The "No EQ" DSO Challenge!

[The Admiral]

4 minutes ago, Nigel G said:

I found the stars quite difficult to control with these, you have them spot on.

Thanks very much Nige, but more luck than judgement believe me!

Ian

[parallaxerr]

Cracking image Ian, it really shows off the red response of your Fuji. I tried the same with my Nikon and the HH is barely visible.

As Nigel said, the stars are very well controlled and I actually like the second image, I'm finding I prefer the more subtle, less saturated colours.

[The Admiral]

I'm on a roll

Here's my shot at the Rosette Nebula. The mount seemed to behave like a bucking bronco for this and I've had to discard a good proportion, leaving me only 73 x 30s usable subs. Not enough data really and framing wasn't the best, but I've squeezed what I can out of it. Heavy application of colour and lum noise reduction in Lightroom (which shows), and for the "colour" one quite a bit of work to reduce the psychedelic colours that the colour module churns out. Gear as before.

No colour module

 

Colour module

I'll need to have another pop at this to add more data.

Ian

[Filroden]

What a really nice HH and Flame. I prefer the second image because of both the colour and the slightly wider framing. And a really good job of controlling the light flare from Altinak. You can see the nebulosity stretching around between the two nebula quite nicely.

I think you've squeezed the Rosette bone dry! Like you say, once you have more subs and the noise levels reduce I think it will be easier to process. I don't think the colours are right in either image. The second looks a little too magenta/purple so in this case I think the first one is a closer match. More data should help that too.

[SteveNickolls]

Hi everyone,

You know what they say about busses, so here's my attempt at the Rosette Nebula from the 2nd January. Taken using the Canon 600D DSLR on the StarWacher Synscan Alt-Az mount. x97 thirty five second light frames at ISO 800 plus x50 bias and x50 flat frames. No dark frames. The frames were stacked using DSS and processed using StarTools. The lens used was set at 300mm at f/5.6 with a 2" Baader semi-apo filter (making its first outing) connected by an adapter to the lens.

Cheers,
Steve

[SteveNickolls]

4 hours ago, The Admiral said:

On 1/3/2017 at 18:54, Nigel G said:

I don't think so, the 3rd image to come from the camera was the Heart and soul nebula which was high altitude approximately 80°  still had lighter subs than those of later dates.

Anything is possible though, that could be a contributing factor.

Cheers 

Nige 

Coming along well with your modded camera Nige.

80° . Good grief, what sort of exposures were you using to keep field rotation in check?

Ian

Blimy Nige,

I'm being far too conservative (again) with altitudes and exposures, thanks for showing the way.

Cheers,
steve

[Filroden]

2 minutes ago, SteveNickolls said:

You know what they say about busses, so here's my attempt at the Rosette Nebula from the 2nd January. Taken using the Canon 600D DSLR on the StarWacher Synscan Alt-Az mount. x97 thirty five second light frames at ISO 800 plus x50 bias and x50 flat frames. No dark frames. The frames were stacked using DSS and processed using StarTools. The lens used was set at 300mm at f/5.6 with a 2" Baader semi-apo filter (making its first outing) connected by an adapter to the lens.

Another nice Rosette. You've got good colours there but you've possibly lost some of the faintest details by clipping the blacks. However, with only 50 minutes of data you probably had to fight the noise levels! How did you find the filter? The stars look good so I'm guessing it's worked well.

[SteveNickolls]

Just now, Filroden said:

Another nice Rosette. You've got good colours there but you've possibly lost some of the faintest details by clipping the blacks. However, with only 50 minutes of data you probably had to fight the noise levels! How did you find the filter? The stars look good so I'm guessing it's worked well.

Hi Ken,

Thanks for this. I'm finding StarTools' modules can perform near miracles with even iffy data, even to making colours much brighter/better than they deserve to be and cleaning up the background too which is my pet 'thing'. I'm pleased with the filter for it's light pollution reduction capabilities and if I had more opportunities I would want to do a comparison without the filter. I have yet to use it with the achromat teelscope for its full capability, just a question of not many decent nights right now. With the Rosette I'm aiming across miles of urban light pollution which the filter is taking out judging by the darker RAW's. At ISO 800 the histogram was showing a peak below a quarter but a clear disconnect from the LHS edge. In February last year I imaged the same target with the camera through the telescope (500mm) and found the target filled the FOV, at 300mm it is better proportioned. There was greater detail in the more magnified shot. 

