The "No EQ" DSO Challenge!

[scitmon]

20 hours ago, Filroden said:

Really nice first attempt. There's a lot of data hidden behind that blue cast. I don't know how to fix it in Photoshop but a quick pass through PixInsight's ColourCalibration and some crude curve adjustments shows you this. I've broken the stars (they are all showing orange) but there is a lot of colour in the nebula that you could bring out.

wow thanks yeah.  I've been playing around with Startools over the last couple of days, as has been recommended and managed to get some more out like you have.  I think you have done a much better job than I have however.  I may try Pixinsight but the price does put me off at this early stage when I have perhaps bigger priorities to spend money on. i.e. equatorial mount.  Although this thread proves that equatorial may not be the be all and end all of astrophotography!

 

I thought jpg's didn't contain curve data?  I thought you could only manipulate the tiff or fits image types?

Edited June 21, 2017 by scitmon

[happy-kat]

There's an excellent blog on StarTools processing I'll add the link later. It's good to get you going but I do my own tweaks now that I am more familiar with StarTools.

link here

Edited July 14, 2017 by happy-kat

[Filroden]

4 hours ago, scitmon said:

wow thanks yeah.  I've been playing around with Startools over the last couple of days, as has been recommended and managed to get some more out like you have.  I think you have done a much better job than I have however.  I may try Pixinsight but the price does put me off at this early stage when I have perhaps bigger priorities to spend money on. i.e. equatorial mount.  Although this thread proves that equatorial may not be the be all and end all of astrophotography!

 

I thought jpg's didn't contain curve data?  I thought you could only manipulate the tiff or fits image types?

You can apply almost all processing techniques to a jpg...you just shouldn't! Jpgs are 8 bit and compressed so they destroy data which means tools like curves can have terrible results, making them look very 'stepped'. You're always better working in at least 16 bits and uncompressed (e.g. TIFF or FITS) so you can work over a better range and not have the steps seen in a jpg.

PixInisght comes with a long free trial but it requires it. I needed lots of tutorials and ultimately a guide book to really start to use it well. You can achieve the same results in Photoshop if you know how. I can do a little in Photoshop, such as level and curve adjustments, but I find the tools in PixInsight more in tune with the way I think. As I said above, I only applied some crude adjustements to see what was under the colour cast. You will be able to achieve far more using the original data and taking a little more time than I did

[happy-kat]

Didn't it get proved hat tiff was not truely uncompressed. Fits is best out of DSS.

[The Admiral]

1 hour ago, happy-kat said:

Didn't it get proved hat tiff was not truely uncompressed. Fits is best out of DSS.

Is that not a sweeping generalisation? TIFFs can be compressed, either losslessly or lossy, or uncompressed. I think it's an issue related to DSS isn't it? Some applications also won't open some compressed TIFFs I believe. Certainly something to be aware of though?

Ian

[icebergahed]

Awesome images taken in this topic. I am picking up a celestron 6SE this Saturday and have been hunting for info for what imaging kit i need. All suppliers have advised me is i would HAVE to spen atleast £700 on a ccd to do any deep sky!!!! 

Im sure they are advising correct as in high end images you get in magazines. But after what i have seen great thread im not sure if i mind a pixel out here and there.

Thanks guys

[happy-kat]

Hi

Take a look at what other members on this thread are doing when they have the 6 or 8SE tripod (it is the same tripod) some are using the tripod but not the telescope. If starting something less demanding like a camera and lens would be perhaps easier. What equipment do you already own?

[alacant]

9 hours ago, icebergahed said:

£700 on a ccd to do any deep sky

Hi. I don't agree with that (sales talk?). I have a dslr which cost far less than half that; it works fine for deep sky stuff.

3 minutes ago, happy-kat said:

some are using the tripod but not the telescope

+1. Start with just a camera. HTH, clear skies and good luck.

[The Admiral]

10 hours ago, icebergahed said:

Awesome images taken in this topic. I am picking up a celestron 6SE this Saturday and have been hunting for info for what imaging kit i need. All suppliers have advised me is i would HAVE to spen atleast £700 on a ccd to do any deep sky!!!! 

Im sure they are advising correct as in high end images you get in magazines. But after what i have seen great thread im not sure if i mind a pixel out here and there.

Thanks guys

Welcome to the thread icebergahed. Sorry, bit of a long answer coming up (never let it be said I don't give value for money . But then I'm not getting paid for this!)

