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Sony IMX183 mono test thread - ASI, QHY, etc.

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#1026 JukkaP

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Posted 11 December 2019 - 01:15 PM

Nice image! You got enough of those long frames.

I have seen with similar scope that it need 50+ frames for clean image.

I have tryed 5min, 10min and 15min exposures. I think the 15min frames are best from dark'ish sky(bortle 5) with f5-f6.5 scope.

Now my second scope heq5 does not guide so well,so I have been using 5min frames. EQ6 does 15min easy.


I still want to try like 2min frames and alot of them. I feel like this camera likes 100-200 frame stack's alot. Might give some better detail and stars also with shorter frames.

Anyone tested short exposure times and 200+ frames stack?
It will be my next test.

#1027 Swordfishy

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Posted 11 December 2019 - 04:36 PM

This is a great thread actually... 

 

 Here is my Ha ensemble, 1.5 hours of integration each in Ha, except IC 410 which has 3 hours worth. I JUST got the kit 3 weeks ago roughly and have been trying to put it to the test Ha wise at least. Once the moon goes away I will try for RGB.

 

 Bortle 9 skies with LED lights making it bright enough to read fine print. It is perpetual light near me. Also nearly full moon.

 

 I keep my exposures to 300 seconds, 200 gain, 10 offset. Astronomik 6nm Ha filter.

 

 https://flic.kr/p/2hY6fNC

 

 https://flic.kr/p/2hY8K3n

 

 https://flic.kr/p/2hY8K2F

 

 https://flic.kr/p/2hY6fAU

 

 https://flic.kr/p/2hY6fvd

 

 https://flic.kr/p/2hY8JTe

 

 https://flic.kr/p/2hY6fsY

 

 https://flic.kr/p/2hY8JPw

 

Would love some input on this, am I going too long with the subs or too high a gain?

 

 I have wondered about it. It is my first time with Hydrogen Alpha so flying dark atm.

 

 The M31 is because I want to use it as luminance later on.

 

 I also noticed that the CCD filter I am using as luminance gets blown out QUICKLY at 120 gain (unity) and 180 seconds, so I will be trying 30 seconds and going up from there at unity for luminance.


Edited by Swordfishy, 11 December 2019 - 04:36 PM.


#1028 erictheastrojunkie

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Posted 11 December 2019 - 05:04 PM

I finally finished a SHO image with the AT65. I feel like I battled some amp glow on both sides of the image but it really wasn't much of a battle IMO. Overall, I'm happy with the way the amp glow calibrated out and the 1.25" Baader filters presented no vignetting problems. Hope you enjoy it as much as I am.

https://www.astrobin...y398v0/?nc=user

That's spectacular, Melotte 15 and the heart nebula is definitely going to be one of my first sho targets. What gain/offset settings did you use?

Sent from my Pixel 2 XL using Tapatalk

#1029 wcreech

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Posted 11 December 2019 - 10:27 PM

That's spectacular, Melotte 15 and the heart nebula is definitely going to be one of my first sho targets. What gain/offset settings did you use?

Sent from my Pixel 2 XL using Tapatalk

Thanks, Eric. I used unity for all three channels. Gain 111, Offset 10 



#1030 Mobile Wizard

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Posted 27 December 2019 - 03:53 PM

Great thread.

 

I've read all 42 pages and some great information.

problem is I've got the colour version.

 

Is there a thread with information on colour version of this sensor. Would be great to see what pictures members of the colour version are getting with gain and exposure settings.

 

Telescope.gif



#1031 sungrazer_2

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Posted 02 January 2020 - 10:44 AM

Hi to all!

I buyed an ASI 183 Pro Mono in April last Year. Before, I could test the 174, 183 and 1600 Mono Pro's to find out what I want (a local Dealer in Germany send me the 3 for testing it within 6 Weeks from the End of September to October of 2018).

I have posted my Results already in Cloudy Nights. If you want the link to that, please let me know.

