After weeks of setting up , bench testing and night testing I’ve finally captured some images with my new 2600MM from my City suburban Bortle 8 location.
NGC 253 Sculptor Galaxy ( Broadband ) total integration 5 hours
NGC 7293 Helix Nebula ( Narrowband) total integration 8 hours
8” f5 Klaus Helmerich Carbon fibre Newt
Skywatcher EQ6-R pro mount
2600MM camera
TS Optics GPU coma corrector
ZWO 2” EFW
Antlia 2” LRGB and 3nm Ha , Oiii, Sii filters
EQMOD and Stellarium
APT
PHD2 Multistar guiding ( guiding most nights was 0.45 to 0.60 arc sec total ) I performed more tuning on the EQ6-R pro mount ( adjusting belts , worms and main axis ) She’s tracking and guiding beautifully !!
Stacked in ASTAP
Processed in Startools V1.8 Aligned Data sets loaded via Compose
After using my 2600MC OSC for just over 3 years this Mono stuff is certainly time consuming and challenging to say the least ( what was I thinking of going down the Mono rabbit hole ?? )
I must say these images are not reflective of what Mono with dedicated filters can achieve as integration times for these dim objects are quite short.
I did find a lot of noise to deal with ( similar to my 2600MC ) but a slight improvement on exposed detail and resolution.
Early days yet !!
Some folk say that Mono takes no longer than OSC but that wasn’t the case with my first two captures and processing. I would estimate at least 3x the hours and that’s conservative.
I must admit I did expect better performance ( lower noise / higher SNR ) from the new camera and filters but integration times were quite short on those two dim test targets and I mustn’t get a head of myself. Integration time is King under heavy LP skies no matter what camera you use.
A big shout out to Mike from Rancho who helped me immensely with my stacking issues. I learnt how to use ASTAP for stacking as DSS gave me some weird artifacts which I’ve never seen before with my 2600MC OSC
Mike, I have a few more questions to ask about ASTAP and stacking multiple nights data on same object.
Heading down to my dark site ( Dome ) next week for 2 weeks so hope to test the 2600MM under darker skies ( Bortle 3 ) unfortunately the Moon will be up so the 3nm Antlia filters can be tested under darker moonlit skies.
Thanks for looking
Clear Skies
Martin
1st Lights using 2600MM ( Broadband and Narrowband )
1st Lights using 2600MM ( Broadband and Narrowband )
- Attachments
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- NGC 253 Sculptor Galaxy LRGB rev 4.jpeg (303.64 KiB) Viewed 14273 times
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- NGC 7293 Helix Nebula rev 2.jpeg (683.76 KiB) Viewed 14273 times
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Mike in Rancho
- Posts: 1166
- Joined: Sun Jun 20, 2021 10:05 pm
- Location: Alta Loma, CA
Re: 1st Lights using 2600MM ( Broadband and Narrowband )
Sweet images, Martin. You can't complain about these as your first "final" photos using a new camera, new stacker, new compositions to learn...
At first glance, the Sculptor seems to lean a bit to the purple side (I have experience with this myself), and in both shots the stars strike me as too bleached out. Undetermined at the moment whether that's just processing choices or something we can chase down as to cause.
In theory, the mono acquisition should get you more efficient, and more pixel accurate, images for the same amount of integration time vs OSC. But in practice there are just so many possible factor involved. But the 2600MC is no slouch of an OSC, and Bayer interpolation can often be quite good. I particularly like ASTAP's astro-simple algorithm. With DSLR I remember doing a comparison once on the Rosette with (I think) ASTAP astro-simple and bilinear, and DSS superpixel and Bayer drizzle, and the astro-simple was the cleanest.
What were the acquisition particulars? One key to mono efficiency is to capture in a 3:1:1:1 ratio for total integration. That really helps rack up the pure luminance detail. Set Compose to match the filter exposure total time, if you want to do L+Synth L, but you can even change that up a bit if you feel it is not reflective of the SNR each filter file is giving you.
Likewise, per-sub exposure time can be captured at similar ratios. In most cases with broadband, I am using 60s subs for RGB, which saturates some pixels but usually not too many. And then for L I take those at 30s. Though really I probably should be taking L at 20s, to match that one versus three ratio and have (ballpark) similar pixel blow-out on every sub.
I have also just always used gain 0 offset 30 for everything, even though some 2600 users seem to prefer gain 100 and claim it has less noise. While the dynamic range in stops is similar, there's still a matter of the full well, and I just really don't want to burn out star cores or take even shorter (and more) subs than I already am.
