PicoChroma : Ambient / Photo / Video Camera Lighting

RE: PicoChroma : Ambient / Photo / Video Camera Lighting

shabaz — Sat, 21 Jan 2023 02:08:04 GMT

LED panel done.. not very ideal, but I can't really spend much time on this since I need to order some PCBs.

The LED driver will come later, but at least I have something to connect it to!

This is very low-cost; the LEDs (part codes mentioned in an earlier comment) will cost around £11+tax per board, and they can be tiled horizontally or vertically as needed. Each panel is 95 x 47mm.

RE: PicoChroma : Ambient / Photo / Video Camera Lighting

shabaz — Fri, 20 Jan 2023 03:44:25 GMT

Not quite finished, just experimenting with how it will be mounted in larger arrays if desired. I have some ideas, just need to flesh it out. This little panel is just approx 100 x 50mm, so I'd like to be able to connect at least up to 2x2. That should be a lot of light!

RE: PicoChroma : Ambient / Photo / Video Camera Lighting

shabaz — Thu, 19 Jan 2023 20:21:57 GMT

I spent some time looking into LED panels, and can't see a way to manage it in one layer, so thinking I might need to use normal FR4 instead of aluminium, and then if it really gets hot, then I'll think again! Realistically it may be about 4-5W dissipation for a panel the size of half a paperback book maybe, if the LEDs are being driven at 75% duty cycle perhaps. I was looking at these LEDs, which look very good for the low price:

Warm LED: [embed:ad4490ac-0ce8-4f2d-a04c-9285646d5689:b451c45d-b458-4f7a-bdcc-68e2bb8df71d:text=Wurth%20158563227A&style=link&farnell=3518066&newark=82AH2536&cpc=&avnetemea=&avnetema=&avnetasia=&comoverride=&cmpoverride=&AreaInteracted=rte-content&bom=]

Cold LED: [embed:ad4490ac-0ce8-4f2d-a04c-9285646d5689:6d26486c-d355-426b-bfb5-fa0ab125c7df:text=Wurth%20158563460&style=link&farnell=2470239&newark=42Y1330&cpc=&avnetemea=&avnetema=&avnetasia=&comoverride=&cmpoverride=&AreaInteracted=rte-content&bom=]

The size seems popular, there are other LEDs in that approximate package in case they go out of stock.

A lot of cold/warm LED modules use series strings of LEDs, and those are arranged on a single-sided aluminium PCB. But, for parallel strings (which is what I want to use, so that I can easily swap out to fewer higher power LEDs if desired), (i.e. constant current to paralleled LEDs purchased on a strip to be hopefully approximately similar, with a small resistor in series with each), I can't route it on one layer. So it will have to be FR4 I guess.

I'm going to try to make an LED array of (say) 4x3 pairs (i.e. 12 warm, + 12 cold), and then many of them can be tiled if desired, but each of these arrays run from one pair of constant current drivers (which I still need to figure out, but they can be on a separate board sandwiched, so that the LED arrays can be easily changed as desired.

RE: PicoChroma : Ambient / Photo / Video Camera Lighting

DAB — Thu, 19 Jan 2023 19:36:18 GMT

Great post.

Being an avid amateur photographer I am very aware of light and its many components.

Also the use of AI software looks interesting.

RE: PicoChroma : Ambient / Photo / Video Camera Lighting

genebren — Wed, 18 Jan 2023 16:28:30 GMT

Very cool project. I have constantly struggled to get good quality and efficient lighting, so I use a lot of LEDs. I have developed a few multi-source lighting systems, mainly mixing white and RGB LED to attempt to achieve the proper balance. I really liked your approach to using and balance of cool and warm LED to get you desired light. This is something that I might need to try out, so thanks for the head start that you have provided.

RE: PicoChroma : Ambient / Photo / Video Camera Lighting

Andrew J — Wed, 18 Jan 2023 11:27:37 GMT

Very informative and well described. Lighting is one of those things hat it seems difficult to get right, particularly when buying for specific scenarios. There’s a lot of info that would be useful in making a decision when buying that is not given. I am generally after bright, daylight lighting for inspection, crafting, construction etc that is noise free, in portable form factor and fixed but readily adjustable form factor. In particular, highly adjustable and noise-free would be a holy grail.

I don’t do a lot of photography or video work anymore so adjustable colour balance is not as important, but I know what you mean when you talk about getting it right. The BBC Look East news programme studio has terrible lighting and always makes the news presenters look green, irrespective of skin tone. I used to think the tv was on its way out!

RE: PicoChroma : Ambient / Photo / Video Camera Lighting

feiticeir0 — Wed, 18 Jan 2023 09:13:59 GMT

Love it !

Great color explanation. I've been reading on colors the affect on people's mood and how blue color helps sleeping at night.

Also, ChatGPT for the win ! I've used it also for some projects and, even mistakes on the code, just asking him with the error, it does provide a correction. Skynet is upon us !

RE: PicoChroma : Ambient / Photo / Video Camera Lighting

fmilburn — Wed, 18 Jan 2023 06:02:56 GMT

Hi Shabaz,

Thanks for a well written and useful post. I’ve played around a bit with ChatGPT also and was impressed with how easy it was to use and it provided a good starting point for writing articles.I also used it to generate code snippets that had better than average documentation.

RE: PicoChroma : Ambient / Photo / Video Camera Lighting

dougw — Wed, 18 Jan 2023 03:38:20 GMT

Great article on lighting and a cool app [mention:b0bc65b9ecdc4307bd967592f00e340a:e9ed411860ed4f2ba0265705b8793d05] .

Research into the physiological and psychological effects of light wavelengths is ongoing. It gets complicated with LEDs because although you can make an perceived color that looks like almost any color on the chromaticity diagram with just 2 or 3 LEDs, the spectral content is radically different from natural light. Even white LEDs have an uneven mix of wavelengths. I'm not sure if this means the specific frequencies of LED light are overloading specific color receptors, while under utilizing others, instead of spreading the load more evenly, but it is an area of research to keep an eye on, so to speak.