Asi533 mc pro on a 1000mm Newtonian

[vlaiv]

21 minutes ago, Adam J said:

If you have a read let me know what you think.

I went thru that thread - but it only gave me headache

I've seen above image, but without raw data, there is really nothing I can do to check what is going on.

Some say that they are happy with their camera, others have issues. Either there is much sample to sample variations - maybe different drivers or perhaps wrong settings / calibration. It is hard to tell really.

What I do know is that I would not mind having a sample of ASI294 and checking it out to see if it works properly

[Craig a]

12 minutes ago, vlaiv said:

What I do know is that I would not mind having a sample of ASI294 and checking it out to see if it works properly

I don’t think I’m going to buy the 294 so you can see if it works properly 😆, They do seem abit hit and miss for my liking, the qhy168c seems like a better option I get the same fov as my dslr and puts me at 0.99 arc sec pp, better than the 533 and on par with the 294, but with the QE at around 50% on the 071 chip is that considered a good QE? 

[vlaiv]

19 minutes ago, Craig a said:

I don’t think I’m going to buy the 294 so you can see if it works properly 😆, They do seem abit hit and miss for my liking, the qhy168c seems like a better option I get the same fov as my dslr and puts me at 0.99 arc sec pp, better than the 533 and on par with the 294, but with the QE at around 50% on the 071 chip is that considered a good QE? 

It looks like quite good camera. I would not mind having one of those either (and no, you don't have to supply one either )

50% QE is not very good, but it's not bad either. Around 70-75% would be good QE, 80% and above is excellent QE.

ASI1600 has QE around 50% mark (maybe close to 60% peak but average is closer to 50% mark) and I have no complaints.

It is similar to pixel size, if you compare 50% QE vs for example excellent QE of 85% - first one will need 1.7h or integration time to match SNR of 1h integration time of second higher QE camera - so it's a bit slower, but not by much.

[Adam J]

1 hour ago, vlaiv said:

It looks like quite good camera. I would not mind having one of those either (and no, you don't have to supply one either )

50% QE is not very good, but it's not bad either. Around 70-75% would be good QE, 80% and above is excellent QE.

ASI1600 has QE around 50% mark (maybe close to 60% peak but average is closer to 50% mark) and I have no complaints.

It is similar to pixel size, if you compare 50% QE vs for example excellent QE of 85% - first one will need 1.7h or integration time to match SNR of 1h integration time of second higher QE camera - so it's a bit slower, but not by much.

I would think that the larger pixels make up for quite a bit of that difference. Dynamic range is good on the 071 / 168c due to 14-bit A/D so you can use it at gain 200 (ASI) and get 2.3e read noise while still having 11 stops.

I think that the ASI294 is better on paper lower read noise higher QE but also much higher dark current, I just have an uneasy feeling about some of the things I have read about it. Equally the 533 is a superior sensor, but its so small and oversampled.......

Easy to go around and around in circles with these choices. Its great that we have so many choices in the modern camera market though.

OP I have said it before but why OSC? I think a ATIK414EX mono (dont touch the OSC) would be a better choice for pure small galaxy imaging on your scope. But the very small sensor means that is all you can do with it.

Adam

Edited August 20, 2020 by Adam J

[vlaiv]

9 minutes ago, Adam J said:

I would think that the larger pixels make up for quite a bit of that difference. Dynamic range is good on the 071 / 168c due to 14-bit A/D so you can use it at gain 200 (ASI) and get 2.3e read noise while still having 11 stops.

I think that the ASI294 is better on paper lower read noise higher QE but also much higher dark current, I just have an uneasy feeling about some of the things I have read about it. Equally the 533 is a superior sensor, but its so small and oversampled.......

Not sure if dynamic range is something that should matter. We take so many subs and increase resulting dynamic range with stacking. Single sub range is not really that important.

I also think that dark current is really not that high to be real concern.

If we keep it at 0C, that is, according to ZWO ~0.025 e/s/px.

If we do reasonable exposure for modern CMOS sensor of about 2 minutes - dark current will be 3e and resulting noise ~1.72e. That is about the size of read noise. If sky glow is swamping read noise at two minutes - it will do the same with dark noise. Impact of dark noise on final image will be very small.

Cooling lower will only make things better (although -35C delta T is not that great).

