P Holdsworth Posted December 9, 2020 Share Posted December 9, 2020 Hi all, I managed to add just an hour to my first session of the Horsehead nebula taking it to 3 hours. I'm fairly happy with how the nebulosity has come out but definitely not the stars. I realise now I should have taken a bunch of short exposures to try and tame the highlights but I'll know for next time. I doubt I'll get any more time on this one due to obstructions so thought I'd post it anyway. Still learning and trying to improve the processing side of things and used starnet ++ for the first time . I did this one in APP, Starnet ++ and Photoshop. I still feel relatively new to astro photography ( just over a year) so any tips on how to improve the processing would be really welcome.CheersPaul 5 Quote Link to comment Share on other sites More sharing options...
TerryMcK Posted December 9, 2020 Share Posted December 9, 2020 That big star is always a problem. I like the nebulosity 1 Quote Link to comment Share on other sites More sharing options...
Stub Mandrel Posted December 9, 2020 Share Posted December 9, 2020 Well done Paul.Lots of nebulosity and great colour, but it looks rather smooth and short on smaller stars, have you been over-aggressive with denoising the image?To control Alnitak don't use gamma to stretch the image, instead use curves and 'fix' the upper section of the curve before adjusting the mid part. This takes some practice but can keep Alnitak as a nice double star. 2 Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 9, 2020 Author Share Posted December 9, 2020 @stub-mandrelThank you Neil,Yes looking at it again it's over processed on denoise for sure. I used a photoshop plugin called Dfine 2 across the whole image which has been way too aggressive. I think you can mask out areas you don't want to be touched so will have a look at it again. Thanks for the tip on stretching ; I'd previously been stretching everything from the mid point. Really appreciate your advice. Cheers, Paul Quote Link to comment Share on other sites More sharing options...
paulgrover68 Posted December 9, 2020 Share Posted December 9, 2020 I think this is my favourite of all nebulae - there's something magical about it and I've loved it since I was a kid. This is a cracking capture. Quote Link to comment Share on other sites More sharing options...
KevS Posted December 9, 2020 Share Posted December 9, 2020 Very nice, really like the way you have caught the nebulosity ? Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 10, 2020 Author Share Posted December 10, 2020 @paulgrover68Thank you Paul,Yes I agree there is something magical about this nebula. It was pictures of this nebula online that got me interested in astro photography in the first place. I would say it's between the horsehead and the rosette nebula as my favourite. Probably it's the horsehead that just edges it ! In my case it's just a bit of a shame that it's so low in the sky and I have obstructions but all in all I'm happy with it. It's definitely one to revisit next year and have already created a folder to keep the subs. One learning for me is I think I need a bunch of fairly short exposures next time to try tame Alnitak.Cheers Paul Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 10, 2020 Author Share Posted December 10, 2020 @kevsThank you Kev, Yes I'm fairly happy with the nebulosity. Probably been too aggressive on the denoise and have been given good advice on the stretching etc. When I first started a year ago I'd no idea that processing played such a big part in astro photography but slowly getting there......I think !CheersPaul Quote Link to comment Share on other sites More sharing options...
Carastro Posted December 10, 2020 Share Posted December 10, 2020 It looks as though it has the potential of a very nice image, but as stated above it is far too fuzzy from denoising procedures.I would suggest you start again with the processing. If it is any help I have a number of tutorials using Photoshop on You tube, though much of them are designed for mono imaging, but there are a couple which would be suitable for DSLR processing.Try the tutorials on levels and Curves and processing the RGB.https://sites.google.com/site/caroleastroimaging/home/video-tutorialsIf you want to denoise, I would suggest you click on the sky background with the magic wand and do a filter/noise/dust and scratches at a low threshold, such as 3. This should then only affect the dark areas and not the nebulosity. With regard Alnitak, I tend to reduce this as I go along in stages, using selective layering. i.e. make a layer, and stretch the top layer rubbing out Alnitak on the upper layer, revealing the less stretched Alnitak on the layer below. You can do this a few times, and it will help to reduce it.HTHCarole Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 10, 2020 Author Share Posted December 10, 2020 @carastroThank you Carole, Yes I'll definitely go to your You Tube tutorials and have another go. If I'm honest I only know the basics in photoshop so this will help considerably. I probably went too far with denoise for sure mainly because I seem to get a lot of gradients from my dslr. You're right though it's affected the sharpness of the overall image and your suggestions on selective layering are really helpful. Thanks again Carole for taking the time to critique and give some excellent adviceCheersPaul 1 Quote Link to comment Share on other sites More sharing options...
