The 10 mt point is covered in ISSF rules available on the ISSF website, section 6.4, and covers all items including light levels. just as a quick guide, drawn from the various sub sections :-

The distance is 10 mts + or - 0.05 mt From the firing line to the target face.

Height to target centre 1.40 mt + or - 0.05 mt

Target centres must be on the centre line of the firing point, variation in either direction 0.25 mt

The firing point must be a minimum of 1.0 mt wide.

The nearest edge of the bench must be placed 10 cm forward of the firing line.

Recommended light over the general range measured midway a minimum of 500 Lux

Target lighting, Minimum 1500 Lux, recommended >1800 Lux

That near enough covers it!
Have Fun
Robin