Hello,
I’m new to the forum, apologies if this is not the right place to post this.
We’re considering the use of Lumen Lights in a live filming environment and I was wondering whether it would be an option to manufacture several of them with a 90 CRI LED variant? 5600K would be ideal, but I’m not sure if the LED manufacturer provides these.
Thank you in advance,
Alex
Hi Alex,
Thanks for the question! I’m interested in learning more about this. It looks like the LED we are using right now is 65 CRI. There are 90 CRI variants of the same LED. They are quite a bit less efficient in terms of lumens/watt but it should be possible to swap for these LEDs instead without much effort.
The ones that are available are 2700K and 3000K. I’m curious how much of a difference it would make in the video color quality.
-Rusty
Hi Rusty,
Thanks for your response! For filming purposes, ideally the light should be 5600K and as high CRI as possible. Shots filmed with a 65 CRI light are going to miss quite a bit of spectrum and will look dull, but 3000K color temperature is going to be too yellow as well.
There are some LEDs with 95-98 CRI, but it looks like integrating them would require quite a bit of re-engineering, as their dimensions and specs differ: High CRI LED Lighting In Fashion System – YUJILEDS
I see that Cree has a 5700K 90 CRI LED available - XHP-70.2 - that seems identical to MK-R in size and spec, at least at first glance, except they’re higher powered (29W / 4000lm): https://www.cree.com/led-components/products/xlamp-leds-arrays/xlamp-xhp70-2
Do you think it might be feasible to build several Lumen Lights with these? Ideally we’d like to install 14000-20000 lumens on BlueROV, so depending on max output, it would need between 4 and 8 lights in 2 or 4 groups.
Alex
Hi Alex,
Wow, those new Cree XHPs are very cool. I hadn’t seen those before. 4000lm in that package size is pretty crazy. There are a few downsides to this line, the primary one being that the voltage drop is 11.2v on the 90 CRI options which would cause problems on the ROV. The lights would get noticeably dimmer when the battery voltage drops, which happens whenever the thrusters are run hard.
I found a similar LED from Lumileds that has a 6v drop just like the one in the Lumens and is a drop in replacements. It’s 90 CRI and should be around 1250 lm output on the Lumen. I’ll order a few and give it a shot!
Thanks for pointing me in this direction! I’ve been meaning to investigate improved color/performance options for the Lumen for a while but didn’t know what to look for.
-Rusty
The XHP 70.2 can be used at 6V also. There is also the XHP 50.2 which is smaller and can be configured 3V/6V/12V, although the output is not great on the high CRI ones. I have an XHP70 flashlight and the output is amazing.
I agree a high CRI option for the lumens would be a nice upgrade.
Hi Tim,
Okay. A quick glance on Digikey makes it seem like the XHP don’t come in combined 6v and 90 CRI. I can take a deeper dive into the data sheet to see what’s available.
We’ll do some testing here and see how it goes. If anyone has any comparison information in an underwater setting, I’d be very curious to see it.
-Rusty
Hi Rusty,
Yeah you should check the data sheet for the desired combination of color temperature and CRI, and output binning. Here’s a middle bin 90CRI 5700K: https://www.digikey.com/product-detail/en/cree-inc/XHP70B-00-0000-0D0UM40E2/XHP70B-00-0000-0D0UM40E2-ND/6802271
These chips are actually an array which can be connected series or parallel, so 6V/12V is determined by which solder pads you use.
Heres a blurb on CRI in underwater lighting: https://uwlightdude.com/high-cri-best-of-both-worlds/
Rusty,
I would be interested in the upgraded higher CRI lights as well. I do a lot of underwater inspections and always looking to improve my video quality. Thank you for considering Alexander’s requests.
Random Information. I have some guts from the Outland Technologies UWL-401 underwater light and they are using COBs, particularly the XNova CXM-14-30-80-36. 24vdc input using 20w. (use them mounted to our diving helmets)
I could try to test different led chips underwater if needed.
@PacNW ,
That makes sense and provides nice flexibility. Those seem to be more difficult to get in small quantities so I’ll test out the Lumileds one first.
Glad you’re interested as well. I think it’s well worth investigating this. We’ll get some prototypes made and see how it goes.
Hi Rusty,
Were you able try 90 CRI LEDs yet? We’re getting close to placing an order and would love to be able get these in the underwater lights.
Hi Alex,
I wasn’t able to get any CREE LEDs but I got some of these Luxeon ones: https://www.digikey.com/product-detail/en/lumileds/LXR9-RW57/1416-1424-1-ND/5126925
They have a different footprint than the CREE ones so I have too make a new board to test. We should be able to get that in 1-2 weeks.
-Rusty
Hi Rusty,
That’s great, I’m looking forward to the results!
Hi Rusty,
I was wondering if you were able to try the 90 CRI LEDs yet? We’ve purchased 8 Lumen lights with our kit already, but if this works, I would really like to get 8 of these 90 CRI from you instead.
Hi Alexander,
We have the LEDs and boards but the footprint on these Lumileds LEDs makes them nearly impossible to solder with hot air! We have a few more on the way after ruining the first ones…
Also reached out to Cree to get our hands on some of the XHP ones.
-Rusty
We should get a toaster oven or skillet to do reflow in the office.
Hi Rusty,
I was wondering how this project is progressing? Any chance we’ll be able to get 8 of these 90 CRI lights any time soon?
-Alex
Jacob, I use a modified T962 for prototype testing, low cost and really quick
Hi! Just a note that the Norwegian Broadcasting Corporation is considering using our BlueROV2 for filming as well, and would be very interested in any upgrades to the available lights!
@Skredfare - Good to know! I’ve had trouble getting samples of the Cree LEDs for testing. The 90 CRI ones are fairly rare and are not stocked anywhere. But, I just met with a representative from Cree who should be able to help with that. I hope to have some progress!