I've researched before on a popular flashlight enthusiast forum and they get right into the smallest details of light shape, spread, temperature, UI of flashlights (yes UI), and a range of other things. It's actually pretty fascinating.
Flashlights are actually another fetish item for me. I came to keyboards via flashlights, weirdly - I was looking for machining projects I could complete by myself. Found flashlights first, and then wondered over here.
As far as desk lamps, I don't think this isn't quite what is desired in terms of looks, but it absolutely rocks for working on keyboards:
https://www.amazon.com/gp/product/B00UW2IRJ2/ref=oh_aui_detailpage_o00_s02?ie=UTF8&psc=1Works great as just a lamp (the lens has a cover), but has super powers.
Another thing that isn't what is being asked for is
https://snakeclamp.com/I love mine. I got the heavy-duty arm, and have a clamp, a tablet mount and made a couple home-brew attachments. It frequently holds lights - I clamp a cheap bulb reflector to it sometimes, and use the clamp to hold a flashlight for close, intense light. If you think you'll be changing the attachments frequently, I recommend getting the quick-change adapters - if you're like me, without them, you'll likely eventually damage the threads.
Again, not sleek and sexy, but very functional and handy. I'm going to get another base/arm - being able to float my tablet over what I'm working on is really nice, and I do that a lot more than I thought I would, but, well, same with a third hand.