Help- any advice - I am using a D300S with a Nikon 70-200 2.8 Mkii attached and a Nikon D80 and D3000 as secondary bodies. I use a Sigma 150-500 on these bodies usually. I photograph mainly aircraft , most in the air. I set the A to f8 and let the camera do the rest. On the D300S I have -3ev set in, and the images seem to be ok most of the time, but with the D80 and D3000 with the 150-500 attached , still using A at f8, the images seem to be overexposed most of the time. I have dialled in -3ev but this doesnt seem to fix the problem fully, so next time I go out photographing I am setting the ev to -7 and try that.
Does anyone have any idea or suggestions. [I am a new boy on the block to Nikon having been a Pentax man for around 50 years] Any suggestions welcome. thanks in advance.