ZWO183MC vs ZWO533MC vs ATIK4120EX

[SAW]

Hi,

Can't decide which to buy out of the above cameras to use with a Skywatcher 72ED and Skywatcher 150PDS ? I have owned a 183MM and the MC version before. I don't won't mono as I'm not buying another filter wheel, filters etc.

[Adam J]

1 hour ago, SAW said:

Hi,

Can't decide which to buy out of the above cameras to use with a Skywatcher 72ED and Skywatcher 150PDS ? I have owned a 183MM and the MC version before. I don't won't mono as I'm not buying another filter wheel, filters etc.

For me the 533 is superior to the other two and by quite a large margin. Just look on astrobin and despite the 533 being relitively new its producing much better images.

Adam

[Dr Strange]

I use the 553 for EAA. It does very well and is cooled which is important. If you are going to do it, go with the 553 simply because of the sensor, cooling, and performance. As Adam said god to Astrobin and take a look at what people are doing each camera. That will help you decide. 

[TerryMcK]

The 183 is well matched to a scope of size of 72ED. It does suffer from amp noise but of course it can be calibrated out really easily. It is really sensitive though and produces excellent results., 

I’ve no experience of the 533 but that is marketed as having no amp noise. Also never used the Atik camera you mentioned.

[kryptonite]

I've also been researching the ASI533. I'm currently using Atik 383L+, but i'm being tempted by ease of OSC and the 533 looks tasty

[kryptonite]

On 10/05/2020 at 20:59, TerryMcK said:

The 183 is well matched to a scope of size of 72ED. It does suffer from amp noise but of course it can be calibrated out really easily. It is really sensitive though and produces excellent results., 

I’ve no experience of the 533 but that is marketed as having no amp noise. Also never used the Atik camera you mentioned.

Unrelated to the post, but noticed your signature.  Dedicated my CPU cycles to Folding@Home 👍  

[AstroRuz]

I used the Altair 183c Pro-Tec on my Sky-Watcher 72ED and it was a good fit certainly. Made some nice images.

https://www.instagram.com/p/B2Ocg-0FGJz/?utm_source=ig_web_copy_link

It certainly worked well but I found DeepSkyStacker wasn't really up to the task of calibrating out the EL-Glow/Amp GLow on the right hand side of the image. I had to use AstroPixel Processor.

https://www.instagram.com/p/B9EZp7ip7nE/?utm_source=ig_web_copy_link

I also have used the ASI 533mc Pro on the Evostar 80ED which gave some really good results. However the 533mc Pro will under-sample a tiny bit. But I suspect you won't notice a difference too much.

I have also got a review of the 533mc Pro on my channel to help you decide.

 

Really, the long and short of it is between the two cameras I miss the 533mc Pro the most. Even if it would undersample a touch with the 72ED but it is in the absolute sweet spot for the 150PDS. Hope that helps at all!

Edited May 19, 2020 by AstroRuz
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[Avocette]

18 hours ago, AstroRuz said:

I also have used the ASI 533mc Pro on the Evostar 80ED which gave some really good results. However the 533mc Pro will under-sample a tiny bit.

Really, the long and short of it is between the two cameras I miss the 533mc Pro the most. Even if it would undersample a touch with the 72ED but it is in the absolute sweet spot for the 150PDS. Hope that helps at all!

Hi Ruzeen,

Could you spell out in a bit more detail what you mention above on the sampling issue? I am presently using my astromodified Canon EOS 550D with my SW 80ED with 0.85x FR/corrector and my SW 150p Newtonian with the SW Coma Corrector which has a 0.9x FR effect. After reflecting for a while on moving to a dedicated cooled astro camera I settled on the ASI533, but in my case rather than the ASI294, for AP and also some EAA in streetlamp influenced skies. Any thoughts?

Ed

[AstroRuz]

55 minutes ago, Avocette said:

Hi Ruzeen,

Could you spell out in a bit more detail what you mention above on the sampling issue? I am presently using my astromodified Canon EOS 550D with my SW 80ED with 0.85x FR/corrector and my SW 150p Newtonian with the SW Coma Corrector which has a 0.9x FR effect. After reflecting for a while on moving to a dedicated cooled astro camera I settled on the ASI533, but in my case rather than the ASI294, for AP and also some EAA in streetlamp influenced skies. Any thoughts?