I use a C8 at f/6, later in this Year I want to use my C11 at F/6 to F/4 or so,

 

Here are some Images of M31 with ASI 183 Mono Pro 

https://www.cloudyni...ro-mono-images/

 

At my Home in Southwest Germany (48.9°N) I have Bortle 4-4.5 most of time.

 

Bye Juergen smile.gif


Edited by sungrazer_2, 02 January 2020 - 11:00 AM.


#1032 cwic

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Posted 26 February 2020 - 06:13 AM

I have Asi183mmc pro since 4 months and weather is not giving me to much opportunities to check its capabilities. For now I was only testing, and I think I am ready for galaxies time in Poland.

Attached 2h of M81 with 15sec exposures at gain 350.

Attached Thumbnails

  • r_M81_2_res_ (1).jpg

Edited by cwic, 26 February 2020 - 06:14 AM.

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#1033 Henry from NZ

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Posted 16 March 2020 - 12:34 PM

Hi all

 

Please help!

 

I am about the buy a second hand QHY183M.

On inspection of the dark frame there appear to be a lot more hot pixels than what I am used to with my older Atik460.

Is this normal for CMOS?

I have included a couple on my dropbox.

If there are more than usual hot pixels I probably will not proceed with sale.

If this is normal for this camera then I will go ahead.

And can someone please comment on the support for QHY183 in SGPro and Voyager in terms of setting gain and offset?

 

Thanks

 

https://www.dropbox....2_Dark.fit?dl=0

https://www.dropbox....0_Dark.fit?dl=0

 

 



#1034 james7ca

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Posted 16 March 2020 - 02:18 PM

Yes, all of my CMOS cameras (including the ASI183MM Pro) have a lot of hot pixels. But, it depends highly on the gain setting and the camera temperature and most of these deviant pixels are taken care of with proper calibration (i.e. dark frames used on your lights).

 

I looked at your first sample and I don't see anything particularly odd about that dark field. However, I don't have any of my own samples that were taken at the same gain, temperature, and exposure time that you used. Plus, you are using a QHY camera, while I have a ZWO.

 

That said, here is a 1:1 crop from a representative area on one of my darks taken with an ASI183MM Pro at gain 270 and a temperature of -15C and with an exposure time of 240 seconds. This was auto stretched in PixInsight. However, since the histogram stretch, gain, and exposure times are different from your sample I wouldn't try to make a direct comparison between your samples and mine. But, you can certainly see many hot or bright pixels in my sample.

 

Lastly, it can be very hard to do visual comparisons between sample images since the level of stretch can vary greatly (particularly given differences in gain, offset, exposure time, and temperature). Thus, the only way to get a valid comparison would be to measure the statistics on each image. I did a quick test on my sample (using the ASI183MM) looking for all pixels that were more than four standard deviations (sdev) from the mean and then I output a file that set all of those outlier pixels to a value of one. I then did the same on your sample and below you can see a small 512 pixel crop from each of the test images. They look pretty much the same, indicating about the same level of "hot" pixels. Still not a completely valid comparison because of all of the other differences (gain, exposure, etc.), but it shows at least some level of similarity.

 

Here is the PixelMath expression to look for hot pixel outliers (where $T is the target image):

 

  iif ($T > mean($T) + 4 * sdev($T), 1, mean($T) + 4 * sdev($T))

Attached Thumbnails

  • DF ASI183MM 240s Gain 279 -15C Sample.jpg
  • Statistical Sample ASI183MM Pro.jpg
  • Statistical Sample QHY.jpg

Edited by james7ca, 16 March 2020 - 06:29 PM.

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#1035 Henry from NZ

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Posted 16 March 2020 - 03:53 PM

Thank you James for the very informative reply. It is very helpful. 
I was initially a bit worried, as the dark frame from my Atik460 is exceptionally clean, even with 20 minute exposure. 
I don’t have enough experience re CMOS camera like the 183.

but you are right in that if it calibrates out then it is not a problem. 
thanks. 



