Color CMOS processing

[69boss302]

One thing Ive noticed, is that looking on youtube and other web pages, processing DSO images has mainly been gray scale with filters.  With some really good OSC cameras on the market today, they are becoming more prevalent. I recently got a 2600MC pro OSC since Im just starting out. I figured Id keep it simple with no filters etc.  Using AA+ for my shooting plan, the images look amazing! It does a live stack as the images roll in and the end result was fantastic.  Well I remove the USB drive and load them in to my PC and they dont look anything like what I saw on the ipad. 

I run them through Deep Space Stacker and that made them worse.

So I guess my question is.... With a decent color OSC what is good stacking/processing software, or are there an decent videos out there that dont assume Im gray scale with a bunch of filters? Id love to process what I have so it looked as good as it did on my ipad.

Thank you!

bob

 

[GoldTop57]

Bob - I've found Siril to be very good for stacking.

[scotty38]

There is a lot to this of course but I assume the iPad was showing you a debayered and stretched image which the raw fits will not be. Until they are debayered they are mono images as such. Are you using calibration frames too?

[Budgie1]

As @scotty38 says, the image straight out of DSS isn't stretched, so you won't see many stars and little to nebulosity or galaxy (if that's what you're imaging). 

Once stacked, it needs to go through post-processing using software like GIMP, Photoshop, PixInsight, StarTools, Astro Pixel Processor and others. This is where the "magic" happens!

If you want to upload one of your stacked files straight out of DSS (in FITS or TIFF format) then we can have a look and see whether the debayer is correct in stacking and also show what it can look like after post-processing.

If you have PhotoShop then here's a basic tutorial I used when I started: https://www.astropix.com/html/processing/digtechs.html

[69boss302]

2 hours ago, GoldTop57 said:

Bob - I've found Siril to be very good for stacking.

Thank you! I have played with that and like it very much. I do have a couple of quirks with it...for example saving my image I need to do it in 16 bit tiff, because if I save it as 32 bit, it looks terrible for some reason.  Also my snapshots that are in my 'working directory' are nowhere to be seen! But other than that, I have had good luck, thank you for the recommendation.

bob

[69boss302]

1 hour ago, scotty38 said:

There is a lot to this of course but I assume the iPad was showing you a debayered and stretched image which the raw fits will not be. Until they are debayered they are mono images as such. Are you using calibration frames too?

That is correct, and yes I took all my calibration frames too.

[69boss302]

7 minutes ago, Budgie1 said:

As @scotty38 says, the image straight out of DSS isn't stretched, so you won't see many stars and little to nebulosity or galaxy (if that's what you're imaging). 

Once stacked, it needs to go through post-processing using software like GIMP, Photoshop, PixInsight, StarTools, Astro Pixel Processor and others. This is where the "magic" happens!

If you want to upload one of your stacked files straight out of DSS (in FITS or TIFF format) then we can have a look and see whether the debayer is correct in stacking and also show what it can look like after post-processing.

If you have PhotoShop then here's a basic tutorial I used when I started: https://www.astropix.com/html/processing/digtechs.html

Martin, thank you for this! I will absolutely watch this! When I get home from work I will try and upload a stacked image to see what can be done with it Thank you!

 

[69boss302]

Autosave.tifOK here is one of my files. I stacked them in  Deep sky stacker, but not sure if I even did that right    50 lights, 100 bias and I think 5 darks.  When I bring it into Siril, I dont have any luck at all      I absolutely have to adjust my field flattener still, it looks like its too close to the sensor, but every night I get it a little closer.

Would love to see what you guys can do with this! Itll help me determine if I need to improve shooting or processing.... (or both).

Thank you!

bob

 

[AKB]

1 hour ago, 69boss302 said:

Would love to see what you guys can do with this

Just very quickly passing over the data (which has pretty severe background and vignetting, so I don't think flats have worked) ...

Tony

 

[69boss302]

Wow thats far better than I got out of it. Care to share your flow, or your apps used? And yes, this was my second night out taking pictures ever!!!! For being my 2nd night I am pretty happy to be honest. Im slowly dialing it in   Thank you for this, I like it a lot. I need to learn the technique.

bob

 

 

[69boss302]

@AKB , after looking at the file and processing it, do you care to make any recommendations on how I capture?  Longer light frames? Shorter? I know I need more of them, this was only about 5 hours worth.  Clearly I need to improve my dark/flat/bias frames as well as my flattener alignment.

