The "No EQ" DSO Challenge!

[The Admiral]

5 minutes ago, Nigel G said:

Theres some great images being posted, well done chaps.

I seem to be loosing the noise battle atm. the last 3 images I have taken have had incredible noise levels. I'm not sure what has changed.

I took 3 hours of 60s exps of Heart and Soul with my 210mm lens, its impossible to work with.

I tried to image the Eastern Veil last night, I could only get about 20 minutes of 30sec subs before light cloud spoilt the session. I used darks and bias but again had a long battle with background noise, I'm struggling to work this out. I realise this is short on total exp time but I have imaged other objects with similar total time without the huge noise levels. I'm sure I'll sus it out, just hope its sooner rather than later.

Seeing appeared to be good and light pollution same as ever.

 Taking 3 hours of subs then 4 hours stacking for a screen full of multi coloured pixels is not what I had in mind . or perhaps I just forgot how to process.

Anyway enough of me moaning Here's my Veil neb, around 20 minutes of 30s, 15 darks 50 bias and a lot of post stacking work. DSS and StarTools.

Any suggestions are welcome.

Nige.

I'm sorry to hear that Nige but I like your Veil nebula very much, your PP work has paid off.

Can I just clarify something? When you say the noise levels have been terrible considering the amount of exposure time, are you comparing the sort of noise you were getting with the 'scope with what you are getting with your camera lens. In other words, is it only bad when you use the camera lens? Also, the number of dark frames don't seem that many to me; personally, I'd aim for say 50, a pain I know. Don't forget that the dark frame is subtracted from the image frame, so if the statistics of the 'master dark' are poor, you'll end up adding more noise to the image rather than reducing it. In order to minimize the random fluctuations associated with the dark frame you need a lot of them. Have you tried stacking without using the darks? Just a thought.

Ian

[The Admiral]

Hey, we just gone over the 1000th post on this thread!

Ian

[Nigel G]

27 minutes ago, The Admiral said:

I'm sorry to hear that Nige but I like your Veil nebula very much, your PP work has paid off.

Can I just clarify something? When you say the noise levels have been terrible considering the amount of exposure time, are you comparing the sort of noise you were getting with the 'scope with what you are getting with your camera lens. In other words, is it only bad when you use the camera lens? Also, the number of dark frames don't seem that many to me; personally, I'd aim for say 50, a pain I know. Don't forget that the dark frame is subtracted from the image frame, so if the statistics of the 'master dark' are poor, you'll end up adding more noise to the image rather than reducing it. In order to minimize the random fluctuations associated with the dark frame you need a lot of them. Have you tried stacking without using the darks? Just a thought.

Ian

Thanks for your kind comment Ian.

I'm having the same background noise with both scope and lenses.

I read in " Making every photon count " I think, 12 - 15 dark frames and 50 bias is all that is needed, the darks are to remove hot pixels and sensor noise I believe. 

Maybe it's different for lots of short exposures?  I think I need to do a bit more research into exactly what is needed for stacking lots of shorts with DSLRs.

to be honest I prefer my image just developed in StarTools, to my eye the nebula is sharper but obviously more noise, horrible background colour and not so visible . I'll post it without noise reduction after I've finished processing another stack I'm attempting now which answers your other querie, this is my first stack without dark frames, early indications are not much difference. 

Nige.

[SteveNickolls]

33 minutes ago, Nigel G said:

I read in " Making every photon count " I think, 12 - 15 dark frames and 50 bias is all that is needed, the darks are to remove hot pixels and sensor noise I believe. 

Maybe it's different for lots of short exposures?  

Hi Nige,

I think you've hit things directly on the head there, if you were taking just a few really long light frames with an EQ mount then a modest number of dark frames would be ok (especially as each dark frame takes the same length of time to take as a long light frame). For us with the Alt-Az gear Ian has the number of dark frames about right at around x50 or so. Having said all this I'm now not using dark frames at all as a trial. My current thinking is that as I can't control the temperature of the DSLR sensor what am I actually doing taking dark frames, they might be making the images worse? 

Sometimes you find you go through a 'dark night of the soul' (no astro-pun intended) before coming out the other end the wiser for it all. With Alt-Az imaging we have to do everything the harder way, we take lots of short images with less S:N ratio, we have to accommodate field rotation effects and the constraints it places on the altitude of the object meaning we image through more atmosphere and light pollution, plus we often have come along this road because we don't live somewhere dark, can't afford the EQ gear or an observatory and maybe can't get out to a dark location if we wanted to or at least not often. If we didn't do this we would just be reading about it instead. We sometime push the boat out more than the gear and our experience to date can handle but the good thing is we can return to the master images later on when we are more proficient. Just keep your chin up, actually you're doing quite fine :-)

Cheers,
Steve

 

Edited September 27, 2016 by SteveNickolls

[SteveNickolls]

1 hour ago, Nigel G said:

Theres some great images being posted, well done chaps.

I seem to be loosing the noise battle atm. the last 3 images I have taken have had incredible noise levels. I'm not sure what has changed.

I took 3 hours of 60s exps of Heart and Soul with my 210mm lens, its impossible to work with.