At first glance, the Sculptor seems to lean a bit to the purple side (I have experience with this myself), and in both shots the stars strike me as too bleached out. Undetermined at the moment whether that's just processing choices or something we can chase down as to cause.
In theory, the mono acquisition should get you more efficient, and more pixel accurate, images for the same amount of integration time vs OSC. But in practice there are just so many possible factor involved. But the 2600MC is no slouch of an OSC, and Bayer interpolation can often be quite good. I particularly like ASTAP's astro-simple algorithm. With DSLR I remember doing a comparison once on the Rosette with (I think) ASTAP astro-simple and bilinear, and DSS superpixel and Bayer drizzle, and the astro-simple was the cleanest.
What were the acquisition particulars? One key to mono efficiency is to capture in a 3:1:1:1 ratio for total integration. That really helps rack up the pure luminance detail. Set Compose to match the filter exposure total time, if you want to do L+Synth L, but you can even change that up a bit if you feel it is not reflective of the SNR each filter file is giving you.
Likewise, per-sub exposure time can be captured at similar ratios. In most cases with broadband, I am using 60s subs for RGB, which saturates some pixels but usually not too many. And then for L I take those at 30s. Though really I probably should be taking L at 20s, to match that one versus three ratio and have (ballpark) similar pixel blow-out on every sub.
I have also just always used gain 0 offset 30 for everything, even though some 2600 users seem to prefer gain 100 and claim it has less noise. While the dynamic range in stops is similar, there's still a matter of the full well, and I just really don't want to burn out star cores or take even shorter (and more) subs than I already am.
Re: 1st Lights using 2600MM ( Broadband and Narrowband )
Hi Mike,
Thanks for the encouraging comment
My Lum subs for Sculptor Galaxy were 90 sec which is probably the reason why stars are bleached ( histogram was off the Richter scale ) Wasn’t thinking that night , should have opted for 60 sec or even 30 sec
Yes your correct about Galaxy colour , a tad to purple
To be perfectly honest, I have more control over colour with my 2600MC shooting broadband, it should be the reverse using Mono and dedicated filters
Good advice about LRGB broadband integration 3:1:1:1
Narrowband integration is obviously based on type of object, brightness and emissions.
I’ve tried Gain 0 vs Gain 100 using my 2600MC under both Bortle 8 and Bortle 3 ( broadband and narrowband)
Under Bortle 8 , Gain 100 is less noisy for both BB and NB
The difference in DR from 0 to 100 is less than 2 stops so not a big sacrifice, although full well at Gain 0 is better for exposure times
In regards to ASTAP and Alignment, I tried your option 1 which worked well but your option 2 , the latest version of ASTAP doesn’t have the Export align button ?
So just sticking with your first option.
For stacking and aligning multiple nights data ( could be a month or two apart in capture ) in ASTAP with same filter for Startools Compose , do you have a proven procedure ?
Finally I don’t capture Darks , only Bias , which has worked well , so I’m just using Bias for Flat darks and Darks in ASTAP
Thanks again you’ve been a great help
Martin
Thanks for the encouraging comment
My Lum subs for Sculptor Galaxy were 90 sec which is probably the reason why stars are bleached ( histogram was off the Richter scale ) Wasn’t thinking that night , should have opted for 60 sec or even 30 sec
Yes your correct about Galaxy colour , a tad to purple
To be perfectly honest, I have more control over colour with my 2600MC shooting broadband, it should be the reverse using Mono and dedicated filters
Good advice about LRGB broadband integration 3:1:1:1
Narrowband integration is obviously based on type of object, brightness and emissions.
I’ve tried Gain 0 vs Gain 100 using my 2600MC under both Bortle 8 and Bortle 3 ( broadband and narrowband)
Under Bortle 8 , Gain 100 is less noisy for both BB and NB
The difference in DR from 0 to 100 is less than 2 stops so not a big sacrifice, although full well at Gain 0 is better for exposure times
In regards to ASTAP and Alignment, I tried your option 1 which worked well but your option 2 , the latest version of ASTAP doesn’t have the Export align button ?
So just sticking with your first option.
For stacking and aligning multiple nights data ( could be a month or two apart in capture ) in ASTAP with same filter for Startools Compose , do you have a proven procedure ?
