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alcol620

HELP first image of the orion nebular

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Hi folks

Managed to get out in the backyard last night, first time for a couple of months and took some images of the Orion Nebular.

I took 10 images of 15 seconds at ISO 1600 using a moded Canon 1100d  attached to mypost-36789-0-67924600-1419189025_thumb.j Celestron 8SE with 6.3 reducer. 10 darks were also taken at the same settings. I am a novice at DSO imaging and would welcome any comments on the attached and how it can be improved using Photoshop.

The images were captured using APT software and stacked using Deep Sky Stacker

Any comments would be welcome, including negatives.

Thanks for looking 

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Rough guess I'd say gradual tweaking of curves or levels ... Pull the left end of the histogram in and the right end in towards the ' bottom of the mountain' ... But for gentle and do it in steps

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Hi,

First things first, you really need a light pollution filter, as that looks quite bad for 15second images, if I take 3 minute subs they look like that and I use a LP filter.

You will notice a real difference, trust me, then you can take longer subs and get a lot more detail

:) :)

SS

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Hi,

First things first, you really need a light pollution filter, as that looks quite bad for 15second images, if I take 3 minute subs they look like that and I use a LP filter.

You will notice a real difference, trust me, then you can take longer subs and get a lot more detail

:) :)

SS

Forgot to mention, with the 1000D camera stick to ISO 800, you will get a lot of noise at 1600, and they will overexposed before you get much detail, because of the LP.

Hope all that helps

SS

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Hi Alcol,

I'm a total newbie to this, but took a few shots the other night of Orion at 1600 and stacked them in DSS. It ended up looking like this...

Iso 1600

Really had very little idea what I was doing so just played with the histogram. Might be similar setting will work on yours if you fiddle with the graph until it looks something like that?

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I agree ... a lot of light pollution seems to be spilling into the image. Check the histogram of the original image, to see where the peaks lie. I can't remember where they are meant to be (probably between 1/3 and 2/3) but obviously if its too far to the right you're losing a lot of detail to LP. Try playing with levels/colour balance/curves in PS and see what you can get. Good place to start. Its seems a tad out of focus .. i'm not sure ... unfortunately not something you carnally fix post-processing. 

Good luck!  :grin:

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Greetings

Although I'm using a 5Dmk2 this is my capture screen in BYO my scope is SW300PDS and IDAS D1 filter ( thanks FLO ) but note the histogram curve.

post-28592-0-84729300-1419202153_thumb.j

I have a bright orange street light 21m away so not a great position for my setup, what ever type of capture software you use try to aim for this type of profile curve for a reasonable capture.

Andy (Mansfield)

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Hi

Just to add - your focus is way off. Either use a Bahtinov mask or the fwhm/hdr values in the APT focus aid :)

Louise

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Hi folks

Thanks for all the helpful comments.

I have been trying to upload the image after processing in photoshop, but I simply get an error message saying file too big. Can someone advise as to the best way to get the image size reduced to allow images to be uploaded. My processed image is still very poor compared to that achieved by Dave - a well done to him.

Can someone also advise on how best to get the image in focus, there did not seem to be an camera image on the laptop screen to focus. Is it a case of focusing the scope and camera on a bright star and then moving the DSO into the picture?

Thanks for the comments on LP, I will get an LP filter. As soon as I get your advice on the best way to upload files I will circulate my best effort post photoshop

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Dave 2112

What camera did you use and what settings ie exposure time and how many exposures? Did you do darks etc?

impressive image, I would be dead pleased if I could do the same.

Regards

Alcol

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Try selecting "RGB Channels Calibration" in the Light section of the  DSS stacking tab. This will try to ensure the background sky is a neutral grey instead of orange. You will also need some flats, as that image has plenty of vignetting when you stretch it.

NigelM

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Hi NigelM

I just checked and I had used that setting when stacking with DSS. What's the easiest way to get some flats?

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Hi folks

After some fiddling with Photoshop this is the best I could come up with. As you said in your feedback, poor focussing and lots of light pollution. presumably the size of the stars in the image, is due to the out of focus, rather than over exposure??

orion.bmp

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Hi folks

Thanks for all the helpful comments.

I have been trying to upload the image after processing in photoshop, but I simply get an error message saying file too big. Can someone advise as to the best way to get the image size reduced to allow images to be uploaded. My processed image is still very poor compared to that achieved by Dave - a well done to him.

Can someone also advise on how best to get the image in focus, there did not seem to be an camera image on the laptop screen to focus. Is it a case of focusing the scope and camera on a bright star and then moving the DSO into the picture?

Thanks for the comments on LP, I will get an LP filter. As soon as I get your advice on the best way to upload files I will circulate my best effort post photoshop

I'm a beginner so take what I say with a pinch of salt.  However, I think I can help with Photoshop.  The way to do reduce size is to resize in Photoshop down to something like 800 - 1000 pixels along the long end.  Image-->Image Size   Use Bicubic Sharper as the algorithm.  Then save as JPG.  That should lead to a less than 0.5MB file.

As to the image - are you shooting in RAW mode?  I'm a bit surprised that it seems a little burnt out, on such a modest exposure.

As to focus, it is indeed a case of focussing on a nearby bright star.  You might want to look up Bahtinov Masks as others have suggested.  

What is your light pollution like?  How are you capturing and processing the images?

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Hi gnomus

Thanks, I will try that in photoshop.

Yes shooting in RAW mode. 

Thanks for confirming info on focussing.

Light pollution not to good. On the evening in question, I did notice some light misty high cloud which probably reflected some of the LP and made it worse.

Thanks again for taking time to comment

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Hi gnomus

Thanks, I will try that in photoshop.

Yes shooting in RAW mode. 

Thanks for confirming info on focussing.

Light pollution not to good. On the evening in question, I did notice some light misty high cloud which probably reflected some of the LP and made it worse.

Thanks again for taking time to comment

I'm reasonably proficient at Photoshop. This AP game, howver, is a little taxing. I took a series of subs a few nights ago. Some were OK with dark backgrounds, others were increasingly orange, all the way through to orange-no-stars. This was certainly cloud rolling in and refecting the surrounding LP. It's probably best to leave the orange ones out when stacking. I'd try again when there is less cloud about - you might not need the LP filter for a little while yet.

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If you mean resize for the Forum, simply use Paint/ PS and resize, pixels 1151x767.jpg.

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Thanks everyone, very helpful feedback. Plenty to take account of when next outside.

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