ZWOASI071MC and new ZWOASI2600MC

[Startrek]

Looking at making the jump from DSLR to cooled OSC Camera mid year and have been spending time reviewing various forums and reviews etc...
Looking at either the ZWOASI071MC ( proven performer ) and the newly released ZWOASI2600MC
Specs for both cameras below -

ZWO ASI071MC Specs

APS-C crop sensor
Sony IMX071 CMOS sensor
16 Mega Pixel
Resolution 4944 x 3284 pixels
Pixel pitch 4.78uM
Sensor size 23.6mm x 15.6mm
Diagonal 28.4mm
Full well 46,000e
Read Noise 2.3e
Bayer Pattern RGGB
ADC 14bit
Weight 640gm
Diameter 86mm
Regulated 2 stage TEC cooling
QE 50%

ZWOASI2600MC Specs

APS-C crop sensor
Sony back illuminated IMX571 CMOS sensor
26 Mega Pixel
Resolution 6248 x 4176 pixels
Pixel pitch 3.76uM
Sensor size 23.5mm x 15.7mm
Diagonal 28.3mm
Full well 50,000e
Read Noise 1.0e to 3.3e
Bayer Pattern RGGB
ADC 16bit
Weight 700gm
Diameter 90mm
Regulated 2 stage TEC cooling
QE 80%

Looking at the specs, the 2600MC is technically superior on paper but unfortunately there are not enough reviews as this camera has only been out 2 months
The image scale on my scopes would be as follows ( similar to my DSLR ) -
6” f6 newt with 071MC 1.09 arc sec per pixel
6” f6 newt with 2600MC 0.86 arc sec per pixel
8” f5 newt with 071MC 0.98 arc sec per pixel
8” f5 newt with 2600MC 0.77 arc sec per pixel

I intend to use APT for frame focus and capture
My 6” newt is used in Sydney under Bortle 7/8 skies
My 8” newt is used at my weekender south coast NSW under Bortle 3 skies
Obviously DSO imaging only with these cameras

I’m still going to use my DSLR but only during the winter months

I’m treading into new territory here with a cooled OSC Camera and will have to get experience through trial and error with things like exposure time , gain settings and offset Etc...
PS: I’m a ZWO man through and through as I’ve been using ZWO guide cameras for a number of years and want to continue the relationship

Any advice on the above most welcome

[The_bluester]

This is one of the first ASI2600 images I have come across. https://www.astrobin.com/full/qoy3js/0/

I am currently waiting for more images to make a decision between an ASI2600 or digging a much bigger hole in my pocket with an ASI6200 (Probably mono, just to make the hole that much deeper again) as my hopefully soon to arrive scope has a 43mm image circle compared to a 43.3mm diagonal on the ASI6200. I plan to track down an M48 format adapter for my wife's full frame Nikon D3 to see if it really does cover that kind of diagonal nicely first.

[PaulSthcoast]

Hi Martin,

do I sense that perhaps you are about to move on from`Beginner` status ?!!

Paul.

[Startrek]

Paul ( The bluester )


Glad I'm not the only one considering the 2600MC.Its a big investment but worth the plunge if its as good as ZWO claim it is. Yes, need to wait for some more results over the next few months ( Usually Cloudy Nights is a reasonable litmus test ) Thanks Paul



Paul ( South coast )


I'm still a beginner Paul and it will take some time to master the cooled OSC camera anyway

Maybe in a couple of years if I'm game enough I might post in the Deep Sky Section ? Who Knows ?

How are you going with your AP set up ?

Next time Im down at the house we might catch up again in town ( A bit busy at the moment , trying to get my 92 year old Dad into Aged Care , not easy )
Cheers Paul

[RyanJones]

Hi Martin,

I’m glad you’ve brought this topic up. I’m also looking to go OSC too around the same sort of time as you know. I’m set on the 071MC simply because I’m stretching myself already to fund that but I’m insistent on an APSc sensor as a minimum. I’ll be watching this thread more so to see if there’s any reason why I shouldn’t buy the 71.