Ed

Hey Ed sure I'll do my best.

 

Under sampling is a term used when (I believe) the amount of sky that fits on each pixel isn't the ideal amount. What this causes is slightly softer images and loss of fine detail. It's usually okay for widefield astrophotography though and it also helps reduce demand on guiding. 

Over sampling is when too many pixels are used for the same patch of sky. This makes images really sharp and stars square (I think) - which can be fixed with drizzling. But generally over-sampling is something to avoid more than undersampling as it adds a huge strain on guiding. But the sharper images might be worth it. 

Someone please fact check me though on that, I always get them confused.

 

As for the ASI 533mc Pro on the Evostar 80ED and the Explorer 150pDS, it's suitability falls in the middle of being perfectly fine for those telescopes. My only reservation is that they're very similarly sized in terms of focal length. But after having used a 72ED and an 80ED at the same time, I understand that even 100mm can make a huge difference. I think you'll be pleased with the combination.

 

Ruzeen

[Avocette]

Thanks for the explanation about the sampling issues.

As you can see in my ‘signature’ I have the three ‘scopes these days, including a SkyMax150 pro which has a very different focal length specified as 1800mm. Actually the focal length can reach over 20% more when you adjust the primary mirror to include a Crayford focuser and camera backfocus, so I have a radical option if the FOV of the others loses interest!
The ED80 is effectively 510mm with the FR and the 150p 675mm with the CC. At the moment I am using the Newt for galaxies where the 30% longer focal length means a bigger image of the target, but I also benefit from the f4.5 versus f6.35 of the ED80/FR.  For the equivalent light capture, the Newt requires slightly less than half of the exposure time, which is great at this time of year.

[CCD-Freak]

I chose the ASI-533MC-Pro and I think I am going to really like it.  I have only had it out once due to the weather but here is a test image of M3.

60 x 10 seconds (10 minutes total exposure) no darks or flats.  This was shot with an old Celestron Ultima C8 at F10  .39"/pixel resolution

I can't wait to get this puppy out to the darks site !!!  😀

John Love
CCD-Freak
WD5IKX

Edited May 21, 2020 by CCD-Freak

[Adam J]

23 hours ago, AstroRuz said:

I used the Altair 183c Pro-Tec on my Sky-Watcher 72ED and it was a good fit certainly. Made some nice images.

I also have used the ASI 533mc Pro on the Evostar 80ED which gave some really good results. However the 533mc Pro will under-sample a tiny bit. But I suspect you won't notice a difference too much.

I have also got a review of the 533mc Pro on my channel to help you decide.

Really, the long and short of it is between the two cameras I miss the 533mc Pro the most. Even if it would undersample a touch with the 72ED but it is in the absolute sweet spot for the 150PDS. Hope that helps at all!

Sorry but thats just not the case, the Daws limit (the limit of resolution due to aperture) for a 72mm scope is 1.61 arcseconds per pixel if the optics are good.

The ASI533 will give 1.84 arc seconds per pixel which is a very good match to the SW72ED.

On the other hand the ASI183MC Pro will sample at 1.18 arcseconds per pixel, this means that its samping at a significantly higher rate than the Daws limit of a 72mm scope and will never acheive that resolution in practice. As such the ASI183MC Pro is over sampled. This will mean less sensitivity for no gain in resolution over the ASI533MC Pro.

I would not recommend the ASI183MC Pro for this reason and would 100% say that the ASI533MC Pro is a better choice for the refractor.

The only way to overcome this oversampling would be to bin the data 2x2 at which point you would be undersampled.

Adam

Edited May 20, 2020 by Adam J

[AstroRuz]

4 hours ago, Adam J said:

Sorry but thats just not the case, the Daws limit (the limit of resolution due to aperture) for a 72mm scope is 1.61 arcseconds per pixel if the optics are good.

The ASI533 will give 1.84 arc seconds per pixel which is a very good match to the SW72ED.

