M31 with 071 and Borg 77EDll

[alan potts]

I am still fighting this Borg 77ED ll which though it looks cute and pretty I am not in love with. Since last years poor efforts I have spent more time focusing and had bought a Astronomik L3  IR/UV filter for it, something quite a few suggested. Still can't say I like the results I get though. I have recently tried the PS gradients technique as outlined by Trevor Jones on Backyard. Though I didn't really spend a lot of time on the process the gradient removal for most subjects seems to work well. I have also got a LED LP filter on the way to hopefully remove some of the sky glow from the town. When I started 14 years ago you couldn't really see any light from the town at all but in recent years with low quality badly shielded LED's it does cause a small problem in the most import area of the sky SE, rising area and now where Orion is sitting. This I normally wait for it to move west of south, where it is black.

Anyway, here is 2 hours of 3 minute subs with calibration frames taken at minus 5C with a 071. Not very cold I hear you say but I have studied a number of my images at different temperature and can't see any real difference.

[michael.h.f.wilkinson]

Nice detail in that shot. The stars and core do seem to have a bit of a yellow cast. I find that gradient removal and star/background calibration in APP work pretty well. Maybe worth a shot

 

[alan potts]

3 minutes ago, michael.h.f.wilkinson said:

Nice detail in that shot. The stars and core do seem to have a bit of a yellow cast. I find that gradient removal and star/background calibration in APP work pretty well. Maybe worth a shot

 

I keep looking at APP but I do not like using cards on line. I did lift the yellow a bit may well have over egged the pudding Michael, feel guiding could have been better, which has been very up and down of late, night before last it was stunningly calm below .2 of a pixel.

Alan

[alan potts]

Toned the yellow down a shade or two.

 

 

Alan

[michael.h.f.wilkinson]

1 minute ago, alan potts said:

I keep looking at APP but I do not like using cards on line. I did lift the yellow a bit may well have over egged the pudding Michael, feel guiding could have been better, which has been very up and down of late, night before last it was stunningly calm below .2 of a pixel.

Alan

I think I paid through PayPal. You can always use the free trial to see how it works.

[michael.h.f.wilkinson]

1 minute ago, alan potts said:

Toned the yellow down a shade or two.

 

 

Alan

Definitely beter. If you could share the unstretched FITS or TIFF I could have a bash in APP, if you like, just to see what it does

[alan potts]

Just now, michael.h.f.wilkinson said:

Definitely beter. If you could share the unstretched FITS or TIFF I could have a bash in APP, if you like, just to see what it does

I will dig it out. I have used the super pixel mode in DSS to reduce the file size but it is still useable

Autosave007.tif

Alan

 

[alan potts]

Just now, alan potts said:

I will dig it out. I have used the super pixel mode in DSS to reduce the file size but it is still useable

Autosave007.tif 14.16 MB · 0 downloads

Alan

 

If anyone else wishes to have a play feel free to download it.

Alan

[alacant]

Quote

 have a play

Hi

I like it. Some lovely detail.

Edited December 8, 2020 by alacant

[alan potts]

1 hour ago, alacant said:

Hi

I like it. Some lovely detail.

How did you process it, you appear to have much smaller stars than I managed?

Alan

[michael.h.f.wilkinson]

I got some odd results in APP. Just removing gradients and its default automatic stretch give this:

This has a similar yellow cast in the stars, perhaps a bit less. If I calibrate star colours, I get this:

In which the stars may be better, but the galaxy is rather too blue. Might want to fiddle around a bit more later

[alacant]

17 minutes ago, alan potts said:

How did you process

StarTools. The latest release candidate. 

HTH

[michael.h.f.wilkinson]

Made two more versions quickly. Basically took the pixel-wise average of the two previous JPEG versions, and fiddled a little bit with curves in GIMP

Upping the saturation got me this

Should really do this in 16-bit TIFF (might do that this evening)

[geeklee]

5 hours ago, alan potts said:

Anyway, here is 2 hours of 3 minute subs with calibration frames taken at minus 5C with a 071. Not very cold I hear you say but I have studied a number of my images at different temperature and can't see any real difference.

Looking good Alan.  As mentioned, just trying to remove the yellow/green cast from the image will help a lot I think.

Just aiming to get a better colour balance (but still not the best) and removing gradients with the above TIF (PixInsight):

...and added a little more colour as mentioned below!

 

Edited December 8, 2020 by geeklee
Added a more colourful version

[alan potts]

I am amazed how many really different colour castes there are going on in one set of data and how different tools change things, PS is easy to add or remover different colours, maybe more so than any other program. I really like the version Alacant has done with the small tight stars but ideally, and only personal taste, would like a bit more colour in the galaxy. Great to see what you all do though.

As per normal, I have just received a delivery from FLO, checked the forecast and it give 8 days of rain cloud, snow and more rain.

Alan

[alan potts]

3 hours ago, alacant said:

Hi

I like it. Some lovely detail.

Can't get a single Tiff file to open in this program.

Alan

[alacant]

53 minutes ago, alan potts said:

Can't get a single Tiff file to open

Oh dear.

Are you perhaps trying to open a compressed/non linear file, such as the one you posted?

Cheers

 

Edited December 8, 2020 by alacant

[alan potts]

7 minutes ago, alacant said:

Oh dear.

Are you perhaps trying to open a compressed/non linear file, such as the OP's?

Cheers

 

I have no idea, the same file you had a play with and produced this rather nice image.

