The "No EQ" DSO Challenge!

[Filroden]

Welcome to the world of alt/az imaging Steve and nice first stack. Certainly much more detail than I ever achieved when I started a year ago and now look where we are! It's great you're also just getting the Running Man. Add more subs and you're away.

And Nige, that's a cracking M42 and the HH really shows the benefits of the modding. I have to agree and I think your background is clipped. With your modded camera and LP filter I think you can start really bringing the background detail out. Your noise shouldn't be as bad now.

And my success for the night..autofocus is now working  It was all about the backlash setting. So I've just started capturing my first hour of new data on IC410 (with hopefully clean filters now) but I will than have to move onto Orion as Auriga will be too high for me to image after about 21:00.

 

[Filroden]

1 minute ago, Steve_Field said:

Also, the old Pentax K100D only allows for 30 second exposures and really lacks in features.  I've got a wealthy friend who has a camera addiction problem that just gave me his old Nikon D80 ... still an older camera and not a Canon but I think it'll work a bit better than my 10 year old Pentax.

Does it not have a bulb setting? Still, I prefer 30s exposures to avoid star bloat. You just need more of them so they take longer to stack.

[Steve_Field]

I figured more frames to stack was the ticket.  I just started fooling with DSS which beats trying to stack in PS.  Curious about dark, flat and bias frames will those help as well?  

You know the Pentax was also a hand-me-down that was just sitting in a closet and it may very well have a bulb setting but it's probably buried in one of the many obscure menus on this camera.  It's OK for a free camera but i'm going broke keeping it in batteries ... i only get about 15 to 20 frames at 30 seconds before I get a battery depleted message and the camera shuts down.  I was going to get an AC adapter for it before the offer of the Nikon came along.

[Filroden]

1 minute ago, Steve_Field said:

I figured more frames to stack was the ticket.  I just started fooling with DSS which beats trying to stack in PS.  Curious about dark, flat and bias frames will those help as well?  

Bias, darks and flats make a lot of difference. Bias and darks can be done once and kept as master files though I think most of us concluded darks were not useful with DSLR cameras because temperatures change too much. Flats are the most important but also the most awkward to take as you have to keep the camera/scope combination unchanged including focus, etc. It took me ages to find a way to do it easily but now I leave the scope on the table overnight and do it in the morning.

[happy-kat]

 Have you got a bunch of old glass to go with your camera? Only sometimes the old glass can take great images and are a good length for m31. Plus these old lenses have buttery smooth focus control and by taking the telescope off the mount may track at its best with a much lighter weight.

[Nigel G]

26 minutes ago, Steve_Field said:

Also, the old Pentax K100D only allows for 30 second exposures and really lacks in features.  I've got a wealthy friend who has a camera addiction problem that just gave me his old Nikon D80 ... still an older camera and not a Canon but I think it'll work a bit better than my 10 year old Pentax.

I'm really curious how you modified your focuser... any details you can give me?

hope this helps  

[Filroden]

Well, my filter wheel got close to the mount much earlier than anticipated so only got 30 minutes of L data on IC410. Now swapped to a new target of IC443 as the Orion targets are still too low. But now I have fast moving clouds passing over (though they should clear within the hour). So now I will have to review every image before integration.

And I set my camera in landscape, forgetting that the Orion targets are better portrait. But as I don't do flats at night, I can's change the camera angle mid-session.

I remember the nights when it was the alt/az causing all the issues! They seem so last year now

[Nigel G]

A quick adjustment to the shadows,  I don't know if I've over done it or not cos I can't find my reading glasses atm.? might be room for more. 

I will reprocess again soon, got the Crescent next. 

Nige.

edit, found glasses, don't like.

Edited December 23, 2016 by Nigel G
found glasses

[Filroden]

21 minutes ago, Nigel G said:

A quick adjustment to the shadows,  I don't know if I've over done it or not cos I can't find my reading glasses atm.? might be room for more. 

I will reprocess again soon, got the Crescent next. 

