Redcat died - should I look at WO GT71 vs WO ZS81 for 533MC?

[drivera]

Hi there,

So my... fiancé broke my Redcat. 🤣

Considerations: William Optics 2019 Gran Turismo GT71 APO Triplet Refractor; William Optics New Super Zenithstar 81 f/6.9 I'm looking at purchasing a new scope. I currently have (had) a Redcat 51 and looking at a new purchase, while also upgrading from DSLR to the ASI533MC.  What would people recommend for this setup? I'm limited by weight with my Sky Guider Pro at this stage.

The WO GT71 is a tiny bit cheaper than the WO 81.

I'm looking at a closer FOV for DSO objects than the Redcat but unsure of the 533MC impact.

OR any scopes like these out of the WO would be worthwile and/or better?!

Thanks!

Steve

[JeremyS]

How did he do that then?

[Alien 13]

Its worth looking at the SW range too, never been convinced by the WO GT range, the Z 61 or 73 are good value though.

Alan

[Adam J]

2 hours ago, drivera said:

Hi there,

So my... fiancé broke my Redcat. 🤣

Considerations: William Optics 2019 Gran Turismo GT71 APO Triplet Refractor; William Optics New Super Zenithstar 81 f/6.9 I'm looking at purchasing a new scope. I currently have (had) a Redcat 51 and looking at a new purchase, while also upgrading from DSLR to the ASI533MC.  What would people recommend for this setup? I'm limited by weight with my Sky Guider Pro at this stage.

The WO GT71 is a tiny bit cheaper than the WO 81.

I'm looking at a closer FOV for DSO objects than the Redcat but unsure of the 533MC impact.

OR any scopes like these out of the WO would be worthwile and/or better?!

Thanks!

Steve

I think that the thing to remember is that the moving to a smaller sensor and a longer focal length at the same time will greatly reduce the field of view from your current setup. 

Personally I would go with the GT71 as it's a triplet shorter focal length and will make the most of the 533 sensor. 

[drivera]

10 hours ago, Adam J said:

I think that the thing to remember is that the moving to a smaller sensor and a longer focal length at the same time will greatly reduce the field of view from your current setup. 

Personally I would go with the GT71 as it's a triplet shorter focal length and will make the most of the 533 sensor. 

Yeah that's my learning curve on this trying to ascertain that and the limitations, I don't want to set myself up for failure!  Having the Skyguider Pro I'm limited to about 5kgs which is also another factor with guidescope and ccd.

Looking at targets like Andromeda, NA etc I realise it'll be filled past the FOV but other ones like Pinwheel, parts of Veil, Crescent etc will be good for it?

We're looking at our home insurance for accidental damage to see if it'll pay for repairs/replacing it. As it seems it'll take months to get it fixed potentially, thats why I'm  looking at different style scope as if I get the Redcat back then I don't want two of the same.

 

[drivera]

12 hours ago, Alien 13 said:

Its worth looking at the SW range too, never been convinced by the WO GT range, the Z 61 or 73 are good value though.

Alan

Thanks Alan, what's the SW range? Do you mind sharing an example for comparison?

I also saw ALTAIR STARWAVE 70 ED TRIPLET  but unsure of that vs the WO Z71?  There's a big difference in price between the Z71 and Z73 so now i'm going down a the rabbit hole.

[drivera]

12 hours ago, JeremyS said:

How did he do that then?

She accidentally kicked the coffee table it was on - rolled off 😕  

[Alien 13]

5 minutes ago, drivera said:

Thanks Alan, what's the SW range? Do you mind sharing an example for comparison?

I also saw ALTAIR STARWAVE 70 ED TRIPLET  but unsure of that vs the WO Z71?  There's a big difference in price between the Z71 and Z73 so now i'm going down a the rabbit hole.

Skywatcher, like the Evostar 72 ED or 80 ED DS Pro or the Esprit range.

Alan

[drivera]

7 minutes ago, Alien 13 said:

Skywatcher, like the Evostar 72 ED or 80 ED DS Pro or the Esprit range.

Alan

Wow the 80 ED DS Pro is nearly half the price of WO! and bigger focal length. I think the weight will max me over 5-6kgs with guides cope + camera etc. Hmm wonder if I could get away with it.
 