#1036 copper280z

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Posted 16 March 2020 - 05:12 PM

This may not be the correct thread, but I have an ASI183mm pro and I've been really enjoying it, when it connects to the PC. It's made for some really fantastic (by my standards) images with modest gear.

 

I have a problem though, it's the least reliable USB device I've ever run across. I'm using it with a lenovo Z40-70 laptop and a custom built desktop PC. Sometimes it connects and works fine, many times it won't. It'll connect and all the controls will work, but it'll display a black image with a scrolling pattern of pixels, left to right. Changing the USB turbo settings does nothing, neither does fiddling with any of the other settings. My only hope when it's being difficult is to just keep trying. This morning I spent well over an hour trying to take flats because the stupid thing won't connect to the laptop. I eventually tried using the desktop and it worked on the rear ports but not the front.

 

Any ideas on making this easier to live with?

 

https://astrob.in/r7c9sq/0/



#1037 Jon Rista

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Posted 16 March 2020 - 06:42 PM

Thank you James for the very informative reply. It is very helpful. 
I was initially a bit worried, as the dark frame from my Atik460 is exceptionally clean, even with 20 minute exposure. 
I don’t have enough experience re CMOS camera like the 183.

but you are right in that if it calibrates out then it is not a problem. 
thanks. 

Hi Henry. I wouldn't worry too much about the number of hot pixels. If they all calibrate properly when you subtract a master dark, then they won't have any meaningful impact to the final image. But, if you can, I would actually TEST that. UNLIKE the ASI1600, which on top of dark current also has burst noise (RTS or random telegraph signal) which can cause semi-variable hot pixels, the ASI183 is, in my experience, very stable when it comes to the hot pixels. 

 

As long as you can get some matched lights and darks, and the master dark calibrates the lights well (removes the hot pixels and the glows), then you shouldn't have anything to worry about. 



#1038 OldManSky

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Posted 16 March 2020 - 09:26 PM

This may not be the correct thread, but I have an ASI183mm pro and I've been really enjoying it, when it connects to the PC. It's made for some really fantastic (by my standards) images with modest gear.

 

I have a problem though, it's the least reliable USB device I've ever run across. I'm using it with a lenovo Z40-70 laptop and a custom built desktop PC. Sometimes it connects and works fine, many times it won't. It'll connect and all the controls will work, but it'll display a black image with a scrolling pattern of pixels, left to right. Changing the USB turbo settings does nothing, neither does fiddling with any of the other settings. My only hope when it's being difficult is to just keep trying. This morning I spent well over an hour trying to take flats because the stupid thing won't connect to the laptop. I eventually tried using the desktop and it worked on the rear ports but not the front.

 

Any ideas on making this easier to live with?

 

https://astrob.in/r7c9sq/0/

Get a powered hub and connect it through that.  It seems likely that your laptop and front PC ports aren't supplying enough current.  The cooler on the 183mm pro is powered by the external power supply, but the camera electronics are powered through the USB port.  If your USB ports aren't supplying sufficient power, things like you describe will occur.



#1039 copper280z

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Posted 16 March 2020 - 09:43 PM

I'll give that a shot, thanks!

#1040 gregbradley

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Posted 21 April 2020 - 01:26 AM

I received my 183mm Pro last Friday and have already done some imaging with it. I am not sure how you post an image here as when you click on image it asks for a URL. I entered one and it would not display the image.

 

So with this thread being quite mature what is the consensus for setting the gain on this camera?

 

I am currently using 53 for LRGB x 300 secs and gain 111 for 600 seconds for narrowband.

 

The amp glow is usually swamped by signal with a little bit showing. Darks (12 darks) remove it completely.

I don't need flats with one of my scopes at this time as there is no vignetting and no dust donuts.

 

What settings do you find useful?

 

Greg.



