Help a Niall. Free Image file!

[wimvb]

2 hours ago, Mr niall said:

Having said that I think maybe putting the money towards investing in a new camera might be the smarter choice! 

That sounds like a good idea. I don't know if large LP filters, similar to daytime UV filters, are available. They might be expensive.

A few years ago, I was in very much the same position as you are now: where to go from here? In my case, I was stuck with an old dslr, that wouldn't connect to a computer anymore, and a mount that leaped like a frog. I bit the proverbial bullet(s), and first invested in a better mount, and later in a better camera. Both investments improved my data considerably. My latest investments, moving to a dark site and building an obsy, had the same impact, but are probably out if reach for many. What can I say, I was a lucky punk. (to paraphrase Dirty Harry)

In the end only you can decide how large investments you can make, or justify. But this hobby does cost, no point denying that. 

Edited April 8, 2020 by wimvb

[jager945]

34 minutes ago, Mr niall said:

Yep did that, not sure what your point is there. With the exception of flats, which I didn't believe I needed at 40mm, everything else was done (including a restack with intersection selected on DSS) I would be amazed if they transformed the situation.

If you'd like to explain to me a good dithering procedure for a 15 year old DSLR with a wide angle lens mounted on a clockwork timer then I'm all ears.

That was literally the point of my post; if it isn't any good then I was hoping for advice on perhaps what was causing the issues I was experiencing. The post is even called "Help a Niall" for goodness sake.

Thanks for being both patronising and condescending. Believe it or not I've been trying to do this for nearly three years with little success. But it is reassuring to know that one quick look at my work is enough for you to make an assessment along the lines of "they've never done this before / or they've no idea what they're doing". Cheers for that. If the solution is to chuck a couple of thousand pounds at mounts at camera's then I'm not really any better off than I was to start with.

Working with good data is easy. I cant get good data. I don't know how to get good data. I don't know why my data isn't good. That's why I'm asking for help. If you'd read my post then you'd see that.

Again - that was literally the point of my post. If I knew what the problem was, I wouldn't be asking for help. That was the point of my post.

Yeah… not sure you how you think you achieved that. Patronising comments aside you haven't actually said anything other than "your data is rubbish". I'm already at "endless frustration", and I'm following the guidance, repeatedly.

WHAT ISSUES!!!????

BTW - I did enjoy the irony of "here's a nice version of your picture - but I'm not going to show you how to do it because you're not good enough yet to deserve it". 

Well thanks, that's me feeling like an idiot again. I'll pack the camera away and try again in another few months. If the sum total of the advice is that I'm either useless or an idiot then that advice probably would have been more useful 3 years and several hundred hours of frustrated effort ago. It's not easy asking for help when are clearly so far behind what nearly everyone else seems to be able to achieve, and believe me I doubt many are "trying harder". 

Your post is probably the most demoralising thing I've ever read. Good work.

I sincerely hope you will re-read my post. It was made in good faith and answers many of your questions and concerns directly or through concise information behind the links.

To recap my post; a great deal of your issues can likely be alleviated by flats, by dithering (giving your camera a slight push perpendicular to the tracking direction between every x frames will do) and using a rejection method in your stacker.

If that is not something that you wish to do or research, then that is, of course, entirely your prerogative. Given your post above, it's probably not productive I engage with you any further at this time.

[Skipper Billy]

@Mr niall  Can we go back to basics.  Can you post a single sub straight from the camera - no processing of any kind. Then we can see if the banding is present on a single sub ie is the problem the camera or the processing. Then we can move forwards. I am no expert but will gladly help if I can.

[Mr niall]

1 hour ago, jager945 said:

I sincerely hope you will re-read my post. It was made in good faith and answers many of your questions and concerns directly or through concise information behind the links.

To recap my post; a great deal of your issues can likely be alleviated by flats, by dithering (giving your camera a slight push perpendicular to the tracking direction between every x frames will do) and using a rejection method in your stacker.

If that is not something that you wish to do or research, then that is, of course, entirely your prerogative. Given your post above, it's probably not productive I engage with you any further at this time.

Yes I'm sure your info probably was well intentioned. My results do actually suggest a 9 year old with a polaroid took them, the fact they were taken by someone with hundreds of hours of reading and practice under their belt doesn't change the fact that they are total garbage. I will review thanks.

[wimvb]

24 minutes ago, Skipper Billy said:

@Mr niall  Can we go back to basics.  Can you post a single sub straight from the camera - no processing of any kind. Then we can see if the banding is present on a single sub ie is the problem the camera or the processing. Then we can move forwards. I am no expert but will gladly help if I can.

I agree with that. I recently saw a post (can't remember where, not necessarily here), where the culprit was the micro sd card. In other cases, usb connections and power cables were found to create artefacts. None of these causes are easy to diagnose. But any hardware issues must show up in single subs.

[Mr niall]

43 minutes ago, Skipper Billy said:

@Mr niall  Can we go back to basics.  Can you post a single sub straight from the camera - no processing of any kind. Then we can see if the banding is present on a single sub ie is the problem the camera or the processing. Then we can move forwards. I am no expert but will gladly help if I can.

@Skipper Billy@wimvb

Yes good thinking - I decided to cut out the middle man and stretch the master dark. The results show the banding. I'll try some darks with another SD card. Added a raw raw too.

 

 

darkstretch.bmp P1080921.RW2

Edited April 8, 2020 by Mr niall

[alacant]

8 minutes ago, Mr niall said:

cut out the middle man

Hi again. @Mr niall. Just to clarify... On this thread, there are now two clean images of the data. One of those has details of how it can be processed. Are we perhaps now more concerned about doing better next time? IOW we're not now trying to rescue the original?

Cheers

[Mr niall]

Just now, alacant said:

Hi again. @Mr niall. Just to clarify... On this thread, there are now two clean images of the data. One of those has details of how it can be processed. Are we perhaps now more concerned about doing better next time? IOW we're not now trying to rescue the original?

Cheers

Yes I would say that sums it up. The ability to rescue the previous data was an uplifting result; but my main aim is to try and understand what caused the specific limitations of the data that I had collected with an aim to doing better in the future if possible (or having a small camera shaped bonfire as an alternative...)

 

[Skipper Billy]

OK - both the unprocessed single light and the single dark both clearly show heavy banding.

This suggests to me that there is an issue with the camera.

I will dip out now as I know nothing about DSLR's and I have heard of 'banding scripts' etc that may cure the problem but I am well outside my (very shallow) knowledge pool 😉 

[alacant]

29 minutes ago, Mr niall said:

what caused the specific limitations

Hi. OK, to help us, next I'd suggest posting a flat frame.

 

[Mr niall]

15 minutes ago, alacant said:

Hi. OK, to help us, next I'd suggest posting a flat frame.

 

I think I may have just had some success - tried a couple of flats and darks with the existing memory card and a shiny new one - shiny new one removed all banding. So it appears that problem is solved. Thanks both that was a great help 👍