Cheers,
Steve

[The Admiral]

31 minutes ago, Filroden said:

What a really nice HH and Flame. I prefer the second image because of both the colour and the slightly wider framing. And a really good job of controlling the light flare from Altinak. You can see the nebulosity stretching around between the two nebula quite nicely.

I think you've squeezed the Rosette bone dry! Like you say, once you have more subs and the noise levels reduce I think it will be easier to process. I don't think the colours are right in either image. The second looks a little too magenta/purple so in this case I think the first one is a closer match. More data should help that too.

Thanks for your kind comment about my HH and Flame. If I am honest I've not done anything in particular about controlling flare; I had hoped to be able to reveal Alnitak's companion and as luck would have it is visible, but luck played a good part and I've not had to do anything special to keep it visible. I did wonder about using ISO400 to give me more DR, but in the end plumped for my usual ISO1600.

"I think you've squeezed the Rosette bone dry!" Ha ha, I like that. I'm not sure I'll ever get the colours right though. If I understand correctly, the outer is Ha, and the inner is Oiii, so red and blue (?). May be more data will help. The first image is the colour that the camera sees, so in that respect is the 'correct' one. ST's colour module creates some bizarre colours as well as a fair number of green stars and I struggle to get anything that isn't too garish. For that reason I often tweak the colours in LR.

Ian

[Nigel G]

Perfect frame size Steve, great stars, good colour, some good detail.

Nice

Ian, good details, nice stars, a little colour work maybe.

Some great images being posted

Keep them coming guys.

Cheers

Nige.

[The Admiral]

53 minutes ago, SteveNickolls said:

Hi everyone,

You know what they say about busses, so here's my attempt at the Rosette Nebula from the 2nd January. Taken using the Canon 600D DSLR on the StarWacher Synscan Alt-Az mount. x97 thirty five second light frames at ISO 800 plus x50 bias and x50 flat frames. No dark frames. The frames were stacked using DSS and processed using StarTools. The lens used was set at 300mm at f/5.6 with a 2" Baader semi-apo filter (making its first outing) connected by an adapter to the lens.

Cheers,
Steve

Nice one there Steve, but I have to agree with Ken that your 'black' sky may be taking away some of the fainter stuff. I usually process in ST to give some background showing (heavens, it's either that or no target visible ), and then adjust the black point later in photo software to suit my mood. At least that way I can see what I might have missed.

Ian

[Filroden]

13 minutes ago, The Admiral said:

If I understand correctly, the outer is Ha, and the inner is Oiii, so red and blue (?).

I think if you're imaging in narrowband the outer rings are red where the Ha dominates and the inside are mapped to a blue/green colour where there is more OIII. However, all the RGB images I see show shades of red, with the centre more rosy pink that the outer edges. It's hard to tell as most of us neutralise green in images which does affect the tone of images where there is a lot of OIII (e.g. the core of M42).

Pixinsight purports to take a scientific approach to the way it calibrates colour by intergrating the colours of the stars and assumes they total the equivalent of a white body (I think). However, I find I end up with stars that only vary from white/pale shades of yellow to dark shades of amber. I rarely see blue stars which suggests I'm not quite getting the white balance correct (probably by not selecting the right areas of the image to calibrate from).

[Filroden]

Debating the merits of setting up tonight. There is really high cloud that is not forecast to shift. Although I can see stars clearly I've found even the slightest haze creates really difficult gradients that obscure faint fuzzies that I end up throwing away all the subs  I had hoped to add more subs to both my Flaming Star Nebula and Rosette Nebula as both have under an hour of data. I also wanted to dust off the SCT and have a pop at M1.

[SteveNickolls]

19 minutes ago, The Admiral said:

but I have to agree with Ken that your 'black' sky may be taking away some of the fainter stuff.

Hi Ian,

Ahh, you know my perchant for dark backgrounds even when they shouldn't be there. I'll have more plays with ST's and see what other rabbits it can pull out of the hat :-)

Best regards,
Steve

[Stub Mandrel]

You could cheat by using hue/saturation/lightness and shifting the magenta channel towards blue and repeating 2 or 3 time (this will have the effcet of reducing the red in the centre which is overwhelming the blue).