#1041 luter68

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Posted 21 April 2020 - 04:28 AM

I received my 183mm Pro last Friday and have already done some imaging with it. I am not sure how you post an image here as when you click on image it asks for a URL. I entered one and it would not display the image.

 

So with this thread being quite mature what is the consensus for setting the gain on this camera?

 

I am currently using 53 for LRGB x 300 secs and gain 111 for 600 seconds for narrowband.

 

The amp glow is usually swamped by signal with a little bit showing. Darks (12 darks) remove it completely.

I don't need flats with one of my scopes at this time as there is no vignetting and no dust donuts.

 

What settings do you find useful?

 

Greg.

Hi, I use your same gain values, 53 for LRGB and 111 for NB, after this great thread. I find them rather good. I think any value around those would work equally well but there is a great advantage in standardizing things. I always use those settings, always the same temperature (-15 deg C) and always the same sets of exposure times (600 for NB, 180 or 90 for LRGB) so that I can build libraries of dark frames that I update only once or twice a year. Hope you find this helpful.

 

Clear skies.

 

Luca


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#1042 OldManSky

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Posted 21 April 2020 - 11:27 AM

I received my 183mm Pro last Friday and have already done some imaging with it. I am not sure how you post an image here as when you click on image it asks for a URL. I entered one and it would not display the image.

 

 

Click on the "More Reply Options" button at the bottom-right of your reply.  A different reply window will open up, at the bottom you'll have the option to upload and attach an image from your computer.

The image must be less than 500k in byte-size.



#1043 gregbradley

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Posted 21 April 2020 - 11:47 PM

Here is first light with my ASI183mm Pro and an AP Riccardi Honders Astrograph -305mm f3.8:

 

Greg.

 

 



#1044 gregbradley

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Posted 21 April 2020 - 11:55 PM

Centaurus A Ha LRGB V8 thumb.jpg

40 x 10mins gain 53 -10C

32 x 5mins gain 53 red

24 x 5mins gain 53 blue

22 x 5mins gain 53 green

12 x 10mins gain 111 -10C Ha. This is Centaurus A, a spiral galaxy merging with an elliptical galaxy.

 

I tested my camera and it goes to 47 degreesC below ambient so I could run it at -15C most of the year except for the occasional hot night

 

Focusing it is noticeably harder than my 9 micron pixelled CCD but I also run focusing on CCDsoft with a large displayed image and its graph. A learning curve there.

 

Loving this camera. Another little gain over CCD is you can abort an exposure in progress and straight away start another exposure with no consequence. I find with the CCDs you have to download another exposure even if only a focus one to clear it otherwise you'll get a half image and the other half is white.

 

I also notice amp glow is minimal on a typical 5 min 53 gain exposure. It was worse on a 5 minute S11 exposure at gain 111 Weak signal meant the glow was not inhibited by a strong signal.

 

Greg.


Edited by gregbradley, 22 April 2020 - 12:02 AM.

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#1045 milesinthesky

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Posted 23 April 2020 - 02:59 PM

Hello there !

 

I've read the 42 pages, I've learned a lot of things, and my brain is overheating now.
Still, some questions remains.


My scope is a 80mm/480mm refractor, so a f6 scope.
With a 183 my image scale would be 1.03". As my seeing is mostly between 2" and 3", a 183 would be nice.

 

But.
Jon Rista's advice with a f4 scope for NB is a 53 gain and 10min exposures so the stars aren't clipped.
With my f6 scope it will take at least 20min to get to that point.


And that's where I have questions.
What would be the best option :
-Reduce my focal to have a f4 scope and be able to take 10min subs at 53 gain but having a image scale of 1.57"
-Keep my scope at f6 but use a higher gain like 111 to be able to take 10min subs and a image scale of 1.02"

 

As I really love stars with rich colors I would tend to go for the first option. But I would feel like I'm not using the 183 to its full potential with my scope.
And maybe higher gain like 111 wouldn't clipped that much the stars ?


