I'm building my 4 foot long UV unit and bought Phillips 40 Watt Black Light bulbs with the mercury and UV hazard warning (at the Home Depot in Hudson NY - for any locals ) for about $15 each. Are these the ones I want? They seem a bit dark when illuminated...?
Thanks

Jersey,

They will work, but they're not the ones I recommend for a few reasons, especially if you are not going to be very dilligent about eye protection.

Many people us the BL lamps, not the BLB lamps that you have purchased. The BLB lamps (black light blue) are very similar to the BL (black light) lamps, but they have an additional visible light wavelength filter on the glass that reduces the visible light output from them considerably.

The BL print a little faster then the BLB, but the difference is apparently minimal for most processes.


---Michael

I use the BLB bulbs, but the whole thing is a little too slow. I am thinking of rebuilding with either electronic ballasts or the spiral BLB bulbs. I live in Hudson, where is the Home Depot?

I use the BLB bulbs, but the whole thing is a little too slow. I am thinking of rebuilding with either electronic ballasts or the spiral BLB bulbs. I live in Hudson, where is the Home Depot?

The one across the bridge near the Thruway. You know..in the Catskill part of Hudson:)

Before you give up on your BLB bulbs consider I am printing with 12 - 24 inch blb's. My print times are anywhere from 3 min - 30 min, depending on the negative. The key I found IS the negative. If you get one that is nice and thick, one that will take a lot of exposure with and enlarger, it WILL take a long time to print. The blb bulbs are not bad, but you will see very slight difference between them and the BL bulbs (check out Sandy Kings article over at www.unblinkingeye.com for an idea of the difference). When the time comes to replace mine I will most likely go with BL rather than BLB, but with over $100 in bulbs right now, I don't plan to pull them out...after all they are working. NOTE:I am using electronic ballasts (thanks to Michael Mutmansky for his help there).

BL bulbs are probably easier to burn with and less dangerous to your eyes since they are not 'fooled' into dilating. You should wear protection though in either case.

I'm using spiral BLBs - with negatives made to print on the last Grade 2 Azo mine take about 8-10 minutes to print. I just start the timer and leave the room to avoid eye problems. Just another part of the slow-down of large format photography.
juan

I'm currently building a UV box and started my tests with both. I definitely get a difference in exposures. I like the BL best. You can get them online for as cheap as 7.28 per bulb. Half the Home Depot price.

You want the F20T12/BL

http://atlantalightbulbs.com/ecart/10Expand.asp?ProductCode=BLACKLIGHTF20T12.BL

Good Luck!

Bill

The 360BL lamps are the usual and best answer, but a lot of things will work as long as they have high output in the blue to ultraviolet part of the spectrum. The alternative materials have very significant sensitivity in the blue region, so the 360BL tubes work better than the 360BLB ("blacklight") lamps. I use ordinary daylight lamps (20F12D) without much penalty. Phillips makes a "high actinic" bulb for plants that looks, in the specifications, like it would be OK (haven't tried it though). Some other "plant and aquarium" lamps with high bllue output may also work. If you can find them at a good price, the blue phosphor fluorescent tubes (20F12B) are excellent. I'm not sure if they are made in small sizes, but sunlight (as for suntan tables) lamps might be interesting.