Quote Originally Posted by sanking
What I wanted to do was point out that these tubes are in fact highly efficient in printing alternative processes.

All alt.processes ?

Yes, the BLB tube is efficient with all alternative processes, at least all that require UV light for exposure.

For efficiency (= printing speed) with iron processes (Cyanotype, Pt/Pd, Kallitype) I rank light sources as, 1) BL, 2) SA,/AQUA, 3) BLB, and 4) NuArc 26-1k.

For efficiency (= printing speed) with dichromated colloids, 1) BL, 2) BLB, 3) SA,/AQUA, and 4) NuArc 26-1k.

The difference is due to the fact that the iron processes have some sensitivity in the 410-30 nm range, and the BLB filters all light above about 407 nm whereas the SA and AQUA put out quite a bit of radiation in this range. With dichromated colloids, on the other hand, virtually all of the useful radiation is below 400 nm.

The BL is the best all-around tube for alternative printing, and is usually less expensive than the BLB, but the actual difference in printing speed is extremely small. And I will say this again, the peculiar nature of the BLB light highlights dust and lint particles and makes them easy to see and remove. I would say without question that in my case the use of the BLB (and I switched from BLs) has lead to less dust spots on my prints.