Can different ballast lead to different luminous intensity in T5

[black_art]

Hi there,
I have used first ballast for 2 years and last week I bought second one. It seems luminous intensity of new one is almost 30% less than my old with same T5 so I was wondering which one is better.

 

[imaan]

i have this problem too.

 

[soeminpaing]

I might be wrong but the longer ballast seem to be the real T5 ballast. The shorter ballast is for powercompact or T8 universal.