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View Full Version here: : More fun with OAG - Two from last night


dcalleja
28-04-2013, 04:30 PM
Hi
Round two and still getting the hang of OAG on the STF8300.
Much better on Omega and the Jewel box. I got both 5 and 10 min subs (mostly) without eggy stars.

Comments and critique most welcome

Thanks
Dan

multiweb
28-04-2013, 04:33 PM
Great star shapes. Working well. :thumbsup:

Larryp
28-04-2013, 04:33 PM
Nice results, Dan. Years ago when I had a 10" Meade s/c, I used to use an OAG-only way to go with a Schmidt/Cass

gregbradley
28-04-2013, 05:02 PM
Round stars - woohoo! Its the first milestone and a difficult one to achieve on a regular basis.

Greg.

dcalleja
28-04-2013, 05:16 PM
Thanks guys - yes I was more than a little surprised.
Had a few issues with the STi (getting it to focus and finding guide stars) .

I got the colour STi (thinking i would do some planetary work too) and am beginning to wonder if i shouldnt have gotten the mono version for more sensitivity. But it does seem to work quite well once you find the right spot and dont oversaturate the guide star

Ross G
29-04-2013, 08:30 AM
Nice looking photos Dan.

I really like your Omega Cent.

Ross.

Merlin66
29-04-2013, 12:11 PM
Dan,
I use the beamsplitter as a "full field" OAG on the C11 @ f10.
Using the Lodestar, finding and guiding becomes boring ;-)
(10min subs on the spectroscope 25 micron slit - what more could you ask for??)
The more you use the OAG, the more comfortable you'll become.

dcalleja
29-04-2013, 07:59 PM
Thanks Merlin
Im intrugued by the beamsplitter reference?



Thanks Ross

Merlin66
29-04-2013, 08:58 PM
Dan,
For spectroscopy I use an "on-axis' guider...it's a beamsplitter plate at 45 degrees which sends 4% of the incoming light to the guide camera and 92% of the light goes through to the slit on the spectroscope.
This arrangement lets me aquire and guide on a target star and accurately position it (using Al's Reticule) onto a 25 micron entrance slit.
Works 110% for spectroscopy.
Hope this helps.