 

[Craig a]

I sure am going round in circles! I really appreciate all your comments, but lying in bed thinking about things and my heart really is set on the 533, I could get that and the skywatcher 130pds and them two together would still be cheaper than buying the 071 or 168 on its own, so I’m seriously considering going that way, and I could always try it on the 10inch inch newt , if it doesn’t work on it it’s the 130pds to the rescue and it would be nice to also have a scope with a wider FOV to compliment the 1000mm larger scope, does that sound like a plan?

[Craig a]

Also the weight loss by getting the 130 will be huge and won’t act like a sail as much as the big Newtonian, so will be easier on the mount to guide 

[vlaiv]

If you have your heart set on ASI533 and it suits your budget - then just go for it.

Later in use, if you find your images are too blurry when looking at them 1:1 - do super pixel debayering. That will create smaller size image - 1500 x 1500, but things should look better / stars tighter.

[Craig a]

So if I got the 130pds with the 533, would my st80 and starshoot autoguider successfully guide it? The 533 and 130pds gives 1.19pp and the st80 and starshoot gives 2.68 pp? I don’t want to go down the OAG route 

[Craig a]

Well I’ve pressed the buy button on the 533 I’ve also got the 130pds and the moonlite installation kit for it so I can take my moolite focuser off my big new and fit it to the 130pds, first light optics saying 15-20 days delivery time on the cam 😀

[Adam J]

I think that the thing to keep an eye on is that any of these cameras are going to be vastly better than what you are using at the moment so thr 533 will produce good images for you in any case.

I would just try it with what you have first, then decide if you want the 130PDS after testing it.

The ST80 is massive overkill for guiding a 130PDS. You are better off with a 50-60mm guide scope.

Adam

[Craig a]

Exiting times ahead!!!!!

[Adam J]

1 minute ago, Craig a said:

Exiting times ahead!!!!!

Nice, be sure to post an image for us all to see. I think that you will find the 130pds complementory.

Adam

Edited August 21, 2020 by Adam J

[Craig a]

6 minutes ago, Adam J said:

I think that the thing to keep an eye on is that any of these cameras are going to be vastly better than what you are using at the moment so thr 533 will produce good images for you in any case.

I would just try it with what you have first, then decide if you want the 130PDS after testing it.

The ST80 is massive overkill for guiding a 130PDS. You are better off with a 50-60mm guide scope.

Adam

I do already have the skywatcher 50mm evoguide I just thought the fl on that with the pixel size on the starshoot would be a mis match?

4.43pp with that 50mm guidescope and guide cam 

1.19pp with 130pds and 533

 

Edited August 21, 2020 by Craig a

[Adam J]

2 minutes ago, Craig a said:

I do already have the skywatcher 50mm evoguide I just thought the fl on that with the pixel size on the starshoot would be a mis match?

You will be able to guide well so long as the guide camera scale is less than 4-5x the image scale.

My image scale is 1.4 and my guide camera is 6.7 and I managed this (and with a mono camera guiding needs to be even tighter).

Adam

[Craig a]

6 minutes ago, Adam J said:

You will be able to guide well so long as the guide camera scale is less than 4-5x the image scale.

My image scale is 1.4 and my guide camera is 6.7 and I managed this (and with a mono camera guiding needs to be even tighter).

Adam

That’s a lovely image btw, do you consistently get good guiding with that ratio?

[Adam J]

13 minutes ago, Craig a said:

That’s a lovely image btw, do you consistently get good guiding with that ratio?

0.6-0.8 RMS in good seeing (80% of the time), of course in poor seeing its upto 1.2 RMS (1 in 8), on a really really good night 0.5 RMS (1 in 50).

With an RMS of less then half the image scale I dont really see any further improvements in image quality though.

So with the 130PDS and the 533 I would think that optimal guiding will be 0.6 RMS or less. Hence you would need an guide RMS or around 0.4 to get full benefit from imaging at 0.77....I have never got down to 0.4, hence its at that point that you need a very serious mount and very good seeing. 

