Upgrade priorities (new scope or new camera) - Forums

With a somewhat limited budget, I am trying to decide what my upgrade priorities should be in the coming year.I am currently using a William Optics Zenithstar 61 refractor (with flattener) and an unmodified full frame Nikon D750 DSLR on a Skywatcher HEQ5 mount. Ideally I would like to upgrade both the scope and camera but being realistic, I only see one in the short term. (Side note: Thanks to the relatively light payload of my current rig I have been able to get away without guiding so far. The HEQ5 with Rowan belt upgrade, has tracked well and I have luckily squeaked by without the extra gear.)Moving forward, I think that I have narrowed things down to one of two options (both in roughly the same price range).Option 1: Keep using my Nikon D750 and upgrade the scope to the William Optics Zenithstar 81 (with flattener/reducer). With the extra size and weight of the larger scope I know that I would also need to start guiding and this option also includes getting the William Optics UniGuide 50mm guide scope and ZWO ASI120MM Mini Guide Camera.Option 2: Keep using my William Optics Zenithstar 61 refractor and upgrade the camera to the ZWO ASI2600MC Pro (OSC). The ASI2600 is marginally lighter in weight than my D750 so I should still be able to get away without guiding... at least for a little while longer.Any thoughts on which option would give me better bang for my buck? If anyone out there has been through a similar upgrade experience I would welcome the feedback.Thanks

Go for the camera. The astro-cam gives you a much nicer experience throughout - both the pictures are much better but it integrates so nicely in NINA, Sharpcap or other astronomical software so that slewing to your target, plate solving, planning your sequence, or even live stacking, is a breeze. The DSLR cannot give you this kind of experience. And also get a dual-band filter (L-ultimate or Antlia Gold) to increase contrast in your nebulae photos.

The scope is more than enough for nice photos.

Later, you can get a larger scope (e.g. 6' newt or larger refractor), and if your mount is not enough for it, get also a better mount.

Get the camera modified to full-spectrum and get a bigger scope. I read (poster above) that you can't use NINA with a DSLR. That's isn't true. At all. You can slew, acquire, plate solve and whatever else you might be needing except the format is still .NEF so it won't have all the tagging that you get with a fits file.

I would say hold on to both.
get your camera modified, get a guiding setup, a mini pc or asi air, an l extreme and pixinsight.
if you have money left at some time in the future, sell the scope and mount, buy a 8inch newtonian, an eq6r and whatever dedicated camera you like.

You will do without guiding but you will add a computer.

Thank you all for your input, it is very much appreciated.

As with most hobbies, budget is often a consideration and sometimes even a roadblock. It is going to be a difficult decision and in the end there is also an "option 3". I might just add a guid scope and guide camera in the short term and hold off on the telescope versus camera decision for a while longer.

Further to some of your comments and suggestions, I probably should have elaborated in my original post… I am currently using an ASIair Plus (and iPad) for equipment control and image acquisition. For image processing, I recently upgraded from Astro Pixel Processor (APP) to Pixinsight (PI). APP was great and I have no complaints about it, but I was intrigued by the additional power and flexibility of PI. I am still working my way up the learning curve and hope to eventually become as proficient with it as I was with APP. (I also still use Photoshop for some final edits too.)

Thanks again to all.

andrea tasselli:
Get the camera modified to full-spectrum and get a bigger scope. I read (poster above) that you can't use NINA with a DSLR. That's isn't true. At all. You can slew, acquire, plate solve and whatever else you might be needing except the format is still .NEF so it won't have all the tagging that you get with a fits file.

*I said that you cannot have the same experience, not that you cannot use it. The experience is worse. I tried with Canon DSLR in nina, native and with ascom driver.... Some crashes. No Mirror lock. No delay after mirror flip to settle. No live view. No practical live stacking. USB 2. I had to use another program BACKYARD EOS in order to use live view and focus with bahtinov mask and then move to nina for sequence, or to take pictures with 2 second delay to settle... It is doable, but the ZWO /QHY etc experience is superior.

I might suggest – if you can stomach a smaller field of view – getting an ASI 533MC-Pro vs. the 2600. That will save you a LOT of money you can apply towards other items like the ASIAir.

For instance, consider upgrading to the ZS103 / AT102EDL. With a 0.8X reducer that's 570mm @ f/5.6. Throw a 0.8X in for your ZS61 (vs. a 1.0X flattener) and you're ~288mm @ f/4.8. Basically a choice between 2.2° x 2.2° with the 533MC-Pro and ZS61+0.8X or 1.1°x1.1° with the ZS103+0.8X.

You'll have an H-alpha sensitive camera with high quantum efficiency, low noise, and something whose file size loads rather quickly. Deep Sky Stacker and PixInsight run MUCH faster with the 533's files vs my modded Nikon D5300, and that's just a crop-sensor camera.

