My quest to image the Orion Nebula

[Robp]

I'm starting up this thread with the aim of completing my first image of the Orion nebula [M42].

I will be building upon the image as the thread progresses, hopefully some of you will follow the progress and offer your suggestions and expertise as I go

Background information

I have been allocated some wall space for some pictures, albeit in the downstairs loo. We all got to start somewhere though right?
Now that isn't as bad as it seems, every guest that comes to our house usually finds themselves in that room at some point so I'm maximizing the viewing potential at least...
My partner has also granted me permission to purchase a CCD camera to help me improve on my 'good work so far'

All of these things have led me to be a bit more focused on what I want to achieve. Usually I set my equipment up and then flirt between different targets during the night.
It has become apparent that I need a single target to expend my efforts onto and I decided that the oft imaged Orion Nebula should be my choice.

I don't have a lot of DSO imaging experience having finally acquired enough gear in July.

Planning stage
The plan so far is going to be gathering data with my newly modified 450D and 130P-DS.

A CCD will surely arrive at some point but that decision requires far more research and decision making before I take the plunge and part with some ££.

Last Friday I managed to get 40 minutes or so practice time on the target during a break in cloud.

The modified 450D is so much more sensitive than my normal 1100D, it really surprised me. My usual 10 minute subs were Destroyed by light pollution.

I'm able to guide up to at least 15 minutes so its a shame that I don't live in a dark site.

Whilst my other half will stretch to a CCD, I don't think a house move is quite on the table (yet ).

I decreased the exposure time down to 6 minutes and got something a lot more manageable.

I could only complete four of these subs before cloud forced me to pack up so I didn't run any dark calibration frames.
I Stacked the four images in DSS and I can see some potential already:


My initial aim is to complete two stages for the image

1. At least one hour of short exposures for the core. I'm unsure on whether this will be 60 or 120 seconds at ISO 400 or 800 (any suggestions?)
2. At least two hours of long exposures for the surrounding nebula (20x6 Minute exposures at ISO 800 which I think is going to be my max with the light pollution I have around.)

My setup for the start at least will be:

Scope: 130P-DS

Camera: Modified 450D

Filter: SW light pollution filter

Mount: HEQ5

Finder Guidecam: QHY5L-iic

Lastly, I was unsure of where to place this thread so feel free to move it if you deem another area more suitable. Hints, tips and criticism is always welcome

Regards,

Rob

[Carina Lass]

Orion is a magnificent beast, is it not?

Because so much light pours from it at so many different levels, the frames you capture also have to be at many different levels to allow a bit of high dynamice range modification.

The centre of Orion is bright - very bright meaning some quite short exposures for that bit .

Further out, the red refecltive nebula is less bright but still substantial.

And the edges of dust and debris which are brown and soft need a lot more light.

So that is really your goal three sets of images which can be nested together to get the optimum values for each section so that we see each in its own glorious colour.

Your initial exposures are smashing for the red parts so it seems that you need some shorter exposures to make sure you can see the centre properly.

Then later if you can get some nights when the humidity is low and seeing is excellent, go for some huge subs to get thesoft browns of the dust and debris

[rob0971]

Try some 10-30 secs exposures for the core. I think I did a set of 10 secs & a set of 30s as well & blended them together in Photoshop.

[Kirscovitch]

Agree with above. The other night I set out to image 42 and totaly blew out the trapezium section with 120 second subs at ISO of 1600. I will be watch..ing this thread closely to see what other tips emerge...

[Feral Rabbit]

 Excellent first picture Rob.

I am just about to get into AP too and Orion will be my first object to attempt this winter so I will be following this thread with a keen eye too.

Regards

Martin

[Robp]

So yesterday I was filled with a little hope. Three separate weather reports all stated clear skies overhead most of the night.

Suffice to say the whole night was clouded over. Looking at the forthcoming forecast, it looks like my next opportunity might be Friday or Sunday evening.

Whilst the clouds refuse to budge, I took a look at the frames i took last Friday to determine how best to frame the target.

