M27 (Dumbbell

(fritz kleinhans)


 

M27 (Dumbbell):
Sept 11-12, 2012; Blackwell Campground

Tec 140 mm x 1.6x TAK Extender
= 1568 mm @ f 11.2; cropped, full resolution, 0.566 arcsec/pixel
AP Mach1 GTO, 50mm f5 Borg Guidescope; Lodestar and PHD
Canon-Griffin 600D, ISO 800; T ~ 50's F
8 min subs x 8 = 64 min
8 lites, 3 darks, 3 flats; captured and processed in Image Plus

I think there was some image train sag.  This part of the image
is excellent, but other parts were seriously messed up.  More
work needed on this setup.


 

 M27 (Dumbbell):
 
August 25-26, 2011; Indianapolis, IN

Tec 140mm f7, AT2FF field flattener, 980 mm fl, cropped, 1.2 arcsec/pixel
 Canon-Hutech 400D @ ISO 400, AP Mach1 mount, 50 mm f5 guide scope.
Cropped, full resolution, 1.2 arcsec/pixel.

16 x 4 min subs = 64 minutes, 4 darks, flats.

This is first light for my TEC 140 from my test location, Indianapolis.  It is incredible how well digital imaging is able to penetrate city light pollution.  Note that the exposures are shorter and the ISO lower than from my truly dark sky site in NM.  When really dark I can go easily go ten minutes at ISO 800.  Here in Indy I was limited to four minutes at ISO 400.  Note that the Canon 400D is the last of this camera series with only 12 bit resolution.  Later models are 14 bit.