ZWO cooled CMOS in design....

[Blazar]

Well it seems ZWO are creating a cooled CMOS as a next project. just seen these on their Facebook page...No notes on CMOS chip yet..

Time to start saving again....

[JamesF]

I did wonder if they might be doing something like this given the way their SDK has been evolving...

James

[michael.h.f.wilkinson]

Very interesting. I have seen some stuff on adding DIY coolers, but this is neater.

[JamesF]

Apparently the current test camera they have uses an IMX178 which has 2.4um pixels.  That looks an odd choice for a cooled astro camera on the face of it.

James

[D4N]

Indeed but there is an ST4 port on the back of that so they must still intend for it to double up as a guide camera.

Sent from my iPad using Tapatalk

[jambouk]

Would this be for planetary or long exposure stuff?

[ronin]

Would this be for planetary or long exposure stuff?

Generally they do both, just the chip is CMOS not CCD.

Not sure what limitations that drags in.

Means it is a good way in to doing/trying both without a great initial outlay then decide to progress to CCD or just stick with the ZWO.

[riklaunim]

ZWO and QHY are working on such cameras. QHY will have miniCAM5s and f (similar to QHY5L-II but with cooling, and 5f with integrated 9-position 12mm filter wheel).

If they will be using small pixels like 3.75 or less DS imaging will be limited - mostly to lenses. If they do plan to have a versatile DS/Planetary camera then IMHO it also should come with additional mini-camera as a guide head so that you get a full package. Instead you would need another guide/planetary camera to guide the cooled guide/planetary camera QHY integrated filter wheel is an interesting idea but it's hard to tell if it will support third party filters which vary in size from 11.7 to 12.8 mm (and in general non-standard size will make problems when searching for more advanced filters).

[D4N]

I imagine they have been looking at how people use the 120mm, mostly for planetary and guiding but also some nice DS images coming out. The problem with the DS images is they are generally unguided short subs so suffer from a lot of noise, cooling the sensor is a logical progression.

Another possibility is that it could be good for video astronomy.

Sent from my iPad using Tapatalk

[jambouk]

It seems a bit gimmicky to me. As said above it is difficult to have one camera which is optimised for both fast frame rate planetary imaging, and for long exposure deep sky stuff. Is there much benefit in cooling a CMOS for planetary imaging?

It will be interesting to see what they put inside the device.

James

[riklaunim]

Is there much benefit in cooling a CMOS for planetary imaging?

There can be for dimmer channels like methane band, UV and alike.

[catman161]

Interesting, but I will wait to see if there is any real benefit to active cooling of a CMOS chip for planetary. Without any kind of active cooling, in the winter I have had chip temps recorded at up to minus 5 on my ASI120MC when doing planetary imaging and I have not noticed any obvious benefits. The problem with any kind of test to see if cooling would actually help is the lack of repeatability. With the ever changing variables, such as seeing, humidity and temperature to name just three it would be nigh on impossible to do a comparison that has any real merit.

Sent from my iPhone using Tapatalk

[Skyline]

The top rear image looks a bit like an Atik 314 type design.

[JamesF]

Interesting, but I will wait to see if there is any real benefit to active cooling of a CMOS chip for planetary. Without any kind of active cooling, in the winter I have had chip temps recorded at up to minus 5 on my ASI120MC when doing planetary imaging and I have not noticed any obvious benefits. The problem with any kind of test to see if cooling would actually help is the lack of repeatability. With the ever changing variables, such as seeing, humidity and temperature to name just three it would be nigh on impossible to do a comparison that has any real merit. Sent from my iPhone using Tapatalk

The ASI SDK appears to allow for setpoint cooling so that may help assuming it's implemented for this camera.

I too am struggling to see where this camera is going to fit though.  Perhaps what they have thus far is just to prove the technology.  I'd have thought that it would have more "mass-market" appeal if it used the IMX174 (just a cooled ASI174, in other words).

James

[Cath]

As far as I know, one big difference between a CMOS and a CCD sensor is that a CMOS tends to be a rolling shutter and a CCD tends to be a global shutter .. which doesn't tend to matter when doing longish exposures, but does matter if you're doing short exposures with fast movements.

[riklaunim]

They were saying about multiple sensors? We shall see what the future will bring

As far as I know, one big difference between a CMOS and a CCD sensor is that a CMOS tends to be a rolling shutter and a CCD tends to be a global shutter .. which doesn't tend to matter when doing longish exposures, but does matter if you're doing short exposures with fast movements.

