The "No EQ" DSO Challenge!

[The Admiral]

There are some StarTools video tutorials here: https://www.youtube.com/user/StarToolsAstro?feature=watch

Ian

[happy-kat]

StarTools loves flats they make a huge difference in image I find. After cropping I like to bin.

[happy-kat]

Yesterday went to Amazon to look at ' Joseph Ashley, "Astro-photography on the Go Using Short Exposures with Light Mounts" ' and it was £7 something for Kindle edition. So today as on the PC go to same link and it is now £14 for the kindle edition. Think it will have to wait.

[parallaxerr]

Ah that's a shame Kat, I got it @ £7, maybe it will come down again. I've noticed kindle book prices jumping around before.

[Goldigger]

I've been watching this thread with great interest, some lovely photos here.

I've just bought a Celestron 6 Evo. Would love to take some astrophoto's but don't have a DSLR. What do I need to look for in a DSLR? Don't want to buy the wrong camera...

[happy-kat]

A flip screen would be handy, not essential but handy. I chose Canon because of great open connectivity and support. I control my dslr from my 7 inch android tablet as I don't have a laptop. If buying second hand Canon 450d and above has rear screen. 600d and above have flip screen.

You can buy nice old lenses to use with the camera (with adaptor) second hand, quite a few of the images on this thread are from camera and lens.

Edited October 8, 2016 by happy-kat

[Herzy]

This was 76 minutes from an AT72ED mounted on a SLT mount. It was 15 second exposures and my computer couldn't handle the amount of files I took in RAW form, so I had to use JPEG. This was just mainly a test with my alt/az while my EQ was packed away ready to move houses. I had to crop in really bad because my AT72ED is giving oblong stars in the corner. Speaking of the AT72ED, the CA is really easily corrected. I used a few methods to remove it on the bright star in the middle and it was gone in seconds. It did leave a few aberrations that I had to blur out, but that was still really easy to fix.

Overall, I've found imaging with an altaz MUCH easier. Other than hundreds of files that I have to work with, it works great for short exposures. I'm worried about imaging really faint objects, however, because the read noise will probably overwhelm the object signal. It isn't a beautiful image, but It's not too bad.CC is welcome!

Edited October 9, 2016 by Herzy

[The Admiral]

I'd be very happy with that Herzy. Good luck with the house move!

Ian

[SteveNickolls]

12 hours ago, Goldigger said:

I've been watching this thread with great interest, some lovely photos here.

I've just bought a Celestron 6 Evo. Would love to take some astrophoto's but don't have a DSLR. What do I need to look for in a DSLR? Don't want to buy the wrong camera...

Hi, I would +1 what happy-kat said. Canon cameras are well used in the astro-imaging community. However 'The Admiral' here has what I would consider a superior Fuji DSLR with a better native red light response and no usual Bayer array. However he has a convoluted process to perform each time he images.

Going back to the Canon DSLR's the articulated 'Live View' screen on the Canon 600D  has proved very helpful when framing images when the telescope is positioned at odd angles. The 700D saw the introduction of a touch sensitive 'Live View' screen and also has a setting allowing a red background as a night view and the more recent 750D has wi-fi control. I can see the usefulness and application of the touchscreen capability for changing settings in the dark, red back ground and the wi-fi ability. I think all of the more recent (and reasonably cheap) Canon's have wi-fi capability. Perhaps go on Jessops site or similar and do a comparison? Astronomiser still sells a range of the new Canon cameras modified to allow a more sensitive hydrogen alpha capture but I recall he has stopped recently doing mods of sent in cameras.

Perhaps a pertinent consideration affecting your choice of equipment will be the option of some 'remote control', whether by wire or wirelessly over proceedings. I'm currently investigating options for controlling my 600D 'at a distance', and while we Alt-Az imagers tend to have to physically set up our gear each session our control of camera/mount will at best be partially manual. However imaging and controlling the Alt-Az mount can be partly remotely done with the definite benefits such as being able to review each light frame as it's taken in Back Yard EOS, or using an suitable android tablet (with DSLR controller) to have a larger 'Live View' screen for focus control than using the 3" one on the camera. I'm still undecided over adding more technology to something that works manually but it's fun finding out. I'm going to see if I can contact Guy-BackYard EOS (BYEOS) to ask when BYEOS will have compatibility with Stellarium and if it will enable Alt-Az mounts to be controlled through BYEOS.

