Orion and running man

[aarong]

Hi guys,

Just playing around with Orion and co.
Not sure why yet, but the stars towards the edges of the frame were eggy?

Meade LX90 8", Canon 1Dmk3, 6.3 Meade focal reducer (that I haven't used much)

Total 2:28hr and 60 light frames.
20 x 15 sec @ 1600 iso
20 x 30 sec @ 1600 iso
27 x 5 min @ 1600 iso
Dark frames:
30 x 5 min @ 1600 iso
20 x 15 sec @ 1600 iso
20 x 30 sec @ 1600 iso

Comments and suggestions are always welcome.
Cheers,
Aaron

More at Facebook (https://www.facebook.com/AaronGreenvillePhotography)

[carlstronomy]

Aaron first of all nice image, good colours and detail for 2 hours of data.

To answer you question on eggy stars you will always get this on the outer field of an F10 scope using an F 6.3 reducer.
You will have to compromise on what you are imaging unfortunately and not use the full field, this will allow you to crop the nasty stars at the edge. With this set up you will not be able to get both of these subjects in the field and have no eggy stars, you will have to choose between one of the two targets for each session.

Keep up the great work and don't over stretch your data, you will great results. :thumbsup:

Carl

[aarong]

Thanks Carl. That is good to know. I now need to clouds to clear to get back out there and practice :)

[Marios]

Noob question, why the differing exposure times for the light frames?:question:

[aarong]

The shorter exposures were to capture Orion's bright core and surrounds. At 5 min the core was blown out, i.e. just white and no detail. Once the images were stacked in DSS, I processed it in Photoshop.

I wasn't sure how DSS would handle the different exposures and if it would lose the detail in the core if I stacked them all together, so I tried it to find out. The last time I imaged Orion I stacked the different exposures separately and then combined them in PS using masks. This time I added all the images at once and it seemed to work. Some selective use of curves and masks bought back the core.

[Marios]

Hi Aaron thank you for your reply, I have one more question.
In regards to colors I find most of my images are redish. how do you obtain such broad range of colors?

[5ash]

You are also using a camera with a full size sensor which shows more of the edge of the field of view than many of the DSLRs used in astrophotography. Nice picture though.
Philip

[rustigsmed]

nice work aaron,

the pic is probably a bit black clipped. i'd like to see a version where the black space background isn't so ... black, it will bring out some more whispy nebula.

but nice work, perhaps a mosaic to rid your self of the eggy stars next time!

all the best.

rusty

[aarong]

Ah yes. Thanks Philip. You can probably see I did crop a bit. Must admit I was originally going for just orion nebula, but got greedy :P Good to learn more about the focal reducer though. So they give you a greater FOV, but it is not that useful due to the eggy stars? Best to use them to reduce the f-ratio only?



Not sure I'm the best person to answer this, but do you have a reddish colour cast across the entire image? Colour casts can be fixed in most editing software. DSS has an option to try during the stacking procedure too. In PS you can use levels and adjust each R, G and B channel separately to fix colour casts as well. Gradients are a little harder, but there are some good tuts on the web. I have recently started to use gradientxterminator, which can also fix colour casts. Also note there is a lot of ionised H out there, which shows up as red. See here (http://curious.astro.cornell.edu/question.php?number=566) for more.

[aarong]

Thanks Rusty. I would love to do a mosaic. I'll do some homework ;)

[BruceG]

That's a beautiful image Aaron. Nobody could say M42 is boring in any way.
I'm a total newbie and have so far only taken one image. Keen for our skies to clear for some more attempts.
Great to hear you can stack all of the different sub exposures at the same time. I don't have PS and wouldn't know how to mask an any case.
Must give Orion a go.
Keep up the great work.
Bruce.

[OzStarGazer]

Beautiful!