M42 - Orion's nebula - 1st attempt

[LouisJB]

Hi,

We had clear skies, although Orion was just a couple of degrees above a lamp post (dah!) and not far East of the really bright Moon.

Still, I pointed my telescope at it and captured some photons. The picture is noisy. No darks taken unfortunately and the sky was quite light.

Also think the focus is a bit out, need to get that Bahtinov mask, but  won't get one until I've decided what OTA to upgrade to, size-wise.

So anyway, here's my 1st attempt to image it using my basic setup (with its many foibles!).

I know the core is very over-exposed.

Thing is I took a bunch of pictures at different exposure lengths, some have overexposed core but contain details of outer nebulosity and others show the core detail but no nebulosity around the edges. 

I believe they can be combined? Problem is I've literally no idea how to go about that.

Any suggestions?

[Zuben Elgenubi]

Not bad at all given the street lamp and moon in close proximity! 

With regards to using subs of different exposure lengths, see SnakeyJ's response (and linked thread) to a similar question that I asked about his M42 image:

http://stargazerslounge.com/topic/199225-m42-first-attempt-with-dslr/

Will you continue to image with the 130P once you have a new scope? If so, then the Bahtinov mask is probably a good investment at £15 or so.

[Sandancer10]

Hi Louis, you have quite a bit of detail there in the outer areas, but you can fix the core with Photoshop. I don't know if you have it or what level you are at if you do.  But, basically you mask the blown out areas and add the photo with the detail of the core. Then blend the two together by using a soft brush - say about 20% which you work over the the where the edges meet and that will give you a soft edge.

Here's a link which may help you to get the basics of blending two images: 

it's in Photoshop Elements, but it's almost the same as Photoshop CS6.

Good luck

Brenda 

[LouisJB]

Hi,

thank you. I have Photoshop so will give these techniques a try.

I won't continue to image through the 130P as the small 1.25" focuser can't take coma correctors (and it's all pretty wobbly when my camera is on it).

The plan is something like the 150PDS or 200mm GSO F5 Newtonians, with a coma corrector (and dark sky) should start to provide an improvement over what I can do now. Once I decide 6" or 8" or on a refractor even then I'll get the accessories. 130P is just acting as a stop-gap, so I can gain some experience to work out what I need next.

  

M42 is very bright isn't it. My exposures were around just 1 minute typically, is that normal? To stop the core being blown out I took some down to below 1 minute, it must be very bright since I was using 5mins+ on other things like M31/M33 and 5 or 6 mins on other nebula captured virtually nothing. So really big differences in brightness you have to take into account. All part of the learning curve I guess and something you build up experience in after trying something out.

In terms of different exposures. I have a few sets of say 2mins, 1mins and <1mins - should they be stacked in DSS first, individually, producing several combined images at the different exposure levels, then combined from the layers in photoshop? Is that how the images would be stacked before layering?

[Stevie P]

Good demo here of combining different length exposures using layer masks and the video is on the same subject matter "M42"..

http://www.eprisephoto.com/layer-masks

[lensman57]

Great first try, try and take a few short subs for the Trap and then combine the long and the short in PS.

A.G

[LouisJB]

Well, here's my first attempt to blend in the Trapezium

However, the colours were very different between my subs so it was hard to blend it in properly.

Still, learning how to do it bit by bit. Will try to get more data next time (this was only 10 subs max) and more subs of the Trap (I've only used 1) - and some darks and lights too to improve the final result. The data from this session was cut short due to the path of Orion intersecting with my house and also the Moon when it rose was pretty bright.

Thanks for the help, I'm not too disappointed with the result all things considered. A better data gathering with my new OTA when I get it and I should start to see something reasonable I hope.

[Pete Presland]

coming along very nicely! there looks like there is plenty of data to play with

[south west stew]

great attempt i had my first try at it on sat took 30 shots and every one was very slightly out of focus was abit anoyed on sunday when i got around to looking at them but a learning curve