On the other hand the ASI183MC Pro will sample at 1.18 arcseconds per pixel, this means that its samping at a significantly higher rate than the Daws limit of a 72mm scope and will never acheive that resolution in practice. As such the ASI183MC Pro is over sampled. This will mean less sensitivity for no gain in resolution over the ASI533MC Pro.

I would not recommend the ASI183MC Pro for this reason and would 100% say that the ASI533MC Pro is a better choice for the refractor.

The only way to overcome this oversampling would be to bin the data 2x2 at which point you would be undersampled.

Adam

The information I'm going by is sourced from the Astronomy Tools CCD suitability which uses Nyquist. So I suppose it's a difference in calculations as I get under sampled with the 533 and well sampled with the 183.

 

I've used the 183 personally with a 72ED and felt the images coming out were good quality and didn't look poor or undersampled, but I'll go round and double check them again and see what the stars look like 

[AstroRuz]

7 hours ago, Avocette said:

Thanks for the explanation about the sampling issues.

As you can see in my ‘signature’ I have the three ‘scopes these days, including a SkyMax150 pro which has a very different focal length specified as 1800mm. Actually the focal length can reach over 20% more when you adjust the primary mirror to include a Crayford focuser and camera backfocus, so I have a radical option if the FOV of the others loses interest!
The ED80 is effectively 510mm with the FR and the 150p 675mm with the CC. At the moment I am using the Newt for galaxies where the 30% longer focal length means a bigger image of the target, but I also benefit from the f4.5 versus f6.35 of the ED80/FR.  For the equivalent light capture, the Newt requires slightly less than half of the exposure time, which is great at this time of year.

 

 

Here you go mate, seems I got it backwards 

[JamesF]

I think you need to be careful when considering the resolution with colour cameras.  I'm sure vlaiv posted some stuff about this recently, but I can't find it at the moment.  The problem is that you can't achieve the resolution suggested by the pixel size because of the colour filter array.  For example on the ASI533MC the pixel size is (IIRC) 3.76um.  But the red photosites are twice that distance apart and only collect photons from one quarter of the area of the sensor.  The same goes for blue.  The green photosites are actually a bit closer at just over 1.4 times the pixel size apart, but still only collect photons from half the area of the sensor.

James

[AstroRuz]

19 minutes ago, JamesF said:

I think you need to be careful when considering the resolution with colour cameras.  I'm sure vlaiv posted some stuff about this recently, but I can't find it at the moment.  The problem is that you can't achieve the resolution suggested by the pixel size because of the colour filter array.  For example on the ASI533MC the pixel size is (IIRC) 3.76um.  But the red photosites are twice that distance apart and only collect photons from one quarter of the area of the sensor.  The same goes for blue.  The green photosites are actually a bit closer at just over 1.4 times the pixel size apart, but still only collect photons from half the area of the sensor.

James

Never thought about the distance of photosites really. Guess that would play into it also. Good to know, might have to look this up. Just found the 183 to work swell with a 72ED.

 

Good to know none the less though!

[JamesF]

1 minute ago, AstroRuz said:

Never thought about the distance of photosites really. Guess that would play into it also. Good to know, might have to look this up

It gets even more fun when the camera isn't RGB at all, but the software synthesises RGB from a completely different set of filters such as CMYG (cyan/magenta/yellow/green).  I believe the colour Lodestar does that.  Possibly some of the other SX colour cameras too.

James

[AstroRuz]

4 minutes ago, JamesF said:

It gets even more fun when the camera isn't RGB at all, but the software synthesises RGB from a completely different set of filters such as CMYG (cyan/magenta/yellow/green).  I believe the colour Lodestar does that.  Possibly some of the other SX colour cameras too.

James

As fun and interesting as it is, I think that's going far too deep than I want to 😂 

 

I say that, but it's in my mind now and I've got that sort of head where I want to go and research it now. Can you point me anywhere to learn more?

[JamesF]

13 minutes ago, AstroRuz said:

I say that, but it's in my mind now and I've got that sort of head where I want to go and research it now. Can you point me anywhere to learn more?

vlaiv definitely posted some stuff here on resolution of colour cameras relatively recently, but my search skills are lacking this evening.  He's usually exceptionally good at showing his working, so if you can find that thread it would probably be quite informative.