[Jackstar]

Hi Martin,

I have been looking to move forward into a dedicated OSC and decided the O71 was the go for me and my set up.
I currently use the modded canon 40d that I bought from the classifieds.
My scopes are the Orion EON 115, f/l 805 mm f7.
And the explore scientific ed80 480mm f6
With this I think will get 1.22 arc sec/pixel for the Orion and 2.05 with the Es ed80

I have been reading this:
http://https://www.atik-cameras.com/news/rules-1-2-arc-second-per-pixel-and-when-to-break-them/

I have been aiming to stay in this 1-2 arc sec per pixel as I have little experience in any of this.

I see that your arc seconds per pixel are much lower and wonder whether I was over thinking it.
Have you taken the arc seconds per pixel into your decision and purposely aimed at close to and below the 1?

I too will be interested in the discussion

Jack

[Startrek]

Jack
Thanks for commenting
My existing image scale with my Canon 600D APS-C sensor is 0.88 and 0.98 arc sec per pixel respectively so both proposed OSC cameras are similar in sampling or over sampling to be correct
Over sampling has worked for me to date ( I’ve been imaging for just over 2 years ) and it’s only when seeing and transparency is really poor I have some issues with my images. The biggest issue I have with my DSLR is noise during the summer months or even warmer nights in spring and autumn. The cooled OSC Camera should eliminate this issue. The DSLR has been a great camera and still is (I will still use it ) but I think I’m ready to make the upgrade later this year
I keep things simple that’s why I use Newtonian reflectors for imaging , plenty of aperture and good focal length , although I would like to push my FL to 1200mm but that’s another story
Thanks again and I hope other Astrophotographers can chime in with comments

[Startrek]

Ryan
Thanks for your comments, hoping there are a few more DSLR prime focus users looking at an upgrade to cooled OSC cameras too
Martin

[The_bluester]

Depending on the camera, binning may be an option if you are excessively oversampled, for instance my ASI294MC Pro still produces a colour image when binned and if I put it back on my SCT at some point it will be oversampled so I may give binning a try there. I never went as far as doing that in the past as I jumped in to short focal length imaging and I am at the other end of the scale, undersampled with about 2.6 arc seconds per pixel. In my case I can use about 5 minute subs so I shoot loads of subs and use a drizzle process in Astro Pixel Processor to recover some resolution that way.

edited to add, the only real issue I know if with the 071 is the sensor package is apparently quite prone to frosting (Not just the ZWO camera apparently, more or less any cooled cam using that chip) and you need to ramp the cooling power up slowly to avoid it. I am finding my 294 is doing similar at the moment so I may have an air leak into the sensor chamber.

[Startrek]

Paul,
One of the first things I do after stacking in DSS and start my processing, is use the Binning module in Startools which trades of a bit of resolution to improves SNR
Default is 50% binning
Other options are 25% and 71% which I’ve tried but don’t use
This process works really well at my image scale and scales down the image to a workable file size too

Martin

[ChrisV]

Love my 071, can't comment on the other. And there's an ASI071 up for sale in the classifieds. Cheaper than a new one.


Disclaimer: it ain't mine.

[Startrek]

Chris
Thanks for posting
Are you able to give us some more of your AP details with the 071MC
Scope
Mount
Guiding set up
Focal length and Image scale
Filters
Capture software
Gain and offset settings for various targets in Sydney
Cooling temps

Don’t t give any trade secrets away ok

Cheers
Martin

[ChrisV]

Most of my nonsense from the asi071 is here
https://www.astrobin.com/users/ChrisFC/

I use both an 8" F5 gso and and 80mm F5.9 WO refractor on a CGEM mount. I think the imaging scales are about 0.9 and 1.6 arcsec/pixel. I particularly like it with the newt.
Guiding 50mm zwo guidescope, phd2.
Capture with SGPro. I use the standard unity gain setting this ascom.
With a UV/IR filter the optimal sub length is 60-90sec (to swamp read noise). Can share my spreadsheet calculator for this.
With the STC duo filter I use 6 min subs, although longer is probably better on some targets.
I used to cool to -5C. But now just to 0C. It doesn't need as much as CCD sensors as the dark current noise is so low.

For processing I don't use bias frames. Not needed!

[Startrek]

Chris
Thanks for the info, fantastic
A great help for us DSLR to Cooled OSC converts
Martin
PS: nice images on Astrobin too , great work well done !!

