On 14/06/2017 22:20, StarDust wrote:
On Tuesday, June 13, 2017 at 9:09:48 AM UTC-7, Razzmatazz wrote:
On Tuesday, June 13, 2017 at 2:52:30 AM UTC-5, Martin Brown wrote:
On 13/06/2017 00:06, Razzmatazz wrote:
M13 is now at a good point, high up at night. A quick (very quick) look at this bauble.

https://www.astromart.com/common/ima...7.jpg&caption=

AP 17" F8 Astrograph
STL11K camera
Single 5 minute Luminance exposure
AP1600 mount

Magnificent! How long an exposure?

Can you find the very small background galaxy in this image? It's at magnitude 18.

Is it the streak about 1/5 across and just over half way up left side?

The exposure was 5 minutes, a single exposure.
Yes, the mag 18 galaxy is about half way up the left side.

Razzy

Ouch!!! Mag 18 galaxy, you need Hubble to see that?

Not any more. Modern CCDs now available to amateurs using 18" scopes
allow photographs comparable with old Palomar emulsion plates and have
done for quite a while now. A good test is IC1296 in the field of M57.
Jack Schmidling nabbed it testing his new kit back in

http://schmidling.com/m57.htm

Web page doesn't give dates but here is the original saa thread. By then
there were colour cameras that could catch the faint galaxy in 18/8/1999

https://groups.google.com/forum/#!searchin/sci.astro.amateur/Jack$20M57$20CCD%7Csort:relevance/sci.astro.amateur/Bdxr7fxprB0/bqqSTGx_KXEJ


--
Regards,
Martin Brown