I received the projector some days after my last post and since then I had no opportunity to use it.
I was keeping a link to this thread so I could report my impressions and thank John the precious help he gave me on this matter.
The projector is very simple to use and the image is fine. I connected it to the MacBook and I have chosen the appropriate definition.
My friends were with me - those from my usual group of photography, just 1 woman and 4 man - and we all appreciated the quality of the images - oh sorry - the quality of the projector, I mean.
The images projected were mines and they were great as usual.
Thank you John for all the information you passed me and all the guide lines.
Have a 2011 with Health with all your family and friends.