Barnard's E

[vincentnm]

Dear All,

Been waiting for a moonless and transparent night to capture this one. After so many rainy nights got a break in the clouds early morning of 7th October.

Dates taken: 7th October 2010

Location: Beckenham, Kent, UK.

Scope: Celestron 8 with Hyperstar 3

Camera: Starlight Xpress SXV-H16

Filters: IDAS LPR

Guiding: Skywatcher ST80 with DFK

Mount: Skywatcher EQ6

Exposure: 300s X 25 subs

Calibrated and Stacked in DSS

Stretched and Noise Reduction in Photoshop CS3

There's a bit of field curvature in the top corners. Not sure that caused it; Collimation? Your comments for improvement are most welcome.

Thanks,

Vincent.

[vincentnm]

BAsed on some feedback from other forums, I think the trailing of stars at the top corners is due to field rotation as the guide star was inadvertently quite far off.

I tried collimation using CCD Inspector. Managed to get the collimation error under 10 pixels. Any further adjustment kept giving me random variations between 3 and 8 pixels. Even consecutive measurements without touching the collimation screws gave this variation. Effect of seeing?

[Tim]

Never seen or heard of this one before Vincent, nice one

The faster the scope, the harder to collimate