Which astro camera for live stacking?

[Ships and Stars]

Hi all, any suggestions on an excellent, yet 'affordable' dedicated astro camera for live stacking on a 20" 2000mm f4 dob with alt/az goto tracking? In other words, for EEVA viewing real time on a laptop? The alt/az tracking mount can do up to 6" sec subs with a DSLR without star trails.

I like the ZWO ASI 533MC-PRO but I don't know anything really about astro cameras and this is really absolute maximum budget - less £££ is better of course! Is the 533 overkill?

Looking for max field of view, quality output and ease of use. Do focal reducers work, or do they create more problems?

Ideally this post complements my other post in the EEVA section which asks a veritable slew of novice questions...😄

Thanks for any camera suggestions...

 

Edited October 6, 2020 by Ships and Stars

[vlaiv]

With such focal length - I would go with real estate rather than "performance" - however, real estate also costs and that is a problem with limited budget.

If you can, depending on your EEVA expecations, go with mono version - it will be better but it will of course only provide monochromatic images (very much like visual on most targets). I don't think you want to mess with filters, so if you really want color - then of course OSC camera is better.

ASI294 is probably better choice with respect to your focal length and even that camera will give you half a degree FOV.

Not sure if there is focal reducer that will work on F/4 newtonian together with coma corrector and illuminate 4/3 sensor size. What you could try, but that will eat most of your budget, is something like this:

https://www.teleskop-express.de/shop/product_info.php/info/p9779_TS-Optics-NEWTON-Coma-Corrector-0-73x-Reducer---2--Connection.html

 

[Adam J]

 

1 hour ago, Ships and Stars said:

Hi all, any suggestions on an excellent, yet 'affordable' dedicated astro camera for live stacking on a 20" 2000mm f4 dob with alt/az goto tracking? In other words, for EEVA viewing real time on a laptop? The alt/az tracking mount can do up to 6" sec subs with a DSLR without star trails.

I like the ZWO ASI 533MC-PRO but I don't know anything really about astro cameras and this is really absolute maximum budget - less £££ is better of course! Is the 533 overkill?

Looking for max field of view, quality output and ease of use. Do focal reducers work, or do they create more problems?

Ideally this post complements my other post in the EEVA section which asks a veritable slew of novice questions...😄

Thanks for any camera suggestions...

 

I think that the 533mc is a good choice for ease of use in live stacking. I would just have a preference for the cleaner sensor over the 294mc despite it being the larger sensor but it depends on what you want to view with it and if those fit into the FOV with the smaller sensor or not. I suspect we are talking about small galaxies and planetaries and globs?  But if mostly galaxies then I would be going mono with very short subs to try and beat the seeing 2s or so as you wont get great colour rendition anyhow. The new ASI294mm pro is a good choice for that...pricey in comparison to a 533 though. 

 

Edited October 6, 2020 by Adam J

[Adam J]

24 minutes ago, vlaiv said:

With such focal length - I would go with real estate rather than "performance" - however, real estate also costs and that is a problem with limited budget.

If you can, depending on your EEVA expecations, go with mono version - it will be better but it will of course only provide monochromatic images (very much like visual on most targets). I don't think you want to mess with filters, so if you really want color - then of course OSC camera is better.

ASI294 is probably better choice with respect to your focal length and even that camera will give you half a degree FOV.

Not sure if there is focal reducer that will work on F/4 newtonian together with coma corrector and illuminate 4/3 sensor size. What you could try, but that will eat most of your budget, is something like this:

https://www.teleskop-express.de/shop/product_info.php/info/p9779_TS-Optics-NEWTON-Coma-Corrector-0-73x-Reducer---2--Connection.html

 

 

With the smaller sensor of the 533 you may also get away with the SW CC with its 0.9x reduction at F4. Not much but it gets him down to F3.5, unlikely it would be up to the task with the 294 though as its not really designed for F4. 