Stub Mandrel Posted December 10, 2020 Share Posted December 10, 2020 Here's a super simple tip for controlling over aggressive plugins - use them on a layer, then adjust its transparency to blend some of the original image back in. 1 Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 10, 2020 Author Share Posted December 10, 2020 @stub-mandrelThanks Neil,Yes that makes a lot of sense. I think Dfine 2 denoise plugin works really well but I checked last night and it doesn't have a feature to mask out so yes to reduce it's strength via a reduction in transparency is a cracking tip.CheersPaul 1 Quote Link to comment Share on other sites More sharing options...
Stub Mandrel Posted December 10, 2020 Share Posted December 10, 2020 So show us your new, improved version soon! Quote Link to comment Share on other sites More sharing options...
MarkAR Posted December 11, 2020 Share Posted December 11, 2020 I think the details are there but just been smoothed out a bit too much. 1 Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 11, 2020 Author Share Posted December 11, 2020 @markarThanks Mark, Yes I've definitely gone too far with denoise but looking at it again I'd removed all the stars in starnett++ to stretch the nebulosity separately and then add the stars back in . On top of denoise I think this adds even more smoothing. Won't be going down that route again ! Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 11, 2020 Author Share Posted December 11, 2020 @stub-mandrelHi Neil,Yes I will do ? Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 13, 2020 Author Share Posted December 13, 2020 @stub-mandrelHi Neil,Just had a go at editing the horsehead again. This one doesn't have as much noise reduction and Alnitak isn't quite so blown out though next time will get some short exposures to help. Hopefully next years effort on this one will be better. Cheers Paul Quote Link to comment Share on other sites More sharing options...
Carastro Posted December 14, 2020 Share Posted December 14, 2020 Is there any chance you can post up the original stacked but unprocessed file anywhere so we can have a go at processing it for you so you, we can then report back what we did.Carole Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 14, 2020 Author Share Posted December 14, 2020 @carastroHi Carole, yes that would be really helpful. The tiff file is completely unprocessed so it's very noisy ; it was captured directly over a street light with a overhanging BT line so obviously I cropped that out but that's literally the only change from the stack.Thanks Carole, I must admit I have struggled with this one compared to my others https://drive.google.com/file/d/1az3Me9_YJjkdIcfBC0oPDj10pNzXOAgi/view?usp=sharing Quote Link to comment Share on other sites More sharing options...
Carastro Posted December 15, 2020 Share Posted December 15, 2020 I had a go at processing this, but unfortunately the image is severely affected by walking noise. I am trying to remember what causes walking noise. Are you guiding?I did my best, but I can see why you felt you needed to blur the image, but the answer is to avoid the walking noise. Perhaps someone will chip in who knows, I have a feeling it is something to do with shifting frames causing a line of hot pixels, thus the question about guiding.I did a lot with levels and curves and a bit of control of Alnitak in layers as I previously described. It finally benefitted from Gradient exterminator isolating the Nebula and bright stars themselves.https://cdn.astrobin.com/thumbs/6G8oEi13JU4a_16536x16536_JXczOqwr.jpg Quote Link to comment Share on other sites More sharing options...
MarkAR Posted December 15, 2020 Share Posted December 15, 2020 Posted by: @Carastro the image is severely affected by walking noiseLack of dithering maybe. Quote Link to comment Share on other sites More sharing options...
AstronomyUkraine Posted December 15, 2020 Share Posted December 15, 2020 Posted by: @Carastro I am trying to remember what causes walking noise.Lack of dithering is the culprit. Dithering in both RA and DEC will reduce/eliminate it. More data would also help reduce the noise. Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 15, 2020 Author Share Posted December 15, 2020 Thanks Carole, Yes it was terrible data (sorry) . Unfortunately the only spot due to obstructions to get this one was around 15 yards from the only street light in the cul- de sac and was pointing directly over it. I'm still glad I went for it but yes the data is severely compromised with noise which I don't normally get to that extent. I think that's why I went so heavy on noise reduction but my version is way too smooth. What I learnt though from your you tube videos was how to control levels and curves much better and I can tell from your version Alnitak isn't blown out. Just to say also I thought your you tube videos were excellent. Appreciate the time you've taken to helpCheers Paul 1 Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 15, 2020 Author Share Posted December 15, 2020 @astronomyukraineYes because they were only 3 min exposures I didn't dither on the first session ( big mistake !). I'll definitely dither every time from now on.Appreciate your help 1 Quote Link to comment Share on other sites More sharing options...
P Holdsworth Posted December 15, 2020 Author Share Posted December 15, 2020 @markarYou're right I didn't dither on the first session which was 2 of the 3hours of data so it's definitely a learning. I think because it was just a couple of hours break in the clouds I went for getting as many lights as quickly as possible. Probably better to have less light frames that were dithered than more that weren't. It's good advice from you all and appreciatedCheers Paul Quote Link to comment Share on other sites More sharing options...
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