We're in an information age explosion free to those with an internet connection and I'm having to make the above statement. That makes no sense.
Color science hasn't caught up with our needs. We need ways to measure color rendering in a way that correlates with how our eyes (and cameras) see. We don't have any such test (yet.)
I just did a test switching between the Soraa lamp, my 4700K Solux bulb, a 120v 90 W 3500 K Solux bulb, and my Home Depot "full spectrum" 5500K CFLs. I was looking at one of
Andrew's test prints and the
Digital Outback Printer Evaluation Image. All the bulbs looked different. It seems to me that the Soraa lamp exaggerates chroma. Andrew's test image has lots of very saturated colors. Whenever I switched to the Soraa lamp, the saturated colors looked too extreme (similar to looking at an sRGB image on a wide gamut monitor in a non-color managed environment (like the Windows desktop.)) The colors in the Digital Outback image are more restrained so the effect isn't as pronounced. The 4700K Solux bulb seemed the most accurate, followed by the 3500 K Solux bulb. Colors under the CFLs look more muted than any of the other sources.
The Soraa bulb made the whites I saw look whiter than any of the other bulbs did. But I haven't tested whites (OBAs, etc.) as exhaustively as you have, so I can't really make a judgement on whites.
If I was judging prints in earnest, I think that I'd want several of the 12V 4700K lamps with the
Plano Convex Diffusers (The diffusers are really needed but they reduce the light level such that it is difficult to use a single Solux lamp.) One of the three fixture track lighting fixtures with Solux bulbs that were described on the
Imatest site clamped to something would probably work.
The Imatest site doesn't say, but I think that it would be prudent to get the more expensive Solux lamps that have a Black Back. The Solux bulbs radiate unwanted light out the back of the bulb. It isn't good to have the unwanted light reflect off the back of the light fixture. I currently use a Solux black bulb shield on the back of my (non black back) Solux bulb, but it doesn't mount to anything. It just bobbles loose on the back of the bulb. I'm afraid that if the bulb works slightly loose in the socket, that the bulb shield would short across the pins. This would be bad. In the future, I'd go for the Solux bulbs that have the back permanently black.
Yeah, the only way to really judge them is get copies of the bulbs so you can test them with your own eyes. Maybe try one of the
120V PAR Solux bulbs.
Wayne