Adam

Edited October 6, 2020 by Adam J

[Ships and Stars]

1 minute ago, Adam J said:

 

I think that the 533 is a good choice for ease of use in live stacking. I would just have a preference for the cleaner sensor over the 294 despite it being the larger sensor but it depends on what you want to view with it and if those fit into the FOV with the smaller sensor or not. I suspect we are talking about small galaxies and planetaries and globs?  But if mostly galaxies then I would be going mono with very short subs to try and beat the seeing 2s or so as you wont get great colour rendition anyhow. The new ASI294mm pro is a good choice for that...pricey in comparison to a 533 though. 

Thank you Adam - a larger FOV is preferable. Yes indeed, galaxies and PN are definitely on the list, globulars too. I'd like to image/stack/live view the smaller nebulae that will fit into the FOV but realise at 2000m focal length, I can't have it all!

[Ships and Stars]

2 minutes ago, Adam J said:

 

With the smaller sensor of the 533 you may also get away with the SW CC with its 0.9x reduction at F4. Not much but it gets him down to F3.5, unlikely it would not be up to the task with the 294 though. 

Adam

Hi Adam, I have the Explore Scientific HR coma corrector, but think it has 1.05 or 1.15x barlow effect, so the wrong direction there! I looked at the 294 just now, looks awesome but yeah, a bit much money! I'd have to sell a few bits, but need to do that anyway. I do like the 294 as well though - good suggestion. I will think on that, I like the FOV very much. 

Edited October 6, 2020 by Ships and Stars

[Adam J]

4 minutes ago, Ships and Stars said:

Hi Adam, I have the Explore Scientific HR coma corrector, but think it has 1.05 or 1.15x barlow effect, so the wrong direction there! I looked at the 294 just now, looks awesome but yeah, a bit much money! I'd have to sell a few bits, but need to do that anyway. I do like the 294 as well though - good suggestion. I will think on that, I like the FOV very much. 

Well the ES HR corrector is supposed to be fantastic at F4 so I am sure it would work well with the 294mc. But hey if you cant afford it then you cant afford it. I am sure you would be pleased with the 533 and it is worth trying the SW CC in my opinion. The come up second hand all the time so you would not lose anything if it did not work out. It will be quite a bit faster than the ES HR when you take into account the HR Barlow and the SWs reduction. 

 

Edited October 6, 2020 by Adam J

[Ships and Stars]

26 minutes ago, vlaiv said:

With such focal length - I would go with real estate rather than "performance" - however, real estate also costs and that is a problem with limited budget.

If you can, depending on your EEVA expecations, go with mono version - it will be better but it will of course only provide monochromatic images (very much like visual on most targets). I don't think you want to mess with filters, so if you really want color - then of course OSC camera is better.

ASI294 is probably better choice with respect to your focal length and even that camera will give you half a degree FOV.

Not sure if there is focal reducer that will work on F/4 newtonian together with coma corrector and illuminate 4/3 sensor size. What you could try, but that will eat most of your budget, is something like this:

https://www.teleskop-express.de/shop/product_info.php/info/p9779_TS-Optics-NEWTON-Coma-Corrector-0-73x-Reducer---2--Connection.html

 

Not the cheapest hobby eh?? 🤣

I agree real estate over performance, though it sounds like the 294 would give a bit of both.

The TS newton CC and reducer is a beauty but yes, that's also a lot of money! Wow, maybe I'll live with a bit of coma this year...or lose some FOV.

I wonder if I could just keep plugging away with my Nikon D810 and stack those? It has a tethering option. Huge file sizes though (36 megapixel)

A dedicated astro camera is bound to be the better option. 

 

[Ships and Stars]

Just now, Adam J said:

Well the ES HR corrector is supposed to be fantastic at F4 so I am sure it would work well with the 294mc. But hey if you cant afford it then you cant afford it. I am sure you would be pleased with the 533 and it is worth trying the SW CC in my opinion. The come up second hand all the time so you would not lose anything if it did not work out. It will be quite a bit faster than the ES HR when you take into account the HR Barlow and the SWs reduction. 

 

I will start looking for a Sky Watcher CC Adam! Thank you. 

[Adam J]

6 minutes ago, Ships and Stars said:

I will start looking for a Sky Watcher CC Adam! Thank you. 