Bear in mind, most objects you're going for are smaller than 1° across.

Just my 1.4-cents' worth.

It'd be worth 2 cents, but that was before taxes.

Clear Skies,
Phil

I have gone from a full from Sony A7III to a 2600MC pro as you are thinking of doing. I also have the ASIAIR plus. I have an 8" Newtonian so I lost the weird shaped corner stars I had been getting as the 2600 is APS-C sized chip not full frame so I lost some field of view but also lost the weird shapes at the edges. However not a problem for you no doubt with a refractor. With more experience now in collimation etc the corner star issue may have been resolved.
I did not miss having to manually focus and nudge the scope in the process. I didn't miss having to label images and sort them out afterwards. I got an electronic focusser with the 2600MC and that helped a lot keeping the images sharp and with the ASIAIR I could have auto focus every 1 C temp change. I can also now see the images on my tablet screen which I couldn't do with the DSLR. It is also cooled to -20C and works much better at the red end of the spectrum. I can power it easily from the ASIAIR.
I think an astronomical camera interfaces much better with the ASIAIR that try to use it with a DSLR. Recently I tried using the DSLR again and found focussing much harder than the autofocussing which is so easy with the ASIAIR.
Anyway that's my experience for what it is worth. You will loose field of view and the extra resolution that comes with a full frame camera if you can focus as well as an electronic focusser. The 2600 is a more recent model than your DSLR so there have probably been some improvements in dynamic range for example.

I would invest soon in an electronic autofocusser and when you can shortly after in a good guiding scope (or OAG) + guiding camera.
Both components will help a lot to get the best out of your current config and you can have a lot of fun and very nice results with this relatively inexpensive update.

The next step then highly depends on what your preferences are….
If natural looking images are your thing then think about investing in a longer lens so that you can enjoy Galaxies… An 8" SCT will work nicely on the HEQ-5, if you go this way buying an OAG in the first step makes more sense and you should invest in a larger guiding cam like the new ASI220 or the old ASI290 cam.
You will have a lot of vignetting with your Full Frame Camera so effectively you will only be able to use APS-C size but if galaxies are your think then I'd think about that combination.

When you prefer going in the direction of Nebulae and HOO or SHO then the focal length of your scope is well suited for a lot of targets and I'd go with a cooled camera (When you do not need to stay in the ZWO family, I'd recommend a Risingstar IMX571 or any other Touptec based camera and from the saved money I'd invest in a good Dual Narrowband filter like the Antlia ALP-T 5nm 36mm filter plus a filter holder).
New cameras allow you to do exposures with high gain so your relatively slow scope will not limit you much when you are able to get 3-4 hrs of integration time.

Michael

Thé imx571 (asi2600) will actually give you better resolution and a very similar field of view on the GT61 as the D750 on the GT81. Basically almost the same result either way so I would go with the camera. You keep it lighter, smaller and easier to manage with all of the benefits plus HA sensitivity. Also add guiding, a filter or 2 and AF if you can swing it. Then buy a scope later that jumps deeper like a 100 ish mm or a 6-8 inch Newt.

I would go for the camera. I don’t have DSLR experience but I’ve heard some of this quarks that users have to do when using them and processing the data. I use dedicated astronomy cameras, ZWO ASI294MC Pro and 071MC Pro and I love them. I’m looking down the road to get the 2600MC Pro myself. At any rate thats my thoughts and I do agree with @Michael Ring about the Antlia ALP-T filter, excellent filter!

Dale

Definitely camera, hands down. So much better than any DSLR.

I also opt for the new Camera first, but please start guiding since you can dither and also drizzle in the stacking routine.
The results will be a lot better , if done right.

Then if you want something with more focal length, try getting a used 130 or 150 PDS Newton. This should give you the best bang for the buck. Collimation a Newtonian is not that hard and cheap refractors (WO builds mostly cheap refractors) are very hit in miss in resulting image quality due to bad collimation unfortunately.

Collimating a refraktor is nearly impossible for the average person.

Stephan

Camera for sure in my opinion. By far the largest jump in my final image quality for me came when moving from a DSLR to an astro cam (533mc pro for me).

BR
Morsing

Truth is 80mm is not that different from 60mm. Assuming similar focal ratio, things will simply look 30% bigger. They are both considered "small refractors" and have the same targets.

A cooled astrocam will make a difference.

Why invest in a quite big colour camera when you can have a medium mono camera with decent filters ? With the 60 mm scope a MX533 mm gives you still a quite big field. Switching from an uncooled non unfiltered OSC (Nikon) to a cooled OSC will give you a bit more sensibility in the Ha but you still loose 75% of the signal and you also loose resolution. For the same budget instead of bying ASI 2600 MC you might consider an ASI 533 mm with a wheel and filters. Much more performant. Much more possibilities. Your choice. Changing the scope is not interesting, I fully agree with dkamen.