I tried to image the Eastern Veil last night, I could only get about 20 minutes of 30sec subs before light cloud spoilt the session. I used darks and bias but again had a long battle with background noise, I'm struggling to work this out. I realise this is short on total exp time but I have imaged other objects with similar total time without the huge noise levels. I'm sure I'll sus it out, just hope its sooner rather than later.

Seeing appeared to be good and light pollution same as ever.

 Taking 3 hours of subs then 4 hours stacking for a screen full of multi coloured pixels is not what I had in mind . or perhaps I just forgot how to process.

Anyway enough of me moaning Here's my Veil neb, around 20 minutes of 30s, 15 darks 50 bias and a lot of post stacking work. DSS and StarTools.

Any suggestions are welcome.

Nige.

 

Hi Nige,

Just saw this, what a splendid image, you should feel very pleased with this indeed. I love the colour of the object and your dark background. Given the small amount of light frames you needed to image the object this is just the tonic for the rest of us to try. I'm trying to think why StarTools would not show the star colours, could you put the master image through the COLOR module or would it just create a lot of noise that way (might be a sign of just needing more light frames).

Cheers,
Steve

[Nigel G]

3 minutes ago, SteveNickolls said:

Hi Nige,

Just saw this, what a splendid image, you should feel very pleased with this indeed. I love the colour of the object and your dark background. Given the small amount of light frames you needed to image the object this is just the tonic for the rest of us to try. I'm trying to think why StarTools would not show the star colours, could you put the master image through the COLOR module or would it just create a lot of noise that way (might be a sign of just needing more light frames).

Cheers,
Steve

Thanks Steve,

I am pleased with it considering the short amount of exposure time, to be honest its better than I expected.

I masked the stars as I could not get a good star colour, they looked fake, this is what I struggle with most on ST I find colour harder than noise to deal with  

I'm going to try different things to see what I can do. That's part of the fun, quite often I make my images worse by messing about and go for a total restart lol.

Cheers

Nige.

[The Admiral]

5 minutes ago, Nigel G said:

I masked the stars as I could not get a good star colour, they looked fake, this is what I struggle with most on ST I find colour harder than noise to deal with  

I'm going to try different things to see what I can do. That's part of the fun, quite often I make my images worse by messing about and go for a total restart lol.

Cheers

Nige.

I always find star colours to be a pain in ST; more often than not the colour module makes them green or purple! And the sensitivity of those colour bias sliders...! To be honest, I'm always starting afresh.

When you stack in DSS, do you use kappa-sigma clipping? If not, it might be worth a try at default settings, particularly if you don't use darks. Something I read somewhere . And speaking of darks, I really do think that you need more. Of course, I've no experience of using long exposures and the darks appropriate for that, and you might indeed be able to get away with fewer. But for 30-40s exposures? Hmm, not so sure. I also wonder if doing flats would be worth a try? It wouldn't be difficult to do them now as you are talking about a camera/lens combination. You wouldn't have to set up your 'scope to do it.

Ian

[SteveNickolls]

Hi Nige,

I know what you mean about making things worse when messing with them. I'm currently struggling with my image of the Heart and Soul Nebulae to tease the nebulosity out while trying to keep a dark background. Have you ever used the LAYER module? I wondered what it could be used to do in StarTools?

Cheers,
Steve

[The Admiral]

Nige, another thing is that the night-time temperatures have been quite high of late, and I wonder if that is resulting in more noise?

Ian

[Nigel G]

22 minutes ago, The Admiral said:

I always find star colours to be a pain in ST; more often than not the colour module makes them green or purple! And the sensitivity of those colour bias sliders...! To be honest, I'm always starting afresh.

When you stack in DSS, do you use kappa-sigma clipping? If not, it might be worth a try at default settings, particularly if you don't use darks. Something I read somewhere . And speaking of darks, I really do think that you need more. Of course, I've no experience of using long exposures and the darks appropriate for that, and you might indeed be able to get away with fewer. But for 30-40s exposures? Hmm, not so sure. I also wonder if doing flats would be worth a try? It wouldn't be difficult to do them now as you are talking about a camera/lens combination. You wouldn't have to set up your 'scope to do it.

Ian

Ian. I use kappa sigma clipping always,  next session I will gather more darks and give flats ago too.

Nige.

[Nigel G]

25 minutes ago, SteveNickolls said:

Hi Nige,

I know what you mean about making things worse when messing with them. I'm currently struggling with my image of the Heart and Soul Nebulae to tease the nebulosity out while trying to keep a dark background. Have you ever used the LAYER module? I wondered what it could be used to do in StarTools?

Cheers,
Steve

Steve, I did use layer module once last week, it seemed to just offset the layers and fuss up the image, mind you I didn't give it much of a chance  ☺

YouTube research needed.

Nige.

[Nigel G]

This is the image before any noise reduction work, Just binned, developed, cropped and a touch of HDR. and a load of noise

To me this looks much sharper but I loose the sharpness during noise reduction and further processing.