Adam

 

Edited August 21, 2020 by Adam J

[Craig a]

Totally makes sense Adam, to be honest I’m looking forward to using that little 130pds my 10inch f4 scope is big and heavy and the slightest gust of wind the sub is ruined, collimation is dark art at f4 also I can spend hours and hours on it and still not be happy, I already have a skywatcher coma corrector for the pds as my first scope was the 200p that corrector also acts as a 0.9x reducer helping to raise that arc sec pp abit more again, I’ve also read thorough that huge thread on here about imaging with the 130pds and have to say there’s some spectacular images in that thread particularly uranium’s images he’s got the 130 down to a t!

Edited August 21, 2020 by Craig a

[Craig a]

Well I’ve got the 130pds here with me now I’ve been tinkering with it already, I’ve painted the inside of tube with Stuart sample black 2.0 paint, it’s totally Matt black the flattest blackest paint ive ever seen also done around the secondary and any shiny nuts and bolts in there, my moonlite mounting kit has also arrive from flo cudos to them they are fast at delivering, so the 130pds has a moonlite dual speed focuser on it now, just waiting on a losmandy plate from Altair Astro to fix the tube rings too, I don’t like the stock vixen bar it came with, next job is collimation

[CCD-Freak]

I finally got out to the dark site to try out my ASI-533MCP.  This image of the Pac Man nebula NGC281 is 60 minutes total (30 x 120sec) Gain=100 @ -5°C I used an 8" F3.8 Newt at .98"/pixel.   The ASI-533MCP is proving to be a sweet camera and I am looking forward to my imaging expedition to south west New Mexico this fall.

John Love
CCD-Freak
WD5IKX

 

[Craig a]

12 hours ago, CCD-Freak said:

I finally got out to the dark site to try out my ASI-533MCP.  This image of the Pac Man nebula NGC281 is 60 minutes total (30 x 120sec) Gain=100 @ -5°C I used an 8" F3.8 Newt at .98"/pixel.   The ASI-533MCP is proving to be a sweet camera and I am looking forward to my imaging expedition to south west New Mexico this fall.

John Love
CCD-Freak
WD5IKX

 

Looking good, I carnt wait to get my hands on this camera, to see the difference between my old 1100d and the 533 will be like going from writing on slate  straight to a computer and keyboard 😀, did you use a uv/ir filter with this camera? 

Edited August 25, 2020 by Craig a

[Adam J]

dam

18 hours ago, CCD-Freak said:

I finally got out to the dark site to try out my ASI-533MCP.  This image of the Pac Man nebula NGC281 is 60 minutes total (30 x 120sec) Gain=100 @ -5°C I used an 8" F3.8 Newt at .98"/pixel.   The ASI-533MCP is proving to be a sweet camera and I am looking forward to my imaging expedition to south west New Mexico this fall.

What coma corrector are you using?

[Adam J]

On 22/08/2020 at 13:36, Craig a said:

Well I’ve got the 130pds here with me now I’ve been tinkering with it already, I’ve painted the inside of tube with Stuart sample black 2.0 paint, it’s totally Matt black the flattest blackest paint ive ever seen also done around the secondary and any shiny nuts and bolts in there, my moonlite mounting kit has also arrive from flo cudos to them they are fast at delivering, so the 130pds has a moonlite dual speed focuser on it now, just waiting on a losmandy plate from Altair Astro to fix the tube rings too, I don’t like the stock vixen bar it came with, next job is collimation

What is the tube length on your moonlight? Just wondering if the SW CC will push it back into the light path. 

Also I would check your mirror clips are not too tight. 

Adam

[CCD-Freak]

9 hours ago, Craig a said:

Looking good, I carnt wait to get my hands on this camera, to see the difference between my old 1100d and the 533 will be like going from writing on slate  straight to a computer and keyboard 😀, did you use a uv/ir filter with this camera? 

I usually use a UV-IR filter but I was shooting this with a Newt astrograph so I did not put it on for this test run.

John
CCD-Freak
WD5IKX

[CCD-Freak]

3 hours ago, Adam J said:

dam

What coma corrector are you using?

I was using the Sky Watcher Aplanatic coma corrector.  the corners look good but I notice a circular halo on the brighter stars so I need to figure out where it is coming from.  I have used this corrector on an 8" F5 and an ASI-1600MC and I did not notice it with that setup.  I will be putting the ASI-533MCP on a 10" F4.7 Newt in the near future.   Here is a pix of the setup for the NGC281 image.

John
CCD-Freak
WD5IKX