Andreas Zeinert:
witching from an uncooled non unfiltered OSC (Nikon) to a cooled OSC will give you a bit more sensibility in the Ha but you still loose 75% of the signal and you also loose resolution

Neither of these assertions is quite true.

Andreas Zeinert:
Why invest in a quite big colour camera when you can have a medium mono camera with decent filters ? With the 60 mm scope a MX533 mm gives you still a quite big field. Switching from an uncooled non unfiltered OSC (Nikon) to a cooled OSC will give you a bit more sensibility in the Ha but you still loose 75% of the signal and you also loose resolution. For the same budget instead of bying ASI 2600 MC you might consider an ASI 533 mm with a wheel and filters. Much more performant. Much more possibilities. Your choice. Changing the scope is not interesting, I fully agree with dkamen

Agree. I was going to suggest the same. ASI 533MM -- use a filter caddy (or even nothing) rather than a wheel and just start with an Ha filter and there could even be enough budget left for a 6 inch Newt or similar that would work fine on the HEQ5. A way to get a setup very distinct from the 61 mm refractor rather than just go to 81 mm which - in a sense - is more of the same.

Many good recommendations listed in this thread. I suggest moving slowly. Keep everything (if possible) add a ZWO focus motor and a 50mm guide scope with a 120mini. Use NINA (free) and PHD2 (free) with Green Swamp. Once you are comfortable guiding and autofocusing (which will help your overall astrophotography experience). I assume your using a laptop at the rig. (I use a mini pc and remote desktop). I would recommend next a camera. (I have a 2600mc/mm, 533mc, 071mc, 1600mm - all pro's). I use the 533mcPro almost every time I setup… (I usually run 2 to 3 rigs). It is a wonderful camera. Pixel size is same as cameras listed above minus the larger pixels of the 071mcPro. I have dropped filter wheels for filter drawers for weight and easy cleaning of filter. A LxTreme or similar is a good option. Search Astrobin for the 533 and scopes with your FL to see if the results are your cup of tea. After that, I would save up and move to a larger mounting in the 44lb class payload. Skywatcher, IOptron, Orion will give you more options when you move to a new (heavier) OTA…

Good Luck and CS - Tim

andrea tasselli:
Andreas Zeinert:
witching from an uncooled non unfiltered OSC (Nikon) to a cooled OSC will give you a bit more sensibility in the Ha but you still loose 75% of the signal and you also loose resolution

Neither of these assertions is quite true.

Maybe I did not write it well Andrea, thank you for pointing it. What I wanted to say is that a cooled OSC delivers much less Ha signal than a monochromatic camera with a Ha filter. Unfiltering a Nikon or Canon makes sens when you just want to stay with a camera without using a computer. (But it makes this Nikon or Canon difficult to use for daylight photos afterwards). Unfiltering might get you a factor of 3-4 in signal which is not bad but clearly below what can deliver a mono camera+filter. Once you decide to jump to a specfiic astro camera with a computer needed, why not use the most performant solution which is mono + filters ? Mono cameras also have a better resolution at same pixel size as you do not have artefacts from the management of the Bayer matrix. Of course a cooled OSC astro and an unfiltered OSC (Nikon) have the same resolution if the pixel size is the same (and antiliasing filters comparable).

Thank you everyone for sharing your experience with me and for providing suggestions and recommendations.

There are so many different factors to consider from both a technical and practical perspective and I will mull things over a bit more before I decide which way to go. Thanks again to all.

I agree with all of that - Certainly an OSC camera will require 4X as long in total exposure time to achieve an HA image with the same SNR and at the same resolution as from a mono camera.

This was discussed at length in a previous thread -- and here - at the bottom of page 5 - I even carried out a practical demonstration of this directly comparing HA imaging using an ASI 294MC versus an ASI294MM.. https://www.astrobin.com/forum/c/astrophotography/deep-sky/dual-narrowband-filterosc-vs-hao3-filtersmono-comparison/?page=5

Particularly for HA (by far the most dominant NB to observe) and luminance (which also adds a great deal) I did find that adding a mono cam to the set up (while still holding on to the OSC) was one of the best purchasing decisions I have made thus far.

Tim

The OP didn't say if performance at NB is a key reason for the desire to upgrade. If it is not then the results are far from being clear cut. This is specially true if you're willing to sacrifice resolution (e.g., do not CFA drizzle), as I recall from the discussion.

andrea tasselli:
The OP didn't say if performance at NB is a key reason for the desire to upgrade. If it is not then the results are far from being clear cut. This is specially true if you're willing to sacrifice resolution (e.g., do not CFA drizzle), as I recall from the discussion.

Exactly right Andrea - and of course in the end the choices just depend what particular aspects of AP end up interesting you the most - that depends on the OP. I and a few others were just highlighting the breadth of options for a similar budget. Lots of possible directions and many good options.