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ASI178 Color or QHY 5-III 178 Color

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#1 aacc66

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Posted 21 April 2019 - 09:36 AM

Hello,

 

I am considering updating my ASI224, that I use as my planetary camera, to a new camera with more pixels and larger sensor area.

 

I was looking at the price of the ASI178 and the QHY 5-III 178.  From the specs they look they have the same sensor, but the QHY is cheaper.  However the the ASI178 is presented as a planetary camera, while the QHY is presented more as a guiding camera.

 

Is my assessment that they are practically the same camera, or there is value to think that one is a better planetary camera and the other is a better guider?

 

Thanks,

 

Alvaro



#2 RedLionNJ

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Posted 21 April 2019 - 10:15 AM

On paper, they would both appear about the same (given the same sensor). The QHY is clearly intended for both purposes:  "The QHY5III178 is designed for wide FOV autoguiding as well as high resolution planetary imaging." (from the HPS website).

 

I would prefer the flexibility of the ZWO casing, though - should you desire a wider light-cone (say, f/5 or something), there is no potentially-restrictive 1.25" tunnel in front of the sensor. You could add one ti the ZWO yourself, by all means, but the QHY doesn't give you the option to remove theirs.

 

Having said that, I don't know how deep (backward) inside the casing the QHY sensor actually resides. I also don't know if there is a removable IR-cut filter in the QHY model.



#3 aacc66

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Posted 21 April 2019 - 09:24 PM

RedLion,

 

Thanks for mentioning the F/# of the imaging systems.  I need to think about it.  The truth is that I use a Sony A7s for DSOs, and I will keep the planetary camera mostly for planetary work which usually is for slow imaging systems, which in my case is F/10 in prime mode, or F/25 when using a Barlow.

 

Thanks for the info.

 

Alvaro



#4 james7ca

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Posted 23 April 2019 - 11:37 AM

I've done a lot of imaging with the uncooled QHY5III-178C. I also have the cooled ZWO ASI178MM. In terms of the 1.25" form factor, you don't have to use it that way since you can mount a short T-thread to C-thread adapter to the nose of the camera. I've used it that way down to f/4.2 on my Tele Vue NP127is and have never noticed any vignetting (and I don't even use flats). In fact, I never mount it in a 1.25" eyepiece holder. You can find lots of images here on CN that I've done with the QHY, both DSO and planetary. I suspect that I was one of the early adapters of that camera, starting about three years ago with sample images here on CN from that time up until just recently -- so several years of continuous use.

 

Here is a link to my "first light" report on the QHY5III-178C that I did in June 2016 (includes early images, with links):

 

  https://www.cloudyni...c/#entry7282894

 

And, below is an image showing the QHY5II-178C with the T-thread to C-thread adapter mounted to a Baader MPCC coma corrector (most of the tubes and adapters are there just to get the required backfocus for the coma corrector).

Attached Thumbnails

  • QHY5III-178C with Coma Corrector.jpg

Edited by james7ca, 24 April 2019 - 12:13 AM.


#5 aacc66

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Posted 25 April 2019 - 12:47 AM

James,

 

Thanks for the information.  Now I need to save some money, but that camera is not that expensive, so should not be that long... unless I run into some other beauty out there.

 

I was surprised that this model has been out for at least 3 years.

 

Alvaro

I've done a lot of imaging with the uncooled QHY5III-178C. I also have the cooled ZWO ASI178MM. In terms of the 1.25" form factor, you don't have to use it that way since you can mount a short T-thread to C-thread adapter to the nose of the camera. I've used it that way down to f/4.2 on my Tele Vue NP127is and have never noticed any vignetting (and I don't even use flats). In fact, I never mount it in a 1.25" eyepiece holder. You can find lots of images here on CN that I've done with the QHY, both DSO and planetary. I suspect that I was one of the early adapters of that camera, starting about three years ago with sample images here on CN from that time up until just recently -- so several years of continuous use.

 

Here is a link to my "first light" report on the QHY5III-178C that I did in June 2016 (includes early images, with links):

 

  https://www.cloudyni...c/#entry7282894

 

And, below is an image showing the QHY5II-178C with the T-thread to C-thread adapter mounted to a Baader MPCC coma corrector (most of the tubes and adapters are there just to get the required backfocus for the coma corrector).




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