I was limited on the last images due to having imaged another target earlier and not wanting to disrupt the image train so I could take some flat calibration frames the following morning.

I have taken the full fram picture of the image posted earlier and rotated it round a little:

I should be able to get the Orion Nebula and the running man in the same image (represented by the red circles).

This will also allow me to crop the corners a little as I sometimes get oblong stars in the corners.

With regards to the shorter exposures for the center of the nebula I think I'll start at ISO800 and go up in increments of 15 seconds until I am satisfied.

I then might drop the ISO down to 400 and double the exposure time to try and reduce noise.

Does anyone know if one hour of shorter exposures will be to much for the core? I suppose it doesn't hurt to take the data and then limit it if needed.

Thanks all for the posts so far

[lensman57]

M42 is a popular target for beginners not because it is easy but because it extremely bright so even with very short subs something will show up. The core is very difficult to control and the usual way is to do a few short subs ( depending on the scope and the camera ofcourse ) of about 10~30s to hold the Trapezium and then do as many long subs as possible. The short stack can then be combined post capture in an HDR manner or by layer masking in Photoshop. The interesting bits of the M42 are the faint outer regions of dust and these need very long exposures. Have a look at the M42 in my sig link . I have only imaged M42 2 or 3 times, one was in Ha which I can not find now, and the one in the link was taken last year during an exceptionally clear early morning period. It is only a stack of 13 X 180s subs taken using an Atik 428 EX and an Ascension mm Apo triplet @ F4.8, no short exposures for the core and it just about holds. If this weather allows I will have a crack at it again but with a different approach and probably in  super widefield. Good luck with your project.

Regards,

A.G

[Robp]

Thanks Lensman57, some very nice images you have collected

For the shorter subs (for arguments sake say 30s exposures) how many would be appropriate to take on a modified DSLR?

I suppose the best answer to that is give it a try and find out. I'm itching to get outside and grab some subs, when will this cloud go away!

[lensman57]

Thanks Lensman57, some very nice images you have collected

For the shorter subs (for arguments sake say 30s exposures) how many would be appropriate to take on a modified DSLR?

I suppose the best answer to that is give it a try and find out. I'm itching to get outside and grab some subs, when will this cloud go away!

Hi,

As you only use the short exposure for the core it does not need a lot of subs. I once tried the M42 with 30s exposures using a modded Canon 1000d and a WO Zenith Star 71 @ F3.5 and it blew the core so I suggest that you do 15 X 10s, !5 X 20s and 15 X 40s and see what you end up with. For the rest try as many 600s subs as you could get to control the noise, also do make sure that the focus is spot on otherwise the running man will show it up. The focus was a bit off in my capture of M42.

Regards,

A.G

[Robp]

Hi all,

I started this thread and then I've had constant cloud ever since

I managed to get an hour outside last night (M42 inst visible from my garden until 2:20am at the moment!)

As my time was limited I had a go at some short exposure core shots. I collected 10 second exposures and 30 second exposures.

I collected 40 shots of each along with calibration frames.

I stacked the best 20 of the 30 second subs in DSS and then layered  it over the test image I captured earlier on. I did this using this guide:

http://www.astropix.com/HTML/J_DIGIT/LAYMASK.HTM

Here are the (cropped) results. The image with the core layer applied is on the left, the original is on the right.

This is only a rough test and I didn't spend long on getting a perfect result but it looks promising.

Now I'm thinking I might be able to push the core a little further so will aim for some 45 and 60 sec exposures just to get some comparisons together until I find the sweet spot.

Fingers crossed for some clear nights once the moon goes away so I can start collecting the long exposure data

[Robp]

So its been a while since I updated this thread.

Since my last clear skies its been pretty darn cloudy and I couldn't get any time on M42.

I decided to go hunting for a CCD camera and decided upon an Atik 314L+ mono.

The camera was purchased second hand along with a Baader ha filter.

The plan is to get some nice ha data and produce a mosaic to get both the Orion and Running man nebula in the same image.

