250W MH bulbs

[yoyoman]

I've decided to go the 250W route, and I have a question about lamps.

On what basis should I compare one vs another? Are F2 lamps better than mogul based lamps? They are definitely smaller in size.

Is there a particular brand/model that you guys like? I know different model bulbs come out, so I'd like to hear what the latest preference is.

[Guy Grotke]

Things to look for in a MH lamp:

low cost per hour of life
long lifetime
high lumens output initially
high lumens output after half the useful lifetime
recommended ballast not too expensive
color temperature in the 5000-5500 K range
CRI over 90
short arc length

If you want to use a particular set of reflector & pre-condensor lens, then you need a lamp form factor that will fit them. All the DIY projector sites that sell reflectors & pre-condensor lenses have recommendations for the appropriate lamp type.