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Advice on paring a William Optics Zenithstar 61 with a one shot colour (cooled) CCD Camera

Nikon D750 Equipment CMOS Buying Advice
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bluespeck avatar
bluespeck avatar
Hi all.
 
I am currently paring my William Optics Zenithstar 61ii (Z61) with a DSLR (Nikon D750). While I am still a beginner, the more I practice and the more I learn about imaging and processing, the more fussy I am becoming with the results. So far I have been quite pleased with some of my images, but I know that my telescope and camera combination does have limitations and I am wondering if it is time to start the upgrading process with a new camera. 
 
I am not yet at the point where I can seriously devote the the number of hours required to properly image with a mono CCD and multiple narrowband filters, so I think that a one shot colour (cooled) CCD might be my best option.  I have heard that some telescopes pair better with certain sensors and was told to be careful with whatever decision I make. This is where I start to get confused.  
 
The world of CCD imaging is totally new to me but from the little bit of online window shopping I have done so far, the ZWO ASI2600MC Pro Colour seem like it might be a good fit. On the other hand I also wonder if it might be overkill for a small wide-field scope like the Z61.  ???

I would be grateful for any guidance and recommendations on pairing the Z61 with a one shot colour (cooled) CCD.  Ideally I’d like to keep it under $2,000 CAD ($1,500 USD) but would be willing to go up towards the $2,300 CAD ($1,800 USD) price range if I have to.
 
Your advice and suggestions would be welcome.  Thanks in advance for any assistance.
bluespeck avatar
bluespeck avatar
The 2600mc is perfectly fine for wide field imaging. I used my 533mc with some wide field scopes and it matches quite well. Could 2x drizzle integrate for some higher resolution images if you dither enough.

Clear Skies

Thanks Allan
John Noble avatar
John Noble avatar
I just stepped back into imaging after a bit of sabbatical and started off with a Canon 6D modified and the Z61 if you are away from the city lights (Bortle 6 on down) you will get very good results with a similar set up (not sure if your camera is modified). I switched to an ASI2600MM Pro after about 6 months and was amazed at the difference when shooting from my Bortle 8/9 backyard.

So to answer your first question the 2600 MC and MM pair very well with the Z61 good field of view and reasonable image scale given the small pixels, much better resolution than with my Canon 6D where the pixels are roughly twice the size.


If you suffer from light pollution I'd strongly recommend you go for the mono option if not then you will be fine with the color version. The real issue with Mono is not time it's money! You have to collect roughly the same number of photons either way so my guess is it balances out - the processing is really very little different. If you are under light polluted skies my guess would be eventually the extra efficiency of the mono chip and the option of narrow band will suck you in.

Hope that helps.
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Bob Rucker avatar
Bob Rucker avatar
I have a Zenithstar 61 and my first OSC was an uncooled ASI294MC. I then upgraded to a cooled camera going with the ASI533MC which worked really well for me. I would typically use drizzle with integration. The only negative with the 533MC is the smaller sensor which makes some wide field targets a bit more challenging. If you have the budget, a larger sensor camera is definitely a plus. 

The ASI294MC is a good larger sensor "budget" camera. Proper calibration frames will correct the amp glow but I have to admit OSC processing was much easier with my 533MC. If I were purchasing another OSC right now, I'd probably want the 2600MC for the large sensor without amp glow. I recently sold off my OSC cameras and made the switch to a mono 294MM. If I every strike it rich, I'd love to have a pair of 2600MC's with both a OSC and mono for ultimate flexibility. Ah, one can dream…
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bluespeck avatar
bluespeck avatar
John Noble:
I just stepped back into imaging after a bit of sabbatical and started off with a Canon 6D modified and the Z61 if you are away from the city lights (Bortle 6 on down) you will get very good results with a similar set up (not sure if your camera is modified). I switched to an ASI2600MM Pro after about 6 months and was amazed at the difference when shooting from my Bortle 8/9 backyard.

So to answer your first question the 2600 MC and MM pair very well with the Z61 good field of view and reasonable image scale given the small pixels, much better resolution than with my Canon 6D where the pixels are roughly twice the size.