It eats into back focus slightly but I dont think that will be a big problem with that scope. 

[vlaiv]

8 minutes ago, Ships and Stars said:

I wonder if I could just keep plugging away with my Nikon D810 and stack those? It has a tethering option. Huge file sizes though (36 megapixel)

A dedicated astro camera is bound to be the better option. 

I would actually recommend you start with that.

Only drawback is it not being cooled, but for the time being and with short exposures, I think you can live with that.

Additional problem is finding CC that will correct and illuminate full frame sensor, however, I don't think that you need sophisticated one. FOV will also be much nicer and you can bin quite a bit to get really good SNR in short exposure.

[Ships and Stars]

1 minute ago, Adam J said:

It eats into back focus slightly but I dont think that will be a big problem with that scope. 

No it shouldn't be, my mind is racing now. I just looked at the ZWO ASI 071MC-PRO. 

Perfect FOV but a lot of money as with the 294! 

I wonder if decent astro cameras hold their resale value very well, or if something better comes out each year...

[Adam J]

7 minutes ago, Ships and Stars said:

No it shouldn't be, my mind is racing now. I just looked at the ZWO ASI 071MC-PRO. 

Perfect FOV but a lot of money as with the 294! 

I wonder if decent astro cameras hold their resale value very well, or if something better comes out each year...

Higher read noise though and lower QE, I would think that the two smaller chips are more suited to very short exposures. You would probably also SW bin the smaller chips to improve image quality unless you find that the short exposures are allowing you get get under some of the worst of the seeing.  

Its not a terrible idea to use the DSLR as above it will not be illuminated but nothing is forcing you to use the entire sensor. 

Adam

 

Edited October 6, 2020 by Adam J

[Ships and Stars]

Just now, vlaiv said:

I would actually recommend you start with that.

Only drawback is it not being cooled, but for the time being and with short exposures, I think you can live with that.

Additional problem is finding CC that will correct and illuminate full frame sensor, however, I don't think that you need sophisticated one. FOV will also be much nicer and you can bin quite a bit to get really good SNR in short exposure.

Thanks very much Vlaiv - I was doing hundreds of 6" exposures with the D810 back in March without any problems. It also has 5:4 crop mode, a mid-range crop mode between full-frame and aps-c, and of course, APS-C crop mode itself which reduces files sizes and gives a nice well-illuminated image. 

I will at least start with that since it is in hand. I was able to image some very faint galaxies earlier this year from my relatively bright home with good results. 

 

[Ships and Stars]

3 minutes ago, Adam J said:

Its not a terrible idea to use the DSLR as above it will not be illuminated but nothing is forcing you to use the entire sensor. 

Adam

 

Agree Adam - I'll probably start that route again. I had good luck with it earlier this year actually. It has a ton of crop modes, from 5:4 down to APS-C. 👍

I'll have to think about a dedicated astro camera as the FOV/larger sensor I'd like is going to cost me. Hope work stays busy!!

Edited October 6, 2020 by Ships and Stars

[Adam J]

1 minute ago, Ships and Stars said:

Thanks very much Vlaiv - I was doing hundreds of 6" exposures with the D810 back in March without any problems. It also has 5:4 crop mode, a mid-range crop mode between full-frame and aps-c, and of course, APS-C crop mode itself which reduces files sizes and gives a nice well-illuminated image. 

I will at least start with that since it is in hand. I was able to image some very faint galaxies earlier this year from my relatively bright home with good results. 

 

Great image. 

[Adam J]

1 minute ago, Ships and Stars said:

Agree Adam - I'll probably start that route again. I had good luck with it earlier this year actually. It has a ton of crop modes, from 5:4 down to APS-C. 👍

I'll have to think about a dedicated astro camera as the FOV/larger sensor I'd like is going to cost me. Hope work stays busy!!

For short exposures (<10s) dark current is not really a thing to be concerned about, what you really need is high QE large pixels and low read noise, as long as the sensor has no amp glow as is the case with the more modern sensors then cooling is not going to help you that much. 

[Ships and Stars]

4 minutes ago, Adam J said:

Great image. 