[SteveNickolls]

1 minute ago, Filroden said:

Debating the merits of setting up tonight. There is really high cloud that is not forecast to shift. Although I can see stars clearly I've found even the slightest haze creates really difficult gradients that obscure faint fuzzies that I end up throwing away all the subs  I had hoped to add more subs to both my Flaming Star Nebula and Rosette Nebula as both have under an hour of data. I also wanted to dust off the SCT and have a pop at M1.

I'd say have a go and see how it turns out Ken, there's really not much to lose. There's been so many poor nights of late so take the chances as you can. I've also set up (like I did last night but fell foul of cloud) in case it stays clear-ish later. I'd like to play with the 85mm lens and its f values then again imaging the Rosette again without the semi-apo filter would be worth doing. We've had clear sky all day but it's clouding over now.

Good luck.

Steve

[Filroden]

5 minutes ago, SteveNickolls said:

We've had clear sky all day but it's clouding over now.

I'm keeping close check and as the air is cooling more haze is forming so I think I'm going to stay warm for at least another hour!

[The Admiral]

Here you are guys, my first attempt at trying to blend short and long subs on M42, and me 'ead's spinning. It's taken many hours and I'm not quite there yet. But I'm packing it in for now . This is a first acceptable image. I tried to use layers in ST, but first off the pics weren't the same sizes because of cropping. And then when I sorted that, the result gave a very poor blend. Anyway, I next tried using my photo software to composite the two images and I thought I'd succeeded but having taken it into LR to polish off I noticed some rectangular shapes which turn out to be caused by deconvolution. So, back the the drawing board again.

So this is 103 x 30s subs with 192 x 2s subs. No colour module, so I might try that, but even a quick check on the 2s subs I didn't get any green!

Here are the shapes generated by decon. Any ideas? I tried the various pre-sets but it didn't make any difference.

Ian

[Stormbringer]

very nice mate 

[Filroden]

1 minute ago, The Admiral said:

Here you are guys, my first attempt at trying to blend short and long subs on M42, and me 'ead's spinning. It's taken many hours and I'm not quite there yet. But I'm packing it in for now . This is a first acceptable image. I tried to use layers in ST, but first off the pics weren't the same sizes because of cropping. And then when I sorted that, the result gave a very poor blend. Anyway, I next tried using my photo software to composite the two images and I thought I'd succeeded but having taken it into LR to polish off I noticed some rectangular shapes which turn out to be caused by deconvolution. So, back the the drawing board again.

So this is 103 x 30s subs with 192 x 2s subs. No colour module, so I might try that, but even a quick check on the 2s subs I didn't get any green!

Here are the shapes generated by decon. Any ideas? I tried the various pre-sets but it didn't make any difference.

Ian

That's beautiful! You've certainly got the data there, and with some more processing I can see a wall mounted picture... You've got the blues of the reflection nebula beneath the main "ring" and your dust looks nice and brown! You might get away with just pulling back the red a little in the overall balance (either in levels in the R channel in Photoshop or maybe just cooling the temperature in Lightroom - but only a smidge (an astronomical technical unit of precise measure)).

Some quick observations:

Many of your stars look square (this is as well as the rectangular areas you've highlighted which cover more than just the stars). That happens to me when I mask stars and get my settings wrong. I don't know how ST does it so I can't help identify where in the process it occurs but deconvolution would be my first guess. Try skipping deconvolution to begin with and see if that fixes it?

Your brightest stars have quite large halos so you may want to blend the stars from the shorter exposures in these areas too? Or mask them during development? That or manually heal them in Photoshop afterwards. I think it only really affects half a dozen stars enough to want to tame them.

But again, wow! I love the image.

[Nigel G]

Lovely looking image Ian.

Have you cropped all the artefacts out, I've not seen that before, every time I have had something unusual with an image its because I left a pixel or 2 of artefacts.

Nige.

[rotatux]

Hello, I'm new to SGL but having patiently read this thread from start to end over several weeks I decided to sign in and post some of my results to encourage others (if still needed :-) ).

FWIW I'm the proud owner of a SW130PDS so I've also read the entire "imaging with the 130pds" thread (over several months).

