Thanks everyone.
I don't even know the reference! It is a China-made, brandless board... I bought it at a home improvement store, it was initially meant to be installed in our new bathroom... Until I thought it would make a great softbox.
It was described in the shop as "neutral white", temperature is 4000K and is not adjustable. The panel costs 59€. There were other panels in the shop, more expensive, with either a blueish tint (cold white) or a yellowish tint (warm white), but I preferred the neutral white.
It really looks like a white board, not like an array of small leds. see the two pictures attached (off and on, obviously...). The "on" image doesn't do justice to the panel, it is actually much more luminous than it looks. The total light emited by the device is supposed to be 3100 lumen, the dimension is 60x60cm. There were other models, some quite larger (can't remember exactly, but close to 50x100cm).
I need to work on a stand in order to handle it more easily, right now it is just a white board.
I agree with Erik about the pupil size, it is one drawback of continuous lighting but I think the effect is not too pronounced here.