Thank yuo. I realise I'm not going to have true astrophotography quality, esp with an alt/az mount, but my main goal is to view fainter objects from home by live stacking/EEVA and capture some record shots of what I've looked at.

Image quality is always a bonus though!

Thanks very much for the information @vlaiv and @Adam J 👍

Edited October 6, 2020 by Ships and Stars

[vlaiv]

2 minutes ago, Ships and Stars said:

Agree Adam - I'll probably start that route again. I had good luck with it earlier this year actually. It has a ton of crop modes, from 5:4 down to APS-C. 

If you can, try to use whole sensor. It does not matter if there is vignetting if you can take sky flats (or have 20" flat panel ). Live stacking can be flat corrected as well.

Remember, Live stacking is about observing / detecting in short time (in digital domain) and not about getting nice image - so don't be afraid to really bin your data in software. I think that most people will enjoy final image that is about 1000px - 1500px in size. With 7360px in width, you can easily bin by x6 for massive SNR improvement on single sub.

[Ships and Stars]

Just now, vlaiv said:

If you can, try to use whole sensor. It does not matter if there is vignetting if you can take sky flats (or have 20" flat panel ). Live stacking can be flat corrected as well.

Remember, Live stacking is about observing / detecting in short time (in digital domain) and not about getting nice image - so don't be afraid to really bin your data in software. I think that most people will enjoy final image that is about 1000px - 1500px in size. With 7360px in width, you can easily bin by x6 for massive SNR improvement on single sub.

Excellent! Looks like I'll be hanging onto the D810 for a while. Sky flats are no problem. Next step - learning how to bin... I have a bit of reading to do now. Thinking Sharpcap is the way to go over DSS live, that will be my next decision.

I really appreciate the information! I'd be lost otherwise. 

[vlaiv]

1 minute ago, Ships and Stars said:

Excellent! Looks like I'll be hanging onto the D810 for a while. Sky flats are no problem. Next step - learning how to bin... I have a bit of reading to do now. Thinking Sharpcap is the way to go over DSS live, that will be my next decision.

I really appreciate the information! I'd be lost otherwise. 

Not sure if Sharpcap can work with DSLR cameras. Maybe best approach would be to search for Nikon ASCOM driver.

I know there is Canon ASCOM driver - there could be one for Nikon as well. With that driver, you can use any ASCOM capture application.

Oh, well, this seems to be sorted (a bit of fiddling to install it required):

https://github.com/vtorkalo/ASCOM.DSLR

[Ships and Stars]

5 minutes ago, vlaiv said:

Not sure if Sharpcap can work with DSLR cameras. Maybe best approach would be to search for Nikon ASCOM driver.

I know there is Canon ASCOM driver - there could be one for Nikon as well. With that driver, you can use any ASCOM capture application.

Oh, well, this seems to be sorted (a bit of fiddling to install it required):

https://github.com/vtorkalo/ASCOM.DSLR

Excellent, thanks again. I'll start with the D810 and keep my eyes out for a deal on a dedicated camera if the need still exists. The D810 is a brilliant all-around camera anyway. I bought it new about five years ago, been flawless, and have three spare batteries so I can image for long periods nightly. 

Shall look into the ASCOM link - appreciate you looking this up.

Edited October 6, 2020 by Ships and Stars

[PeterCPC]

This may help. https://www.cloudynights.com/topic/657429-how-to-use-sharpcap-with-a-dslr/

 

Edited October 6, 2020 by PeterCPC

[Nik271]

Great idea!

I believe with this scope even the liveview feed from your camera will be bright enough to see colour. 

I recently saw this video of a guy comparing 12inch with 16 inch dobs. The Dumbbell nebula was bright and green in the video feed:

 

[vlaiv]

1 hour ago, Nik271 said:

Great idea!

I believe with this scope even the liveview feed from your camera will be bright enough to see colour. 

I recently saw this video of a guy comparing 12inch with 16 inch dobs. The Dumbbell nebula was bright and green in the video feed:

I don't think that is actual color of nebula - I think he is using night vision device attached to eyepiece and filming that and not camera in prime focus.

Green color comes from night vision device.