View Full Version here: : What seeing is this ?
Hey crew.
I wasnt sure where to put this thread,but its a pic so i hope its ok. Ive never observed with anyone else so there lots i hear everone talking about but im not really sure. This is one of about fifty shots of mars the other night. This is about as clear as it looked visually {some moments were a little clearer}
Two questions:
1. What seeing would this be {i would say bad but i have no idea what number} ?
2.Is it worth trying to get a shot when its like this ?
Thanks for any tips. {sorry if its in the wrong spot ice}
rumples riot
20-10-2005, 11:10 AM
By the shape of the planet being nearly oval I would say around 3/10 max. This is also confirmed by lack of detail.
Still it is hard to judge without having an avi to gauge the seeing. That is the real test, when you can see what it looks like. In 7/10 seeing the planet will be very still hardly even moving and the detail will be very sharp. I don't get that very often here in Adelaide, most commonly during late summer/early autumn.
That should give you some idea though.
xstream
20-10-2005, 11:16 AM
Hi Josh,
Seeing is usually determined by viewing a star, at a rough guess form your pic I would of said seeing was approx. 4-5
The link below will help you to determine seeing.
http://uk.geocities.com/dpeach_78/pickering.htm
like what paul said... it kinda hard to judge by the pic. :confuse3:
davidpretorius
20-10-2005, 11:34 AM
john, what magnitude star and i assume near the zenith.
i am hanging out for star camp for this main burning question of mine to see the diffraction rings on my scope!!!
iceman
20-10-2005, 11:57 AM
It's also hard to tell from an afocal shot, rather than an avi which you can see the image bubbling and boiling away.
xstream
20-10-2005, 02:58 PM
Yes Dave as close to the zenith as possible (Least amount of atmosphere to look through).
Someone correct me if I'm wrong but I don't think the mag. of the star matters that greatly.
rumples riot
20-10-2005, 03:23 PM
Mag of the star should be about 2, easier to make an assessment than with -1 or -2mag.
Thanks xtream, that link cleared alot up for me.
So after you have established what seeing you have is that then the determining factor as to whether you bother trying photography ? i.e if the seeing is around 2-3 is it still possible to get good shots? or do most of you normally not go for the camera unless its much clearer ?
Sorry if it seems a strange question but im just not having much luck with mars,and im not sure if i should be trying when the seeing is not that good.
Thanks all for the help.
Back to scatching the noggen
davidpretorius
21-10-2005, 06:08 AM
that is where where taking movies of stars comes in. If you say take say 20 sec @ 5 frames a sec ini a movie format, hopefully, you will have 1 or 2 good ones!
ok. ll give a movie a go, ill have to work out stacking though{had to happen some time} Thanks for the help.
davidpretorius
22-10-2005, 10:22 PM
josh, you got an email, i have zipped up my little jupiter bmps that i have centred for you to have a play with in registax. have a look at some of them and you will see the variability in visibility.
the zipped up file is 1.15mbytes
Hey thanks alot for that. Im off now to have a try.
ill let you know if i can do anything.
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