My first orion

ThatDrGuy

Tried out my new DSLR setup with a classic - the orion nebula. A bit of a rush job, had to grab the exposures during breaks in the clouds. I also have next to no idea how to process the images correctly. But here is first attempt anyway - at least you can see clearly why m43 is called the comma nebula.



Update : I tried some Digital processing - that stuff is magic.I cant believe you can do this stuff from your backyard.



After some very very basic colour correction and brightness adjustment in photoshop:

slade_x

ThatDrGuy wrote: »

Tried out my new DSLR setup with a classic - the orion nebula. A bit of a rush job, had to grab the exposures during breaks in the clouds. I also have next to no idea how to process the images correctly. But here is first attempt anyway - at least you can see clearly why m43 is called the comma nebula.

Well done, what equipment?

ThatDrGuy

I used a Celestron 11 gps with canon DSLR,Nebulosity and focal reducer.No polar align just alt-azi. Stacked 30 x 10 second exposures. Light pollution and clouds were terrible. Steep learning curve indeed for a first go.

dbran

Hi


Very good. Makes me want to dust off my equipment and try a few shots at astrophotography again. It has been quite a while :rolleyes:.

There is quite a bit of field rotation in the 2nd and 3rd shots that is not so apparent in the first given the shortness of the exposures.

Do you use deepsky stacker to stack the images? You might try chucking out any of the subs that are showing trailing and only stack the better ones and see if it improves things.

Kind Regards

dbran

Tzetze

Good job. M42 is a fine target. My current setup is too narrow a FOV to frame it, but I hope to capture the horsehead and flame next door to M42 soon if the weather conditions will allow it.

I'd echo what dbran said about DSS. You can get it to stack the best X% of frames. Did you check out the photoshop tutorials on astrocasto.blogspot.com?

I don't know much about the c11 gps. It's an alt-az mount right? Would you need a wedge to get long exposures?

ThatDrGuy

Hi Dbran. Thanks a lot.That was my first ever go at still long exposure imaging. I had the camera and T-ring for a while but couldnt figure out how to mount it
on my scope. Came up with an idea around 9 pm and by about 2 am I had some images. I used nebulosity to stack the images. Only had 30 x 10 second ones becase of the weather. I think I lost about 5 due to clouds, didnt know enough then to edit out the movement artefact ones. Im going to try tonight to clean it up a bit. I caputured (wrongly - full colour not raw) the images and stacked them in Nebulosity. Is deepsky better for stacking ?

Thanks Tzetze. I found the focal reducer really helpful, improved the short
exposure images a lot. I had a look at the tutorials, going to try and clean it up tonight. I was impressed the effect auto colour and brightness/contrast adjustment had. My mount is alz-az but can do polar. I even have a wedge for it but unfortunately cant manhandle the scope with it on it. Also my camera is limited to 30 second exposure without an expensive shutter control cable. So even if I managed to align it polar it would be wasted at the moment without a long exposure. The weather lately has been so terrible, I think I have had the scope out twice in 3 months

Tzetze

DSS is handy because you can just load in all your subs, darks and flats of different exposure lengths and different ISO, check a few settings set it in motion and it will take care of everything for you. Whereas with Neb, you have to create your own master dark and master flat and step through the alignment procedure with it choosing stars for alignment. On top of that, DSS is free. DSS Tutorial

If your camera has a bulb setting (which I imagine it does), then you can use 'Astro Photography Tool' to take exposures longer than 30s. I highly recommend this piece of software - it might look a little daunting at first, but it's simple enough really. There's a freeware version of it which has very good functionality. You can also setup imaging profiles. For example, setup a profile to take 60x 30s exposures at 800 ISO, then 60x 60s exposures at 800 ISO, 90s, 120s, etc. Click start and it will take care of all your shots on your chosen subject for you. You just need to check in every so often to make sure your subject is still framed how you want it.

dbran

Hi

I would use DSS over Nebulosity as it automates everything. It is better at stacking and it may help you with your derotation issue also.

Only issue with DSS I found is it dosen't let you pick the stars manually and on occasions where the subs are not distictive enough it can miss them.

I believe from memory it needs to find at least eight stars in each sub or it will not stack the sub.

Nebulosity is good if DSS dosent work as you can pick the stars manually. It also combines the images in LRGB which DSS does not.

Hmmmmmm I feel I am getting the bug again....

Regards

dbran

ThatDrGuy

Hi,
I tried out DSS. I followed the instructions in the tutorials to the letter. My results looked exactly like emission spectra. Not a nebula to be seen.
I tried using the default settings then, it kept stacking a grand total of 1
image out of 30 no matter what I did. Played with number of stars from between 10 and 6000 - no difference. Tried reference frame too, didnt help. Must read up some more on it.

Tzetze: My camera is cannon 350 D, still needs shutter cable to control bulb - even in Astrophotography tool

Dbran, Id love to see some of your stuff. Maybe if there are enough of us shaking our fists at the sky every night, it will clear up.

dbran

Hi

This is the problem with deep sky stacker that I have also found to my cost. It picks the stars using an algorithim so if they dont look round enough, are trailed or too faint then it considers then to be just noise or hot pixels. So for deepskystacker to work well you have to have relatively good subs with bright well rounded stars. So you will need to solve your field rotation issue next time out.

I image in ALt Az also and at times have been able to get up to 90 seconds before field rotation becomes a problem. But a lot depends on where the target is in the sky. Other times I have had to be content with 15-20 seconds. Remember that the longer that you go the more you rely on your mount not to shake or vibrate in the wind etc.

You should perhaps try shorter subs but more of them. That way you can afford to throw away those subs that are not up to standard and you will have enough to stack.

I have a tutorial here that I did up many years ago on DeepSkyStacker which you might find usefull http://www.irishastronomy.org/index.php?option=com_kunena&func=view&catid=29&id=52019&Itemid=40#52019

Anyway here is a shot that I took about a year ago (last time out I recall). It was taken up at Melifont Abbey of NGC2903.

I hear ye, one more person shaking their fist at the clouds may be all it takes



Lx90 8' Altaz 80 subs 25 sec each 0.5 focal reducer using Atic 16ic ccd camera.



This is a stack of 30 images with 30 second exposures of the ring nebula m57. But what Im quite pleased about is my first runty galaxy to the left, IC1296 a 15 mag galaxy.

ThatDrGuy

Those are fantastic. Really shows off what alz/azi can do. Skies finally cleared a bit last night and I had another go at some astroimaging. Tried running man, pinwheel and little dumbell. Can spend the next cloudy weeks processing them. DSS doesnt like me. Now it gives me out of memory errors every time I run it (my mainframe has 27gb of ram) for some reason. Might try using the more precise goto set up - reduce the trails a bit.

dbran

Hi Thatdrguy

You may be setting DSS to detect too many stars when you are stacking.

You should limit the amount of stars DSS picks to between 40 and 100 maximum otherwise you will be picking hot pixels and noise. Also if you pick too many stars it means the dss will have to track each star through all the subs which will definately chew up memory on your PC.

Regards

dbran