If you suffer from light pollution I'd strongly recommend you go for the mono option if not then you will be fine with the color version. The real issue with Mono is not time it's money! You have to collect roughly the same number of photons either way so my guess is it balances out - the processing is really very little different. If you are under light polluted skies my guess would be eventually the extra efficiency of the mono chip and the option of narrow band will suck you in.

Hope that helps.

Hi John.  

Thanks for good the feedback.  I am currently doing most of my shooting from backyard Bortle 5 skies with the Z61 and an unmodified full frame Nikon D750.  I also recently joined a regional astronomy club and am looking forward to future opportunities to image from Bortle 3.5 skies at their roll top observatory (which isn't too far from where I live).

Your point about the cost of mono (with filters) versus one shot colour is a very important one (thanks) and will most likely sway me towards the ASI2600MC Pro (color).

Btw... I also sometimes use a crop sensor Nikon D7100 and had been contemplating whether I should astro modify it or just upgrade right into CCD imaging. I am leaning towards skipping the astro conversion and putting the money towards the CCD.  

Thanks for your assistance. 
  is
bluespeck avatar
bluespeck avatar
Bob Rucker:
I have a Zenithstar 61 and my first OSC was an uncooled ASI294MC. I then upgraded to a cooled camera going with the ASI533MC which worked really well for me. I would typically use drizzle with integration. The only negative with the 533MC is the smaller sensor which makes some wide field targets a bit more challenging. If you have the budget, a larger sensor camera is definitely a plus. 

The ASI294MC is a good larger sensor "budget" camera. Proper calibration frames will correct the amp glow but I have to admit OSC processing was much easier with my 533MC. If I were purchasing another OSC right now, I'd probably want the 2600MC for the large sensor without amp glow. I recently sold off my OSC cameras and made the switch to a mono 294MM. If I every strike it rich, I'd love to have a pair of 2600MC's with both a OSC and mono for ultimate flexibility. Ah, one can dream...

Hi Bob.  Thanks for sharing your experience with your Z61 and one shot colour CCD camera.  Funny you should mention the ASI294MC. It is actually the camera that William Optics suggested might be a good fit with the Z61.  I think that the new ones are cooled but I can't help thinking that the larger sensor in the ASI2600MC might be a better long term solution, especially if I decide to upgrade to a larger scope at some point down the road.  Thanks again.
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wsg avatar
wsg avatar
Hi Bluespeck

start at the top

https://www.astrobin.com/users/wsg/
bluespeck avatar
bluespeck avatar


Take a look at this site to compare sensors and telescope suitability: https://astronomy.tools/calculators/ccd_suitability

Thanks for for this additional info.  It is very helpful.
bluespeck avatar
bluespeck avatar
Hi Bluespeck

start at the top

https://www.astrobin.com/users/wsg/

Hi WSG,

Thanks for the link... beautiful work!  It is so nice to see the results possible with the Z61 / ASI2600MC combo.  I notice that you also image with an ASI533MC.  Any personal feedback about pros and cons between the two?
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SemiPro avatar
SemiPro avatar
You didn't ask me but I have used both the 533 and 2600. Think of the 2600 as the 533's bigger brother. Both are fairly new and have no amp glow. Both have the same sized pixels. Same everything actually, aside from the 2600 being 16 bit and 533 being 14 bit.

I would say the 533 is easier to use because of the smaller frame, but considering you are coming from a full-frame camera I don't think that is a problem UNLESS you found that to be a problem.

If you are in Canada, the 2600MC is actually on sale right now for $2,268 CAD!
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bluespeck avatar
bluespeck avatar
You didn't ask me but I have used both the 533 and 2600. Think of the 2600 as the 533's bigger brother. Both are fairly new and have no amp glow. Both have the same sized pixels. Same everything actually, aside from the 2600 being 16 bit and 533 being 14 bit.

I would say the 533 is easier to use because of the smaller frame, but considering you are coming from a full-frame camera I don't think that is a problem UNLESS you found that to be a problem.

If you are in Canada, the 2600MC is actually on sale right now for $2,268 CAD!

Thanks Semi.  
bluespeck avatar
bluespeck avatar
You didn't ask me but I have used both the 533 and 2600. Think of the 2600 as the 533's bigger brother. Both are fairly new and have no amp glow. Both have the same sized pixels. Same everything actually, aside from the 2600 being 16 bit and 533 being 14 bit.

