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That is a huge improvement Robin - and a really lovely image, congratulations! Thanks for your kind words but the improvement is really all down to you, your determination and dedication, I just gave you a couple of pointers. As for getting this in the right forum, one of the mods (@steppenwolf or @MartinB or @John) should be able to move it for you.

Lovely image Carole. You've got the colours of the Ha exactly right for me - not too pink, but not too crimson.

That's very nice. Despite having a large angular size M33 is a tough target... I agree with others that on my monitor it looks just a bit over-saturated, particularly the reds but that's a matter of personal preference.

Nice write-up Frooby and congrats on the progress you've made. Look forward to seeing more of your images in future.

Some good data there. I have to say that the Crescent is one of those targets that almost always looks over-processed to me and I do find this a bit harsh personally but you've got good definition and good detail so... as long as you're happy with the scheme it's a job well done.

I do like the most recent image you posted Jason, but the first one (the jade one) is something different and sometimes it's good to be different!

Ah... it's a good question. There is a lot written and discussed about this: lots of theory, plenty of opinion. But from my experience focal length and image scale are more important than f-ratio. If you are imaging a small target (small galaxies or planetary nebula) then you want longer focal length, but you also want to match the focal length of your scope to the size of the pixels on your camera sensor. You'll ideally need an image scale per pixel that is half to a third of your best seeing conditions. Image Scale Per Pixel (in arc seconds)= (~200 * the size of the pixel in microns) / focal length in mm (iirc) Typical seeing in the UK is, I believe, one or (more likely) two arc seconds so you should be aiming for an image scale in the range 0.33 to 1 arc second and you ae probably pretty safe at the thick end of that... This should ensure that you are not over or under-sampling your data. After that, the lower f-ratio the better but it's really only fair to compare a 1000mm focal length f/5 scope with a 1000mm focal length f/10 scope when you are talking about how fast you can acquire the data...

That's a lovely, lovely image. Wonderful field of view and beautifully framed. Just goes to show you don't need blingy colour (or indeed any colour) to create a stunning image.

I like this Mark - your choice have colours has brought out some interesting variation with the nebula.

Thanks Dave. I found this to be a fun target because there is fairly strong signal in OIII and Ha across the frame so there is endless opportunity to experiment with the balance and interplay of the colour and contrast of the channels which lead to radically different results... it does make it tough to decide exactly which way to go - which isn't my strong point - but it's fun nonetheless so I would strongly encourage you (and indeed others) to give this target a go. I forgot to mention that I captured this data back in January / February this year so was able to get good chunks of good SNR data on each, rare, clear night.

Really nice image Geof. I've been playing with Affinity Photo too but have hit a couple of issues: sample points only sampling one pixel for example, but also the relative crudeness of the macro function versus PS actions. I've bought a licence but don't feel I can completely jump ship just yet...

Wonderful images.

Well, the longer the exposure the more thermal noise you get but since you want to capture the apparent movement of the stars you'll want to find a happy medium and this will depend on many factors including your camera and the ambient temperature. As with lots of things in astrophotography the best thing to do is experiment. People on here are usually good at explaining what they have done so search for star trails in the wide-field imaging section and see if you can find some images you like taken with similar kit to yours... if they list the ISO, f-ratio, and exposure setting then that will give you a starting point (and if they don't, you can always ask!)

That's very encouraging - well done!

The QHY5L II is also a popular choice and for reasons I've neve understood the colour version is cheaper than the mono...

There is quite a lot you can image with a camera and a tripod. You said you've imaged the moon, you can also do nice nightscapes that will show the moon and bright stars, and another popular thing is to record the trailing of the stars as the Earth rotates - this is particularly effective if you point your camera lens at the pole star as the trails will appear to be circular. Digitally stacking images together is sort of equivalent to taking a longer exposure, but there are physical characteristics of digital camera sensors that means it's not quite so... For instance read noise is introduced each time a frame is taken so you would have 100 times more read noise in a stack of 100, 6 second exposures that you would in one 600 second exposure. Depending on the focal length of the lens you could take a number of shortish exposures and stack them, but you would probably be limited to a fairly wide field. I have tried this in the past with pretty poor results and in any event I don't think that approach would allow you to replicate Carole's images...

Thanks Robin, newbie alert, Wyvernp - appreciate you taking the time to comment. I'm pretty pleased with this one (though a lot of data helps!) Cheers, Ian

Thanks guys. I feel a bit embarrassed that I asked now. I guess I got a bit carried away zooming in... here is the difference by the way: As you've said I should have just left it without the NR since the difference is imperceptible... but it's good to have it confirmed that the noise reduction doesn't make the image look plasticky... Really appreciate the comments - thanks!

That's a fair point - I guess I was sensitive to posting more than one version because I've been looking at so many variants. Anyway here's the version with no noise reduction. To be honest I have to pixel-peep to see the difference but then my eyes get crossed when I've been looking at an image for too long!

This is undoubtedly one of my favourite emission nebulae targets - the gas and dust around the Melotte 15 star cluster at the heart of the Heart Nebula. Melotte 15 comprises of mostly young, hot, blue stars which are 'only' around 1.5 million years old. Some of these are around 50 solar masses but most are smaller than our sun. I collected 10 hours of Ha in 600s subs and a further 18 hours of OIII in 1200s subs. I think this is the most data I've ever captured on a target and the first time I've gone over 100,000 seconds; it made the data a dream to process. The Ha signal is very strong and OIII covers most of the frame so I spent most of my time playing with endless variations of the balance between golds and purples - and I could have posted a dozen variants! As it is I've taken my time and settled on this as my favourite rendition. The data meant even the lowest signal areas were pretty clean and after much procrastination this version does have some noise reduction applied. I'd be really interested in views on whether it's too much and I should have left it alone - I really hope that I've done the data and the target justice. I first imaged this back in 2013 but vowed to go back with a longer focal length so this is with my 130mm TS apo (860mm focal length, f/6.6). I've gone for a similar palette to my earlier version because I like the colours so much. I did capture about 5 1/2 hours of RGB data but I haven't used it in this image as it didn't really add anything (most of the stars a blue anyway) but I will come back to the data and do a version where I add some of the narrowband data to the RGB. Kit used was TS Optics 130 Apo; iOptron CEM40; Atik OAG with QHY5L II; Atik EFW2 with 5nm Ha and 3nm OIII Astrodon filters; Atik 460 ex. Captured using SGPro and processed using PixInsight and PS. Thanks for looking, Ian

Breath-taking image Kinch. I think you can safely say that one is in the can and move on to your next target.

I actually really like the original version - a take on this object that I've not seen before and it looks very sympathetically processed.

That's lovely Steve - absolutely fantastic vista that tempts me to give a mosaic a go myself one day...

Absolute stunner and beautifully processed.

Lovely - what a a terrific field of view...