Visibility of 30mW Beam

IsaacT · Apr 3, 2014

Hey,

If anyone has a 30mW 532nm or 473nm laser I am wondering how visible it is. I am about to place an order for a Dragonlasers Spartan 30mW and I want to be sure I am not wasting money on something that will not be very visible. Obviously an 80mW from CNI would be cool but with the recent price changes it is unrealistic.

Adam from Dragonlasers agreed to check a few of them for one with a very clean beam and guaranteed an average power of over 30mW. I just have to pull the trigger.

Just sold my bar of silver so I am getting a little something for me

Thanks,
Isaac

PS - Anyone with 30mW of 589nm would be great but that is a lot harder to find for obvious reasons. lol.

Zeebit · Apr 3, 2014

30mW of 532nm will be visible but nothing impressive. It also depends on the atmospheric conditions. My 80mw will look something like a 150-200mW on a humid night and other times it is hard to see.

I don't have a 473 so I can't compare the two. So I were to see a 30mW green beam, I would be like "meh"

Blackwolf · Apr 3, 2014

30mw of 521 is the same brightness as 30mw 589 so I would use a low power 520 for comparison. I can see my 5mw 473 beam on any night but it is very thin and dim. looks amazing with fog though.

hwang21 · Apr 3, 2014

50mW of green can be on the dim side, it's usually enough to star point though. So figure a bit less apparent than that

Blarg King · Apr 3, 2014

30 mW of green would be okay. I have an ebay pen thats around 30 mW and I can see the beam in a well lit room. The dot is fantastically bright, and you'll see the beam easily outdoors at night.

Can't speak for 473 (Yet) but from what I've gathered its a fairly visible color too. You can see the beam of a 10 mW in a dark room so I imagine 30 mW would be decently visible.

zyxwv99 · Apr 3, 2014

For night vision (scotopic) the human eye is most sensitive to 507 nm (blue-green). For color vision (photopic) peak sensitivity is at 555 nm (yellow-green). At 532 nm, the eye is at 88% of peak (photopic) compared with about 10% at 473.

It would take a 255 mW 473 to equal the apparent brightness of 30 mW 532.

A 30 mW 473 should look as bright at a 3.5 mW 532.

http://www.ecse.rpi.edu/~schubert/Light-Emitting-Diodes-dot-org/chap16/F16-06 V(lambda).jpg

zyxwv99 · Apr 3, 2014

Blackwolf said:
30mw of 521 is the same brightness as 30mw 589 so I would use a low power 520 for comparison. I can see my 5mw 473 beam on any night but it is very thin and dim. looks amazing with fog though.

Actually the 589 would need to be 43 mW to equal the brightness of 30 mW 521, or about 43% more power. However, since our perception of brightness is logarithmic, that 43% is probably not enough to notice.

"Perceived loudness/brightness is proportional to log10 (actual intensity measured with an accurate nonhuman instrument)"

Weber?Fechner law - Wikipedia, the free encyclopedia

brucemir · Apr 3, 2014

Hey WBS,
I have a Laserbtb PL473nm 30mw and I have your 100mw 473nm (my best favorite and best laser) so I think I can give you a nice comparison, since you know the 100mw well. The 30mw is certainly visible in the dark. Before I got the 473 from you I used my 30mw quite a bit a in my photography and it is plently bright enough when I used it with other nm's. When I have had your laser side by side with the 30mw, the 100mw is obviously brighter, but the 30mw is not washed out by the 100mw and holds it own.

IsaacT · Apr 4, 2014

Thanks for all the opinions guys. Brucemir, do you think I would be satisfied with a 30mW?

Also, a bit off topic, but what output do you consider ideal for photography?

Shakenawake · Apr 4, 2014

I could slap you silly for selling that silver, it's sub-$20 right now, time to buy not sell. (IMO)

IsaacT · Apr 4, 2014

I have been seriously broke. Until yesterday I had 10 dollars to my name.

Shakenawake · Apr 4, 2014

me too, guess I am just more patient, trust me, there is a couple thousand worth of stuff I wish I could buy right now, namely those new 9mm diodes. patience. don't sell any more if you still have it, try to wait until it's at least $30, I'm holding on to mine, hoping for it to hit $50 or higher, which is very possible and even likely, just a matter of time.

for much of history the ratio to gold has been 15:1 even though it's extracted at roughly 10:1 current prices are closer to 65:1. if this changed back to the old 15:1 or the 10:1 to match extraction, either silver would need to rise to $86-$130, or gold would need to fall to $200-$300. the latter seems far less likely

You talking the 100 OZ bar. dang, I'll let you do the math

IsaacT · Apr 4, 2014

I had a car note to pay, gas to buy, and an oil change to get. Doesn't matter how patient I am at that point.

brucemir · Apr 4, 2014

Hello again WBS,
I think a 30mw 589 should be acceptable for beam brightness. As I have told you before, the DL 589nm 30mw will be the next laser I purchase since it looks like the CNI GB will never happen.

For my photographing of lasers I like to use lasers between 50mw and 100mnw for the blues, reds and greens. I find that more powerful blues and greens washout all of the subtle details of what I am trying to do. I do use 500mw 405nm's, but since the beam from them are dim anyway, it meshes in nice with the other colors. When I use my 589 and 593.5 nm's, I have to turn down the shutters, or block the beams of the greens and blues during the exposure to compensate for the more powerful lasers so the yellows can be seen and will stand out. That is why I think a 30mw 589 should be bright enough with low to moderate mw of reds, green, and blues to look really nice

Visibility of 30mW Beam

IsaacT

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Zeebit

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Blackwolf

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hwang21

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Blarg King

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zyxwv99

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zyxwv99

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brucemir

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IsaacT

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Shakenawake

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IsaacT

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Shakenawake

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