First things first, a lot of imagers will tell you nothing less than an EQ mount will do, and then a dedicated astro camera is to be preferred. Totally untrue, but there are limitations doing Alt-Az imaging with a DSLR, but so long as you are content to stay within those limitations, all well and good. The principal limitation is that with an Alt-Az mount, the image will rotate as the target moves across the heavens. You can get around this peripheral star streaking by using short exposure times, say 30s or less, sometimes more, depending on which part of the sky you are looking at. The consequence of that is that you will need to take an awful lot of pictures, many dozens, if not hundreds, in order to suppress the noise in the image. The second thing is that Alt-Az mounts move in two directions to keep a target centred, in a kind of zig-zag pattern, and with the cheaper mounts these movement aren't necessarily very fine, and you will find that some of your frames will show star streaking, even if, on the whole, the target remains centred. You cannot use such frames and so you will end up discarding a percentage. This mount inadequacy is made worse when you have long focal length 'scopes, such as the 6SE. OK for visual, but a bit of a challenge with photography. You can ameliorate this by using a flattener/reducer, such as https://www.firstlightoptics.com/reducersflatteners/celestron-f63-focal-reducer.html. This does three things. Firstly it reduces the FL of the telescope and so it will be less susceptible to mount inadequacies, but secondly, and just as importantly, it will give you a wider field and in doing so will concentrate more photons onto each pixel. In other words, improve your recorded signal of these faint objects, and help improve your image, but at the expense of a wider overall field of view. Thirdly, it will keep the image sharper across the frame, rather than sharpness being confined to the centre of the frame. This isn't an essential accessory, but I think it would be worthwhile. Some others may chip in here. Interestingly enough, the starter of this thread asked a similar question about this back in 2012 (https://stargazerslounge.com/topic/167836-focal-reducer-on-nexstar-6se/). I'm sure that plenty of material on this can be found on this site with a search.

Finally, I'd thoroughly recommend reading "Astro-photography on the Go - Using Short Exposures with Light Mounts", by Joseph Ashley.

Good luck, and looking forward to see your images on here!

Ian

Edited July 26, 2017 by The Admiral
Further thoughts!

[icebergahed]

Hi thank you for the help. I was going to get the focal reducer, that way i have 2 scopes for the price of 1. Plus it doubles the eyepieces modifications range.

Even thou there will be field rotation and i will need plenty of shots, it will a good learning curve.

I had a manual 200mm eq reflector years ago which i found frustrating setting up. It put me off for a few years. Now that tech has moved along and the astro bug in me has come out again.

My short shopping list at the moment is

Nexstar 6SE

Wifi module

Focal reducer

The appropriate lenses??

Lithium battery pack

 

Thank

 

[Shaun_Astro]

A nice clear night last night. I tired using my 1300D and 75-300mm lens (impossible to properly focus manually) at 300mm on M31,

Managed to get 65 usable frames out of about 130 with my star discover mount. Might be that I kept walking past it, and there was a little bit of wind.

Would be nice to add to this, but the focus is off, so doubt I'll bother.

 

[Nigel G]

4 hours ago, Shaun_Astro said:

A nice clear night last night. I tired using my 1300D and 75-300mm lens (impossible to properly focus manually) at 300mm on M31,

Managed to get 65 usable frames out of about 130 with my star discover mount. Might be that I kept walking past it, and there was a little bit of wind.

Would be nice to add to this, but the focus is off, so doubt I'll bother.

 

 

Good frame size for M31 and not bad at all for a 300mm lens, can you use live view on a bright star or the moon to focus before targeting ?

Do you connect to a laptop or tablet device for capturing.

Nige.

 

 

[Shaun_Astro]

7 hours ago, Nigel G said:

Good frame size for M31 and not bad at all for a 300mm lens, can you use live view on a bright star or the moon to focus before targeting ?

Do you connect to a laptop or tablet device for capturing.

Nige.

 

 

Thanks. I focus with 10x zoom on a star. It's mechanically too course to achieve good focus. I think it's nearly impossible, as the best focus I could achieve gave stars witha  /\ like appearance still.

 

 

[The Admiral]

5 hours ago, Shaun_Astro said:

Thanks. I focus with 10x zoom on a star. It's mechanically too course to achieve good focus. I think it's nearly impossible, as the best focus I could achieve gave stars witha  /\ like appearance still.

That's a nice image Shaun, the dust lanes are showing well and you have colour in the stars. There does appear to be a blue 'wedge' associated with the bright stars so I suspect that is due to lens aberrations and you may never be able to sharpen them up more. A likely problem with a zoom lens with IS I suspect. Is it focus by wire? Sometimes they can be hard to adjust. Was this at full aperture? The chromatic aberration might be improved by stopping down.

