Alright, I've had my telescope for 2 weeks now and my new SPC900NC arrived yesterday (thanks AlexN for the advice!) - so I had my first serious attempt at astrophotography last night, so you'll have to excuse the crap quality .. I'm just learning
Setup:
8" f/6 Dobsonian (so untracked)
SPC900NC (unmodified)
Cheap 2x Bintel Barlow
Shutter: 1/33 exposure (I think?)
Framerate: 5fps
Everything else: as recommended by the tutorials here
Processed in Registax and GIMP (sharpened and slightly enlarged)
Took a few movies of Jupiter but got the best and stacked/waveletted it (see below). I'm pretty happy to have captured the GRS on the first attempt as I've never been able to see it by eye.
Any suggestions? The colours aren't perfect (I didn't bother playing with the colour settings on my first run), and I had quite a lot of stiction trying to adjust the azimuth ... need to modify the Dob base - registax had a lot of difficulty tracking the zigzag pattern of Jupiter.
Two questions for those with more experience:
Does it make sense to rotate the camera so that the object of interest travels horizontally across the camera image as opposed to diagonally? I could probably squeeze more frames out of the object that way
Is 5 or 10fps better in general? In daylight they both look completely identical (15fps is the first noticeable jump) .. but would double the number of medium-quality frames be better than a regular number of high quality ones when it comes to stacking?
Good effort Ash for 1st attempt considering no tracking and only 2x Barlow! It's always exciting to see GRS for the first time isn't it?
Jupiter is now 3 months past opposition and appears smaller by the day.Won't be long before we can't image Jupiter anymore this year.Keep it up you can only improve now. The next thing is tracking by either equatorial mount or EQ platform so you can take much longer video and a 5X Powermate to increase image scale.
Iceman suggested 5fps only when seeing is excellent. Use 10fps otherwise.
If object drift diagonally across FOV then you can take a slightly longer avi therefore more frames to stack.
Practice on the moon's craters after first quarter and get ready for Saturn in Dec.
Thanks guys. Unfortunately an EQ mount isn't financially possible at the moment, maybe next year - so I'll have to squeeze as much out of the Dob as possible.
I've already fixed the protruding-nail teflon on the Alt controls and loosened the spring connectors, will probably grab some weights if I decide to unspring it completely. I've chamfered the Az teflon and about to grab some sliders for the base. Hopefully the next manual-tracking session won't be as jerky after these changes .. it was close to impossible tracking Jupiter with so much resistance and overshoot!
Now to figure out why the camera drivers crash my PC.
Sorry I missed this thread earlier Ash... I just followed the link from your most recent image.
For a first attempt, untracked, I would have been STOKED with a result like that... mine was more of a redish circle with some slightly lighter bands in it.. Yours on the other hand has come out quite nicely indeed.
It's funny how on my very first attempt with almost completely random camera settings (colour, shutter, gamma, etc), no hartmann-mask assisted focusing, an aborted mirror cool-down sequence (I wanted to take photos ASAP), hasty post-processing .. and generally no real idea of what to expect - I managed to get results I still haven't been able to top yet ..
I'll just blame seeing
The EQ6 is arriving on Monday. I knew it wouldn't arrive today because the forecast is clear for another 4 days - that would be too perfect
heh... I've been DYING in this damn cloud fest we've had...
I just want to get out imaging... its leading towards depression...
You'll love the EQ6 mate.. Your setup will look a hell of a lot like mine did in 3 months ago... 8" newt, eq6, 900nc
Just so you're aware, the EQ6 does not come with a power source of any kind, just a lead to a cigarette lighter plug... you'll need either a 240v to 12v transformer (must be 2 amps minimum, preferably more) or, as seen in my pic, a 12v battery unit.. That unit cost me $80 from Supercheap auto, and runs my mount for about 7~8 hours..
Nobody told me about that when I ordered my EQ6, it arrived, skies were clear, but I had NO WAY TO POWER IT!!!
Yeah I rang around and found out about accessories. I managed to find an EQ6 (non-GOTO) for about $1300 including shipping, included dovetail bar. It was either than or a GOTO HEQ5 for the same price, so I went the sturdier mount ... giving up automation.
Seems to have plenty of adapters, hopefully this will do the trick.
I can't see the SCP from the back yard but I have a digital elevation meter and will find myself a compass. Should be good enough for planetary shots yeah? Just spend a while setting it all up, then sit back at the laptop - then corrections every couple of minutes?
I have one of those power adapters also... Works fine!
I think I've got a spare connector somewhere that will lengthen the hand controllers cable quite a bit, so you could have your hand controller next to your laptop and make adjustments without even getting up
for the first few months with my EQ6 I 'eyeballed' my polar alignment with a compass and inclinometer, I got it very accurate a few times, to the point where Jupiter would stay on the screen for 2hrs or so, with a 5x powermate... (tiny field of view) So yeah, your digital elevation meter and compass will work fine....
I might be wrong, but im fairly certain that even a non-goto EQ6 can use EQMOD.. You can plug the EQ6 directly into your laptop (without a hand controller) and use a program such as The Sky or Starry Night, and effectively have GOTO via the PC... I'll check if it works with a non-goto eq6, but im fairly sure, as the only difference between the goto and non-goto is the hand controller (afaik)
Just checked, EQMOD will work with a non-goto mount, and then you will have GOTO... EQMOD is free software, you'll need an adapter, I've ordered mine from shoestring astronomy for $39USD
Yeah it's a shame I don't have even this - stuck with 2x, 8x and 16x speeds on the basic EQ6.
But for $1300 I can't really complain. Can always upgrade the motors/controller later. Basic tracking should do for now .. much better than having my hand behind a dob moving it around
First light: Jupiter (GRS) - 2008/10/03
It's always exciting to see GRS for the first time isn't it?
its leading towards depression... 
