WO Zenithstars/Redcat choices?

[Chromium]

If you were to buy a William Optics Zenithstar, or possibly a Redcat, which would you buy and why? I'm looking at the range and curious to find out why they're all fairly close in price and size.

The candidates are;
WO v2-U RedCat 51 APO
WO Zenithstar 61 II APO
WO Zenithstar 73 III APO
WO Zenithstar 81 APO

Ultimately I plan to build a rig using my recently purchased SWAGti, possibly with one of the above, a Guidescope and camera, all tied into a ZWO ASiair Plus 256G.

I've very recently purchased an Askar FMA135 135 mm f/4.5 ED APO Astro graph and it's a great quality little scope but not had a chance to use it properly yet. 

As a beginner, I very much appreciate any comments, criticism, suggestions etc. 

Thanks, Steve

[Elp]

Aperture will give you more "speed" and resolving capability, if the mounts up to it the larger the better.

Redcats are nice because the flatteners are built in so likely you can get an even and flat field across the FOV out the box, good for mosaics. I find though they are too close to my Samyang 135 (the SY is also much faster) so for me they are not really an option, but I also have a Z61 which I can also image at F3.8 and 234mm FL, so again beats the Redcat though I don't have a flat field.

But, I can use the Z61 for visual and AP, I can use whatever reducer that fits (hence the above f ratio and FL) so I can choose my framing on targets better. TBH it's such a versatile scope and has excelled at everything (visual, AP, lunar, white light and HA solar (with filters/equipment), planets (though small but sharp)). It's small to boot so perfect for travel.

But if I were buying new I'd likely also consider the GT81 triplet for AP use (standard not the WIFD one), though from my experience doublets work perfectly fine.

[Veloman]

Hi Chromium,

I've got a WO Megrez 80 II . As far as price is concerned you need to check the specs- although they're all described as APOs some may be triplets, others doublets and also check to see what glass is used.

Good luck.

Rob

[PhilB61]

I think all the WO scopes would give you great performance, the main difference being aperture and focal length so depends on what you want to target. However, with your mount if you want half decent guiding performance then you probably need to stick to the 50% weight capacity "rule" for astrophotography. So with the scope, camera and imaging accessories that would rule out the two larger scopes on your list. Other than the Redcar you would also need to factor in a flattener/reducer 

[Chromium]

Ahh... Yes of course... Thanks... Weight of rig... Doh!

Certainly will affect the scope choice... Shame as I was leaning more towards the 73 or 81. 

By the time the DSLR, flatner, Guidescope & camera, ASiair etc is added you're quite right it may add up to a considerable amount... Time to get the calculator out methinks. That will certainly affect the choices of guiding equipment. But I suppose I could mount the ASiair to the tripod leg possibly? 

UPDATE: following some preliminary calculations, it appears the 73 is about 600g heavier than the 61, coming in at 2.8kg, the Redcat however appears to only be 1.47kg.

So that with all the other bits... DSLR, ASiair pro,  32mm Slide-base Uniguide, ASI290MM, etc. 

Would be 3.96 with a 73 and 3.63 with a 61... Hmmm both over the 50%. With a Redcat... 2.39

 

Cheees, Steve

Edited February 4 by Chromium
Additional info

[LaurenceT]

Slightly left field approach, some of your choice of scope depends to a degree on the performance of your AZ GTi.

I have an Asiair FMA180 and my AZ GTi coped wonderfully with that. 2 minutes unguided was no problem and I even experimented with 3 minutes successfully.

However the mount didn't behave so well with my ZS61 II. Unguided I had poor stars at 30 seconds and guiding was better but still not acceptable.

These little mounts are brilliant but immensely variable in engineering quality and as I have the engineering capabilities of a gnat I decided not to open up mount and fiddle with it and changed to a different small mount so fingers crossed.

Other people are able to put quite heavy scopes on their mounts so you could be lucky with yours.

It would be nice if you could test the AZ GTi on a heavier scope first but I understand that may be difficult.

 

[900SL]

Redcat 51 is quite wide FOV and undersampled on 3.75 micron pixels, but is a great little scope on APS-C sensors.  

Tracking and guiding are much easier at shorter focal lengths too. 

I started with a GT71 scope, which was a bit of a handful on a tracker. Really needed a HEQ5 class mount, but a good match for a 533MC Pro camera

[Albir phil]

17 hours ago, Chromium said:

If you were to buy a William Optics Zenithstar, or possibly a Redcat, which would you buy and why? I'm looking at the range and curious to find out why they're all fairly close in price and size.

The candidates are;
WO v2-U RedCat 51 APO
WO Zenithstar 61 II APO
WO Zenithstar 73 III AP 
WO Zenithstar 81 APO

Ultimately I plan to build a rig using my recently purchased SWAGti, possibly with one of the above, a Guidescope and camera, all tied into a ZWO ASiair Plus 256G.

I've very recently purchased an Askar FMA135 135 mm f/4.5 ED APO Astro graph and it's a great quality little scope but not had a chance to use it properly yet. 

As a beginner, I very much appreciate any comments, criticism, suggestions etc. 

Thanks, Steve

I have the WO 81 GT triplet it is more expensive but gives great results,as already said in my opinion go for the standard version not the new one with the focuser half way along the tube, but that's only my opinion, good luck.