I would say the 533 is easier to use because of the smaller frame, but considering you are coming from a full-frame camera I don't think that is a problem UNLESS you found that to be a problem.

If you are in Canada, the 2600MC is actually on sale right now for $2,268 CAD!

Thanks Semi.  

Btw, as an aside... I was looking at some of the great images on your Astrobin page and noticed that you are using a William Optics Fluorostar 91.  I have been very interested in it as an upgrade from my Zenithstar 61.  I know that it is a little off topic from my original post, but I'd welcome you feedback on that too. Thanks.
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SemiPro avatar
SemiPro avatar
Its a great telescope, a triplet as opposed to your doublet. I chose it because it has a pretty good focal ratio and a decently wide field which other triplets in the 90 - 100 range struggled with. The other one I was looking at was the Esprit series since they were the only other scopes I found with a low focal ratio that didn't cost an arm AND a leg. The FLT was just an arm smile It is actually the only telescope I have bought new.

What I really like about it is the included field rotator. Really helps with my mosaics! I am not sure how much imaging you have done but if you are still starting out I would suggest sticking it out with the Z61 until you find your "calling" so to speak. Different telescopes are good at different things.

For example: As you can probably tell from my profile I have a bit of everything in there, but I really love planetary nebulae and mosaics so my choice of scopes reflect that (by mostly using an RC and the FLT 91). I actually found a used RASA on the cheap so that will become my mosaic workhorse for broadband data. It will also help when I am stuck in the inner city because at 200mm aperture and being f/2 it will build a good SNR like its no ones business. I also have to stay portable since I am in bortle 8-9 so again, my choice of equipment reflects that. So that is an example of how what you like to image or where you live can dictate what kind of scope you get.
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losman_2 avatar
losman_2 avatar
I have a Z61 and use the 294mc-pro. I’ve been happy with the combination, especially as I consider a slightly  larger scope. Admittedly I’m starting to research issues with this camera and filters like the l-enhance from Optolong. Some of my flats have been weird (with the filter), though I’m not sure if it is user error or some sensor issue. I considered the asi533 and that was recommended by Highpoint Scientific for this scope, but after talking with someone who had both I was talked into the 294 (FWIW).
bluespeck avatar
bluespeck avatar
Its a great telescope, a triplet as opposed to your doublet. I chose it because it has a pretty good focal ratio and a decently wide field which other triplets in the 90 - 100 range struggled with. The other one I was looking at was the Esprit series since they were the only other scopes I found with a low focal ratio that didn't cost an arm AND a leg. The FLT was just an arm It is actually the only telescope I have bought new.

What I really like about it is the included field rotator. Really helps with my mosaics! I am not sure how much imaging you have done but if you are still starting out I would suggest sticking it out with the Z61 until you find your "calling" so to speak. Different telescopes are good at different things.

For example: As you can probably tell from my profile I have a bit of everything in there, but I really love planetary nebulae and mosaics so my choice of scopes reflect that (by mostly using an RC and the FLT 91). I actually found a used RASA on the cheap so that will become my mosaic workhorse for broadband data. It will also help when I am stuck in the inner city because at 200mm aperture and being f/2 it will build a good SNR like its no ones business. I also have to stay portable since I am in bortle 8-9 so again, my choice of equipment reflects that. So that is an example of how what you like to image or where you live can dictate what kind of scope you get.

Thanks for the very helpful reply. It is much appreciated.  
bluespeck avatar
bluespeck avatar
I have a Z61 and use the 294mc-pro. I’ve been happy with the combination, especially as I consider a slightly  larger scope. Admittedly I’m starting to research issues with this camera and filters like the l-enhance from Optolong. Some of my flats have been weird (with the filter), though I’m not sure if it is user error or some sensor issue. I considered the asi533 and that was recommended by Highpoint Scientific for this scope, but after talking with someone who had both I was talked into the 294 (FWIW).

I have looked at the 294 and 533 too, but think if I can save up the extra dollars, I'll probably go with the 2600.  Thanks so much for sharing your experience with the Z61 and ASI294.
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Giambattista Rizzo avatar
Giambattista Rizzo avatar
Utilizzo uno Zenistar 61 col suo spianatore con la mia Nikon D750 Full Frame ma non è affatto spianato fino ai bordi. Inoltre non riesco a trovare in nessun modo il giusto backfocus