I am between scopes to begin with. - Forums

Topic starter

Jul 19, 2025

Hello,

I am intrested in DSO astrophotography for a while now and whant to build my own rig. I am still between 3 scopes wich are the Red-Cat 51, Red-Cat 71 and the Zenithstar 73. As camera i was thinking to get ASI585MC Pro to begin with. What will your suggestion be for me.

Thank you, Deniz
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Dunk

Jul 19, 2025

As I'm sure everyone is going to say: you didn't mention which mount? This is almost more-important than the scope or camera and should probably be your first cost to figure out…

(All 3 scopes you mention are fantastic first scopes btw and are all quite lightweight and easy for almost any mount on the market. And the 585MC Pro is also great. You could also look at the 533MC Pro if you can afford).

And then you'll likely want a electronic focuser, filter(s), a filter drawer… the list is long.. :-)

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Dunk

Jul 19, 2025 · Edited: Jul 19, 2025

If you are in the US there is both a Redcat-51 and 71 for sale on marketplace right now - they both come with a bunch of other goodies also..

Tommi Liinalampi

Jul 19, 2025 · Edited: Jul 19, 2025

I would buy some Askar scope. Much more cost-effective solution than WO scope. If you would like to buy a fast wide field scope then Askar FRA400 with F/3.9 reducer will be a good option. Faster and cheaper than Redcat 71 but you still get very sharp images.

I have also owned WO Zenithstar 81 and I would say that Askar FRA400 beat Zenithstar-option 10-0.

Deniz Üzel

Topic starter

Jul 19, 2025

Hello, thank you for the responces. Sorry for not mentioning my mount, i was thinking of heq 5 pro or ZWO AM3. I am very confused about how these scopes changes the image for me and wich one would be the best option for me as well. Also my budget is a little elastic, i can switch on buying a Red-Cat 91 as well. But as i said i am very confused about what would change for me. Also in my rig i will get the ZWO EAF, Guide cams and asi air plus all the stuff. If you have any suggestions on my first rig setup i will definetly think on it. I am very open to suggestion. Thank you.

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Aloke Palsikar

Jul 19, 2025

If you are looking at Red Cat 51, would recommend if you can also look at Askar SQA 55. Almost similar specs but much lower in price. As regards Mount if you are considering ZWO AM3 then you may look at AM5N instead as it is more robust and can carry a larger payload which you may require as your grow your kit going ahead

You will require other accessories like a controller. say ZWO ASI Air Plus ( incase you want to go for a all ZWO option) . In addition you may want to consider guiding equipment . A 30/60 mm Guide scope or an alternative in form of Off Axis Guider (OAG) may be considered.

As you progress other accessories like Filters, Filter Wheel, EAF etc may be obtained as you expand your budget !

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Deniz Üzel

Topic starter

Jul 19, 2025

Thanl you Aloke. One question. How do i polar align with a ZWO mount ? Is it posible without using a software such as ASIAIR. Also do you think i should go for a asi533mc pro or asi585mc pro ?

Dunk

Jul 19, 2025

My strongest recommendation is to buy used gear until you are deeper into this hobby and have figured out what you want.

Everything above from everyone is good advice.

Deniz Üzel

Topic starter

Jul 19, 2025

Thank you so much for the quick recponces i will definetly consider every thing you guys suggested to me.

Aloke Palsikar

29 days ago

Deniz Üzel:
Thanl you Aloke. One question. How do i polar align with a ZWO mount ? Is it posible without using a software such as ASIAIR. Also do you think i should go for a asi533mc pro or asi585mc pro ?

If you have a ZWO ASI Air then Polar Alignment is an integral feature of the controller. After a few attempts till you get used to, it is easy and can be done in less than 5-10 min with a reasonable accuracy. If you are not using ASI Air then you can try using some Open Source Softwares like PHD2 or N.I.N.A which will give you a similar result

On camera, I personally have a ZWO ASI 533 MC Pro and am quite satisfied with the performance. You can decide based on your Budget and choice. 585 MC is also good entry level camera and you can try it as well. The difference is in the specifications of the SONY sensors in both. You can compare the Sony sensors IMX 533 with IMS 585 and take a call.

