Re: [APML] Need help identifying lens problem

["T&JDiana" <tomdiana@acegroup.cc>]

Jim,

 

IMHO, it looks like some field rotation.  How accurately was your mount polar aligned?  Or maybe you were targeting far away from where your scope was pointing.

 

Tom

----- Original Message -----

From: Jim Ives

To: APML

Sent: Sunday, March 17, 2002 9:23 PM

Subject: [APML] Need help identifying lens problem

I took this photo Saturday night with a 400mm telephoto. I don't know what kind of optical aberration I'm looking at here. Can someone help?

Here's the photographic data:

400mm Telephoto f/5.6

Photo shot at f/5.6

Guiding ST-4 AE=3 @ 2000mm with SCT.

Is this a problem I could eliminate by stopping down the lens 1 stop and exposing longer??

The photo can be seen here: http://flyboy999.freeyellow.com/Nebula/IC405400mmSmall.jpg

Thanks for the help!

Jim Ives