James

[Adam J]

12 hours ago, AstroRuz said:

The information I'm going by is sourced from the Astronomy Tools CCD suitability which uses Nyquist. So I suppose it's a difference in calculations as I get under sampled with the 533 and well sampled with the 183.

 

I've used the 183 personally with a 72ED and felt the images coming out were good quality and didn't look poor or undersampled, but I'll go round and double check them again and see what the stars look like 

Sampling is not just about what the stars look like it's about resolvable detail and photon pixel flux. Unfortunately that calculator is only considering star roundness as related to seeing within its calculation if it's the tool I think it is. 

The stars in your images will look fine, not bloated or blocky as both cameras are in that optimal range of 1-2 arcseconds per pixel. But that's only part of the picture. It's about how much detail / resolution you expect to attain in the DSO you are imaging itself. That is limited by more than just your image scale, it's limited by guiding, seeing, Daws limit and signal to noise in the image. A good debayering algorithm will get most of the resolution lost by the RGB matrix back. So you certainly don't end up at 50% image scale in the red / blue. But in the end a 70mm scope does not grab that many photons so you can't just keep spreading them over increasingly smaller pixels and expect to attain sufficient signal to allow you to extract additional detail. 

In the end what I am saying is this. If you take your 72mm scope at about 400mm focal length and 1.1arcsecond image scale and put that up against my 100mm scope with 550mm focal length and 1.4arcsecond image scale. Which do you think will image a target like m81 in more detail and achieve a better image. I believe strongly it would be my scope and so at that point I would say your oversampled and you would be better off moving to larger pixels for an increased SNR as clearly the smaller pixels are not helping you. 

Adam

Edited May 21, 2020 by Adam J

[AstroRuz]

39 minutes ago, Adam J said:

Sampling is not just about what the stars look like it's about resolvable detail and photon pixel flux. Unfortunately that calculator is only considering star roundness as related to seeing within its calculation if it's the tool I think it is. 

The stars in your images will look fine, not bloated or blocky as both cameras are in that optimal range of 1-2 arcseconds per pixel. But that's only part of the picture. It's about how much detail / resolution you expect to attain in the DSO you are imaging itself. That is limited by more than just your image scale, it's limited by guiding, seeing, Daws limit and signal to noise in the image. A good debayering algorithm will get most of the resolution lost by the RGB matrix back. So you certainly don't end up at 50% image scale in the red / blue. But in the end a 70mm scope does not grab that many photons so you can't just keep spreading them over increasingly smaller pixels and expect to attain sufficient signal to allow you to extract additional detail. 

In the end what I am saying is this. If you take your 72mm scope at about 400mm focal length and 1.1arcsecond image scale and put that up against my 100mm scope with 550mm focal length and 1.4arcsecond image scale. Which do you think will image a target like m81 in more detail and achieve a better image. I believe strongly it would be my scope and so at that point I would say your oversampled and you would be better off moving to larger pixels for an increased SNR as clearly the smaller pixels are not helping you. 

Adam

Oh well yes I would agree that your larger telescope would get more finer detail and resolution. I guess in this case then I was just talking in general about under/over sampling as mentioned by the CCD Calculator. In terms of resolution and what sort of detail it can pull out, yes larger aperture is always better. To a limit I guess due to the atmosphere.

I would really enjoy using a larger telescope sometime in order to compare the difference in resolution, that's for sure.

[Adam J]

18 minutes ago, AstroRuz said:

Oh well yes I would agree that your larger telescope would get more finer detail and resolution. I guess in this case then I was just talking in general about under/over sampling as mentioned by the CCD Calculator. In terms of resolution and what sort of detail it can pull out, yes larger aperture is always better. To a limit I guess due to the atmosphere.

I would really enjoy using a larger telescope sometime in order to compare the difference in resolution, that's for sure

I think the issue with CCD calculator is it was written prior to the CMOS age. The smallest pixel CCD was around 4.5u when it was made and so it was virtually impossible to oversample with a small refractor. Hence there is no catch to tell you that you are trying to image at a smaller scale than the Daws limit of your scope. Smaller aperture refractors <80mm have also become much more popular. It could use revising. 

Edited May 21, 2020 by Adam J