ASI 294MC-Pro (or maybe not?)

[agthomson]

Morning all!

I am in the process or upgrading my portable set-up. This currently stands as a SW Star-adventurer on a decent tripod, unguided with a Sony A6000 mirrorless, unmodified APS-C camera attached to a William Optics ZS61 with Flat61. I can quite happily get subs of 30-60s with this set-up with good PA, and I like the sensitivity / SnR of the camera. However, and this is a big one, the camera does not play nice with most tools commonly used for Astrophotography, and Sony's algorithms applied to long exposure images make AP challenging to say the least, especially if I need to go beyond 30s into bulb mode. I don't want to buy another DSLR, so plan on buying a dedicated CMOS (probably OSC) camera. I say OSC as although mono may in theory be quicker it's another thing to consider, to break, to worry about. OSC is just simpler.

Right now with my setup, I have long-ish USB leads and sit in the warmth of my kitchen using my Surface Pro to actually image using Sony's Remote Camera Control (wired) and autohotkey for exposures >30s in Bulb. That is, after I have achieved focus properly, polar aligned (pain) and then aligned to my target (pain with no remote live view). I was planning on buying a PoleMaster to help me polar align and then maintain it, but as somebody suggested I can just use a Finder-Guider for this, and then double it up as a guider, so I will be adding a guider to guide in the single direction of the SA before getting the new dedicated camera. Yes, i'm aware of the limitations of my mount, but for now I am desperately needing to get rid of the A6000, and would rather have an overkill camera that will come into its own when the mount is upgraded than upgrade the mount and be limited by the camera.

My options just now are:

Option A - ZWO

When browsing FLO for cameras that fit my budget (somewhere around £1k) I went straight to ZWO as they are generally cheaper. The ASI294MC-Pro looks very appealing - USB3, buffer, decent FOV. To be honest the 183MC-Pro is probably acceptable too, but at the lower end of my acceptable FOV. I can later look to add the ASIair (if the reviews are good) and then remove the cables running from the kitchen to the set-up, and control it all from my iPad. Early indication is that ASIair will only work with ASI cameras, and I would have to make sure my guide camera is not the 120MC or MM model (mini seems to be fine?). 

Option B - Atik Horizon

The thing that drew me to this was the live image building, and video streaming. It just seems to work, and having the option to show the wife / friends in real-time (ish) what it is i'm doing would be pretty good, especially if i'm normally tucked away for a few hours with little to show for it. I read a quote somewhere recently that said hardware is all much about the same, but it's the software that makes or breaks many AP products. Atik, although more expensive seem to have this nailed down, and have better customer feedback (subjective). FOV is pretty much the same as the 294 chip, and it has nearly the same feature set from what I can tell (256Mb buffer etc). Video / EEA has suddenly appeared on my radar thanks to this camera.

 

Are there any obvious things I'm missing? Are these cameras okay in terms of pixel size for the ZS61? What one would you pick?

 

[London_David]

I have a 294Pro and really like it. I mainly use it for eea rather than full on imaging. With Atik what you pay for more than anything else is the software. The Horizon and the ASI1600 are virtually identical cameras except in price and software control. 

There is more detail about that here:

 

As I mentioned, almost all I do with the 294 is live stacking eea using SharpCap which is great. Indeed, that’s why I bought the 294. I’ve not used the Atik software but it is meant to be very good and easy to use however essentially it’s ~£250 built into the cost of the camera. The alternative sharpcap is £10/year or free if you don’t want to use the more advanced features. I really like sharpcap since it is easy to use with fantastic new features coming out all the time. All things considered I’d say the 294 is actually a better live stacking eea camera than the Atik. So if you want live image building style observing I’d tend towards the 294.

However, the 1600 chip in the Atik and the asi1600 is very popular for astrophotography and does have certain wins over the 294 (sorry I can’t remember them at the moment, I think pixel size and image scale is one), however the 294 blows it out the water on full well depth, and is more sensitive — sensitivity was the key for me since I use it for eea.

If your interested in the Atik I’d also take a look at images and discussions here and on cloudy nights about the asi1600 since you’ll get pretty much identical performance to the Atik from it. 

Pixel size should be fine - I use mine on a WO GT71. However, you should check out astronomy.tools to make sure you’re going to get the view you want from either camera. It depends what you want to be imaging.

To answer your final question... I’d buy the 294 - I already did this research and picked! I’d make the same choice again between he horizon and the 294.  If I was more oriented to ap however, I’d take another look at the ASI1600 or if zwo have a new camera out that is more ap oriented I might look at that. 

[agthomson]

Thanks for your reply. I had read that article and seen a YouTube video that compares at least the Horizon to the 1600MM Pro in terms of capturing images.

The FOV of both sensors is similar, with the 294 giving me a wider FOV but marginally narrower vertically.

I also read a discussion on Cloudy Nights discussing the relative sensitivity and noise of the sensors which roughly concluded that when cooled the 294 was better at the same exposure length, but due to sensitivity could cope with shorter exposures. I think i've pretty much made my mind up on the 294, especially considering it has a USB hob whereas the Horizon doesn't, and will order it in a few weeks when it starts getting dark enough to use. Going to order the finder/guider first so the Mrs doesn't notice lots of expensive looking boxes all turning up at once!

[Adam J]

From everything I have seen the 294 is the most sensitive OSC camera in its price range.