Good luck with your choice of camera.

Cheers,
Steve

Edited October 9, 2016 by SteveNickolls

[alacant]

On 7/10/2016 at 16:26, happy-kat said:

After cropping I like to bin

Hi. For me it's not so much a preference, more a necessity. Unless you've a top end gaming machine with oodles of RAM, it's the only way to get stacked and processed before xmas! No but seriously, it's not just StarTools. I'm sure processing raw images takes a lot of computing power no matter what you use.

[Stub Mandrel]

1 hour ago, alacant said:

Hi. For me it's not so much a preference, more a necessity. Unless you've a top end gaming machine with oodles of RAM, it's the only way to get stacked and processed before xmas! No but seriously, it's not just StarTools. I'm sure processing raw images takes a lot of computing power no matter what you use.

Just for comparison, I've got a quad-core 3.4 GHz machine with 8gig of RAM, which although it sounds impressive is far from exceptional these days. As an experiment, I've just done a stack of 159 lights, 154 darks, 36 flats and 70 bias frames from two sessions. DSS took 1 hour and 18 minutes, hardly instant but worth the wait for three hours imaging time.

[parallaxerr]

4 hours ago, Stub Mandrel said:

Just for comparison, I've got a quad-core 3.4 GHz machine with 8gig of RAM, which although it sounds impressive is far from exceptional these days. As an experiment, I've just done a stack of 159 lights, 154 darks, 36 flats and 70 bias frames from two sessions. DSS took 1 hour and 18 minutes, hardly instant but worth the wait for three hours imaging time.

I've just had to buy a 12GB triple channel kit for my i7-940 quad-core. Star tools is the first program that's maxed out my current 6GB!

Edited October 9, 2016 by parallaxerr

[parallaxerr]

Forecast clear, clouds slowly disappearing, flats in progress, fingers crossed...

[Herzy]

You should try putting a blanket over the setup while taking flats. There is probably a lot of stray light getting in that will effect the accuracy of the flats.

[parallaxerr]

Yeah the lights went off and the blinds were closed for exposures, this was just for show

Edited October 9, 2016 by parallaxerr

[parallaxerr]

Had a reasonably clear last night so had a second stab at M31.

I've got to grips with the Auto Two Star alignment via camera live view much better now. I found a grid overlay option which allows me to put the alignment starts absolutely central  and I then carried out a precise goto align on Mirach as suggested by the mount. After slewing to M31 I took a few subs to confirm alignment and it was very good.

I stepped up to 30secs exposure this time as per Ians suggestion, accepting that I would lose some subs to trailing. In total I captured 225x30s lights + 50x30s darks. Flats and dark flats were carried out prior to lights, 50 of each.

Total light frame capture was limited due to physical camera/mount interference at 60° Alt. My setup is still tail heavy so come payday I'm planning on getting an ADM dovetail to shove the whole lot forward so it balances better and will increase available alt. I did note however how the mount accelerated in alt later in the session and field rotation got faster.

Threw the whole lot into DSS about 11pm and went to bed. Had my stack waiting this morning so put it through ST and got the image below. Much better than last time, calibration frames certainly reduced gradients & vignetting. Still finding ST a little clunky, so just got a trial licence for PixInsight and will have a play with that over the next month or so.

 

[The Admiral]

Well done Jon, a successful first attempt with Alt-Az imaging. Your stars are point-like, which is great. M31 looks a little odd to me though, as though you've used a mask for the central area. I feel that with the tightness of stars and the number of subs, this image should have a lot more to give, even with StarTools. It does take quite a while to get familiar with it though, so don't give up on it. PI is I'm sure great, but it comes at a significant price and by all accounts demands an even greater learning curve than ST. Give it a try and see what you think, but either program will take some while to master and give you what you want. Ken (Filroden) has gone down the PI route.

If you were interested you could perhaps post the FITS file from DSS into a drop-box for others to see what lurks in your data. From looking at many of the offerings on this site it does seem to me that the image processing is as critical a part as getting the data in the first place, so it would be a pity if you are not getting the most out of your image. Knowing what is achievable is part of the mind-set.