[Startrek]

Chris
I have an 8” f5 newt as well , what adapters , extension rings etc did you require between the camera and the 2” focuser barrel to allow you to focus ?
Also I use a Baader MCCP Mk 111 coma corrector with my DSLR and will use it for the proposer cooled OSC as well. The coma corrector would have a bearing on what adapters and extension rings I would need to achieve focus ?

Appreciate any advice on back focus with the cooled OSC

Thanks in advance

[PaulSthcoast]

Paul ( South coast )


I'm still a beginner Paul and it will take some time to master the cooled OSC camera anyway

Maybe in a couple of years if I'm game enough I might post in the Deep Sky Section ? Who Knows ?

How are you going with your AP set up ?

Next time Im down at the house we might catch up again in town ( A bit busy at the moment , trying to get my 92 year old Dad into Aged Care , not easy )
Cheers Paul[/QUOTE]



Hi Martin,

yes would love to catch up when you are down next, all going to plan I will be in a better position to get out and about.

I`m eager to get out and put my gear to use.

A few clear nights might help !!

Hope all goes well with Your Dad.

Keep in touch,

Paul.

[ChrisV]

It's simple - the zwo cameras come with two solid T-spacers. Baader into the 2" focuser barrel of your newt, then two T-spacers, then camera. Gives the correct spacing.

There's two spacers. One can be replaced with a filter wheel, the other with an oag.

[Startrek]

Chris
Thanks for the advice
Martin

[ChrisV]

I'm sure the 2600 will be similar with spacing if you go with that. It does look like a nice camera !

[Startrek]

Chris
Thanks I did check the ZWO website and it shows the configuration for back focus
Looks like a fantastic camera on paper
Quantum Efficiency around 80%
Smaller pixels and more of the them so higher resolution ( obviously dependant on seeing conditions )
16 bit
Almost no amp glow
Lower dark current
Deeper well depth

But all the above comes at a price !!

I’ll just play the waiting game and review any comments posted on various forums over the coming months

[The_bluester]

If you mean the 2600, images are just starting to turn up on astrobin. Like this one taken with an SCT and Hyperstar.

https://www.astrobin.com/full/qoy3js/0/

[Startrek]

Paul
Thanks for checking, nice image but looks a little bit blown out or overstretched
I’ll look forward to seeing some images using a 6” or 8” newt
Cheers

[The_bluester]

I would probably not stretch or saturate it so hard either, but as a first image from one of those cams it looks fairly promising.

[Startrek]

Just found a really good detailed review of the new ZWOASI2600MC camera on AstroNorth.com ( Tim Connolly )
Plenty of detailed hands on descriptions and images to review
Camera is looking really promising ( excluding the price tag $4K )
Probably the biggest learning curve jumping up from a humble DSLR is being able to “tame the beast”
Just enquiring whether any members in Australia have one of these cameras in their arsenal
Thanks in advance

[gregbradley]

This may be an excellent camera. File sizes won't be so huge as the 6300 and vignetting would be less of a problem. Less expensive and filters wouldn't have to be as large.

Full frame though gets a wider field of view which always looks better in 90% of images.

80% QE, 16bit and high dynamic range. Tempting.

This must be the same APSc sensor used in the Fuji XT3 and 4.

Just looked around a bit more and there isn't a mono version. I wonder if they plan to release one later.
One shot colour may be convenient but I would rather do filtered imaging.

Greg.

[Startrek]

Greg
The sensor on the ZWOASI2600MC is a back illuminated Sony IMX571 APS-C , don’t know whether it’s similar to the Fuji
I’m considering buying one over the next few months but supply is difficult at present due to Corona and I’m happy to wait for some more reviews
I will be using it under Bortle 3 skies south coast NSW and in Sydney under Bortle 8 ( thinking about a OSC narrowband filter , duo band , tri band or quad band )
Camera has incredible specs but reviews are just as important too

[gregbradley]

26mp BSI Sony sensor is almost certainly the same as the Fuji 26mp Sony BSI sensor.

But of course the Fuji has its own proprietary colour matrix (not Bayer its a 6 x 6 grid with more emphasis on the green). Plus there are threads now showing Fuji like Sony engage in filtering their RAW data resulting in some green faint stars.