 

[AKB]

1 hour ago, 69boss302 said:

Care to share your flow, or your apps used?

I’m certainly no expert, and I happen to use PixInsight, but there are plenty of others to choose from.  The workflow I used was extremely simple, just to give an impression of what’s there.  Your basic acquisition seems OK, apart from the back focus to your field flattener, but you know that already.

• colour calibration
• background subtraction
• mask and stretch (including saturation)

Mono with filters is mostly just extra hassle to combine them in the first place, so almost everything you see about processing in general should be just as applicable.  My biggest concern, and opportunity for improvement, would be in the correct acquisition and application of flats.

Having said that, for someone starting out, you seem to be doing exceptionally well (and having a good camera does help.)

Tony

 

PS: I used to live in Brookfield CT, near Danbury, and worked in Ridgefield.  Beautiful place, especially this time of year.

Edited November 17, 2021 by AKB

[69boss302]

@AKB Appreciate the kind words!  I do see a lot of good results from people with Pixinsight, maybe I need to put down the money for that, even though its a little spendy. But when comparing it to the investment in the gear, it seems trivial.  Thank you for the tips, I really appreciate it. 

I do need to work on my flats/darks.  They turn in to a single .fit file, which I suppose is OK, then I import them into DSS as that single file.

Ill watch some youtube videos on Pixinsight and see how that works. 

Bob

 

[scotty38]

PixInsight has a free trial but it's certainly a different way of doing things but there are hundreds of tutorials all over the place, my favourite being Adam Block so worth having a look at his videos. I too looked around at what to use and could see that fantastic images were possible using PixInsight so that's why I stumped up for it. I have touched maybe 1% of its capability but at least I know it's only me letting me down rather than the software 🙂 🙂

[69boss302]

24 minutes ago, AKB said:

 

 

PS: I used to live in Brookfield CT, near Danbury, and worked in Ridgefield.  Beautiful place, especially this time of year.

I just noticed this!  You sure made a substantial move to the UK!!!   This is a beautiful place this time of year, and nice and dark!!

[AKB]

24 minutes ago, 69boss302 said:

You sure made a substantial move to the UK!!!

No, no... it was a substantial move from the UK.  CT was lovely, certainly nicer than TX where I was for 5 years!

[almcl]

Bob 

Here's an alternate rendering, this time in StarTools.  Like Pixinsight, it has a trial version, but is significantly less expensive if you purchase a full licence.

I think you need to take flats and am not sure that 5 darks are actually helping, maybe try stacking without darks and see if that makes a difference?

 

[powerlord]

I'd recommend Affinity Photo. It's easy to use and learn (unlike PI), it's cheap (unlike PI), and it's imho just as powerful, arguably more so. Certainly I forced myself to try PI (yuck yuck yuck), went through the tutorials, etc.. and sure you can get good results with PI. I then went and did the same images in affinity using the techniques in the tutorials - and got the same results if not better. Oh and you can just download a trial - rather than having to persaude a bunch of backwards paranoid mathematicians you are a real person before they bless you with an evaluation licence.

you may pick up a slight bias I have here.. sorry about that, but I have no time for PI at all at any level. It's truly abysmal software from a UI/UX viewpoint, from a 'devs are all mental' viewpoint, from a licencing model viewpoint, and from a cost viewpoint IMHO.

Don't feel you need to get sucked into it just because others are doing it is all I'd say, it's use is not required to create top level images by any means. Just my 2c.

 

[ollypenrice]

I like AstroArt. I've used it for stacking and calibrating for over a decade and find it intuitive and fast. (The 'fast' bit really matters with CMOS cameras and their huge number of short subs.)  It gives great results with an ASI2600C like yours, though in our case there is always a colour gradient which follows the camera, not the sky. It's a red-green imbalance across the chip which is easily dealt with using PI's ABE.

Olly

[69boss302]

53 minutes ago, powerlord said:

I'd recommend Affinity Photo. It's easy to use and learn (unlike PI), it's cheap (unlike PI), and it's imho just as powerful, arguably more so. Certainly I forced myself to try PI (yuck yuck yuck), went through the tutorials, etc.. and sure you can get good results with PI. I then went and did the same images in affinity using the techniques in the tutorials - and got the same results if not better. Oh and you can just download a trial - rather than having to persaude a bunch of backwards paranoid mathematicians you are a real person before they bless you with an evaluation licence.

you may pick up a slight bias I have here.. sorry about that, but I have no time for PI at all at any level. It's truly abysmal software from a UI/UX viewpoint, from a 'devs are all mental' viewpoint, from a licencing model viewpoint, and from a cost viewpoint IMHO.

