After having worked on this for a couple of hours, I think it is done. I'm sure it can be enhanced further, and I'd be happy if someone else was to have a go or give me pointers on how to fix it.
Bear in mind, it's just the one image; a ten second exposure.
I'm getting the hang of Registax which I think is very important. What an amazing piece of software!
Mate....that's a very nice image! Fixing? Looks good enough to me as is! But no doubt someone in here can make it look better....Not me lol. I don't know the first thing about DSO processing.
Great work mate, although your method is not quite right for processing, if you duplicate the image then stack, you are stacking noise aswell. The idea of taking several exposures is to reduce the noise in the image but keep the aligned stuff like stars and nebula. Start off with a few shots like the one you have (5 images @ 10 seconds) then process them the same way, I am pretty sure you will get a better effect.
At least give it a go, doesnt hurt. Welcome to the world of Astrophotoraphy!
Other guys here may have more ideas on the processing side, who can guide you through it.
Do you have the original?, there is a ton of detail in there but would need original file to work with. I tried it out on the posted image but the compression was too great.
Hi Humayun, nice wide-field milkyway shot. Sounds like Astroman has some good advices for you. I'm pretty familar with registax, but only on planetary.
anyway,well done, and look forward to your results when you start stacking up the big numbers
Especially from a static Tripod. You have had some tips already - stacking copied images will not get you any signal/noise advantage stacking more images will, also taking longer images will, however you are then constrained by lack of tracking and a desire to see stars as points not trails. You can use this "rule of thumb" formula to calculate the max exposure without noticeable trails
700/F where F is the focal length so here it is 700/50 = 14s
This is for stars at the celestial equator though and stars closer to the pole appear to move more slowly you can use 1000/F at 50 Degrees S, even more closer to the pole.
So take a set of images based around 20s in + and -5s steps use the greatest ISO you can (1600 on a 350D?) and shoot in JPEG to start with, once you are happy with the image and focus switch to RAW and take a set of 10 to 20. Convert to TIFs for registax - and reduce to 1024x768 or so for initial sorting/processing (faster than working at full scale). If you do not have the ability to go over 30s you will need to get a cable release (highly recomended).
You might also try stopping the lens down a little - now this sounds silly when you want as much light as possible but it will reduce the any distortions due to the lens, try going down a 1/2 - 1 stop, a UV filter will help reduce the blue halos (CA).
That's enough for now I think, and welcome to IIS !!!
Great first shot Your first real astro shot is something that will stick with you for a long time. It's a real kick to get started on this journey.
ditto to what has been said above. Stacking multiple images is definately the go. As John H says you should be able to get around 20 sec for a crux shot. But why not get yourself a piggyback bracket for your LX90??? You will still get field rotation eventually but you will be able to get longer than 20 sec. Depending on the direction your are shooting (ie pole or celestial equator) You may be able to ge a minute or more of usable image at 50 mm. Strange as it seems but if you mount it on your LX90 and as long as you aren't pointing near the zenith/meridian, then shooting at 0 deg dec will probably give you the longest shot. Opposite to the still tripod shots.
As a comparison, I did a crux shot similar to yours a few months ago using the 50mm f/1.8 (Check here http://www.iceinspace.com.au/forum/s...ead.php?t=2731) Makes a hell of a difference if you can lengthen your exposure times. All the images are 240 sec stack. On an equatorial mount though.
Mate....that's a very nice image! Fixing? Looks good enough to me as is! But no doubt someone in here can make it look better....Not me lol. I don't know the first thing about DSO processing.
Hi John,
Thanks for the complement, mate.
I'm sure it could have been better. Maybe next time.
Great work mate, although your method is not quite right for processing, if you duplicate the image then stack, you are stacking noise aswell. The idea of taking several exposures is to reduce the noise in the image but keep the aligned stuff like stars and nebula. Start off with a few shots like the one you have (5 images @ 10 seconds) then process them the same way, I am pretty sure you will get a better effect.
Hi Andy!
Yeah, I spoke to someone who is a bit into imaging and he told me the exact same thing regarding replicating the noise, but I thought I'd just give it a go anyway and see what happens.
Quote:
Originally Posted by Astroman
At least give it a go, doesnt hurt. Welcome to the world of Astrophotoraphy!
Cheers!
Quote:
Originally Posted by Astroman
Other guys here may have more ideas on the processing side, who can guide you through it.
