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View Full Version here: : M20 Trifid, GSO RC8 - (with asteroid)


davewaldo
14-07-2010, 04:08 PM
Hello everyone,

I wasn't going to post this image as I was just testing new gear, but it has turned out better than I expected.

This image is my first attempt at serious astrophotography. I have taken the occasional single frame before but this was my first attempt at stacking multiple subs and seriously trying to get a worthwhile image. On a side note its amazing how good gear makes the process SO much more enjoyable. I had struggled in the past with webcam guiding and manual focus. Now that I have a dedicated autoguider and motorised feathertouch focuser the process was much more fun and less annoying. :D

I was testing a GSO RC8 and a QHY5 guider. Both performed well, the QHY5 makes life a breeze!

Upon processing I discovered the image contained the movement of asteriod 700 auravictrix For more info and to see an animation see this thread. (http://www.iceinspace.com.au/forum/showthread.php?t=63506)

This image contains 4x3min 2x 5mins 1 x 10mins exposures @ ISO 1600. The mix of exposures was really just to test my tracking. I also took and used some dark frames and loaded them into DSS but I really don't know what I'm doing yet and haven't tried flats or bias' yet.

Canon 20D
GSO RC8
HEQ5

Stacked in DSS, curves and saturation in PS CS3.

Feel free to tell me how I can make this image or my process better. I have HEAPS to learn. Obviously it needs MUCH more exposure/subs for more data and less noise. I think the collimation is close but needs to be tweaked.

Thanks for looking, :)

Dave.

jase
14-07-2010, 05:03 PM
Good effort for a test shot Dave! You've highlighted your test session learnings such as more exposure time, collimation and a few other items. Just need to bring those all together. I would be focusing on obtaining the highest quality data your set up will deliver. When it all clicks and you're satisfied with the data set, hone in on your processing skills. Keep at it.

strongmanmike
14-07-2010, 05:24 PM
Reeeeally Jase :question:...sooo insightful master Jennings :rolleyes:...:lol:

Great job Dave I like it :thumbsup:

Mike
ps. I have a smile on my face Jase, just ribbing ya :poke: :P

Paul Haese
14-07-2010, 05:48 PM
Dave, just a couple of small things.


Make sure your focus is spot on and check this often during imaging. The carbon fibre units hold focus well generally but using a bahtinov mask will certainly get you really sharp.
Make your subs longer. Use 15 minute subs at a lower ISO. Or go as long as 20 minutes.
This is a good first image and given your experience it is a very good image. Keep them coming.

jase
14-07-2010, 06:01 PM
Stick with me Mike...you may just learn something. :D ;)

Garyh
14-07-2010, 06:16 PM
Looking good Dave! guiding, focus look all on track!
Just like what Paul mentions, a lower iso with longer subs would be the way to go..:thumbsup:

davewaldo
14-07-2010, 09:47 PM
Thanks Jase, Mike, Paul and Gary for your comments and help.

I now have a Bart mask so I'm looking forward to using that for focusing. I'm not convinced I got it spot on for this shot.

I'm happy how my mount is tracking / guiding, but I don't think I can go beyond 10min subs due to light pollution. I'm using an IDAS filter to cut the pollution as much as possible.

Would I be correct in assuming that when the subs have a very washed out background they are too long? Once I hit 10min subs the background density reads about 80 out of 256, is there any point going longer from my location?

Cheers,

David.

strongmanmike
14-07-2010, 10:18 PM
:computer:... :bashcomp:......:help2:.....JASON JENNINGS.....:thanks:....:love2:


...sorry Dave :thumbsup:

davewaldo
15-07-2010, 06:33 PM
By all means... carry on :lol:

RobF
15-07-2010, 07:07 PM
WTG Dave!

I'm still amazed at the quality of your first serious astropics here, but then for a seasoned photographer you've already got to be a fair up the mountain than where many of us started :thumbsup:

gregbradley
16-07-2010, 08:56 AM
Just curious, how are you using your QHY5 autoguider - are using a guidescope or an off axis guider?

Your tracking is very good.

Greg.

davewaldo
16-07-2010, 05:48 PM
Thanks Rob, you're pics (and everyone commenting in this thread) have been an inspiration. :thumbsup: I feel very confident adjusting images in photoshop, but pretty much everything else is a steep learning curve!

Hi Greg,

I use my QHY5 guider in a vixen 70S guidescope (400mm FL). The scope is a dream to use also as it has built in X, Y adjustments but remains quite stiff. But I'm thinking I should use a barlow as well as my imaging pixel to guiding pixel ratio is a bit low.

Yes I am quite happy with my guiding. At 100%, some of the images have slightly eggy stars so I discard these. Considering this scope is 1800mm focal length I'm not complaining :D:P

Thanks again everyone for looking and tips.

Dave.

RobF
16-07-2010, 07:37 PM
No need to rush into barlowing Dave if you're getting results that good. I've found for the 1000mm FL Newt I'm getting tracking as good as ever at 200mm in the guidescope versus old 700mm with a piggy back refractor (albeit a refractor with none of the sophistication of your little Vixen).

Craig Stark is always telling people about the marvels of subpixel guiding current software is capable of now, and with your QHY5 you'll definitely get all the benefits of that with your increased sensitivity.

davewaldo
17-07-2010, 06:16 PM
Thanks Rob, thats interesting what you say about guiding.

I guess what I need to know is just how good is guiding software at picking up movement? A lot of people say it can pick up 1/4 of a pixel movement (therefore the guiding pixels/arcsec can be 1/4 of imaging chip). If this is so my imaging chip will notice the movement before my guiding chip in its current setup, however if its more sensitive than this I should be ok.

I guess I'll have to do some tests, but like you say, there is no rush as I'm getting quite good results already. Hopefully I can get out again this week and do some more. :D

Hagar
17-07-2010, 07:34 PM
Very nice start Dave and to capture the asteroid is a bonus.
Well done.

Screwdriverone
17-07-2010, 08:12 PM
Veeery nice Dave,

Hang on...this looks a lot like MY one - you copying me???? :lol:

Oh, you posted this 3 days before me....DOH!

Keep it up, if you need a hand, let me know.....I have some tips for you......HA HA HA.

Nice start, well done.

Cheers

Chris

davewaldo
18-07-2010, 09:38 PM
Thanks Doug.

Nice one Chris... Maybe you stole from ME! :P

Screwdriverone
18-07-2010, 09:51 PM
HA HA :lol: Dave,

Shhhh! dont tell anyone!

Cheers

Chris