I will then move on to another filter until I can build up a complete colour image.

As such the kit list for this thread will now change to:

Scope: 130P-DS

Camera: Atik 314L+

Filter: Baader 7nm Ha

Mount: HEQ5

Finder Guidecam: QHY5L-iic

I have managed to get a small set of data with this new camera so will process and provide some results soon

[Robp]

So my first image is 8x900second exposures and 50x 10 seconds for the core:

My second image is with a pane of the running man added to give me an idea of the mosaic layout I will need to achieve

Both shot with:

Scope: 130P-DS

Camera: Atik 314L+

Filter: Baader 7nm Ha

Mount: HEQ5

Finder Guidecam: QHY5L-iic

They are both test images and due to Ha imaging with a mono camera are black and white.

I believe they are suffering from coma in the corners as I wasn't using my corrector at the time. I now have the relevant kit to achieve the correct spacing for the coma corrector so the next image will be a fresh start and hopefully coma free. I will eventually add layers of colour using different filters when clouds permit.

[Robp]

Some more updates from me

Since my last post I have purchased an OIII filter  and also managed a few more hours of capture time.

I have taken the ha and OII data and combined it into a bicolour image with a synthetic green layer (using the Cannistra guide). Hope you all like it, comments and criticism welcome

Total capture time is a couple of hours for each filter with a two image mosaic. The bottom portion is lower quality as I was only able to capture a few exposures for this area.

I'm quite pleased with the results so far so will keep at it. I plan to add more data to this image, and then expand the mosaic out a bit more.

I also need to find out what has caused some of the stars in my OII data to produce rings around them (see close up crop below). Any ideas then let me know

[Selborne]

Hi Robp, I think your pictures are great, love the detail, for reference here is one of mine, taken with my Canon 60Da and a Canon 400mm lens, 1 min exposure f6.3 ISO320, I also use a EOSclip CLS filter as I live in a own 

[mbalkham]

I had a crack at M42 for my first image with the new scope (200p). I didn't shoot separate core images all the lights were 30 second exposures.  The images are in my gallery,  My question is about the post work and colour processing. I'm stacking in DSS and then processing in PS and LR.  I've tried a variety of edits and not really sure what to do with the colours. Any tips?

[Atreta]

mbalkham,

how are you doing the pre-processing in dss?

did you line up the rgb sliders? you got some good shots but you're black clipping your data, try to keep it more to the right(somewhere in the middle).

keep on it

[Robp]

Hi Mbalkham,

To balance colours in images I save the image from DSS without applying any modifications.

Open it up in Photoshop and use the histogram and levels to balance out the colour.

I could do a more detailed explanation if you require it but I'm still learning myself so you may be best served by finding an online guide or requesting instructions from the Imaging - Image Processing, Help and Techniques board ?

[Uranium235]

Having rings around your bright OIII stars is pretty normal, they can be controlled by a layer mask, but also can be created by the same process.

As long as your stars are round, thats all that matters

In regard to your mosaics, its best to crop the images very slightly before stitching together. That will ensure stacking artefacts are removed so you cant see the join between panes. Looks good so far, you know youre getting somewhere when you can see the fluff inbetween M42 and the running man (which you are just starting to pick up).

[Robp]

Cheers Uranium235, saves me a trip over to the Image Processing, Help and Techniques board to get an answer.

This is a new way of imaging for me and is proving to be quite a challenge and the lack of clear nights to test things really doesn't help matters. Hoping for a clear 2015

[Robp]

Hi all,

I have managed to get a couple of breaks in the cloud. I have gathered two panes for the ha layer that I am happy with.

I've worked out how to stitch them together and also worked on the angle each pane is produced at so they stitch together easier.

The mosaic stands at two panes

Pane one is 10x900sec and 61x30secs for the core

Pane two is 10x900sec

I have included the image below but I'm uploading from my phone so fingers crossed it's ok

[Robp]

Hmm the image looks lower quality than I remember on my computer, I'll upload it again when I get home later this afternoon.