From: Ray Byrne <ray@in4media.co.uk>
Date: December 1, 2008 2:25:55 PM MST
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Re: a large piece of moonscape
Alan,
I sent my concerns to Mick after my reply to you and he felt the same way as you - although didn't spell it out so eloquently. I think that it must be dedication that gives such great results and for this you are duly worthy of all the commendations you receive. Thanks Alan.
On 1 Dec 2008, at 19:00, Alan Friedman wrote:
Thank you Ray. The seeing at my location is not very good overall - it takes a lot of sessions at times that a sensible person would use for sleeping to come up with one or two data sets where processing is worth the time. On this night it was good early on - I prepared a decent image of Clavius at f30 earlier that night - but then it deteriorated to the point where I would usually pack it in. I was excited by my first night out with the big 41AF02 camera, so I pulled out the barlow and gave it another try at the 10"s native focal length - f14.6.
I would really like to see a new analysis method for planetary seeing that utilizes the streaming camera. The Pickering scale is really more of an averaging analysis - like FWHM - and does not tell enough about the micro environments that are seen when capturing 30 or 60 frames per second. The average seeing at my location peaks at a pickering 6-7/10 and averages about 5/10. There are some types of 5/10 seeing where none of the captured frames show good resolution. Then there are other occasions where some fine detail is recorded in 20% or so of the frames, but the detail morphs considerably from frame to frame so that stacking them produces a very much softened average of the shapes. Then there is a jittery 5/10 with 20% good and consistent frames that emerge from a large amount of awful stuff. This last type, when saved as a movie with the bad frames deleted, will look very much like 7-8/10 seeing and will respond very well to the modern miracle of multiple alignment point processing. You can make a darn good image from this type of data - albeit with inferior results (and much more time and work) than can be achieved in true 8/10 seeing from Florida or other tropical locations. But it gives us enough to keep us busy and allows us to sleep in our own bed too!
best wishes,
Alan
On Dec 1, 2008, at 10:47 AM, Ray Byrne wrote:
Hi Alan,
What a treat I shall pour over this for hours. You've managed to pick out the rille in the Alpine Valley really well (quite a feat in it's self). This is for all the world a view of the Lunar landscape like those from Apollo. You must have had good seeing that night although I know the labourious lengths you go to to create these stunning images. I never seem to get any decent data to even attempt to try the techniques you've explained to me. An astronomer/astronomy supplier friend of mine Rob Dalby suggested that I may have serious trouble with my observing site. I live in a mid-terrace 3 storey house with a very small garden (so I'm fairly close to the house - 5/6 yards). The position of the house means that I observe in the Lee of the prevailing wind and I will have eddys nearly always around my local sky. Over the Christmas holidays I'm going to put my mount on a tripod and go out the front of the house and see if it makes a difference.
Our mutual acquaintance Mick Hyde lives around a mile from me and uses the same gear and does get better data to start with (although like yourself puts in the spade work + gets out a lot, he has an obbo)
Anyway bit OT sorry
Lovely lovely image thanks Alan you're an inspiration as always
On 1 Dec 2008, at 15:27, Alan Friedman wrote:
Hi all - Thanks very much for the positive feedback!... and for taking
the time to wait for this big download.
best wishes,
Alan
ATB
Ray Byrne
in4media | graphic and website DESIGN
T: 01793 435704
ATB
Ray Byrne
in4media | graphic and website DESIGN
T: 01793 435704