Nige.

edit, found glasses, don't like.

I like it. I think there is more to be had in the shadows. 

[Filroden]

TeamViewer is changing my life. I now have it set up on both my main PC and my iPad so I can either monitor the laptop from the warmth or, with the iPad, I can now check framing and focusing whilst at the scope. Previously I would have to balance the laptop on the kitchen window sill and try and see through the window from outside. Now I can see it on the iPad on the eyepiece tray on the tripod and use the handset to better frame the target. This little things make life so much easier!

I can also transfer the files from laptop to main PC whilst imaging, saving me the time the next day in using a USB stick.

I could see the left most side of the Jellyfish in my red subs so if the clouds hold off, I may run another hour on this target. Given how windy it is, my HFR scores are re-markedly good. I have noticed that through the session, as it auto-focuses with each filter change, not only are my filters not parfocal (but within about 10 steps out of a 9000 range so pretty close) the best focus point for the filters has been changing quite a lot. Even after 30 minutes. How often are you all checking focus through the night?

[Nigel G]

5 minutes ago, Filroden said:

How often are you all checking focus through the night?

Ken Glad your auto focuser is now working properly.

Normally focus just the once, unless I change orientation of the camera or change the battery. 

Must check and see if it changes.

Might get a chance tonight and to get some more on Rosette as the rain has stopped and clear patches are showing.

Cheers 

Nige 

[Filroden]

My L filter (effectively the clear filter) changed by 30 steps out of 9000 in an hour on an evening that's not seen a huge temperature difference. I doubt that's enough to make a lot of difference visually but I suspect it will be a bigger issue when the temperature drops a lot. I might check the relationship between temperature and focus point to see how steep the change is. I've read that many check focus for every 2C drop in temperature.

[Filroden]

Well, 30 more minutes on the Jellyfish and it's hit my altitude limit (which appears to now be only +51 so I may have to move the scope on its bar). Checked on Orion and it's already around the side of the house  So I may just get some subs on the Rosette before it joins Orion. I'm going to have to plan my sessions much better in future as it seems I have a very limited window.

[Steve_Field]

No doubt Ken, lately it seems like the clear nights are few and far between and with Christmas parties and family stuff I've found that I've had to do a lot more planning to get set up.... Wife made me play dominoes with the kids on Wednesday night and completely blew up the entire evening for me!  Now it looks like it'll be overcast down here until next week some time grrrr.... so much I'm dying to try out next time.... prbably need a checklist now!

So I've not touched the focuser on my scope since I took the M42 photos... I suppose I could take some flat frames with it.  The only reason I hadn't was that I thought the telescope needed to be at the same temperature as it was when I was imaging.  

[Filroden]

25 minutes ago, Steve_Field said:

So I've not touched the focuser on my scope since I took the M42 photos... I suppose I could take some flat frames with it.  The only reason I hadn't was that I thought the telescope needed to be at the same temperature as it was when I was imaging.

Temperature is important for the camera when taking darks. This works well if you have a cooled camera. If your camera is not cooled then it's almost not possible to match temperatures and you introduce more noise than you reduce. That's why we've tended not to use darks, just bias and flats with hot pixel removal in processing. 

Flats are just about the optical train. Temperature can affect focus but I doubt enough to affect flats. 

[Nigel G]

I managed to get only 30 minutes imaging last night before cloud and rain started. A very quick pack away and 5 minutes later the sky was crystal clear, but didn't set up again.

I checked focus after 20 minutes and still spot on. 

After last night's efforts I only added 15 minutes of data to Rosette, 

Nige.

[Filroden]

I had a hit and miss night, eventually suffering some alt/az related issues:

1) IC410: managed 60 L subs before it rose too high for my mount

2) IC443: managed 120 L subs but only 20 each for RGB before it rose too high for my mount

3) NGC2239: managed 60 L subs before tracking went haywire - the first time that's happened in a long time

So I have some B&W images to process (though I can add a little colour to the Jellyfish). I now have to capture a lot of colour data on IC410 (will need a 18:00 start for that one) and more subs for IC443 and NGC2239.

