[Guest]

Hello everyone,



First thanks Klaus for this pleasant upgrade of PZ forum !



I've had lately an issue when shooting night sky with 2 tele primes. Actually the stars were blurred, just as if lenses cannot reach focus on infinite.



To give more details

• shutter was set on 30s (no moving star effect that happens when you have a several minutes exposure)
  
  
• manual focus on infinite (I double checked number of times)
  
  
• body on a tripod (and no wind)
  
  
• lenses were 135 at f2 to f2.8 and 100mm at f2.8
  
  

I tried to activate the focus micro adjustment available on my body, but I didn't achieve to get a sharp result. I got better results, but nothing perfect <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/sad.gif' class='bbc_emoticon' alt='' />



Any idea of what would be this phenomenon and how it could be corrected ?



Thanks !