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ASI294MC Pro vs SkyRaider DS10C-TEC comparison

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#126 jimthompson

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Posted 02 February 2019 - 11:27 PM

One thing I am puzzled about is why according to your analysis cooling makes no difference to SNR for exposures less than 100s for the ZWO. Jim, why do you think that is?

 

Although having said that the overall difference in SNR seems negligible. Should make no difference in EAA or traditional astro photography.

 

I would love to test the MC camera - maybe Rock can provide one for independent testing?

Hi Hiten,

 

Good question regarding the SNR not responding much to cooling on the ASI294.  My guess is that at lower exposure times the noise is dominated by sources that are not sensitive to sensor temperature.  It is only after the exposure time gets longer that temperature dependent noise sources become more important and thus cooling shows a larger impact.  Based on your experience, can you think of any sources of noise that are not strongly dependent on sensor temperature?  Shot noise, but what else?

 

Of course there is a whole other possible reason why the observed SNR does not improve dramatically with cooling at lower exposure times, and that is what is the actual sensor temp versus the reported sensor temperature.  At shorter exposure times, because the sensor is operating at a higher duty cycle, the heat production rate is higher.  So even though the sensor temp reading says it is being cooled, maybe at short exposure times it is actually significantly warmer than at longer exposure times.  Does that make sense?  This is pretty speculative, and I am not sure how we could confirm it without taking a camera apart and installing all sorts of temperature sensors.

 

Best Regards,

 

Jim T.


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#127 Astrojedi

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Posted 03 February 2019 - 01:02 AM

There should be no difference in shot noise between the two cameras. That is a property of light and as long as you are using the same camera settings and optics it is not a factor.

Read noise could in theory vary between the two cameras. Do you have a sharpcap pro license? If so, can you run a sensor characterization for both cameras.
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#128 mclewis1

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Posted 03 February 2019 - 10:24 AM

Can you run the sensor characterization in SharpCap using ASCOM camera device divers? 

Can you compare a characterization done with one camera using a native driver and another using ASCOM drivers? If not then someone will need to run both cameras with ASCOM drivers.


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#129 DSO_Viewer

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Posted 03 February 2019 - 12:58 PM

Hi Steve,

 

Careful as what I said after the last test report (#4) is that all things considered the two cameras perform pretty similar to each other.  To be more specific:

 

- If your planned usage consists of live observing with single exposures or stacks adding up to not more than a minute or two, then yes I'd say the DS10C-TEC is the better camera.

- If your planned usage consists of live observing with 10 to 60sec subs stacking to a total of 5 to 10 minutes, then the two cameras perform almost identically.

- If your planned usage is for AP, using subs longer than 60 sec and stacking for 30 or more minutes, then the ASI294 performs better.

 

The value of other non-tangible benefits like good customer service, strong user base, etc. are things that you will have to determine for yourself if it is worth the higher cost.  FYI, I have successfully used the DS10C-TEC with SharpCap, so software does not need to be a deciding factor anymore.

 

Best Regards,

 

Jim T.

Thank you Jim for the helpful suggestions. I use my edge C11 at f5 with my current ASI224MC camera and know that I will have to use a slower f ratio since the size of the ASI294 sensor is much larger. I mostly take 30 to 60 sec sub images of 5 to 10 while observing and stack them in Sharpcap . I will be doing the same with the ASI294 and since I am so used to using Sharpcap, I want to stay with that program. Does the DS10C-TEC work just as good as the ASI294 when using Sharpcap?

 

Steve



#130 jimthompson

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Posted 03 February 2019 - 11:10 PM

There should be no difference in shot noise between the two cameras. That is a property of light and as long as you are using the same camera settings and optics it is not a factor.

Read noise could in theory vary between the two cameras. Do you have a sharpcap pro license? If so, can you run a sensor characterization for both cameras.

I do have a Pro license but I already gave the camera back to the owner.  I didn't think about the Sharpcap sensor analysis tool...dang.

 

Jim T.



#131 jimthompson

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Posted 03 February 2019 - 11:17 PM

Thank you Jim for the helpful suggestions. I use my edge C11 at f5 with my current ASI224MC camera and know that I will have to use a slower f ratio since the size of the ASI294 sensor is much larger. I mostly take 30 to 60 sec sub images of 5 to 10 while observing and stack them in Sharpcap . I will be doing the same with the ASI294 and since I am so used to using Sharpcap, I want to stay with that program. Does the DS10C-TEC work just as good as the ASI294 when using Sharpcap?

 

Steve

I had good success using the DS10C-TEC in Sharpcap via the DirectShow driver.  Cooling, White Balance, Gamma, those image controls were all accessible.  There are however a couple of features available in MallincamSky that I could not figure out how to access in Sharpcap, the main one being Binning.  I did not try the ASCOM driver.  Note that MallincamSky is also a very capable software package.  It can do all of the image processing tasks that Sharpcap can.  It just doesn't have the extra tools like focusing aid, polar alignment, and camera sensor analysis.  In time those features may be added too.  MallincamSky seems to get updates fairly regularly.

 

Best Regards,

 

Jim T.


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#132 diceless

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Posted 04 February 2019 - 02:43 PM

Jim,

 

You mentioned you used the DirectShow driver, what color space was it running in?  I know for the RT224, the DirectShow driver runs in RGB24 (8 bits per channel) compared to 12 bit if I did ASCOM.  I personally prefer the DirectShow driver as it is more feature rich but only running in 8 bit per channel does cause me to have to stack more before I stretch the image as much as running 12 bit raw. 



#133 Plains Dweller

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Posted 04 February 2019 - 04:39 PM

Jim - Thank you for putting the time an effort into this.  Much appreciated.


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#134 jimthompson

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Posted 05 March 2019 - 09:55 AM

Jim,

 

You mentioned you used the DirectShow driver, what color space was it running in?  I know for the RT224, the DirectShow driver runs in RGB24 (8 bits per channel) compared to 12 bit if I did ASCOM.  I personally prefer the DirectShow driver as it is more feature rich but only running in 8 bit per channel does cause me to have to stack more before I stretch the image as much as running 12 bit raw. 

Sorry, I forgot to answer your question.  I performed all my testing in 8-bit mode, on both cameras.  The reason was that I wanted to work with 8-bit per channel images to keep file sizes and processing times low.  Certainly there is some impact on the precision of my measurements, but the trends and relative differences between the cameras should still be valid in my opinion.  One thing to note, at least for the ASI camera, is that hardware based binning is only engaged when using the camera in 8-bit mode.  I guess this is just how ZWO decided to write their camera firmware.

 

Cheers,

 

Jim T.




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