473 nm high power portable recommendations?

[Radim]

Sorry for that, Alaskan. However I think you are some time in the hobby already to know that it is quite expensive. But it is a beautiful wavelength IMO - must have in the laser collection.

 

[Alaskan]

About three years in now and 20K USD. Here's a comparison between 473 ad 532nm for those who might want to see how their brightness compares for the same power outputs:

 

[Radim]

Well, that means it is serious. I think - for three years - such an amount (and more) you can spend in lasers, cars or women of course...

Is there photopic or scotopic luminosity function used in the comparsion? I did not checked these comparsion as it was not really relevant to me - I just want 473 nm.

Edit: Looks more like photopic (daylight) comparsion to me.

 

[Alaskan]

I am sure it isn't scotopic, I would sure like to see a curve which shows the difference between daylight and low light viewing of the beam.

Edit: Found this http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html

 

[Radim]

Here it is for example:


(click the image for source)

I think it approximates a beam as well. However blue light is diffused more in the air (that's why sky is blue and sunsets/sunrises red). Some time ago I've made some simple excel model for that used luminosity function values I found on internet to calculate estimates of various danger distances of my lasers (like flashblindess hazard distance). I might find it and put the source of the website I used if you like.

 

[Alaskan]

Huge difference, peak sensitivity to wavelength slides down about 50nm, that is very substantial. I read somewhere that on average, for most individuals, the peak sensitivity to wavelength slides down from 555 to 507nm, but nice to see it in a curve. Thank you.

 

[Radim]

Yes, this is why it is wise to specify which light condition when comparing visibility. And of course it is individual to each - these curves are some kind of "average". You can see it in photopic functions - there are even more options shown. For example I can see a bit of IR spectre quite well (from TV remote control or IR port of my mobile for example), also people see 405 nm differently - I remember there was a thread on this some time ago, in addition people with artificial corneas might see UV as these wavelengths might not be filtered by implants.

 

[Alaskan]

Here's a question for you, or someone. I assume our cameras are adjusted to have the same sensitivity across the visible wavelengths as our eyes have, otherwise the colours would come out wrong, correct? Of course, our cameras can see IR when we can't whether IR filtered or not, I haven't seen a camera yet which has a filter that cuts out all of the IR, at least, not in the general consumer market, so not referring to that.

 

[Radim]

Well, its a bit tricky. Of course manufacturers tend to capture what human eye see by their cameras. But there exist some color spaces (like for example CMYK for printed stuff - subtractive mixing, sRGB and Adobe RGB for displayed stuff - additive mixing). Cameras use some RGB spaces, however the color space of human perception is much wider than most commercial technology can capture and display. For example, when I took some pics of 520 nm and 532 nm, they look about the same, however you see them different. And the blue is the most tricky in my experience so far.

Also human brain just adjusts color perception according to lighting, that's why you have to balance white differently for example under lightbulbs and under daylight lighting.

I fight with that stuff, when I'm adjusting my artworks to look like by human eye as much as possible, but with precise laser wavelengths it is just not possible due to current technology imperfections.

Check this (look for 520 nm where it lays):


(source is wiki - just click on pic for more info)


Regarding IR - it is not supposed that IR is present much in most cases that much to influence picture too mich in most cases: In cheap cameras (like mobile phones) you can clearly see it, however DSLR and more serious cameras are IMO somehow IR filtered, how would you take pic of fire for example? There is a lot of "heat" radiation - IR. Try it with mobile and with some DSLR and you will probably see the difference.

Just for interest look here: https://www.extremetech.com/electronics/144388-how-to-turn-your-dslr-into-a-full-spectrum-super-camera

Very interesting photography under IR.

 

[Radim]

Fresh news: I've just updated my signature!

Ordered, coming soon:
473 nm | 100 mW | Jet Lasers PL-E Pro

:drool:


Thanks to everybody for your recommendations.

I've had a quite long discussion with Gray about my selection, therefore many many thanks to him (and Jet Lasers team) - superior customer service - the best from all of my laser purchases so far.

It was not really easy to select, but I went for black version with beam expander and some other accessories. I might write some points from the entire selection process later, if you like...