Richard,

interesting comparison. The C14 is a clear winner here. Probably the old
saying that larger optics have better contrast (everything else being equal
of course) is not so wrong :-)

Stefan

"Richard Crisp" schrieb im Newsbeitrag
. com...
Here's another comparison image. This compares Thor's Helmet Halpha taken
with an Astro-Physics AP155EDF and ST10XME camera (binned 1x1) with one
taken with a C14 and IMG1024S camera. In this comparision, the plate
scales
were close: AP155/ST10XME: 1.29 arc-sec/pixel, C14/IMG1024S: 1.12
arc-sec/pixel.

In this comparison, all sub exposures were 20 minutes. There were four
such
subs with the AP/ST10, while there were three subs with the C14/IMG1024S.

http://www.rdcrisp.darkhorizons.org/..._thor_page.htm

Even though the AP155 has a focal ratio of f/7 and the C14 is at f/12.46,
the C14 goes deeper with the same sub exposures.