Another Horse (of course)

[BruceG]

OK this is my second ever astro image. The first one failed as I only got one sub before the camera battery gave out. Now armed with new camera batteries and waiting for a clear night I had another try.
This time it was 12 x 3 minutes as I only had around 1 hour for the nebula to emerge from one set of trees to disappearing into the next tree.
All in all 36 minutes of subs with 7 darks. (I haven't got into the light and bias frames yet).
I am pretty happy with the result, considering I don't have much data.
So much to learn!!

[cometcatcher]

It's very good!

[BruceG]

Thanks Kevin, I'm pretty happy, a couple of points though, the image seems a little soft - maybe after the noise reduction program I used (neat image I think) - it's a trial version and perhaps a little too aggressive. I also would have like to bring out some stronger colour or intensity in the Ha regions - I know it's only 30 minutes of integration, but I might be able to get some more out of nebulosity after a few more plays with it.
Will appreciate any other thoughts or suggestions from out there, I haven't had any experience with these photo manipulation packages before - I'm an old darkroom type who until now has not dabbled in the digital world.

[Rigel003]

A great result for your 2nd astrophoto. Good detail and colour and nicely framed. Best bet is to increase the length of your subs if you can without increasing noise enormously, otherwise take lots more subs. 3 mins isn't really long enough to work up a decent signal to noise ratio and the noise limits how far you can stretch the image. I can relate to the tree situation,my backyard is the same. Can you leave it set up and grab more subs on a second night? Only other issue is that focus looks a little soft. I think those stars are a bit bigger than they could be.

[BruceG]

Hi Graeme, thanks for the encouragement. I don't know if I can go longer with the subs - my raw exposures at t 3 minutes are quite red all over, which I assume is sky glow? (although I don't know if it is or isn't) - I haven't tried to go beyond 3 minutes, but it is worth a try - maybe 5 or 6 minutes.
I like the idea of leaving everything set up for consecutive nights, only that the weather never seems to co-operate. I do have a method of achieving reasonable polar alignment at each setup. I have 3 steel right angle brackets hammered into the lawn (purchased from Bunnings) - these already come with 2 holes through each face which allows the end of the tripod legs to stay securely in the holes. I spent a long night initially leveling everything and a couple of hours of drift alignment. In the end I was aligned quite well. If I don't collapse the tripod, I can plonk it into the appropriate holes, set the telescope and other bits and pieces on it and I'm ready to image - I call it my poor mans pier. These brackets were not my idea, but a good friend of mine, Mel, who is responsible for me taking the plunge into astronomy after a virtual lifetime of interest in the subject.
I guess the only other thing I need do to ensure correct registration of the 2 sets of images is to leave the DSLR on the scope and the scope on the rings - although I'm thinking "align and rotate" would correct that (am I correct here?).
Thanks once again for the advice - I need as much as I can get.
Cheers,
Bruce.

[alpal]

Hi Bruce,
Nice shot.
The red is caused by thermal noise in the camera.
It is always much worse in summer.

Couple of hours of drift alignment?

You can get a perfect drift alignment in under 15 minutes
if you use your camera & it's so easy:

To adjust the right ascension:
Point North at about 50 degrees altitude.
Take a 70 second exposure while tracking for 5 seconds, slewing E for 30 seconds then slewing W for 35 seconds at a x1 rate. Your image will show a star and a V shaped trail. The size of the opening of the V at the is the amount of drift in 60 seconds and its location relative to the star shows you which way the mount needs to be adjusted. Adjust the RA screws left or right mount until the V collapses to a line that passes through the star and you'll be polar aligned.

Elevation alignment is similar but point the mount to the Eastern or Western Horizon & adjust the elevation screw.


cheers
Allan

[BruceG]

Hi Allan, thanks for the info. I have a 300d no live view so not very convenint for the camera method, particularly at or near the zenith. The old fashioned method with illuminated reticule drifting to get close and then PHD by switching dec off and watching the graph gets me over the line. I have found I can track nicely each time I setup without any further alignment. In other words, I find I can setup and start pretty much straight away.
Bruce.

[cometcatcher]

Hehheh, yeah I have a darkroom under the house my father built for me in 1982. It had 20 years of use before I permanently converted to the dark, I mean digital side.

As for colour intensity in the Ha regions, it's easy in Photoshop. Here I duplicated the image, selected the red channel, copied it back onto the original as a luminance layer and then adjusted the saturation to compensate. It's noisier, as any aggressive processing would be, which is why we always need more and more subs. The more subs, the harder the image can be pushed to bring out the faint bits before noise takes over.

[alpal]

Yes - that's another good method.
I wasn't talking about live view but taking a 70 second exposure while pushing the East then West buttons at a rate of x1.

[BruceG]

I understand Allan, after the exposure I need to get under the mount to check the image on the rear screen or do you mean to download the image to the laptop and see it there?

Kevin - that's pretty impressive manipulation. I'm afraid I don't know anything about how to use Photoshop it - I don't own a copy in any case. I do have Gimp 2 which is supposed to be a PS-like free alternative, but I haven't done any real reading about it's capabilities. I guess I will just have to be more patient and collect more data. I know patience is a virtue, and one that I need to work on haha.

The air has been real smokey here in the last few days, but I'd rather practice imaging under less than ideal conditions than those endless knights of cloud. I go back to work on Thursday (blah), so I should make hay while the stars shine :)

[alpal]

Under the mount?
I mean to look at the exposure on your camera screen or laptop screen.

[BruceG]

Lol, what I mean is when the camera is imaging near the azimuth the rear if the camera is pointing down. I have to then struggle to see the fore mentioned V.

[LightningNZ]

Allan - since there's no Live View on a 300D you can't see the screen unless you twist your head at a crazy angle and look straight at it. I also have the (mis)fortune to have this camera.

Bruce - nice work, and don't be afraid to stretch the pants off the image. Kevin's done a great job of pull out the detail in your image. I think you can be very pleased with what you've captured there. :)

[BruceG]

Hey thanks Cam. I gotta say I'm totally chuffed with my new hobby and thanks for the encouragement.
I had to give it another crack and tonight I did 20 subs at 4 minutes (had to delete 2 due to satellite trails) and 9 darks.
Got to say I'm very happy with the result. Note to self - be careful of the camera angle - I've straightened it a bit, and now don't mind the composition. Thanks everyone for the support and tips!

[cometcatcher]

Much better second try Bruce!

[BruceG]

Thanks Kevin. Bed time for me now. I hope tomorrow night is clear. I can feel a Rosette coming on :)