Finally I don’t capture Darks , only Bias , which has worked well , so I’m just using Bias for Flat darks and Darks in ASTAP
Thanks again you’ve been a great help
Martin
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Mike in Rancho
- Posts: 1166
- Joined: Sun Jun 20, 2021 10:05 pm
- Location: Alta Loma, CA
Re: 1st Lights using 2600MM ( Broadband and Narrowband )
Hi Martin,
Well I did the same back in the beginning. I had 50 bias taken at my go-to cooling of 0°C, and so each time in ASTSAP I tossed all those into Dark Flats for use with the Flats. And I went through those steps first. Then I loaded the same files into Darks, and had it create a master dark. Since that gets saved, I then just loaded that master dark, which was really a master bias, every time for my darks. I can't remember if ASTAP complained about the exposure times not matching. Maybe. Worked anyway. Until I got tired of hot pixels, and so simply made a darks library at my handful of usual exposures.
I've been using an ASTAP from Sept 2022 and with the H18 database plus hyperleda. Just now I downloaded the latest release edition and the D50 database. For my desktop anyway. I'll maybe do it later for my laptop which is where NINA uses a Feb 2022 ASTAP for solving. Anywho, the ASTAP I just installed still has Export Aligned in the Blink tab.
Of course Han makes new versions constantly, and it looks like right now there's also a beta/development version. Maybe that one doesn't have the Export button in Blink?
But option1 works too, and that's the way I always did it myself, which also puts interesting specs in the columns and you can see which filter it chooses at the reference. I actually didn't know about option2 until a few days ago.
Unlike DSS, and a few other stackers I believe, ASTAP doesn't have a save file list, so I can't load something from the past that I new worked and see what my settings were.
The boxes you would use will depend on what data you have and how you did it. I tended to toss everything into ASTAP (all filters, all dates, each filter having its own specific flats per date) and letting it figure it out based on the boxes I checked. So if the different nights have their own flats, you would
1. Put your bias files in the Dark Flats
2. Load your flats - all of em. Check Classify by Flat Filter and the bottom and Classify by date for master creation at the top. If you only have one filter then you don't need to check Classify by Flat Filter. Hit analyze. If all looks good (no "?" in the list etc) then hit replace checkmarked by master flat with dark flats included.
3. Load darks. If exposure times are different (usually the case with L, RGB, and NB), check Classify by dark exposure time at the bottom. Classify by date for master creation would not be needed. In the future I would just load my masters for the matching exposure times needed. In your case with bias only, I don't believe you need to check anything.
4. Load lights. Check classify by Light filter. If you only have one filter then not needed. Then just analyze/organize, and if all is good, hit go (stack, with your chosen method, likely sigma clip average skip LRGB combine, or sigma clip average with just one filter.
Really that's all there is to it, and that's probably pretty much what you've already been doing. Based on your description, the only thing that needs classification is having different flats per the sessions. And for that, checking classify by date for master creation (in Flats) is sufficient. Two master flats will be generated, and they will be used to calibrate the proper lights. There is nothing extra that needs to be changed in the lights tab.
Alignment will be done automatically as part of the usual stacking process. ASTAP will pick the best sub out of all the nights as the reference, and everything will get aligned to that.
Hopefully that makes sense! I might be a bit confused by what you are meaning by "... with the same filter for Startools Compose." So, let me know whether I answered the right question.
Well I did the same back in the beginning. I had 50 bias taken at my go-to cooling of 0°C, and so each time in ASTSAP I tossed all those into Dark Flats for use with the Flats. And I went through those steps first. Then I loaded the same files into Darks, and had it create a master dark. Since that gets saved, I then just loaded that master dark, which was really a master bias, every time for my darks. I can't remember if ASTAP complained about the exposure times not matching. Maybe. Worked anyway. Until I got tired of hot pixels, and so simply made a darks library at my handful of usual exposures.
I've been using an ASTAP from Sept 2022 and with the H18 database plus hyperleda. Just now I downloaded the latest release edition and the D50 database. For my desktop anyway. I'll maybe do it later for my laptop which is where NINA uses a Feb 2022 ASTAP for solving. Anywho, the ASTAP I just installed still has Export Aligned in the Blink tab.
Of course Han makes new versions constantly, and it looks like right now there's also a beta/development version. Maybe that one doesn't have the Export button in Blink?
But option1 works too, and that's the way I always did it myself, which also puts interesting specs in the columns and you can see which filter it chooses at the reference. I actually didn't know about option2 until a few days ago.
Unlike DSS, and a few other stackers I believe, ASTAP doesn't have a save file list, so I can't load something from the past that I new worked and see what my settings were.
The boxes you would use will depend on what data you have and how you did it. I tended to toss everything into ASTAP (all filters, all dates, each filter having its own specific flats per date) and letting it figure it out based on the boxes I checked. So if the different nights have their own flats, you would
1. Put your bias files in the Dark Flats
2. Load your flats - all of em. Check Classify by Flat Filter and the bottom and Classify by date for master creation at the top. If you only have one filter then you don't need to check Classify by Flat Filter. Hit analyze. If all looks good (no "?" in the list etc) then hit replace checkmarked by master flat with dark flats included.
