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505nm and 480nm diode RESULTS

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HydroSean

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~500nm is ok. 495 is where it's at. Look for one of those.
if you go to wolframalpha's wavelength to color widget here are the 495 and 500 wavelengths.


I think they're pretty much the same but if you look at the difference between 500 and 520, now theres a difference (shown below)


you will see how just a few nm at around 493 makes a huge difference, here are the respective wavelengths from 490 to 495
 
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paul1598419

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I can tell you from experience that at or around 500nm, you can tell the difference between 5nm in either direction. The diodes DTR is selling are from an iteration known as SB147EC91, for the micro-printing around the diode's window. These have been shown to be 510nm. There are some 505nm, but they are all case positive and can be purchased on eBay. Now, we do have some 492nm to 495nm diodes, but they aren't available to everyone just yet. Take a look at the wavelengths in my signature. :D
 
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HydroSean

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I can tell you from experience that at or around 500nm, you can tell the difference between 5nm in either direction. The diodes DTR is selling are from an iteration known as SB147EC91, for the micro-printing around the diode's window. These have been shown to be 510nm. There are some 505nm, but they are all case positive and can be purchased on eBay. Now, we do have some 492nm to 495nm diodes, but they aren't available to everyone just yet. Take a look at the wavelengths in my signature. :D
got links to where I can buy those diodes?
 

paul1598419

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Here's a link for a 505nm diode, Sharp, for $23.45 total. www.ebay.com/itm/253309741957.

Since these are case positive, and the Vf is so high, the really only option for driving it is the Blitz Linear driver from SL. That is, unless you want to isolate the diode. We set them to 275 mA for about 130 mW with an acrylic lens.
 
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DTR

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Another thing that is worth note is how driving them higher than spec current will also increase the wavelength. As mentioned the 505nm diodes I have test on the plus side of the typical variation between 507m-509nm at spec current maintaining spec temps. This is within the drift variation for the 505nm GH05035A2G diode if that is actually what they are. I do take datasheeets supplied with diodes or even model numbers of said diodes with great scepticism unless purchased through official channels. The Nano I pair that diode with is only capable of going down to 275mA which I am sure this is also bumping up the wavelength quite a bit. You can still see the difference if you put it right up against a PL520's but nowhere as impressive as 500nm which I had the pleasure of owning for a little bit.:(

Anyway just thought I would note that since you did order it with the driver and think you might rather wait for the cheaper one from china which might get you a few nm lower or wanted to try finding a driver that could run it at a lower current.:beer:
 

HydroSean

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Here's a link for a 505nm diode, Sharp, for $23.45 total. www.ebay.com/itm/253309741957.

Since these are case positive, and the Vf is so high, the really only option for driving it is the Blitz Linear driver from SL. That is, unless you want to isolate the diode. We set them to 275 mA for about 130 mW with an acrylic lens.
Getting cheap now, $15us from Techhood and newgazer;

https://www.ebay.com/itm/NEW-Sharp-...8-Brand-New-/263522537906?hash=item3d5b2ad1b2

These i assume are the case positive iteration, but the higher w/l's from ~505-510nm, as they have the same diode also listed at $35
I wasn't talking about the 505s I was asking for links to the others in his signature like the 493 one called "501B"

Another thing that is worth note is how driving them higher than spec current will also increase the wavelength. As mentioned the 505nm diodes I have test on the plus side of the typical variation between 507m-509nm at spec current maintaining spec temps. This is within the drift variation for the 505nm GH05035A2G diode if that is actually what they are. I do take datasheeets supplied with diodes or even model numbers of said diodes with great scepticism unless purchased through official channels. The Nano I pair that diode with is only capable of going down to 275mA which I am sure this is also bumping up the wavelength quite a bit. You can still see the difference if you put it right up against a PL520's but nowhere as impressive as 500nm which I had the pleasure of owning for a little bit.:(

Anyway just thought I would note that since you did order it with the driver and think you might rather wait for the cheaper one from china which might get you a few nm lower or wanted to try finding a driver that could run it at a lower current.:beer:
a hundred is an impulse buy, besides I will always purchase the diodes from you because you have a quality standard that is unmatched by fleabay. furthermore if a lower nm diode pops up ill nab it too
 
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BowtieGuy

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Welcome back, HydroSean, nice to hear from you again! :beer:
Those 493-495nm diodes that Paul mentioned are a fantastic wavelength, but I don't think that there are any available right now.
I've heard that there will be more, but couldn't say when, maybe one of the other guys would have more info. on that.
Here is a -link- to a 493nm that I built recently; the color is even more beautiful in person. :yh:
 
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paul1598419

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These diodes have been shown to shift up to ~2nm with current. They will, however shift more if you allow them to get hot. I have heat sinked mine pretty well, so the measured WL is only about 1nm higher than measured at 18* C.

I am hoping it won't be much longer before more of the 495nm diodes arrive for sale. I haven't personally looked into it as I have other projects taking much of my time. If no one else shows up to supply more 495s soon, I will look into doing so myself.
 

DTR

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These diodes have been shown to shift up to ~2nm with current. They will, however shift more if you allow them to get hot. I have heat sinked mine pretty well, so the measured WL is only about 1nm higher than measured at 18* C.

I am hoping it won't be much longer before more of the 495nm diodes arrive for sale. I haven't personally looked into it as I have other projects taking much of my time. If no one else shows up to supply more 495s soon, I will look into doing so myself.
Either those don't shift as much as the ones i have or my eyes are very sensitive that that range as I can really see the difference going from 100mA to say 300mA on my supply.
 

paul1598419

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Just going by mine and Singlemode Laser's spectrometer measurements. It is far less subjective than eyesight. Could some of what you are seeing be happening between threshold current and the higher current readings? I have noticed that before threshold the color shifts considerably once you go above threshold. IDK, just trying to guess.
 

Zom-B

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I still swear by 505nm. If you look at the CIE 1931 chromaticity diagram you see 505 on the far left, meaning it has the least amount of red cone stimulation. Go lower in wavelength and you add tiny amounts of red again.
 




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