17 replies to this topic

[The Rigger]

I'm pondering my next gear purchase, and an curious what others' experiences have been.  I've been working with a pretty good first system - a ZWO ASI533MC Pro camera coupled with an Askar 71F scope - and have thoroughly enjoyed the process. I've recently come into a decent amount of money that's not earmarked for anything else (yay!!), which would be enough to acquire either another camera (most likely an ASI2600) *OR* another scope (almost certainly an EdgeHD 8")....

 

And thus is the dilemma. Whether 'tis nobler to put an APS-C camera on the 71F, or to slap my "starter" ASI533 onto a 2000mm Celestron?  What's the smarter choice, and why?  Or is it basically a "no-wrong-choice" situation?

 

I know... First-World problems...

[happylimpet]

You'll open up a far larger universe of objects with a bigger scope (which lets you see, basically, much farther, and thus a much larger volume of space and objects) than with a slightly larger sensor, which will just show a handful of nearby objects more completely. Unless your main interest is nearby, large objects. But there arent many of those.

[michael8554]

You'll need a camera with much bigger pixels to avoid oversampling on the Edge.

 

Both cameras are 3.75um

[Zambiadarkskies]

I see two completely different styles of imaging here so there is no way anyone can say what you should do - only you and your imaging preferences can do that. Personally I went from a 533 to a 2600mc on my 65mm 416mm focal length scope. But that's because I wanted a larger sensor because I really like wide field imaging. All with the expectation of someday adding a refractor of around 120mm aperture someday. But no rush.

For various personal reasons I have no interest in reflecting telescopes.

So my vote is 2600, but then that is not going to get you any deeper and that seems to be where you want to go...

What about going mono?

[afd33]

You'll need a camera with much bigger pixels to avoid oversampling on the Edge.

 

Both cameras are 3.75um

"need" By far the most common camera used with the EdgeHD 8" on Astrobin is the 2600.  Then the 294, then the 1600 and 533 are basically tied. Only the 294 has smaller pixels.

 

When DSO imaging, worrying that much about sampling is over rated. In my opinion, out of cameras currently available any benefit you'd get from sampling is going to be negated by the older technology of the camera. The IMX533, 571, and 455  are the best sensors out there right now by far and all have the same pixel size. The sensor close is the IMX585, but that's only an option if you want a tiny sensor.

[jml79]

"need" By far the most common camera used with the EdgeHD 8" on Astrobin is the 2600.  Then the 294, then the 1600 and 533 are basically tied. Only the 294 has smaller pixels.

 

When DSO imaging, worrying that much about sampling is over rated. In my opinion, out of cameras currently available any benefit you'd get from sampling is going to be negated by the older technology of the camera. The IMX533, 571, and 455  are the best sensors out there right now by far and all have the same pixel size. The sensor close is the IMX585, but that's only an option if you want a tiny sensor.

The 294 has the biggest pixels of all of those cameras, not the smallest. The 492 has an optional small pixel mode but it would be useless on an 8" SCT.

[The Rigger]

What about going mono?

That's a long term plan; I'm not there yet.

[The Rigger]

The 294 has the biggest pixels of all of those cameras, not the smallest. The 492 has an optional small pixel mode but it would be useless on an 8" SCT.

Maybe I'm reading things wrong, but I'm seeing the 294's pixel pitch as 2.3µm. Only the 2400's IMX410 sensor has larger pitch than the 2600/533, at 5.94µm, and that camera's WAY beyond my budget.

Edited by The Rigger, 18 March 2025 - 01:02 AM.

[bobzeq25]

I'm pondering my next gear purchase, and an curious what others' experiences have been.  I've been working with a pretty good first system - a ZWO ASI533MC Pro camera coupled with an Askar 71F scope - and have thoroughly enjoyed the process. I've recently come into a decent amount of money that's not earmarked for anything else (yay!!), which would be enough to acquire either another camera (most likely an ASI2600) *OR* another scope (almost certainly an EdgeHD 8")....
 
And thus is the dilemma. Whether 'tis nobler to put an APS-C camera on the 71F, or to slap my "starter" ASI533 onto a 2000mm Celestron?  What's the smarter choice, and why?  Or is it basically a "no-wrong-choice" situation?
 
I know... First-World problems...

My experience.

I went from 600mm (starting out) to 1300mm. The experience resembled stepping off a cliff. My progress came to a halt for months. So I tried 1000mm.

Much better. <smile>

You're at 490mm. I wouldn't recommend anything above 1000mm. My best recommendation would be about 800mm.

2000mm? In my personal opinion, that would be a wrong choice.

Edited by bobzeq25, 18 March 2025 - 01:17 AM.