Don't feel you need to get sucked into it just because others are doing it is all I'd say, it's use is not required to create top level images by any means. Just my 2c.

 

@powerlord  I can tell you're really on the fence here, when you make a final decision, let me know!!!      Funny you mention the licensing thing. When I went to their web site even that was confusing and the needing to apply for a license was a little off-putting.  Ill definitely take a look at Affinity, thank you for the recommendation.

Bob

 

[69boss302]

1 hour ago, almcl said:

Bob 

Here's an alternate rendering, this time in StarTools.  Like Pixinsight, it has a trial version, but is significantly less expensive if you purchase a full licence.

I think you need to take flats and am not sure that 5 darks are actually helping, maybe try stacking without darks and see if that makes a difference?

 

Wow, also a beautiful result! (Will I get kicked out of here if I say its a 'stellar' result?)   I will look at that software as well. And thank you for taking the time to show me the image's potential. With the processing you guys have accomplished really makes me see I need to make more adjustments!

bob

 

[The Lazy Astronomer]

1 hour ago, powerlord said:

rather than having to persaude a bunch of backwards paranoid mathematicians you are a real person before they bless you with an evaluation licence.

Haha. I'm currently trialling Pixinsight, and to be honest I quite like it actually, but I know what you mean about applying for the licence - it seems a little OTT.

@69boss302: on the subject of darks and flats, you may even be able to get away without them entirely with the 2600mc (how's your vignetting and dust bunny situation?). There's a guy on here (can't remember his username right now) who uses that camera with no calibration frames and seems to get good results. Just worth bearing in mind as sub optimal flats can introduce more problems than they correct. 

[Budgie1]

I had a go with PixInsight this evening and came up with the image below.

First off, I would try to get the back focus correct to get the stars equal across the image, which you know about already.

Calibration frames:

• Darks: You may not need them with this camera but try stacking both with & without Darks to see what difference it makes.  You can take Darks at any time. The beauty of these cameras is they don't need to be on the scope to take darks. When it's cloudy, that's when you start making a Darks Library. Cool the camera to the same temp you have it at for imaging, cover the sensor with a dark cover and take sets of images to match the exposure lengths you're likely to use. I normally take 20-30 frames for each set. Once you have these, you can simply re-use them.  
• Flats: Looking at the vignetting on this image, I think flats would be worth trying to eliminate this. Again, 20-30 frames is my normal amount.
• Dark-Flats & Bias: Some cameras need these, others don't. Have a look around the forum to see what others are using with the ASI2600MC. I use the ASI294MC Pro and I don't use Bias frames, but I do use Dark-Flats. Sometimes it's just a case of trying it to see what works best for your setup.

Overall, the focus is good, there is colour in there and you'll get more detail coming through with more time on the target.

Software wise, I have used PhotoShop CS3, PixInsight and StarTools. I find I get the best results from PixInsight, with the occasional final tweak in PhotoShop. All I would say is; look at all the recommendations, try them out if they offer a free trail, and see what works best for you. This is a hobby and should be enjoyable, if the post-processing becomes a chore because the software is too complicated then that's not the right software for you.

[rickwayne]

I haven't seen anyone mention Astro Pixel Processor, which has a really straightforward workflow, and fewer knobs and levers than PixInsight. PI is still the class of the industry, but IMO APP is going to be hella easier to learn. Gradient/light-pollution removal in particular is simply amazing, and amazingly easy. It's also unsurpassed at doing mosaics.

APP also has a free trial for a month.

[powerlord]

I like APP, I really do. And it's available for mac. What I don't like it it's 200 quid* price tag for a stacker. When it's up against DSS which is free. Obviously that pricing model works for them, but it doesn't work for me. When a professional image editor (affinity) costs 60 quid (AND has a stacker).

At 30-40 quid... startools money,  I'd have bought it.. but for 200 quid, they can run and jump. Clearly they see themselves competing with PI.. but I don't see it myself - it's a powerful stacker with some frills (mosaics, background tidy, etc) . And when that competition is also really, pretty good - you've got to wonder where they get off on charging 200 squid imho.

*im ignoring the 'renters' aka subscription price as I hate them with a passion.