Hello Pierre,Pierre Traverse wrote: Y a t il sur le LhiresIII une longueur de chip maximum utilisable (comme par exemple 36mm si on utilise une caméra 24x36mm)?
10mm is the recommended size. At 36mm you will lose resolution at the edges because of the aberrations from the simple doublet lens. See Christian's page here for example
http://www.astrosurf.com/buil/lhires_eval/optique.htm
Etienne did you notice any loss of resolution at the edges with the 183MM pro ?
Cheers
Robin