[beka]

14 hours ago, drivera said:

Hi there,

So my... fiancé broke my Redcat. 🤣

Considerations: William Optics 2019 Gran Turismo GT71 APO Triplet Refractor; William Optics New Super Zenithstar 81 f/6.9 I'm looking at purchasing a new scope. I currently have (had) a Redcat 51 and looking at a new purchase, while also upgrading from DSLR to the ASI533MC.  What would people recommend for this setup? I'm limited by weight with my Sky Guider Pro at this stage.

The WO GT71 is a tiny bit cheaper than the WO 81.

I'm looking at a closer FOV for DSO objects than the Redcat but unsure of the 533MC impact.

OR any scopes like these out of the WO would be worthwile and/or better?!

Thanks!

Steve

Sure it was accidental - maybe jealous?😀

[Dave Lloyd]

52 minutes ago, drivera said:

She accidentally kicked the coffee table it was on - rolled off 😕  

That's a change. It's usually having to justify a new purchase to your better half. She's done the hard part for you. 

[drivera]

1 hour ago, Dave Lloyd said:

That's a change. It's usually having to justify a new purchase to your better half. She's done the hard part for you. 

Haha exactly!

[drivera]

1 hour ago, beka said:

Sure it was accidental - maybe jealous?😀

Haha I thought she'd want to keep it in pristine condition to have peace and quiet when I disappear for imaging haha

[PadrePeace]

Hope I’m not teaching you to suck eggs but try putting the various scope FL options and the 533 into the Telescopious Telescope simulator which will allow you to see the framing of almost any target you might think of. It allows you to rotate framing plan mosaics and use the native and reduced FL as well. It reads out Dawes limits, pixel scale, FOV and target coordinates which is helpful to assess almost any combination of gear. 

I have a 71GT and have mounted it with an ATIK 460EX on a Sky Guider Pro. Fully rigged with a filter wheel and focus cube as in the picture it weighed in at 4.5kg which is pushing the 5kg mount limit. I have shot images with this rig reduced to 336mm FL and got good 4 min guided subs but I had it all very meticulously balanced which gave the mount a fighting chance. 
 

Hope this helps

 

[michael8554]

3 hours ago, drivera said:

She accidentally kicked the coffee table it was on - rolled off 😕  

Could have been worse - you might have been married........... 

(sorry, couldn't stop myself).

Michael

[drivera]

10 hours ago, PadrePeace said:

Hope I’m not teaching you to suck eggs but try putting the various scope FL options and the 533 into the Telescopious Telescope simulator which will allow you to see the framing of almost any target you might think of. It allows you to rotate framing plan mosaics and use the native and reduced FL as well. It reads out Dawes limits, pixel scale, FOV and target coordinates which is helpful to assess almost any combination of gear. 

I have a 71GT and have mounted it with an ATIK 460EX on a Sky Guider Pro. Fully rigged with a filter wheel and focus cube

Thank you so much for sharing! This is extremely extremely helpful!
I'm amazing it's 4.5kgs with that setup, that's great. I was guesstimating my weight with the 71GT around 4.5 too.  It's great to see you got it working and set up and getting 4mins.  It gives me confidence!  I was thinking I'll go and place the guidescope on the counterweight side too to reduce the it if needed, but maybe not needed?
I'll be technically a few hundred over budget if i did the 71GT but feel it would be worth it in the long run?

RE: Telescopious - thanks for sharing that. I've been going over and over on that with subjects etc, but I'm so new to this that I think I've done it wrong - not including the flattener and how that impacts FOV/reducing it?

 

[drivera]

9 hours ago, michael8554 said:

Could have been worse - you might have been married........... 

(sorry, couldn't stop myself).

Michael

Haha won't be long now - so lets see how many more scopes hit the dirt lol

[PadrePeace]

Here is a screen shot of the telescope tab. Once you have loaded and saved your native scope details into the app you just need to set the reduction amount located at the bottom of the tab, in this case it’s a 0.8 reducer (if barlowed it would be something like 2.0, 3.0) and turn the setting on or off to change your image effective FL and hence FOV, pixel scale et al….