That's what I'm here for -- to learn!
Quote:
Originally Posted by Astroman
Do you have the original?, there is a ton of detail in there but would need original file to work with. I tried it out on the posted image but the compression was too great.
I do, I do. If you hop on IRC, I'll send it across. It's approximately 3 MB. Otherwise, email?
Hi Humayun, nice wide-field milkyway shot. Sounds like Astroman has some good advices for you. I'm pretty familar with registax, but only on planetary.
anyway,well done, and look forward to your results when you start stacking up the big numbers
cheers,
Thanks for the heads up, Robert. I look forward to taking more shots!
Especially from a static Tripod. You have had some tips already - stacking copied images will not get you any signal/noise advantage stacking more images will, also taking longer images will, however you are then constrained by lack of tracking and a desire to see stars as points not trails. You can use this "rule of thumb" formula to calculate the max exposure without noticeable trails
700/F where F is the focal length so here it is 700/50 = 14s
This is for stars at the celestial equator though and stars closer to the pole appear to move more slowly you can use 1000/F at 50 Degrees S, even more closer to the pole.
So take a set of images based around 20s in + and -5s steps use the greatest ISO you can (1600 on a 350D?) and shoot in JPEG to start with, once you are happy with the image and focus switch to RAW and take a set of 10 to 20. Convert to TIFs for registax - and reduce to 1024x768 or so for initial sorting/processing (faster than working at full scale). If you do not have the ability to go over 30s you will need to get a cable release (highly recomended).
You might also try stopping the lens down a little - now this sounds silly when you want as much light as possible but it will reduce the any distortions due to the lens, try going down a 1/2 - 1 stop, a UV filter will help reduce the blue halos (CA).
That's enough for now I think, and welcome to IIS !!!
Hi John,
This is exactly what I wanted someone to post -- so that I can learn.
I have taken your points on board and will employ them the next time I get out in the field.
Great first shot Your first real astro shot is something that will stick with you for a long time. It's a real kick to get started on this journey.
Thank you! Yeah, I am pretty happy with the way it turned out. I think the most important thing is that it has given me a starting platform. I have a bit of an idea of what it is that I'm supposed to do with the software.
Quote:
Originally Posted by [iponders]
ditto to what has been said above. Stacking multiple images is definately the go. As John H says you should be able to get around 20 sec for a crux shot. But why not get yourself a piggyback bracket for your LX90??? You will still get field rotation eventually but you will be able to get longer than 20 sec. Depending on the direction your are shooting (ie pole or celestial equator) You may be able to ge a minute or more of usable image at 50 mm. Strange as it seems but if you mount it on your LX90 and as long as you aren't pointing near the zenith/meridian, then shooting at 0 deg dec will probably give you the longest shot. Opposite to the still tripod shots.
In the time since I took that image, I have purchased a piggyback bracket for my LX90. The last time we went to Kurnula, I wanted to try it out but I left the battery for my EOS-350D in the charger at home. I was bummed about that!
Thank you for the details as well. I really need information like that which will help me. Cheers!
Quote:
Originally Posted by [iponders]
As a comparison, I did a crux shot similar to yours a few months ago using the 50mm f/1.8 (Check here http://www.iceinspace.com.au/forum/s...ead.php?t=2731) Makes a hell of a difference if you can lengthen your exposure times. All the images are 240 sec stack. On an equatorial mount though.
I remember seeing those images, they are remarkable. I love that milky texture. That's what I'd love to achieve.
You will see my re-processed version down the thread which looks quite different - and I agree with others - the best thing you can do now is get that piggyback mount going - you should then be able to go out to 200-300mm FL and 2-3 mins or, perhaps 5-6 mins at 50mm unguided that way depends on your mount precision. If you use those Canon zooms you will have to stop down - stars look like trumpets in the corners (spherical abberation) and have halos (Chromatic Abberation) if you don't - I use f8 on my zooms, hell of a penalty to pay but astrophotography is really demanding on those optics..so its $$$ for L glass or stack a lot....
Sounds like Astroman has some good advices for you. I'm pretty familar with registax, but only on planetary. 
![[1ponders]'s Avatar](../vbiis/customavatars/avatar45_9.gif){kind=avatar}
Your first real astro shot is something that will stick with you for a long time. It's a real kick to get started on this journey. 
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