Ideally, a pair of fixtures like the DT Photons for copy stand work (large documents, camera scanning) and a pair of DT Photon XLs for lighting artwork. Both from Digital Transitions. (In my dreams.)
Ok - so rectangular flat panels. The easiest then would be to start with the panelled LEDs (the ones you have been looking at) and perhaps DC (constant voltage) power supply. That will be straightforward to connect. Then after mounting it on some backing panel in the case with diffuser, you can run them in for some time, monitoring temperature and doing periodic measurements to monitor for thermal/current related colour shifts and whether they are within your tolerance levels. If they are then you may be perfectly happy with just DC power supply. The constant current approach is not going to work with the panels (due to the ways the soldered) or strips.
In case of Yuji - their panels are MCPCB (metal core boards) so they do have better heat dissipation that normal PCB and you may not need any heatsink installed.
Those
Yuji panels by my calculations contain 21 LED in each strip: 3 parallel strings of 7 LEDs in series with resistor(s) each. Incidentally the
panel's single strip specification is shared on that very page (dimensions current etc).
But in the real world I've been making do with hardware store clamp fixtures and hardware store bulbs (first "full spectrum" CFLs and now "high CRI" LED bulbs). When shooting art I use cross polarization which sucks up a lot of light. I need about 600 watts (equiv.) to keep shutter speeds in the one or two second range when shooting base ISO. Six clamp fixtures (5 inch reflectors) give me enough uniformity for my standards.
That powerful lighting may need to consider COBs - only they will give you that light density in a relatively compact package. But as you know that means fiddling with heatsinks and backing and perhaps even adding active cooling (fans).
I looked at those videos and also related ones that Youtube offered. That involves a lot of heavy duty metal work with the heat sinks. (Also I figured out what "grow lights" are usually used for. Apparently not for growing roses.)
Orchids from what I looked at. Some of those videos go through more complex setups (multicoloured LEDs etc) but in essence it is simple. Finding the metal backing, drilling a pair of wholes for each COB fixture (if you attach them mechanically with connectors), add thermal paste and fasten the COBs with connectors. Then on the back of the metal panel all extra heatsinks or fans if needed. There is alternative approach of course and that is why I posted a photo of my setup - no COBs are screwed to radiator there at all and no holes are drilled.
Aluminum backing? Do you mean heat sinks?
I mean aluminium extruded strip designed to hold LEDs (those are frequently used in kitchen lightings). But those are for long and narrow strip mountings usually.
For Spectron?
Which is really cool but is a different use case than mine.
Again I posted those not as something you should do but as example of fairly easy and compact package giving me 2400lm light source with fairly good heat dissipation and not a lot of mechanical work. I put 4 COBs on thermal glue (flexible one that expands and contracts) on a heatsink, soldered their inner bits with small wires (so they connected in series). Then cut out the board to the radiator size (used the single sided PCB board material) with the square inside to go around LEDs and attached metal pins to the board (soldered but could be glued or screwed) that aligned with the LED contacts. Those go off the board as wires to the power supply. The board simply sits on top of the LEDs screwed to the heatsink. Took me about couple of hours to do the prototype (mainly to cut square hole). What you see on a photo is the same board fabricated on one of the PCB services (mainly because I like things neat and tidy) but it worked fine with just what I described.
