Hi Ian, I make light boxes for members here, what do you mean how long should it be? Are you referring to the length of the light box itself, if so it depends on the scope you are making it for, weight considerations, reflection of internal light source etc etc.
G'Day Peter,
I have a Meade LXD 8" sn and I have been on the internet looking but their are so many difference types and length .
If you can tell me how long it needs to be that will be great
Ian .C