The Great Orion Nebula 2nd attempt.

[Tommy B]

Hi folks,

Hope everyone has had a nice christmas and acquired a heap of astronomical goodies. The heavens themselves decided to give me an early christmas gift in the form of clear steady skies on the 23rd.

Back in March I made my first attempt at the great orion nebula and was the first deep space object that I managed to image and get a half decent newbie result. So, I decided to go for it again with new equipment and see how far I have come since then and here is the result!. I never thought I would progress this far

Kit used,

Skywatcher Equinox 80ED

Orion Starshoot guide cam/50mm finderscope guided with PHD

Neq6 mount

Atik 314L+ (colour)

Baader Neodymium filter for my aweful light pollution.

Stacked in DSS and processed in photoshop 7.0

20x 120s Exposures

No darks and no flats.

I also took 20x 30s and 20x 5s exposures for the core but after doing a composite I decided that I dont actually like a controlled core and prefer the intensity from the longer exposures. The composite also seemed to make the image a lot flatter.

My neodymium filter is also giving me jip with nasty rainbow diffraction lines on brighter stars that I just can't seem to solve. If anyone has any Ideas why my filter might be doing this I would be very greatful.

Thanks for looking

Tommy B.

[Venus_is_my_friend]

It's amazing! Great work Tommy.

[Quatermass]

Thats a lovely image you should be very pleased with that for sure very well done :beer:

Sent from my GT-S5670 using Tapatalk

[Tommy B]

Thanks guys

[swlloyd3]

That would make an awesome poster

[SJJ]

Well done Tommy, lovely image.

[Uranium235]

Odd diffraction spikes are usually a sign of incorrect focus or something is intruding into the light path (were you imaging close to any trees or fences?). When you get perfect focus on an ED80 you will notice 4 small diffraction spikes (that look a bit like a newt would give) on brighter stars - well thats what happens with mine anyway

[Tommy B]

Odd diffraction spikes are usually a sign of incorrect focus or something is intruding into the light path (were you imaging close to any trees or fences?). When you get perfect focus on an ED80 you will notice 4 small diffraction spikes (that look a bit like a newt would give) on brighter stars - well thats what happens with mine anyway

Thanks for the reply on this. I have experimented over the last few clear nights before this image was taken and Im certain the spikes are being caused by the neodymium filter. The anomaly is not present whenever the filter is removed and this is the case on both my ED80 and 8" newtonian. If you look at the running man nebula thats just showing in the top right of the image you can see two rainbow spikes. I have tried cleaning the filter but that seemed to have no effect at all.

I have attached another pic that shows the problem more clearly.

[Uranium235]

Hmmm, this is interesting as I also use the neo filter (old version) with the Atik when doing LRGB, but I get no spikes like the ones demonstrated above - although my 314 is the mono version. Maybe you need to try another filter - which is where it will start to get a bit expensive (especially if 2").

Maybe you can try a different spacing for the filter with shorter or longer nosepieces and see if that changes anything?

[Tommy B]

It is rather mystifying. I have tried mounting the filter on the nosepiece of the camera and further away on the end of the focus extension tube I use but that seems to have no effect at all. The problem also appears whether I am using my Atik 314L+ or my Canon 1000D!

I have inspected the filter many times and can find no signs of any imperfection or damage