Ian

Edited October 10, 2016 by The Admiral

[parallaxerr]

1 hour ago, The Admiral said:

From looking at many of the offerings on this site it does seem to me that the image processing is as critical a part as getting the data in the first place

Agreed. As it happens I came across this post just after posting my image...

Although it was taken on an EQ mount with a little more aperture and longer subs, it's only about 60% of the exposure time of my attempt. Definitely think there's more processing required. One issue I find with my images is a complete lack of colour, they're almost B&W after stacking.

Also, some peoples images show far more detail than mine post stacking, before being processed?

EDIT: Just re-visited my RAW light frames and I've noticed a good proportion have cloud cover. I didn't notice last night when adding them to DSS. I assume DSS rejects these, is there a way to find out how many were actually stacked?

 

Edited October 10, 2016 by parallaxerr

[Filroden]

That's a really good improvement and just shows what flats can do to simplify processing. I think you've probably over-developed the image again, with the background looking very black, suggesting you've lost a lot of the fainter detail around the arms. I'd be expecting to see much more detail for almost two hours of integrated image. I believe DSS scores each image and you can set what % of images you take through stacking or you can manually deselect images. I don't know if it has an option to reject subs with scores less than a certain score, etc.

I was also surprised by the lack of colour. With 30s subs you should not be saturating your stars. I wonder if you're missing a setting in either DSS or StarTools that is not debayering the subs correctly?

It's always worth taking a single sub through a basic stretch. I've not used Gimp but I assume it has a levels function similar to Photoshop. If you load a single image and move the mid-point to the left (towards the black) until the image starts to appear, you should see what sort of detail/colour you could expect in your finished integration. If you're not seeing colour in the stars in the single sub then I suspect the RAW file is not being handled correctly. If you are seeing colour, then something is stopping it from carrying over into the integrated image. I've not used DSS for such a long time now that I can't help much more.

As Ian said, I moved to Pixinsight for my stacking and processing. It has a very steep learning curve (I've had to read full books and follow pages of tutorials just to get to where I am) but it suits the way I think about an image more than DSS with StarTools or Photoshop. This is the single best tutorial I found: http://www.lightvortexastronomy.com/tutorial-example-m31-andromeda-galaxy---dslr.html and the bonus is that it used M31 as its subject and images from a DSLR so everything should be applicable to your images. It takes many hours to run the full tutorial and the first few times I was following it blindly not knowing when or by how much to tweak some of the settings, but I still saw a noticeable improvement in my images compared to levels/curves adjustments in Photoshop.

[parallaxerr]

18 minutes ago, Filroden said:

I don't know if it has an option to reject subs with scores less than a certain score

Yes there is Fil, I've just found it and I am re-stacking with frames under a score of 1000 ignored.

18 minutes ago, Filroden said:

I was also surprised by the lack of colour. With 30s subs you should not be saturating your stars. I wonder if you're missing a setting in either DSS or StarTools that is not debayering the subs correctly?

Definitely think I'm missing something. After developing and wiping in ST I've got a B&W image. Not sure if it's DSS or ST settings that I need to adjust, will have to play around a bit. ST does offer 3 options on loading a new image that mentions debayering so will look there.

Also, ST wont open the autosaved TIFFs from DSS, but WILL open a TIFF if I save it manually. However, in the latter case the file size is about half?

[Stub Mandrel]

DSS seems to judge frames on how round the stars are and how many stars it finds. You set a percentage of best frames to stack.

You tell DSS the percentage to stack. I get rid of obviously cloudy or otherwise spoilt subs and then tell DSS to stack the best 90% of the rest.

If you untick 'register previously registered frames' it will be a lot faster second time around.

[happy-kat]

Please you should only be using the autisaved fits file in startools. The autosave tiff file IS compressed.

[parallaxerr]

1 minute ago, happy-kat said:

Please you should only be using the autisaved fits file in startools. The autosave tiff file IS compressed.

ST won't open it for some reason, says it's incompatible?

[happy-kat]

I have a feeling the DSS settings used are not optimised for startools, this has been covered, haven't got a link handy.

[happy-kat]

Ignore tiff file(s), only use the autosave fits file