Also not 16 bit (14bit) and not cooled.

Same with a Sony A7riv its the same BSI full frame 61mp sensor but of course with a Bayer colour matrix and not cooled plus some RAW filtering.

These ASI and QHY cameras are getting results way past what you could get with the mirrorless cameras using the same sensor.

ASI2600MC sounds great but I would've personally wanted the mono. Also I find the specs listed by ZWO misleading. Saying 84% QE for the ASI2600MC is a lie as that would be the QE for the mono version not the colour. Probably more like 60% or so (QE's for popular cameras are listed somewhere - it may be Christian Buil's site, 65% is about as high as they go) much like CCDs except mono CCDs utilise every pixel and are best for narrowband. One shot colour is fun but its way slower and dim areas suffer noise plus weaker at narrowband which is where these cameras excel.

Not trying to be a downer but its better to go into it with eyes wide open.

Greg.

[Camelopardalis]

Just curious, but why would the QE be lower for OSC than mono? Obviously the Bayer array is doing the colour filtering, but if a red photon hits the red photosite, then it's not otherwise impeded? Likewise for the other two channels of course.

The 183 is listed as 83-84% QE also, doesn't seem unreasonable for back-illuminated sensors.

[gregbradley]

http://www.astrosurf.com/buil/50d/test.htm

Scroll down a bit and you can see the QE for some older Canon cameras. Pretty low compared to CCD or modern Sony or Panasonic CMOS.

Bayer Matrix means less light hitting the sensor. Also that 4 pixels are used to make 1 colour pixel. Mono uses all pixels and nothing is inhibiting light from hitting the sensor.

I did see a long list of modern cameras and their QE. As I recall the highest were the latest Sony's like the A7riii and A7riv. QE is up around 65%.

So marketing claims of 84% for a one shot colour is misleading as that is the QE for a mono chip not a one shot colour which are always considerably less.

I agree 84% for a mono BSI sensor is realisitic. Its not for a one shot colour sensor.

Greg.

[Camelopardalis]

QE is measured at a spread of wavelengths, hence the plots. Peak QE will be quoted at the wavelength where this is highest. For Sony sensors to demonstrate QE in the 80s % isn't unreasonable given advances in sensor tech in the last 10 years. I'm not defending ZWO's data one way or another.

This (reputable?) doc makes for an interesting sensor QE comparison: https://www.flir.com/globalassets/iis/guidebooks/2019-Machine-Vision-EMVA1288-Sensor-Review.pdf (note: they specify 530nm)

QE is a measurement of the output of electrons from photon strikes...mono or OSC makes no difference. The pixel in a mono sensor can't tell the difference between a colour filter in a wheel and a colour (Bayer) filter printed on. If a given filter is less efficient than another, that's a disadvantage for sure. Given the competitive market of the sensor business, it wouldn't make any sense for Sony to scrimp on the quality of the Bayer filter.

Of course, the mono is more versatile...and we can get "full" resolution for a given colour filter rather than the reduced colour resolution of OSC, which I think is what you're getting at?

These sensors have made me consider going back to OSC, the 2600 sure does look good on paper.

[Startrek]

Yes specs look impressive
I guess there would be a huge backlog or orders from around the globe for this camera due to our current situation
I’m happy to wait a while and look at some more reviews but will probably bite the bullet towards the end of winter and order one

[gregbradley]

I notice on ZWO's website for the colour version of their chips in a comparison table they list these 80% QEs for the mono and for the colour they show TBD (to be determined). They do state the high 80 and 84% QE on some individual colour camera specs. Maybe its right. I don't think so as these are the same full frame sensors used in the Sony A7riv and they are more like 65% QE.

Regardless of the actual QE for the colour sensor it does look like a big step forward for these CMOS cameras.

From my recent study into them it seems the 2 main issues with CMOS has been amp glow and uneven dark noise that does not calibrate out.

Whether you can get around that with careful calibration (my setups already require careful calibration anyway) is another story but its good to know the actual pros and cons of the gear away from the marketing materials which have every scope as a fluorite triplet and the best camera ever.

What I would want to see is that this 2600 gives decent colour.

Greg

[SuperG]

If you're looking to jump mi-year then place your order now. Orders are taking a couple to a few months to be fulfilled.