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M31, M42, M1 and M97 with GPCAM


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Thought I'd try some more DSO with the GPCAM, mixed results as the mount was misbehaving and I wasn't sure of my PA.

M31, 57 minutes of 1 minute exposures, 20 Darks. Stacked and processed in DSS and Registax. Taken with an Atair GPCAM and a 135mm 2.8 Chinon lens at F4:



M42, Also with Chinon lens and GPCAM. 33 x 1 minutes exposures, 20 Darks:



M1 Crab Nebula, Same camera, imaged with a Skywatcher 130p. 14 x 1 minute exposures, 45 darks. This is heavily cropped as the mount was wandering and the wind was gusting:



M97 Owl nebula. Same camera and 130p. Again heavily cropped. 37 x 1 minutes, 45 darks, 45 Flats, 45 Bias:





I really need to get good flats. I get the feeling that when I get them right my images will look a lot better

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Hi Cuivenion

Your making good progress! the stars are nice and round and your getting some good results for the amount of data you have gathered.

I have some suggestions (I hope you don't mind).

On your M31 and M45 image there are some gradients on the edge of the images. I'm not sure what the cause of this is but if its optical then calibration frames should remove it. If its light pollution then you should be able to remove it with imaging software. There are processing steps you can take to prevent or remove the glow around the stars. The images also look quite Blue to me so I was wondering if you did any colour balancing at all? These are all processing skills that you will use all the time so they would be worth learning.

What software do you use to stretch/manipulate the data as we may be able to provide some instructions.

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Hi Rob thanks for the comments. I definitely want constructive criticism so don't worry about that. At the moment I just align the colours in DSS and do do some simple stretching and auto colour correct in Registax.

Out of all the processing packages I've tried I prefer Astroart, but I can't justify the money for that at the moment. The blue colour in M31 and M42 is I think due to the lens. The colours are much better when imaging with the 130p, and there's no star halos either.

The gradients you mention are amp glow I think. For some reason the darks have not removed them as they should.

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If its Amp glow then yes you should be able to remove it with calibration frames. The dark's should be taken at the same temperature as the lights so if your camera has no cooling take them straight after the lights (trying not to let the electronics cool down)

The lens will be where the halos are coming from but they don't detract from the image. There is detail in the dust lanes and the core is well controlled on M31, its also very nicely framed.

I use Photoshop myself as I like working in layers but some people on the forum do use GIMP which is free. It doesn't do everything the paid for programmes do but it may be handy.

Any idea what your next target is going to be?



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Thanks for the kind words. I've tried GIMP, but I don't like it, plus it only works in 8 bit as well. I really like planetary nebula's so I thought I'd try the Eskimo nebula at some point. The Pleiades, Perseus double cluster and M33 would make good targets for the lens.

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