...Although would the NV Green on a 2032 really be brighter than the orange? I figured that as the orange has a much lower Vf, depsite it's lower maximum brightness, would be the better choice on the single 2032. Or is the eye's greater sensitivity to cyan coming into play here?...
Ding, ding, ding, ding -- I think we have a winner here. J/K -- I've always wanted to post that.
The orange light
may have to be brighter than the cyan to compensate for the fact that orange light is so much harder to see with (for shape recognition.) To put it another way, the orange PF may be brighter than the cyan PF but that does not automatically mean that you will be able to see better with it. For me, cyan wins because I find it so much easier to see with at lower output levels.
Actually, I think that more than one factor comes into play on this question and the deeper one digs into the use of monochromatic colors in the
real world the more difficult it will be to precisely quantify all of those factors.
Some of you who read this post will probably strongly disagree but I'm ok with that. YMMV. I'm just facinated with this subject -- it's got more bends and twists than a girl learning to curtsy.
First, lets tackle the more concrete issues.
- Conversion-
- Monochromatic B/C/G LEDs will have a chance of out performing a white LED in brightness if we assume that both LEDs represent the same state of advancement in LED technology because the conversion to white involves a performance hit in the process. As mentioned above if the blue PFs had the same LEDs that the white ones in the PFs are based on -- they would definately be brighter. While I doubt that the various colors available are a sample of the same level of technology I wish I had one of each for an eyeball test. I'd rather rely on my eyes than on the raw numbers on this one.
- Voltage-
- I don't think that the lower voltage is as big an issue with the non-R/O/Y lights as it may seem. Even with one cr2032 the circuit will still get 3V. It's not the stock 6V -- but then none of them need 6V either.
- Sensitivity-
- Things are getting muddier as we go down the list. First, here's an interesting sensitivity chart which shows both the scotopic and photopic curves together:
While it's depiction of sensitivity (in shape recognition) of the greens and cyans is quite dramatic (and true) the chart can't really tell the full story. Below is a chart that will give you a ballpark idea of how many nanometers a given LED may be. This is all anything but precise but it may still be helpful when you're trying to see where a given color falls on the first chart.
One must also bear in mind that in order to get meaningful numbers for B/C/G PFs running on cr2032s you won't be able to use the published wavelengths for those LEDs -- you'll have to swap out the stock pairs of cr2016s that they came with for cr2032s and then compare the actual beam with the second chart to find out what color the LEDs are actually putting out at the lower voltage. Armed with that info one may then go back to the first chart to see how sensitive the human eye is to that color.
- Semantics-
- Speaking of muddy, any discussion of monochromatic lights as dim as PFs run on cr2032s needs to briefly touch on what most light manufacturers call "red." In any group of people discussing dim lights, some will be there because they want to preserve dark adapted vision. Most lights sold as red have shorter wavelengths than the sensitivity cutoff of the rods -- ~640nm. Most lights advertised as red are actually in the 625-630nm (orange/red) range and may still impact the rods. The color chart above doesn't show any difference but it is the best chart I could find. I don't know the wavelength of the red PF. The only light I know of sold with true red LEDs is from Rigel (660nm).
I think that this is important enough to touch on when comparing the brightness of red and orange/red. The more orange a light is the brighter it will seem when compared to a true red because true reds are so very hard to see with -- so is orange, for that matter.
- Practice and experience-
- And now to the muddiest part... IMO the most subjective aspect of all of this has to do with how much experience and practice one has with these colors. That may not seem important, but it is. Look at where we all come from and what we have the most experience with. It is very tempting to just hold all light to the same standard, the light that we're most used to -- the bright, floody, white light from the sun. We all developed a preference for that kind of light years before we ever got our first flashlights. Many will pick up their first monochromatic light, switch it on and decide instantly that it is of no value and often this decision is based completely on the fact that it is so different than what they have grown accustomed to for all these years.
My perspective on monochromatic lights is different than most because of where my life took me and the colored lights I had to learn to use in various jobs. I spent years in one profession where I had to use red lights on an ongoing basis. (They were actually orange/red lights but blessedly no one knew that.
) I also worked in another profession for years where I had to become proficient at accomplishing tasks with blue lights. At that job I also learned that there actually was something that people call a trained eye. I still find this very interesting and continue to use and experiment with monochromatic lights even though I haven't needed to use them on a job in 15 years or so.
Aside from ~625nm (orange/red) and ~455nm (royal blue) I've also spent years using and experimenting with ~525nm (green) and ~495nm (cyan).
I bring this up because those who work with these lights on a continuing basis are definitely going to use them differently and even
see differently with them than those who only use them occasionally. It is a factor that cannot be dismissed IMO.
Thanks for reading