All the best

Stjepan Prugovečki

29 days ago

There are 3 important things in astrophotography : Mount, mount and …. mount . Joke aside, but good mount is your base that you build upon. Perhaps , iOptron HAE 29, ZWO AM5 , or if you are not in USA you can get Ragdoll mount (good, reasonably priced from proxisky.com). As the scope is concerned , Redcats are good choice, but price/performance is not the best . As mentioned before, Askar scopes do have better price/performance ratio. In fact, I think that currently the best price/performance for small refractor is SW Esprit 80 , if you can still find one. No, it is not Petzval, but it is razor-sharp, and a good offers can still be found. AsiAir gives you quick start , but up to large extent binds you to ZWO. I would rather buy miniPC and install NINA and PHD2. It takes a bit of an effort to learn a bit , but gives you a total freedom. So, if you save a bit on the mount and scope, you can invest that money into Touptek 571 camera (does not work with ASiAir though)

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TiffsAndAstro

29 days ago

Deniz Üzel:
Hello, thank you for the responces. Sorry for not mentioning my mount, i was thinking of heq 5 pro or ZWO AM3. I am very confused about how these scopes changes the image for me and wich one would be the best option for me as well. Also my budget is a little elastic, i can switch on buying a Red-Cat 91 as well. But as i said i am very confused about what would change for me. Also in my rig i will get the ZWO EAF, Guide cams and asi air plus all the stuff. If you have any suggestions on my first rig setup i will definetly think on it. I am very open to suggestion. Thank you.

Clear Skies

You can put scope and camera details into telescopius.com and see how various targets frame up.

Michael Nemetz

29 days ago

Or look for an Apertura CarbonStar 150 Newton, forget about all that fearmongering about collimating and enjoy a real keeper telescope.

dkamen

29 days ago

Deniz Üzel:
Hello,

I am intrested in DSO astrophotography for a while now and whant to build my own rig. I am still between 3 scopes wich are the Red-Cat 51, Red-Cat 71 and the Zenithstar 73. As camera i was thinking to get ASI585MC Pro to begin with. What will your suggestion be for me.

Thank you, Deniz
Clear Skies

I have the ZS73ii and the RedCat71.

The latter is clearly superior in every regard, but the 73 is also quite decent and a tad more lightweight.

Keep in mind the 73 has no flattener built-in, you will have to buy one and get the spacing right so factor that in when comparing prices.

Redcat 51 is significantly smaller and lighter, extremely portable actually, I think it makes more sense for a beginner.

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Rajat Kumar

29 days ago · Edited: 29 days ago

@Deniz Üzel i am currently using Z73. Have used GEM28, AM3 (borrowed for a short while) and currently using Ioptron HAE29C. The only difference is that I have a 2600 MC and not 585 sensor.

Regarding the Z73, you would need a flattener. If I had an option between Z73 and Redcat 71, I would go with Redcat. The Z73... From where do I start. I hated it when I got it. The stars were really bad because of which the images looked very very bad. After wasting a couple of months and going through everything that internet had to offer, the issues remained unresolved. Ultimately, after consulting a senior member of our astronomy society, we decided to use a 2mm aperture mask and see what happened. I think the front lens holder cell has some element which is interfering with the light path. On the internet, there are all sorts of reviews - this is the bestest to the worst thing ever happened. Anyway, that aperture mask worked and improved things a lot. I have been using the scope with the aperture mask for the last two years. I had installed an EAF after couple of months and things have been satisfactory. Yeah, it's satisfactory. Askar PHQ series is something you should also include in your budget. Don't fret over f numbers.

As far as the mount is concerned, the models being suggested here are all good; you need to make a decision on one depending on your conditions. Zwo mount would make you go in their ecosystem, even if you dont want to. Eventually.

Z73 progress over the years in pictures:

This was the first light: https://app.astrobin.com/i/7y7sp1

The Bad stars: https://app.astrobin.com/i/qz07iv?r=B

Things got better:https://app.astrobin.com/i/yw0yz5

Things now

https://app.astrobin.com/i/ixecrw
https://app.astrobin.com/i/c44m0x
https://app.astrobin.com/i/36303b?r=0
Day before yesterday, I sold the Z73 and am going for a bigger aperture.

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