And while imaging time is an important point, I'm still considering the 1600.
Because I'm living in a very strong LP area I'm only imaging under dark skies 2 days a month when it's not 2 days for two month.
The 1600 would allow me to take more subs with the little time of imaging I have.
Also I could still shot some Ha at home with both.

 

What are you thoughts about this ?

 

PS: English isn't my native language, sorry if I made some mistakes.


Edited by milesinthesky, 23 April 2020 - 03:00 PM.


#1046 OldManSky

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Posted 23 April 2020 - 05:35 PM

milesinthesky,

Bumping up the gain a little (to a lot) and keeping the subs under/around 10 min would be the best option.

You'll have to do some experimenting with your particular setup to find the best values -- Jon's terrific advice is a great starting point, but your mileage may vary and doing your own testing is the best way to nail down what works for your setup.

I do all my narrowband imaging with the 183mm-pro at gain 117 ("unity" on the 183mm-pro).  I vary the exposure time (from 3 to 6 minutes) depending on which of my scopes I'm using, to keep from blowing out stars.  That works best for me. :)



#1047 Henry from NZ

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Posted 26 April 2020 - 03:07 PM

Quick question: do you notice the 183 shows more corner aberrations compared to your larger pixel cameras? When using my Atik460 my corner stars are round, but with a 183 which is similar in sensor size the corner stars are ever slightly not round (even though one needs to zoom 1:1 to see it). I am trying to decide whether I have an optic problem, a spacing problem or a camera problem. I do not wish to fiddle with collimation with my OTAs as they work well with my 460 which I still have, but I am suspecting the problem lies with the optics and the 183 is just showing up the miscollimation due to its small pixel size. Thoughts?

 

Example - 

https://www.dropbox....E_300.xisf?dl=0

 

This is 15x5 min subs using my Takahashi e130 newt. The corner stars are all a bit oblong when viewed at 1:1, and in different orientation which would suggest tilt rather than spacing. Being a pixel peeper it bugs me but at the same time I am not sure if I want to embark on a new attempt to collimate the e130 when it has been working well with my 460.

 

On the other hand using PI I have the following eccentricity and FWHM plots, which would suggest the collimation is probably as good as it can be?

Screen Shot 2020-04-27 at 8.14.31 AM.png

Screen Shot 2020-04-27 at 8.14.18 AM.png


Edited by Henry from NZ, 26 April 2020 - 03:16 PM.


#1048 james7ca

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Posted 26 April 2020 - 08:19 PM

Quick question: do you notice the 183 shows more corner aberrations compared to your larger pixel cameras? When using my Atik460 my corner stars are round, but with a 183 which is similar in sensor size the corner stars are ever slightly not round (even though one needs to zoom 1:1 to see it). I am trying to decide whether I have an optic problem, a spacing problem or a camera problem. I do not wish to fiddle with collimation with my OTAs as they work well with my 460 which I still have, but I am suspecting the problem lies with the optics and the 183 is just showing up the miscollimation due to its small pixel size. Thoughts?

 

Example - 

https://www.dropbox....E_300.xisf?dl=0

 

This is 15x5 min subs using my Takahashi e130 newt. The corner stars are all a bit oblong when viewed at 1:1, and in different orientation which would suggest tilt rather than spacing. Being a pixel peeper it bugs me but at the same time I am not sure if I want to embark on a new attempt to collimate the e130 when it has been working well with my 460.

 

On the other hand using PI I have the following eccentricity and FWHM plots, which would suggest the collimation is probably as good as it can be?

attachicon.gifScreen Shot 2020-04-27 at 8.14.31 AM.png

attachicon.gifScreen Shot 2020-04-27 at 8.14.18 AM.png

That's a huge difference in the image scale between those two cameras and I don't think you can make any direct comparison between the two. The ASI183 produces a scale of 1.15 arc seconds per pixel while the Atik 460 is 2.18. Then, looking at those FWHM plots from the ASI183 you could perhaps guess that the Atik would produce FWHM measurements down near one pixel which would suggest under sampling with the Atik. If you slightly blur one pixel (from seeing, focus, or optical aberration) you'll probably end up with a round looking star. However, if you do the same to a 2.7 pixel star you'll just have a slightly degraded spot which may or may not look round.