Ian

[rotatux]

22 hours ago, Shaun_Astro said:

Managed to get 65 usable frames out of about 130 with my star discover mount

At your current keep rate, you may also improve it dramatically by dropping your sub exposure time a little, say from 30s to 25s or 20s. BTW you don't tell how long your subs are.

Nice pic however, it has depth and colors; Details and your processing skill will improve with time and practice (and yet more subs as always :-P)

[Shaun_Astro]

Yeah it was 30s@ iso1600, I prefer the look of 800. Which is what I used here with my 130 PDS.

Again binned more than half my subs! Maybe If I used 20s I might have more usable subs with less star trailing, but I think less longer subs would have a better SNR ratio.

This is 74 30s subs @ iso800. Still need to get the my coma corrector!

...............

Story of last night is pretty funny. I got home from work at 2330. Put my 130pds on the sofa, it rolled off onto the floor and then made a horrific grinding noise when I tried to focus it! Fixed it now and it could have been a lot worse!

Then after finally getting set up and taking pictures, after 30 mins I went to check on the alignment, and realized I hadn't properly clipped the shutter release button down.

So by then it was nearly 01:30 and I decided to carry on, it was a lovely clear night not to be missed!

By the time I finished the darks and flats, and taking apart and repairing the focuser which had jammed one of the focusing knobs into the housing, Venus was due to rise, which I wanted to snap with my barlow and webcam.

So I aligned everything up again and waited until 03:30, then noticed the alignment was way off, maybe aligned to the wrong star! So I tried to align again, but clouds and daylight prohibited it, and Venus got covered in cloud. So I packed up and just as I put my mount inside the sky cleared up, Deneb, Hamal, Altair, Venus, Alerberan and Capella were all easily visible to align off of. What a sight Venus is in the morning sky! Next time!

 

Edited August 2, 2017 by Shaun_Astro

[Nigel G]

Sometimes things just don't go right  

Nice Andromeda image, I love seeing Venus its always a grand sight to see especially at twilight.

Nige.

[Shaun_Astro]

I've overlain a less stretched version on top of the core to remove it being blown out.

Also have applied a blurred inverted duplicated layer in GIMP as "soft light" which works as a sort of luminace layer.

And a version over as a mask over a black layer set to "darken",  removed it over the galaxy with a fine spray, and adjusted curves as a sort of "star mask".

Looks a lot better I think!

 

Edited August 2, 2017 by Shaun_Astro

[SteveNickolls]

12 minutes ago, Shaun_Astro said:

Looks a lot better I think!

That's a great looking image you have there-well done indeed. I don't use the software you do in processing. In StarTools there is a module called LENS to help remove coma and also the module called REPAIR.

Cheers,
Steve

[Shaun_Astro]

1 hour ago, SteveNickolls said:

That's a great looking image you have there-well done indeed. I don't use the software you do in processing. In StarTools there is a module called LENS to help remove coma and also the module called REPAIR.

Cheers,
Steve

Thanks! Lightroom has a manual lens profile function, I used a tad of this, but enough to remove the coma completely warps the diffraction spikes and looks bad. My coma corrector arrived today, hopefully it wont do the same!

[DarkD]

Hello guys,

several months without imaging, and finaly last july during a week in the south of France I had the opportunity to play again with my setup... altaz of course

Unfortunately we had clouds and lots of wind and the 400mm aperture doesn't like it !!

Here are some pictures  taken the last 2 nights...

clear skies

 

Not enough time exposure but the signal is here anyway

Edited August 14, 2017 by DarkD

[Filroden]

23 hours ago, DarkD said:

Here are some pictures  taken the last 2 nights...

Those are lovely. There sure are some nice advantages to a fast wide aperture! Though there are probably just as many disadvantages

[happy-kat]

What a light bucket you are using, particularly like the first image.

[geopopescu2000]

Hello i have a question if someone can help me.

i Have an Skywatcher 120/600 with an ALt az Goto Mount. Also an Sony A7 and SOny A6500 and my question is if i can take picture with long exposure without star trails. I tried but my mount doesn`t track well and i thought i don`t know how to use it.

Thanks

[Cornelius Varley]

1 minute ago, geopopescu2000 said:

Hello i have a question if someone can help me.

i Have an Skywatcher 120/600 with an ALt az Goto Mount. Also an Sony A7 and SOny A6500 and my question is if i can take picture with long exposure without star trails. I tried but my mount doesn`t track well and i thought i don`t know how to use it.

Thanks

You asked the same question in this thread