of the issues that have been raised in this review regarding power levels, labelling and what have you.
We order large numbers of bench lasers from CNI at various wave lengths and power levels and only retail a few of them. For the lasers we do retail, the power level of every laser is carefully tested to verify CNI’s stated power levels. The power levels are normally above and some times below CNI’s power levels. We use the power levels as we measured them to determine prices and to be on the safe side, always use a value lower than the tested value. When the tested power level is above CNI’s, this can result in a profit. It also results in a loss when the tested power is below CNI’s.
The reviewed blue laser for instance had a tested power level in excess of 70mW. We would sell it as a 50mW. We would not sell it as a 70mW laser because that is not conservative enough. You can see from our price list that we sell 50mW not 70mW 473nm lasers. With the review laser in question, the price was $800-$850 for a 50mW laser tested at 70mW by us and independently at 75mW. The final half price of $400 for a 50mW laser was a special price because of all the work that was put into the review and for the convenience of tying up loose ends.
Leaving the sticker on the laser was not an “honest mistake” or “stupidity on our behalf”. A quick browse of our website will show that in our in house photos, we clearly leave the stickers on the labels as a deliberate policy. The idea is to be open and transparent the way we do business and deal with potential and actual customers.
It is well known that there are a number of “drop shippers” who modify lasers to give them higher power ratings and subsequent higher profits. In working with CNI we have seen quite a number of these modified lasers returned during the warranty period and it is very clear that the lasers have been opened and modified. The output power of our lasers is always the manufactured output, never a modified output. Our close working relationship with CNI often allows us to source lasers that are significantly above the labeled powers.
Thank you very much Adam/Buffo for the great independent review and sorry for being fielded some awkward questions over power level issues.
Oh and thanks Aij for your insight into the practices of Chinese drop shippers and raising these issues so I could address them.
But its a 20mw laser ?
IE: The sticker on Buffo's laser reads MBL-20