 

Plus, the smaller pixels in the ASI183 may not handle off-axis illumination quite the same as the Atik (which could result in other off-axis changes in performance).

 

All that said, I would appreciate it if you posted your latest Eccentricity and FWHM plots for your Takahashi e130 over in the below thread on image quality. I've already given you the image scales and with that information and the plots and your scope and camera makes (mono or color) you've got almost all of the information that you need. The only other addition would be your effective fields of view with both sensors (in arc minutes or degrees) and an AberrationInspector matrix from PixInsight. I see that you made some posts to this thread back in 2018 (with a color camera?), but it's apparent that you may have some more recent data.

 

  https://www.cloudyni...y/#entry6627920


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#1049 Henry from NZ

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Posted 26 April 2020 - 11:01 PM

Hi James, I have posted my plots in your thread - I am not sure if this is what you are after.

 

Before I fiddle with the collimation of my e130D, I probably should make sure the problem does not lie with the camera. However what you said makes sense, and I have read in other places that the 183 is unforgiving in terms of optical problems due to the small pixel size. I am just a bit surprised that it would show up given the relative small sensor size.

 

I think the first order of business I have is to confirm that the problem is to do with collimation. To do this I will probably bring out my reference scope (being the AP 130GT) and see what the images taken with the 183 look like. If the images look good with the AP130GT but not with the Tak e130, then I have the choice of either live with that or take another plunge collimating the Tak (which I do not look forward to). Does it sound like a reasonable debugging procedure?

 

Postscript:

 

On further research, it may be that the 183 out-resolve the e130D. I have downloaded the spot diagram of the e130D and measure the spot size:

e130D spot diagram.jpg

 

It shows that the spot size on axis is about 13 micron (the spot is about 8 px wide, the 100 micron box is 60 px wide).

At 7 mm off axis (which is at the far corner of the long edge of the 183 sensor, the spot size is 13x16 micron

 

I am not sure if I understand how to read the spot diagram properly - please correct me if I am wrong: The stars at the corner of the 183 sensor are oval, with the long edge 3 micron greater than the short edge. Since the 183 has a pixel size of 2.4 micron, The elongation is visible on the 183, whereas the 460 has a pixel size of 4.54 micron, the elongation is not visible. Therefore even if my e130D is correctly collimated, there will still be visible corner star elongation with the 183. If I need round stars to the corner, I need a scope which has a tighter the spot size at 6-7 mm off axis. 

 

Have I misinterpreted things?


Edited by Henry from NZ, 26 April 2020 - 11:43 PM.


#1050 james7ca

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Posted 27 April 2020 - 12:18 AM

I'd be wary of trying to use those spot diagrams to predict the measured star sizes with your scope. Those diagrams are most likely based on ray tracing and thus they wouldn't include the effects of diffraction and they certainly aren't based on actual measurements taken on an optical bench.

 

However, note that the Airy disk on an unobstructed 130mm aperture scope at f/3.3 is just over 4 microns wide in green light (or 1.97 arc seconds). But, you'll never get that kind of performance on a DSO because of your seeing conditions. Plus, the energy that does into the diffraction rings is likely to expand that spot rather notably when you overexpose the star's Airy disk (it's actually very had to record or resolve the diffraction rings on a star, you need very good seeing and fairly short exposures).

 

I don't know, with such a "fast" scope it might be hard to find anything that will produce a totally flawless image. If you do a 50% downsizing on your images from the ASI183 how do the stars look?


Edited by james7ca, 27 April 2020 - 01:50 AM.

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