i haven't processed any of the data i got on friday night because i was embarrased by the results. i used a bahtinov mask to focus on a star at f20 thinking that this would be good to focus with - how wrong i was. i went to mars first, and the image was dancing in the middle of frame and to be honest my eyes were telling me it was focussed but it somehow seemed very soft, but on the monitor i could see some dark bits. oh well on to saturn - it was like it was in a clear soup - wave upon wave of light warping and dancing the rings , but over all the image seemed soft. I really need to understand how you focus for these planets. i was using the new dbk21AU618 camera at f20 through the meade 14(f10 with 2x tview big barlow) on the titan mount . unguided the mount kept the blurry bit in the middle for over 1.5 hours while i was mucking about. I have posted some screensnaps to show those out there that this is the other end of the scale far from the Paul's and john's of the world getting fantastic crisp images of these planets.
SCTs are notorious for tube currents and take a very long time to cool.
Seeing also plays a huge part in planetary imaging so it's not just focus.
How did you process the data, what software?
looks like poor seeing to me, but nothing embarrassing at all. Ease of focusing is a good indicator of seeing - if it is hard to focus, the image will be ordinary. As Andrew points out, the scope must also be in thermal equilibrium with the air or you will get boiling of the image from tube currents and boundary layers in addition to the seeing effects.
FWIW, I use the appearance of fine detail in the image (if there is any) to focus and just wait long enough at each setting to make sure I get a good sample of seeing to decide if it needs tweaking. Be thankful you are using a colour cam - with mono you have to do it 3 times for each image.
I suspect that everyone has hard disks full of useless images taken in poor seeing.
Regards Ray
Your description of the planets dancing around is probably a combination of scope currents and poor seeing, that is how it is, but the Saturn image also looks like it could be processed better to get a more impressive result.
My own efforts from some very average seeing a few nights back sound exactly like you described, it was jumping around like a cork in a washing machine, and the avi looked awful: http://www.iceinspace.com.au/forum/a...e.php?a=111043
But it processed into this: http://www.iceinspace.com.au/forum/a...e.php?a=111042
which is not great but far less awful than the .avi looked.
Try running the videos through Autostakkert just using the defaults and see what you get.
Or post the videos somewhere so we can have a go at processing.
The mars is overexposed by the look of it, and both images are suffering from colour balance being out when capturing.
Can you post a couple of the Saturn best frames from the .avi file, that way we can see what it should look like.
well its always cooling down - its in the observatory....... i opened up the observatory and put the fan on for 3 hours before imaging
Is the fan blowing across your OTA or just extracting air from the dome?
I use a 12" fan blowing across the OTA of the C11 because it takes forever to cool compaired to the C8. The fan needs a good 1 to 1.5 hrs to get rid of the tube currents in the airey disc (throw it out of focus and you'll see the tube currents as a vertical column or "trees" through the airey disc). Then you've just got normal cooling rates to worry about.
I can also get rid of half my dome to help it cool too... prolly not so easy in a full dome.
I know your frustrations, Dave. I'm absolutely rubbish at planetary imaging, but I do have a DBK21 camera and I have seen the colour and white balance issue on your Mars shot a bit. Took me some tinkering to figure out what was going wrong.
Not sure which image capture software you're using. I tried using K3CCDTools, but the latest version of Imaging Source's IC Capture seems very good and been using that.
Anyway, seems to be the auto white balance settings. So I untick the auto WB option, and manually adjust the R and B keeping an eye on the histogram. Just need to make sure none of the channels go over saturation as they fluctuate.
Sorry if all of the above you're already familiar with. Just that I lost a few nights figuring this out and if I can help save you some time... That auto WB issue is something us with the DBK have to deal with that the mono guys don't AFAIK.
I know your frustrations, Dave. I'm absolutely rubbish at planetary imaging, but I do have a DBK21 camera and I have seen the colour and white balance issue on your Mars shot a bit. Took me some tinkering to figure out what was going wrong.
Not sure which image capture software you're using. I tried using K3CCDTools, but the latest version of Imaging Source's IC Capture seems very good and been using that.
Anyway, seems to be the auto white balance settings. So I untick the auto WB option, and manually adjust the R and B keeping an eye on the histogram. Just need to make sure none of the channels go over saturation as they fluctuate.
Sorry if all of the above you're already familiar with. Just that I lost a few nights figuring this out and if I can help save you some time... That auto WB issue is something us with the DBK have to deal with that the mono guys don't AFAIK.
i used the IC capture software - i never even though of the white balance just used it straight out of the box so i made a mistake and assumed it would be right....information greatly appreciated
put the best AVI thru castrator and zip it and upload it to files.
That way we can see what it looked like for you live.
Did it look like these? This was average seeing, long cool down, cold night.
Potential image scale and detail are definitely promising though.
The Saturn for sure. Was it early evening (low) or later (higher in sky)?
Steve
yeah saturn was low and mars is off in the north low
Quote:
Originally Posted by Shiraz
looks like poor seeing to me, but nothing embarrassing at all. Ease of focusing is a good indicator of seeing - if it is hard to focus, the image will be ordinary. As Andrew points out, the scope must also be in thermal equilibrium with the air or you will get boiling of the image from tube currents and boundary layers in addition to the seeing effects.
FWIW, I use the appearance of fine detail in the image (if there is any) to focus and just wait long enough at each setting to make sure I get a good sample of seeing to decide if it needs tweaking.
I suspect that everyone has hard disks full of useless images taken in poor seeing.
Regards Ray
i think it was seeing and the focus wasnt right
Quote:
Originally Posted by Poita
Your description of the planets dancing around is probably a combination of scope currents and poor seeing, that is how it is, but the Saturn image also looks like it could be processed better to get a more impressive result.
My own efforts from some very average seeing a few nights back sound exactly like you described, it was jumping around like a cork in a washing machine, and the avi looked awful: http://www.iceinspace.com.au/forum/a...e.php?a=111043
But it processed into this: http://www.iceinspace.com.au/forum/a...e.php?a=111042
which is not great but far less awful than the .avi looked.
Try running the videos through Autostakkert just using the defaults and see what you get.
Or post the videos somewhere so we can have a go at processing.
The mars is overexposed by the look of it, and both images are suffering from colour balance being out when capturing.
Can you post a couple of the Saturn best frames from the .avi file, that way we can see what it should look like.
the videos are too big to post even after shrinking and autostakkert didnt help - much of a learning curve for that programme as well
Quote:
Originally Posted by sheeny
Is the fan blowing across your OTA or just extracting air from the dome?
I use a 12" fan blowing across the OTA of the C11 because it takes forever to cool compaired to the C8. The fan needs a good 1 to 1.5 hrs to get rid of the tube currents in the airey disc (throw it out of focus and you'll see the tube currents as a vertical column or "trees" through the airey disc). Then you've just got normal cooling rates to worry about.
I can also get rid of half my dome to help it cool too... prolly not so easy in a full dome.
Al.
maybe an airconditioner - i saw one at homeart yesterday for500 dollars -maybe?
Peter, what processing software were you using to transform that image of Saturn into that glorious end result??? Would love to know how you did that!!
however i did like the image scale i got
.
Would love to know how you did that!!