Edited July 25, 2021 by PadrePeace

[PadrePeace]

12 hours ago, drivera said:

Thank you so much for sharing! This is extremely extremely helpful!
I'm amazing it's 4.5kgs with that setup, that's great. I was guesstimating my weight with the 71GT around 4.5 too.  It's great to see you got it working and set up and getting 4mins.  It gives me confidence!  I was thinking I'll go and place the guidescope on the counterweight side too to reduce the it if needed, but maybe not needed?
I'll be technically a few hundred over budget if i did the 71GT but feel it would be worth it in the long run?

RE: Telescopious - thanks for sharing that. I've been going over and over on that with subjects etc, but I'm so new to this that I think I've done it wrong - not including the flattener and how that impacts FOV/reducing it?

 

Talking weight, I do have a autofocuser and a filter wheel which you most likely won’t need given the 533 is a colour sensor. Without those  I recon you’d save close to 800g over my setup which is significant. There are some very reasonably priced (SVBony on EBay) mini guide scopes on the market which will help reduced bulk and weight. You could pay three times the amount but at the FL you are talking about here the EBay ones will perform fine. Every little helps as they say. 

Edited July 25, 2021 by PadrePeace

[david_taurus83]

I think the GT71 might be a bit much for the SGPro. 

[PadrePeace]

2 hours ago, david_taurus83 said:

I think the GT71 might be a bit much for the SGPro. 

That worth stating for sure as the heavier your rig the more strain on gears and the like. That’s why mine was balanced very carefully for each session. The WO71GT is only 2.2kg so I guess it’s all about what you are going to add to that. As I understand it the SGP 5kg limit is for imaging as I cannot see anyone doing visual work with it so working in the 3-4 kg range would be a comfortable upper end target.
Balance is important as is the length of the rig as inertia is a consideration. That said mine guided through PHD to 0.40 arch seconds on RA which I’d say endorsed it for me. 

[drivera]

7 hours ago, PadrePeace said:

Here is a screen shot of the telescope tab. Once you have loaded and saved your native scope details into the app you just need to set the reduction amount located at the bottom of the tab, in this case it’s a 0.8 reducer (if barlowed it would be something like 2.0, 3.0) and turn the setting on or off to change your image effective FL and hence FOV, pixel scale et al….

Oh that is awesome! thank you for sharing that. Now it makes sense.

I was wondering how to understand the 'flattener/reducer' impact per lens (new world).

[drivera]

3 hours ago, PadrePeace said:

That worth stating for sure as the heavier your rig the more strain on gears and the like. That’s why mine was balanced very carefully for each session. The WO71GT is only 2.2kg so I guess it’s all about what you are going to add to that. As I understand it the SGP 5kg limit is for imaging as I cannot see anyone doing visual work with it so working in the 3-4 kg range would be a comfortable upper end target.
Balance is important as is the length of the rig as inertia is a consideration. That said mine guided through PHD to 0.40 arch seconds on RA which I’d say endorsed it for me. 

Thats really interesting. I thought it was 2.93kg so I have been pre-empting my total weighting around 4.3kg with all the stuff. I'm wondering if I do move the guidescope/cam to the counterweight bar it can assist.

[drivera]

I'm thinking I'm going to pull the trigger - it's about 250 over budget for me. But if the triplet is better than the doublet and if my mount may struggle now, it sets me up for the right one in 12-24 months when I get a better mount (GoTo etc).

I was leaning around the WOZS71 after all the reviews/back & forth etc than the WOZS81 due to the price as its about on point for budget.

The WO ZS71 looks decent so was trying to now narrow if its worth the difference and price pain.

[PadrePeace]

12 hours ago, drivera said:

Thats really interesting. I thought it was 2.93kg so I have been pre-empting my total weighting around 4.3kg with all the stuff. I'm wondering if I do move the guidescope/cam to the counterweight bar it can assist.

It seems you are right on the weight of the new 71GT which seems to have put on some weight since I bought mine(see my attached manual which states 2.2kg). Could be the handle which is a ‘nice to have’ but not essential in my view especially on such a small light scope. 
https://williamoptics.com/download/support/GranTurismo_71_Owner_Manual%2Bver.1.0%2B2017.06.pdf