3. Load darks. If exposure times are different (usually the case with L, RGB, and NB), check Classify by dark exposure time at the bottom. Classify by date for master creation would not be needed. In the future I would just load my masters for the matching exposure times needed. In your case with bias only, I don't believe you need to check anything.
4. Load lights. Check classify by Light filter. If you only have one filter then not needed. Then just analyze/organize, and if all is good, hit go (stack, with your chosen method, likely sigma clip average skip LRGB combine, or sigma clip average with just one filter.
Really that's all there is to it, and that's probably pretty much what you've already been doing. Based on your description, the only thing that needs classification is having different flats per the sessions. And for that, checking classify by date for master creation (in Flats) is sufficient. Two master flats will be generated, and they will be used to calibrate the proper lights. There is nothing extra that needs to be changed in the lights tab.
Alignment will be done automatically as part of the usual stacking process. ASTAP will pick the best sub out of all the nights as the reference, and everything will get aligned to that.
Hopefully that makes sense! I might be a bit confused by what you are meaning by "... with the same filter for Startools Compose." So, let me know whether I answered the right question.
Re: 1st Lights using 2600MM ( Broadband and Narrowband )
Mike,Mike in Rancho wrote: ↑Thu Sep 21, 2023 5:51 am Hi Martin,
Well I did the same back in the beginning. I had 50 bias taken at my go-to cooling of 0°C, and so each time in ASTSAP I tossed all those into Dark Flats for use with the Flats. And I went through those steps first. Then I loaded the same files into Darks, and had it create a master dark. Since that gets saved, I then just loaded that master dark, which was really a master bias, every time for my darks. I can't remember if ASTAP complained about the exposure times not matching. Maybe. Worked anyway. Until I got tired of hot pixels, and so simply made a darks library at my handful of usual exposures.
I've been using an ASTAP from Sept 2022 and with the H18 database plus hyperleda. Just now I downloaded the latest release edition and the D50 database. For my desktop anyway. I'll maybe do it later for my laptop which is where NINA uses a Feb 2022 ASTAP for solving. Anywho, the ASTAP I just installed still has Export Aligned in the Blink tab.
Of course Han makes new versions constantly, and it looks like right now there's also a beta/development version. Maybe that one doesn't have the Export button in Blink?
But option1 works too, and that's the way I always did it myself, which also puts interesting specs in the columns and you can see which filter it chooses at the reference. I actually didn't know about option2 until a few days ago.
Unlike DSS, and a few other stackers I believe, ASTAP doesn't have a save file list, so I can't load something from the past that I new worked and see what my settings were.
The boxes you would use will depend on what data you have and how you did it. I tended to toss everything into ASTAP (all filters, all dates, each filter having its own specific flats per date) and letting it figure it out based on the boxes I checked. So if the different nights have their own flats, you would
1. Put your bias files in the Dark Flats
2. Load your flats - all of em. Check Classify by Flat Filter and the bottom and Classify by date for master creation at the top. If you only have one filter then you don't need to check Classify by Flat Filter. Hit analyze. If all looks good (no "?" in the list etc) then hit replace checkmarked by master flat with dark flats included.
3. Load darks. If exposure times are different (usually the case with L, RGB, and NB), check Classify by dark exposure time at the bottom. Classify by date for master creation would not be needed. In the future I would just load my masters for the matching exposure times needed. In your case with bias only, I don't believe you need to check anything.
4. Load lights. Check classify by Light filter. If you only have one filter then not needed. Then just analyze/organize, and if all is good, hit go (stack, with your chosen method, likely sigma clip average skip LRGB combine, or sigma clip average with just one filter.
Really that's all there is to it, and that's probably pretty much what you've already been doing. Based on your description, the only thing that needs classification is having different flats per the sessions. And for that, checking classify by date for master creation (in Flats) is sufficient. Two master flats will be generated, and they will be used to calibrate the proper lights. There is nothing extra that needs to be changed in the lights tab.
Alignment will be done automatically as part of the usual stacking process. ASTAP will pick the best sub out of all the nights as the reference, and everything will get aligned to that.
Hopefully that makes sense! I might be a bit confused by what you are meaning by "... with the same filter for Startools Compose." So, let me know whether I answered the right question.
Thanks for the prompt reply
All good , question answered perfectly
Regards
Martin