Alan

[alacant]

1 minute ago, alan potts said:

the same file

It's compressed. Save it as a pure tiff ( or better .fits) after you have stacked your frames. I converted it.

HTH

[alan potts]

8 minutes ago, alacant said:

It's compressed. Save it as a pure tiff ( or better .fits) after you have stacked your frames. I converted it.

HTH

It was just out of DSS, How can you convert them, I will try a FITS DSS stack a bit later. This free software, do you know how long it lasts?

Alan

[alacant]

38 minutes ago, alan potts said:

It was just out of DSS

So save it as .fits and avoid the DSS intervention.

 

40 minutes ago, alan potts said:

This free software, do you know how long it lasts?

Stacking? Siril. Forever.

[ollypenrice]

Colour was tricky, with rather overbearing greens in the galaxy and very red stars. There isn't a lot of colour differentiation to work with either, but that's usually a matter of integration time. I felt it was beginning to go in the right direction by the end so more data would help.

PI dealt with the background sky nicely (DBE, not too many markers) and SCNR green helped with the colour. Stars removed in Starnet++ and then replaced in Photoshop with a soft stretch used in blend mode lighten.

Olly

[alan potts]

12 hours ago, ollypenrice said:

Colour was tricky, with rather overbearing greens in the galaxy and very red stars. There isn't a lot of colour differentiation to work with either, but that's usually a matter of integration time. I felt it was beginning to go in the right direction by the end so more data would help.

PI dealt with the background sky nicely (DBE, not too many markers) and SCNR green helped with the colour. Stars removed in Starnet++ and then replaced in Photoshop with a soft stretch used in blend mode lighten.

Olly

Thanks Olly, a nice rendition as one would expect from you. You talk of integration time, any pointers of which way to go on this. The Borg is F4.3, a devil to focus and not giving the results I would expect for a scope costing close to 2000 usd, not that I paid that. It also is not ideally matched with the 071 but I do that purely for the wide field. No matter what I do you do seem to get these orange stars coming through in the images more than I would like. I have tried the two different IR/UV filter, L2 & 3 and now have a IDAS D2 filter to see if that helps with all my scopes. I have a bit of LED glow to the SE sky from the town, they call it progress. As luck would have it all other directions are free of any LP for many miles

 

I had another play about and turned it up what I feel is the right way and it does I think look a bit better

 

Thanks for you efforts  Alan

[ollypenrice]

4 hours ago, alan potts said:

Thanks Olly, a nice rendition as one would expect from you. You talk of integration time, any pointers of which way to go on this. The Borg is F4.3, a devil to focus and not giving the results I would expect for a scope costing close to 2000 usd, not that I paid that. It also is not ideally matched with the 071 but I do that purely for the wide field. No matter what I do you do seem to get these orange stars coming through in the images more than I would like. I have tried the two different IR/UV filter, L2 & 3 and now have a IDAS D2 filter to see if that helps with all my scopes. I have a bit of LED glow to the SE sky from the town, they call it progress. As luck would have it all other directions are free of any LP for many miles

 

I had another play about and turned it up what I feel is the right way and it does I think look a bit better

 

Thanks for you efforts  Alan

That's very good, Alan. Flat background and tight stars. (Always the hardest parts!) You could bring in the black point a tad, too, maybe.

My own feeling on playing with the data was that the scope had done a decent job. Stars were consistent across the frame which is the main thing. With the present post-processing tricks now available, having inherently tiny stars is no longer such an imperative. There are two things I'd want to understand better:

1) Colour. What's the camera? Unfortunately I have zero experience with LP filters so can't be of any help but maybe those used to using them could chip in.

2) The data seems to me to cut off rather dramatically around the outer part of the galaxy. There is faint galaxy to be had beyond what we are seeing here but I couldn't find it in the data. Maybe it just isn't getting through the filter, in which case more subs/longer subs might find it. (In the end I prefer your stretch to mine because you haven't chased that outer signal and I've chased it too hard.)

Olly

Edited December 9, 2020 by ollypenrice

[alan potts]

58 minutes ago, ollypenrice said:

That's very good, Alan. Flat background and tight stars. (Always the hardest parts!) You could bring in the black point a tad, too, maybe.

My own feeling on playing with the data was that the scope had done a decent job. Stars were consistent across the frame which is the main thing. With the present post-processing tricks now available, having inherently tiny stars is no longer such an imperative. There are two things I'd want to understand better:

1) Colour. What's the camera? Unfortunately I have zero experience with LP filters so can't be of any help but maybe those used to using them could chip in.

2) The data seems to me to cut off rather dramatically around the outer part of the galaxy. There is faint galaxy to be had beyond what we are seeing here but I couldn't find it in the data. Maybe it just isn't getting through the filter, in which case more subs/longer subs might find it. (In the end I prefer your stretch to mine because you haven't chased that outer signal and I've chased it too hard.)

Olly

You don't miss anything do you. First this was taken with my 071 which is of course a OSC. I am only trying this filter from IDAS as it is meant to filter out LED and in the south east I have an LED glow from the town, but nowhere else, it's just easier for me to image that way as my walnut trees reduce south west time on objects. The reason why there is the cutoff that you picked out is that I don't have any graduation software so I use the healing tool technique in PS to graduate the background, which I thought I had got away with, but not from you. So it may well be there but I could have covered it. It is a good technique but maybe this galaxy is a bit too big to use it, works a treat on smaller ones. I can easily go to 5 minute subs here and probably longer 

It could also be a tad darker so I agree with you, I tend to hurry processing and that is not a good thing,

Many thanks Alan