Buying A PRO DSO Camera

[Leo.G (Leo)]

I'm about to purchase my first dedicated astronomy camera (if I don't count my old Starlight Express OSC I picked up second hand and could never get working).
I was thrown as to whether to get the ZWO ASI294MM Pro or the QHY294M Pro.
I have a 152mm Achromat refractor with a 1,200mm focal length, a 102mm Achromat refractor with 1,00mm focal length and an 8" GSO Newtonian with a 1,000mm focal length.
I have a William Optics DDG for Synta rafractor focuser I swap between the refractors, sturdy and capable of holding the camera (and now fitted with stepper motor focuser WO stated could not be done (they haven't met me)).


Prototype bracket and drive belt:

https://i.postimg.cc/8PvpMRqs/IMG-1025.jpg


I've done a lot of research and because I'm either in the position to buy an APO or the camera and I've been wanting a dedicated camera for 30 years the camera won out. I've been strongly advised to go mono due to CA of the Achromats so I guess mono it is.


I was discussing getting a ZWO kit at a reduced price from a major Sydney seller (I won't drop company names), ZWO release other mono cameras in kit form but don't do the ASI294MM as one standard. A little confusing. I Know I'll benefit from the larger pixel size with the longer focal length telescopes (otherwise I'd have bought the Rising Cam with the IX571 chip from China cheap)



I was ready to throw a deposit down as there are currently no ASI294MM cameras in the country then found I can buy the near identical QHY unit $500 cheaper from the same people. It's also not in stock so I wait either way. As a disability pensioner this is a huge outlay for me and $500 is a lot of money.


Having absolutely no experience beyond DSLR and Philips SPC900 (modified) I've done so much research and it seems the cameras are closely matched with many people stating ZWO have better software and support. I'm more concerned with the quality of the hardware than the software, my son can and will write any code I may need if it's a software issue.

My question is, is it worth $500 more to buy the ZWO over the QHY?
The savings on the camera ($500) filter wheel ($69) will buy me a good guide camera for the same price as camera and filter wheel from ZWO.


I've read every article I can find and I'm still confused as hell. I've been to stargazers, cloudynights and here and am no closer to knowing what I should buy.
Is there any deciding factor I'm not seeing or should I just use the savings and my financial position as the deciding factor?


Talking about cameras and scopes, this was shot through a 90mm Skywatcher Achromat with an old Samsung s8 phone hand held the other night on a b@stardised mount with a Celestron 130 Astromaster mount dovetail head fitted to a Skywatcher equatorial head while I tested the b@stardisation of 2 equatorial mounts to have dovetail capabilities for a mount I'm loaning to a friend:


http://i.postimg.cc/Gp6SyGRc/Stacked-Mine.jpg


The black shadow on the lower right is I believe a mosquito that got in the light path for the 1/1000 second exposure (6 images stacked in Autostakkert and ran through a filter in Aurora HDR

https://i.postimg.cc/htS0Cyvh/Moon-DD.jpg
I've called it "Duck Dodgers in the 24 1/2 century", lol

[raymo]

I personally wouldn't use either of the achromats. Assuming that it has enough back focus, the 8" Newt would be my choice every time, much shorter subs, no CA, and better resolution, no contest. You would just need a coma corrector, if you don't already have one, and you are off and running. It also just occurred to me that the 152mm is photographically slow at almost f/8, and the 102mm is painfully slow at almost f/10, meaning much longer subs than either the 8" Newt or an APO.
raymo

[xelasnave]

Go narrow band.

You won't regret it.

That is a dedicated astronomy camera ..one shot colour not so much.

So get the osc use it and finally realise you really want to go narrow band...do it now and save time and money..one capture in Ha and you will wonder why you did not do it earlier.

I was uncertain, the money and all that but one HA capture it was worth every cent...best astronomy pirchase ever...changed everything.

There should be zwo 1600s going used and they are terrific.

I have bought a zwo mono 2600 and a one shot colour 2600 but there is no way I will sell my zwo 1600.

Alex

[Leo.G (Leo)]

My mirrors are currently off with Palmway optical getting a re-coat after they were long ago stuffed in the same process by someone who charged me way too much and stuffed the primary right up, then, apparently died before I could do a darn thing about it. That was before GSO primary mirrors were available in the country. I've not even mounted the 8" after getting the primary back totally stuffed up.


Though now with COVID and everything else the 8" f5 mirror that was $220 when I didn't have the finances is currently only $120 cheaper new than the entire OTA. NO way I was going to pay that.

Wayne at Palmway said he'd look after me and it's a coating that will last my life out.


I'm going mono because of the CA through the Achromat refractors, that was my deciding choice and I like my 6" refractor and it will likely be my primary scope. I'm sure the 8" Newt will get a look in depending on targets. Any CA can be removed post processing and I've been told I can't shoot through the luminance filter (or not to) as that will cause CA, advised only to use the RGB and narrow band when I have the money to buy them, better still if I can find an used set of 1.25" narrow band filters for a good price somewhere.



The 1600 I've left out of my choices because it is a smaller pixel size and will not be as good through longer focal length tubes, or so I've been told by a lot of people and read about on a lot of other forums. Plus, I've done my money on used Nikon lenses in the past and would rather buy something new that's going to be working out of the box and not keep thinking it must be something I'm doing wrong only to eventually find I've been had.

[AdamJL]

The CA on an achromat can indeed be tamed by going mono, but not on your luminance data. If all you're doing is narrowband, then an achromat is fine, but if you shoot luminance, you'll get the CA issues there too, they'll just be in mono.

[Leo.G (Leo)]

I understand the problem with CA and such but to my original question, ZWO ASI294MM Pro vs QHY294M. As mentioned, I'm a disability pensioner so the initial $500 savings on base QHY camera would be a lot of money to me.

any opinions?

[sunslayr (David)]

Convenience is the difference, the QHY lacks a usb hub for a guide camera and filter wheel. Whether that is worth $500 is up to you. Like everyone else has already pointed out I personally would go for a ZWO 1600mm Pro / QHY163M used, they should go for about $1300. It is perfectly acceptable in a 1000mm scope with good seeing.

[Leo.G (Leo)]

Well now I'm super confused. Previous images I'd seen of the QHY294M Pro had shown it to have a filter port (CFW) and an USB3 port. Now the images I'm seeing only show the USB port.
No, an USB hub isn't worth $500 to me, I can chuck a $20 USB3 hub I already have here into the mix a hell of a lot cheaper (disability pensioner, not cheap mongrel).


I've done a lot of research and spoken with several people including the technical expert at Bintel and several Astro Imaging members of the astronomical society I'm a member of and they have all recommended the larger pixel size for my scope, not the ASI1600.
Being new to this aspect of A-I I figured it was best to listen to people with a lot of experience yet here everyone (who I'm still assuming have a lot of experience) are saying get the 1600 ZWO. Every bit of research I've done (going into a LOT of hours of research) seems to point to the larger pixel size of the 294, whether QHY or ZWO being better for imaging with my telescopes.


Maybe I should just spend my money on an old Honda CBR1000 and be content with the knowledge I can still ride it when it's raining or cloudy....