In article ,
"Dave Plowman (News)" writes:
Have a pretty old twin 6 ft fitting (ballast and starter) where an
original T12 tubes has failed. Replaced it with a T8 - which is very
noticeably dimmer than the other old T12. Swapping them makes no
difference, so not the control gear?

Blurb says they are more efficient than T12. Does that also mean less
light?

They have a noticable run-up time, particularly when not used for
a long time (e.g. when brand new). Leave them on for 10 mins, rather
than comparing at initial switch-on.

(T12 also have a run-up time which is actually much longer, but the
initial light output is not as low as with a T8.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]