Theres a link to the fts at the bottom if anyone is bored and wants something to process  

 

https://1drv.ms/u/s!Av3mI1-jgAvwcIvZwbzjRcPwXIU

[Nigel G]

9 minutes ago, The Admiral said:

Nige, another thing is that the night-time temperatures have been quite high of late, and I wonder if that is resulting in more noise?

Ian

That's a good point Ian.

[SteveNickolls]

35 minutes ago, Nigel G said:

This is the image before any noise reduction work, Just binned, developed, cropped and a touch of HDR. and a load of noise

To me this looks much sharper but I loose the sharpness during noise reduction and further processing.

Theres a link to the fts at the bottom if anyone is bored and wants something to process  

 

https://1drv.ms/u/s!Av3mI1-jgAvwcIvZwbzjRcPwXIU

Thanks Nige,

I will give your image 'a go' later tonight, right now I'm sapped of the will to live with StarTools :-)

Cheers,
Steve

[Stub Mandrel]

I've looked at a couple of runs of DSLR darks and DSLR lights and the temperature stability. I will post results in another thread.

[The Admiral]

Nige, I can't resist a challenge, stop, stop it!

Well, this is what I managed to get out of it. Completely different in appearance, a very fussy background of, what I take to be, stars. I used the colour module with this, it didn't seem to 'go ballistic' as it sometimes does. Finished with a bit of fettling in Lightroom. I must say that that you have a hell of a lot of gradient in there, (or is it uneven noise), so I really think flats and darks would ease the processing demands. No masking used.

Ian

PS I still prefer yours though, the starfield doesn't impact on the image as much, and the stars seem much smaller. Anothef one of those 'start again' moments perhaps 

Edited September 27, 2016 by The Admiral

[Nigel G]

30 minutes ago, The Admiral said:

Nige, I can't resist a challenge, stop, stop it!

Well, this is what I managed to get out of it. Completely different in appearance, a very fussy background of, what I take to be, stars. I used the colour module with this, it didn't seem to 'go ballistic' as it sometimes does. Finished with a bit of fettling in Lightroom. I must say that that you have a hell of a lot of gradient in there, (or is it uneven noise), so I really think flats and darks would ease the processing demands. No masking used.

Ian

 

I'm not sure if its my scope causing the gradients coupled with an entry level DSLR, The secondary mirror supports are quite thick relative to an imaging scope plus I have around an inch of draw tube extending into the main tube. Non of this helps my imaging.

Without the isolation tool in the life module I don't know what I would do. Thank StarTools.

Nige. 

[The Admiral]

But this isn't with the 'scope, is it? I though it was a csmera lens.

Ian

[Nigel G]

On ‎22‎/‎09‎/‎2016 at 16:25, Filroden said:

I apologise now to anyone who might have had a clear forecast tonight. I've just received my new camera. I've treated myself to one of the new ZWO ASI 1600 mono cooled cameras. I figure it removes the noise problems I suffer from using the DSLR (I can make darks for set point temperatures now, plus I can cool the thing to -30C). I also figure that as a mono camera I can image more in our limited capture windows - a huge boon I'm hoping. So I'm going to be trying LRGB imaging on AltAz, hopefully within the next week/month/year/century.

Had a chance yet ??

[Nigel G]

6 minutes ago, The Admiral said:

But this isn't with the 'scope, is it? I though it was a csmera lens.

Ian

The veil is with my 150p scope.

 

[The Admiral]

Ah, my mistake!

Ian

[Filroden]

Hi Nige

Here's my attempt. I also struggled with the gradient and because I couldn't effectively remove all of it, I was left with a lot of residual noise that I couldn't remove without losing signal. There is definitely a lot of colour in the image and you can clearly see it in the Veil. I think with flats (and possibly without using darks) you may reduce some of the effects.

I think the Veil is too high for me to image right now, but it certainly looks a nice target. I hadn't thought to include it on the list.

[Filroden]

24 minutes ago, Nigel G said:

Had a chance yet ??

Not yet. I had a really clear night on Sunday but I'd just returned from a 300 mile journey and hadn't tried the camera in daylight so I missed the opportunity. I now have it working and tested. I'm having to learn a new capture software (having loved BackyardEOS) and it's certainly slower to find focus but I have a set of bias and darks all ready captured.

Tonight could be clear but they are forecasting very strong winds so it's 50/50 for tonight. If I do get out I may go for the Soul again (as a comparison) or for the Pinwheel (given it's both low and to the East). If the wind is kind and I have the stamina, I really want to image M45. It was one of my first targets and I got nothing but stars the first time so now I've had much more practice I'm hoping I can capture something more.

[Nigel G]

Ken.

The only way I could rid the gradients and noise was with isolate tool.

I think as many have pointed out, flats will (should) help with the gradients, I'll get right to it.

Nige.

[The Admiral]

2 minutes ago, Nigel G said:

Ken.

The only way I could rid the gradients and noise was with isolate tool.

I think as many have pointed out, flats will (should) help with the gradients, I'll get right to it.

Nige.

In addition to close cropping, I tried upping the wipe aggressiveness a lot to get rid of apparent gradients, but who knows whether that got rid of nebula as well. I also tend to use a dark anomoly filter setting of 10 or 15, don't know if that helps.

Cheers, Ian

Ian