Sony IMX174/249 use global shutter, planetary Micron sensors in ASI/QHY use rolling, but they do work.

What do you say about this:

[Florin Andrei]

Since ZWO keeps announcing more actively cooled models, here's a speculative question:

Is there any chance that an actively cooled ZWO ASI174MC could reach the same level of noise like an ATIK 420C (or close to it)? I'm asking because the price of the cooled ASI174MC might be around $900, which places it fairly close to the 420C.

If it gets close in terms of deep sky performance, then a single ASI174MC-Cool could replace a two-camera combo (a fast planetary + a 420C for deep sky).

[D4N]

I think the IMX chip in the ASI174 is designed for video at a high frame rate, this is suited to short exposures on bright targets at high magnification. The ICX chip in the Atik is designed for low noise which is more suited for long exposures on faint targets. The new Atiks are also a lot more sensitive.

Remember that not all noise is thermal, I regularly image at -20C and see noise.

You would certainly be able to use the Asi as a deep sky camera but it may be better pressed into service as a guide camera. That's what I do anyway

Sent from my iPad using Tapatalk

[SnakeyJ]

Are these likely to come with 16bit ADC? The nine position 12mm filter wheel looks very useful and at this size it might not cost both arm and leg to fill!

The IMX174 would be tempting for imaging small DSO's, PN's and GC's at longer focal lengths.

[SnakeyJ]

Coming from the other direction, there's not a lot of room to pitch below the atik 414ex - at least with the expensive IMX174 sensor.

[michael.h.f.wilkinson]

I think the IMX chip in the ASI174 is designed for video at a high frame rate, this is suited to short exposures on bright targets at high magnification. The ICX chip in the Atik is designed for low noise which is more suited for long exposures on faint targets. The new Atiks are also a lot more sensitive.

Remember that not all noise is thermal, I regularly image at -20C and see noise.

You would certainly be able to use the Asi as a deep sky camera but it may be better pressed into service as a guide camera. That's what I do anyway

Sent from my iPad using Tapatalk

The IMX174 has a peak QE of 78%, so it is no slouch on that call. The read-out noise of the ASI174MM is beautifully low (very important for planetary, much less for DSO work (but still welcome)), and the thermal noise can be reduced nicely by cooling, as shown here:

http://stargazerslounge.com/topic/252669-diy-asi174mm-tec-cooling/

The first results are certainly interesting.

Inspired by those results, I am aiming to add a Peltier element to the rear of my ASI174MM, to have a bash at DSOs, just to see what happens

[miafey]

The IMX174 has a peak QE of 78%, so it is no slouch on that call. The read-out noise of the ASI174MM is beautifully low (very important for planetary, much less for DSO work (but still welcome)), and the thermal noise can be reduced nicely by cooling, as shown here:

http://stargazerslounge.com/topic/252669-diy-asi174mm-tec-cooling/

The first results are certainly interesting.

Inspired by those results, I am aiming to add a Peltier element to the rear of my ASI174MM, to have a bash at DSOs, just to see what happens

Very interesting. 

I have a ASI174 and currently planning to do plantery only for now but it would be nice if a cooling unit can be added to the camera. 

I personally think it is perhaps too luxury to use it as a guide camera - a QHY5L-II will do this job admirably. 

[kdstaller]

The main difference between the CMOS and CCD imagers is the frame rate.  On a CMOS camera, you can do live image focusing in real time, adjusting the feather touch for the smallest star diameter.  On a CCD, there are 10-15 second download delays and you end up chasing a FWHM graph to focus, taking much longer time.  The ASI174 is about one half the field of view of a standard Canon DSLR.  If the noise floor is much better from the cooling, it should make an excellent DSO camera that is easier to set up than the similar CCD units.  

Has anyone compared the dark frames between ZWO's standard and cooled ASI174 cameras?

Now if we can just get a manufacturer to make a cooled CMOS camera with Canon-sized field of view (or full-frame size) and keep it in a coke can sized package for hyperstar-friendliness, they could corner the market in amateur astrophotography.

[Uranium235]

26 minutes ago, kdstaller said:

 On a CCD, there are 10-15 second download delays and you end up chasing a FWHM graph to focus, taking much longer time.

Not strictly true,  becuase most (if not all) CCDs offer a subframe function by where you can just choose to read part of the chip (ie: a small area around the star), giving a pretty much instant download time. Even with an 8300 based camera (with a shutter) you can get some fast feedback. But I guess it depends on whether the capture software you are using supports that function