Yoshihide Yamanaka/M31

Photographer: Yoshihide Yamanaka , Date: 3. Aug 2007, Location: Araragi-kogen Nagano-Pref, Japan, Pentax 105SDP 515mm F4.9 ,
Astro 400D, No noise reduction ISO400, 2 x 30min +  2 x 45min

Photographer’s Comment:
” Why many people use high ISO at cooled-camera.
 I think it is better to use under ISO400. I think that less than ISO400 are desirable to get a good work.
 ………………..In particular Cooled camera. “