685nm 35mW Laser Diodes on Ebay!

Nice beam shots, but due to most cameras auto-white balance those pics are not
satisfying my curiosity entirely.
Could we please have some with another red side by side for comparison?
A 650nm, or even 635nm in case you have one?

That would be great.
Pwetty pwease.

^ it's not even white balance ... Deep reds are not in the camera's gamut, making it impossible to replicate. Using expanded color spaces like Adobe RGB doesn't do it. Even if you could set an even wider color space, at this wavelength you start running into the sensor's IR filter.

aryntha said:

Mine arrived, but unfortunately they had been stepped on, the leads completely crushed and one window cracked... Disappointed in that, looks like the thin envelope they were in had been stomped on or driven over.

To those who have gotten these working - is it definitely deeper red, to you, than 650?

Click to expand...

Man that stinks. I would contact the seller. Did both package get crushed as i think you said you ordered 2. I hope not.

Yes the Beam is Much Deeper in Red. The Dot is similar to 650nm but it is a deeper red but resembles 650nm. But the Beam is For sure Noticeably different. Its a Deep Red.

THis Picture below is exactly the color of the beam:


Here is a Picture of the 650nm 13mW on the Left and 13mW 685nm on the Right Slightly defocused when the dot is Focused you can tell the difference between the 2 as the 685nm has a deeper tone to it but they are similair.:


Hope that answers your questions.

If you have any specific Request Please feel free to ask and ill do the best o could to Answer.

anselm said:

Nice beam shots, but due to most cameras auto-white balance those pics are not
satisfying my curiosity entirely.
Could we please have some with another red side by side for comparison?
A 650nm, or even 635nm in case you have one?


That would be great.
Pwetty pwease.

Click to expand...

Thanks Here are some Comparison shots.

I turned down my LPC-815 to 13mW to compare with the 685nm. Iam running the 685nm diode at 48mA and it is doing ~13mW to 14mW. I must have gotten a low efficiency one.

I have not tested the others yet as i want to wait until the hosts come in to crack them open.

Here are the comparison shots at your Request with SMOKE:

13mW 685nm on the Left & 13mW 650nm on the RIght.


13mW 685nm on the Left & 13mW 650nm on the RIght.


13mW 685nm on the Left & 13mW 650nm on the RIght.


13mW 650nm on the Left & 13mW 685nm on the RIght.


Next Few Beam shots are Just the 13mW 685nm.







I cant wait to test the others two and see if they are going to be 35mW. It will be more visible then the 13mW and i will be able to take better beam shots.

Iam Happy with this Wavelength. Red is one of my Favorite Wavelength and these 685nm Diodes Give a Deep Deep Red Beam with a similar dot to 650nm but just a deeper tone.

You might be confusing deeper with dimmer.

jib77 said:

^ it's not even white balance ... Deep reds are not in the camera's gamut, making it impossible to replicate. Using expanded color spaces like Adobe RGB doesn't do it. Even if you could set an even wider color space, at this wavelength you start running into the sensor's IR filter.

Click to expand...

Exactly.
As the wavelengths start getting redder, the camera will start to render them as oranges and then pinks once you get closer to 808nm.
It depends on the camera, though, so don't count on an accurate color representation at this wavelength.

As Cyparagon says, there will be little to no difference in color to 650nm.
780nm looks exactly like 808nm. 808nm looks like a dim 650nm.
It's just nice to have more wavelengths.

When I get one up and running I'll be sure to document it with some pictures (assuming the IR filter on my dSLR doesn't block it).

You need to turn off the auto-white balancing function and manually balance the white point (if the camera have this option) if you want to see the differences ..... an auto-white balance camera will give you accurate colors only if it can have white in the image for self-compare it, but that function will become "fooled" if the light is monochromatic, usually.

In fact, the supposedly deeper 685 actually looks like a LOWER wavelength, in terms of how the camera is balancing it. In fact, to me, those photos look like they've got orange tones - which I'm sure they don't in reality.

In fact, what might be a useful comparison would be:
Beam: (650nm 3mw) vs. (685nm 35mw)

At those mW ratings, the two should appear similarly bright. Might make for a more meaningful visual comparison.

Left is the 13mW 650nm and RIght is the 13m 685nm. I made the video in HD. (Sorry about the ticking sound its the toaster.)



Since mine is only putting out 13mW i have a 650nm Key chain that does 1-2mW. I will make a video comparing the 2.

But still in my eyes the 685nm is a deeper red.

I totally understand dimmer but i see the 685nm as a darker color. Not the same as 650nm/660nm but dimmer. It does resemble it but its a deeper red.

Has anyone else put one together yet.?

Got them too, gonna use the same host as jib77.

Here are 2 Videos comparing 1-2mW of 650nm to 13mW of 685nm. I still see a difference in color.

I used rhd Cool Brightness Calculator to calculate the Brightness between the 2. This is the closest i can get to them being even in Brightness.
Beam: (650nm 1mw) vs. (685nm 13mw)

If you can Watch in HD Please do.

Left is the 1-2mW 650nm and RIght is the 13mW 685nm (Lights Off):


Left is the 1-2mW 650nm and RIght is the 13mW 685nm (Lights On):

^I bet in a double-blind test, if you had a watt of 685 compared to a mW of 660, you'd say the 660 was deeper.

I just got mine. One is 685.5, one is 686, and one is 684.

Great!
And? How do they look/compare to your sceptical eye?

Cyparagon said:

^I bet in a double-blind test, if you had a watt of 685 compared to a mW of 660, you'd say the 660 was deeper.

I just got mine. One is 685.5, one is 686, and one is 684.

Click to expand...

Strange how that works. I mean there's a huge difference in color between 445 and 405.

mfo said:

Strange how that works. I mean there's a huge difference in color between 445 and 405.

Click to expand...

Also 445 and 473.

did anyone get the lens spec? seems like the link was bad, even when going to Thorlabs directly

Cyparagon said:

^I bet in a double-blind test, if you had a watt of 685 compared to a mW of 660, you'd say the 660 was deeper.

I just got mine. One is 685.5, one is 686, and one is 684.

Click to expand...

Thank You for Checking the Wavelength and iam happy to see that they are "Close" to 685nm.

+ For that:beer:

I Used rhd Brightness calculator to compare a 1-2mW 650nm to 13mW of 685nm and according to that the 685nm is brighter by ever so slightly.
Beam: (650nm 1mw) vs. (685nm 13mw)
Still the 650nm did look Brighter but still had a diffrent color to it.

How come when Comparing 635nm to 650nm witch is around the same difference between the 650nm/660nm to 685nm that the 635nm looks a different color too.?

How come when comparing a ~25nm Difference from other wavelengths you can see a difference.


Would this same concept go for every wavelength.? So if i had a 445nm and a 473nm laser i would not see a difference in color.? Witch i know for sure there is a difference in color. How is this different.

I still dont see it being a dimmer version of 650nm/660nm. It is dimmer then 650nm/660nm but it is a totally different color that is dimmer not the same color as 650nm/660nm and dimmer.

I dont know what else to say because now iam starting to dough myself if iam really seeing a difference in color or its just dimmer.:undecided: Am i missing something here.:thinking:


Has anyone else put one together yet.

LASER66 said:

did anyone get the lens spec? seems like the link was bad, even when going to Thorlabs directly

Click to expand...

The Lenses look like nothing spacial. They are not air coated and wont fit in an Aixiz Module.

You will have to figure out a way to Mount them. But they are small. I am guessing around 4mm or so. I dont know how to test them as i dont know how to Mount them.