[dswtan]

Maybe I'm reading things wrong, but I'm seeing the 294's pixel pitch as 2.3µm.

Only the mono version of the 294 (MM) has the “bin1” mode that gets you 2.3µm. The OSC one (MC) can only go down to 4.6. It sounds like you are only looking at OSC options.

 

The OSC 294 also has the problematic calibration issues. (Some even have trouble with the mono.) The 294 is not a good choice today unless you are also considering mono. 
 

FWIW, I like my 294 monos a lot, but I seem to be rare in this. I have used them on various scopes, including the EdgeHD 8, and now EdgeHD 11. I would never get an OSC one though.

[Jared]

Going to the larger camera will be a much easier jump. You won’t be pushing the mount as hard—in terms of either carrying capacity or focal length. I’m not certain whether you are guiding yet, and if so whether it’s with an OAG or a separate guide scope, but the Edge will all but require guiding, preferably with an OAG. The larger camera will not change your guiding requirements. If you are happy with the 533 from a resolution standpoint, you’ll be happy with the larger camera.

Which is the better choice will ultimately depend on whether you are going to image larger objects or smaller ones, but the easier jump to make is the larger fields of view.

[archer1960]

You'll need a camera with much bigger pixels to avoid oversampling on the Edge.

 

Both cameras are 3.75um

Bin!

[jml79]

Maybe I'm reading things wrong, but I'm seeing the 294's pixel pitch as 2.3µm. Only the 2400's IMX410 sensor has larger pitch than the 2600/533, at 5.94µm, and that camera's WAY beyond my budget.

 

Only the mono version of the 294 (MM) has the “bin1” mode that gets you 2.3µm. The OSC one (MC) can only go down to 4.6. It sounds like you are only looking at OSC options.

 

The OSC 294 also has the problematic calibration issues. (Some even have trouble with the mono.) The 294 is not a good choice today unless you are also considering mono. 
 

FWIW, I like my 294 monos a lot, but I seem to be rare in this. I have used them on various scopes, including the EdgeHD 8, and now EdgeHD 11. I would never get an OSC one though.

Like dswtan pointed out, only the mono version is capable 2.3um and that is the 492 sensor but it is often better at the stock 4.63um setting. The OSC version of the camera can only run at 4.63um. I too love my 294 mono cameras, they have a lot of benefits and advantages but they are not easy to use and require special calibration procedures. The 533/2600 is much more forgiving and easy to use. I know the 8" SCT's are very popular but I went the other direction and bought an 8" Newt. The focal length and price are much more forgiving but honestly I think they both require about the same amount of tinkering just different kinds of tinkering but I have never owned an SCT so I could be very wrong. My Newt has a focal length of only 800mm and is very fast at f/4. The learning cliff is still going on but I hope to have it dialed in very soon. 

[The Rigger]

You won’t be pushing the mount as hard—in terms of either carrying capacity or focal length.

My mount is a Wave 150i; it should handle both the weight and focal length with no trouble.

 

I’m not certain whether you are guiding yet, and if so whether it’s with an OAG or a separate guide scope, but the Edge will all but require guiding, preferably with an OAG.

I'm guiding already, with an ASI120MM-S on a separate SvBony 30mm scope, which is dandy for the 490mm Askar but probably dreadfully undersized for the EdgeHD 800. I'd probably change over to an OAG for the new scope, as from what I've read that's a better method.

 

My primary desire to make the jump to the longer focal length is to be able to do planetary work, and also shoot smaller nebulae than the 71F can reach for. I'd also occasionally use it for visual work, sort of an ad-hoc outreach program - I've got a ton of inquisitive kids in the neighborhood...

 

I appreciate all the comments and insight from everyone. Keep 'em coming; I'm still pondering...

Edited by The Rigger, 18 March 2025 - 12:51 PM.

[The Rigger]

It sounds like you are only looking at OSC options.

Yes, I am.  I'll probably make the jump into mono eventually, but that's a very long-term goal - I feel I've still got some ways to go and stuff to learn before then.

[bobzeq25]

Planetary/lunar and visible will be easy.

Small DSOs - not so much. <smile>

Similarly, a number of people have had serious issues calibrating lights on the old 294. In some cases they've given up. Unacceptable risk, in my opinion.

No such problems with the newer 533s and 2600s.

Edited by bobzeq25, 18 March 2025 - 02:28 PM.

[The Rigger]

Planetary/lunar and visible will be easy.
Small DSOs - not so much. <smile>

Well....  For certain rather abstract values of the word "easy," at any rate... 

[The Rigger]

Epilogue: I went with the scope...
Found a great deal here in the classifieds for a hardly-used 8" EdgeHD with a bunch of accessories for both imaging and visual work.