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# 445nm vs 532nm brightness comparison.

#### leukoplast

##### New member
I realize a 532nm is going to be perceived as significantly brighter to a equal output 445nm laser. What I would like to know is the estimated guess in brightness from people who have personally compared their 445's to their 532's.

For example. Lets say somebody has a 1000mW 445nm, and they think it is about as bright as a 100mW green. That is all I would like to know.

Reason I ask is because I am going to be starting a 445 build here within the next week or so. I want to make one that outputs roughly 150mW. So based on the responses in this thread, I will be able to make a estimated ratio of which I could apply to the 150mW I want to build. This way I can get a idea of how bright it might actually be.

Appreciate it!

#### DJNY

##### Well-known member
You need 3-4x the power of 445nm to get same brightness as with a 532nm.

Here is a shot 1000mW 449nm vs 200mW 532nm

The 449nm is a tick brighter.

Asa

#### x101xtreme

##### New member
1.1 Watts of 445nm is about the same brightness to me as a 250-300mW Green at night.

During the day, it looks the same as a 150mW green.

#### Burnsy

##### New member
1.1 Watts of 445nm is about the same brightness to me as a 250-300mW Green at night.

During the day, it looks the same as a 150mW green.
That's because the eyes sensivity peak of light is during day at about 555nm but decreases in night to about 515nm (correct me if I'm wrong)
so closer to blue, seen on Wiki here (sorry it's german):

blue curve is at night, red during day

#### rangedunits

##### 1
1.1 Watts of 445nm is about the same brightness to me as a 250-300mW Green at night.

During the day, it looks the same as a 150mW green.
True. I saw the same thing.

Had my evo pro130 and my 900mW 445nm. And the blue dot was about the same at over fifty meters. in the full sunlight .

#### HumanSymphony

##### 1
Looks like they intersect right at 532nm Making that the optimal wavelength for any conditions

#### Kenom

##### Well-known member

This is a comparison of 600mw of 445nm and 400mw of 532nm.

#### leukoplast

##### New member
Awesome, thanks ken! That is actually pretty close in terms of brightness. That is good to hear. I am attempting to build a 50-75mW 445 in a pen, and I was hoping it would still be pretty bright. Based on this, a 75mW 445 may be equivalent to a 40-50mW green. And a 50mW would be similar to a 30mW green. Which is actually still quite bright!

#### RA_pierce

##### Well-known member
250mW of 445 is about as bright as 50mW of green. Low light. Just tested it.
Edit:
300mW of 655nm about as bright as 250mW 445.

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#### Traveller

##### New member
That's because the eyes sensivity peak of light is during day at about 555nm but decreases in night to about 515nm...
Very interesting...! Thx for the insight, +1 :beer:

#### .3lite

##### Member
250mW of 445 is about as bright as 50mW of green. Low light. Just tested it.
No, I find 445nm very dark, blue but dark, and I can't even imagine comparing to 532nm because it's just too dark.

I see this color (445nm) compared to 532nm exactly like on this graph, 532nm is way more brighter for me, like ten times or so.

click-the-pic

#### RA_pierce

##### Well-known member
No, I find 445nm very dark, blue but dark, and I can't even imagine comparing to 532nm because it's just too dark.

I see this color (445nm) compared to 532nm exactly like on this graph, 532nm is way more brighter for me, like ten times or so.
Hmm...
I would actually say that 655nm and 445nm are almost the same brightness per milliWatt.
In direct sunlight, red is brighter.

Edit: I'm talking about the "spot," not the beam, since that is dependent on many more things.
And Traveller, that is a great photo. The color looks very realistic.

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#### jbtm

##### New member
New Page 1

Shots of 600mA set 445nm diode compared to 200mW green. You can see the blue vs green on wall, hince why my room glows more blue than green.

#### RA_pierce

##### Well-known member
New Page 1

Shots of 600mA set 445nm diode compared to 200mW green. You can see the blue vs green on wall, hince why my room glows more blue than green.
It's hard to determine "brightness" in a photo.
For example, my camera makes 250mW of 445nm look brighter than 130mW of 532nm which is not the case in reality.

A 200mW green should be much brighter than a 445nm ~500mW.

#### Traveller

##### New member
It's hard to determine "brightness" in a photo.
For example, my camera makes 250mW of 445nm look brighter than 130mW of 532nm which is not the case in reality.
That's interesting, particularly since almost all cameras favor green, just like the human eye. The Bayer filter pattern is either GRGB or RGGB... :-/

EDIT: look at my photo (above) and tell me which color is more striking to you...