To get two hours on a target I need to start imaging before it gets much above +30 or I have to find a way to gain more clearance. And I also have to check when targets are moving south as I'd lost my chance on more subs on the Flame/HH unless I moved the scope (which either requires me moving the laptop outside or much longer cables).

[Filroden]

IC443 Jellyfish Nebula and surprise friends

Well, it wasn't a complete bust. I think i was imaging too close to south last night and that was giving me star trails. It was worst for NGC2239 which I had to throw away all the data. I just accepted them in IC443 which I've shown processed below (and also shows vdB75 and DG99 to the left of the Jellyfish). This is all 30s subs at 139 gain and 21 offset at -20C: 105 x L, 20 x R, 20 x G, 20 x B. There is far too little data here, particularly colour but I'm pleased I could see the Jellyfish.

And annotated (done before processing in Adobe Lightroom, so you can see the difference those final few tweaks can make).

Edited December 24, 2016 by Filroden

[Nigel G]

Lovely Jellyfish Ken

You had better luck than me with the weather.

2 images, a redo of Crescent with 1.25 hours of 30s, 45s and a couple of 60s. And a redo of Rosette with twice the original time, 30 minutes of 30s and 45s.

Nige.

[Filroden]

It just goes to show how extra subs make a difference. The Rosette Nebula is really starting to take shape and there's far more detail in both images.

[Nigel G]

And a remould of HH, I can't seem to get much more without causing noise, I can keep going with brightening the shadows but it starts to turn nasty. It's better than before, the blue fog has gone, but you can see the noise reduction quite clearly.

I think I'll have a trial run with PI just to see the different processes.

Nige.

[Herzy]

22 hours ago, Nigel G said:

A quick adjustment to the shadows,  I don't know if I've over done it or not cos I can't find my reading glasses atm.? might be room for more. 

I will reprocess again soon, got the Crescent next. 

Nige.

edit, found glasses, don't like.

You seem to have a lot of patterned noise. Are you dithering? If you look closely it looks like there is a checkered pattern to the noise. That may be a result of drifting of the object in your FOV.

[Nigel G]

3 hours ago, Herzy said:

You seem to have a lot of patterned noise. Are you dithering? If you look closely it looks like there is a checkered pattern to the noise. That may be a result of drifting of the object in your FOV.

I think the chequered pattern has come from a stacking artefact, I noticed it in a couple of images, if you look at Rosette last process you can see the bottom right has a clear artefact. I have been cropping very close to the obvious Alt-AZ rotation artefacts. Miss by one pixel and it plays with the processing.

You can see the pattern is at a slight angle which would be rotation of the frame I clipped while cropping.

On the last HH the pattern is not there, I rotated the image slightly to get the biggest crop and miss the overlaps.

Nige.

[Filroden]

Last night was clear but the winds were very high so I decided to give the 85mm lens a try out. Once the last remaining high clouds had passed I think I managed to collect about 700 5s subs covering parts of Auriga and Orion. IC410 was visible in individual subs but IC405 was not. M42, the Flame and M78 were visible in the Orion single subs and what I think was the very faintest of Horsehead but no Bernard's Loop. I had high hopes once I'd integrated the subs. However, on closer inspection my stars were terrible; looking almost like crow's feet. I'd taken the images at f2 (one stop in from open) but I think I will have to experiment and maybe drop back as far as f4 and then maybe take a similar number of subs but at 15s exposures. So I have no images to show for the night but I'm getting closer!

Tonight looks to be much better - both clear and low winds - so back to my original plan of collecting colour data for IC410 then adding maybe 2 more hours of data on the Jellyfish and, if time allows, starting on the Rosette.

[Nigel G]

Good luck for tonight Ken, experimenting is the name of the game, hope your conditions are good tonight.

I had a fairly good night last night. Attempting my first mosaic. processing now, quite good for first try.

Not sure what to go for tonight though.

Nige.