(sorry if I'm a bit long for this first post)

My first images were about 3 years ago on Nexstar SLT mount. Here the kind of thing I got:

Infos: Capture = 3 lights x 20s x 800iso, 2 darks, Olympus E-PM1 with Celestron MAK127 on Celestron SLT mount, dydimium filter; Processing = ImageJ + Gimp

Then I mostly turned to wide-field with old lens on self-made barn-door-tracker, had some nice images but always from only a few subs, due to my software pipeline of that time.

Then 1.5 year ago I bought a RA-motorized EQ3/4-class mount, in the hope to do unguided longer subs. I found it's good enough but is cumbersome to take to my pet dark spot (16kg+optics to take 50km and 45mn from home). I did some imaging with it and it's average, allowing good 30s subs but 60s is harder and depends on good polar alignment (which is too long for me and wastes rare good nights time).

So after reading this thread I thought "why not give my SLT a try again". In the meantime I have discovered Regim and it has changed my astro-imaging life ! Though it's not good at everything, it now allows me to properly align and stack many more subs. So stacking a quite high number of subs from an Alt-Az mount doesn't frighten my any more.

Here's one I did 2 months ago:

Infos: Capture = 103 lights x 8s x 1600iso, 21 darks, Olympus E-PM1 with Skywatcher 130PDS and CC on Celestron SLT mount, TS contrast filter; Processing = Regim, Fotoxx, Gimp

I am quite pleased with it since it's from Paris suburbs with huge light pollution, as this shows:

This shows possibilities are limited in such conditions without a good LP filter... so I had another try a few days ago on holidays from deep country and quite very dark spot:

Info: Capture = 86 good of 101 lights x 15s x 2500iso and 48 NG darks + 11 x 10s x 1250iso and scaled master dark, Olympus E-PM1 with Skywatcher 130PDS and CC on Celestron SLT mount, TS contrast filter; Processing = Regim, Fotoxx

My current masterpiece

[The Admiral]

Thanks guys. In the main image I've dropped the decon stage to avoid the blemishes. Ha ha, I think I actually pushed the magentas more towards the red in Lightroom! The reason for the stars having haloes is because the 2s subs give small stars and the 30s subs the larger disks. I didn't do any masking when I blended them, but I could either leave them just large and fuzzy, or try the opposite.  ST offers to make a star mask automatically before deconvolution, and I've not fiddled with that.

As to the blocky stars, I noticed that when I looked at an enlarged image on my tablet; I don't know if that is the case with the source image. Or for that matter, whether it's from the 2s or 30s subs. I only binned 50%.

Ian

[Filroden]

3 minutes ago, rotatux said:

Hello, I'm new to SGL but having patiently read this thread from start to end over several weeks I decided to sign in and post some of my results to encourage others (if still needed :-) ).

Welcome to the dark side (though with serious light pollution)

I think your journey mirrors many of our own. Your first M42 looks surprising like mine:

Followed by some improvement as I read this thread:

And now to my latest attempt:

I still only feel I'm halfway there, even in Alt/Az terms let alone what the EQ imagers achieve. We still have far more we can squeeze out of our mounts. As an example, I used to only ever achieve subs of 6s. I then pushed this out to 10s then 15s. Now (though a different scope which made a huge difference) I can easily do 30s to 60s and have gone as far as 90s and occasionally 120s! So keep pushing that mount harder! This thread is great because every time I think I've pulled ahead, someone leaps ahead of me (looking at you Ian this time, after your latest M42). It's a great way to  drive us all to improve.

You also seem to be managing your light pollution very well. You will be surprised how well software can remove light pollution gradients. So if your target is brighter than the sky background then you can recover great images.

Have you considered using DeepSkyStacker to stack your images? It is free and relatively easy to learn though there are some specific settings that make a big difference to your results (and you need the very latest version if you want to use RAW files - v3.3.4?).

[Filroden]

1 minute ago, The Admiral said:

Ha ha, I think I actually pushed the magentas more towards the red in Lightroom!

I think that's the right call, but hue adjustment in Lightroom is in quite narrow ranges so you've got a good balance of the red shades within themselves but probably a little out of balance overall (if that makes sense). So I would keep your reddened magentas (and possible bluen your purples) but change the overall tone with the temperature slider towards the blue (maybe only by a couple of points). I'd usually do this in Photoshop as I would just slide the R levels back a little. I think if you checked the RGB histogram your red channel will be far ahead of the blue (which is right, it is a red dominated image, but probably just a little too far ahead).