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Yet another diagonal vs reducer related upgrade - Evo 9.25

Celestron equipment eyepieces SCT accessories EAA
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#1 Viktorious

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Posted 12 October 2019 - 10:14 AM

Time for yet another cry for help when it comes to choosing diagonal. I have read the many similar threads and gathered some knowledge (too many to start linking). I have come some way in my process and now that it is coming to final decisions I would like to hear from the experts. Not many of threads I have read end with the OP returning to deliver some review/verdict of his/her final decision. While I wait for response on some thread where I asked about the result, the eagerness in me forces me to write my own thread. Perhaps some of the people asking these questions before can now answer in my thread as experts! smile.gif

 

I have the Nexstar Evolution 9.25 and am currently using the stock diagonal. My eyepieces are the Baader 8-24 mm zoom and the stock 40 mm Plössl. I would also like to upgrade EPs and there I'm looking at something better in 24 mm range, as well some nice low power for more FOV. I'm following threads such as Daniel's and Russ' with great interest for this. Can say that I'm currently leaning towards the 1.25" 24 mm ES 68° and 2" 36 mm Hyperion aspheric (if going 2" route). 

 

I'm thinking 2 alternatives (including a budget alternative for one of them). I'm looking at Baader mainly for ClickLock (and expect good optics):

  • Baader T2 Zeiss prism with a 1.25" ClickLock EP (T2 part #08) -OR- the 2" prism with 2" ClickLock (splurging that is).
  • The budget alternative would be to get the non-Zeiss T2 prism instead for the 1.25".
  • Worth noting that I would like to get the Celestron f/6.3 Reducer/Corrector. This would be for future purposes of delving into EAA but of course I would use it visually as well (especially if choosing the T2 route).

 

The reasoning for my alternatives:

  • Go for the 2" Zeiss prism to theoretically get the best of the best in visual terms. I would make better use of the 46 mm baffle tube opening. Theoretically possible to combine with the R/C thanks to relative short light path (although not necessarily needed with 2" EPs). Downside of going to 2" accessories would be the cost, EPs, filters etc., on top of diagonal. Would not be able to spend all these costs at once.  
  • Cheaper route with T2 prism (especially the non-Zeiss), not only diagonal but also the other accessories. Cost of the R/C would be comparable to e.g. the 36 mm aspheric and give similar power and FOV with the 24 mm ES, i.e. the 24 mm would act as both. Extra plus is the ClickLock clamp for 1.25" with built in fine focusing not involving the mirror. Downside of knowing that not all light coming out of baffle tube is used. To get the wide FOV (24 mm + R/C) I'm adding glass to the optical train (theoretically not a good thing).

 

I'm leaning towards the T2 as it would be a cheaper diagonal and for EPs I would only need the 24 mm and then the reducer instead of a 30-40 mm, so saving the expense of one EP. Then I would already have the reducer for continuing into EAA. The questions I hope the experts here can help with:

  • The old reducer vs 2" diagonal question. With R/C and the 24 mm I can get roughly the same mag and FOV as e.g. the 36 mm Hyperion (technically 38 mm vs 36 mm and 68° vs 72°). Also reading good things about the ES 68° and with R/C the EP should behave the same. Am I missing something here? The logics say that the I would lose some contrast with the R/C (not using full opening + adding elements), correct? Possibly flatter fields though (not important now, hopefully the linked EP threads might tell soon enough).
  • The Zeiss vs non-Zeiss T2? Big differences? I have read a few posts on this so most to get some updated views here (have read that Baader has changed some things over the years).
  • Using the R/C (f/6.3) with these prisms. I know f/7 is mentioned as "the limit" but also remember BillP's test where he was happy down to f/6 with the prisms (in 2014 at least).    
  • Perhaps most important: have I missed some other obvious alternative here? 

 

Maybe I have forgotten some question here but perhaps for the best as I assume those who have gotten this far are tired of reading now. Thanks for getting here though! 

 

Thanks,

Viktor


Edited by Viktorious, 13 October 2019 - 06:26 AM.


#2 Viktorious

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Posted 13 October 2019 - 06:35 AM

Just going into some economics of it, as I would go for the T2 mainly for the financial reasons. 

I can get a complete T2 Zeiss + reducer for ~50€ more than the 2" alone. Then I would have to get a ClickLock VB or locking ring for the 2", so the cost would be roughly the same. Then for EPs it would be enough with the 24mm for the T2+reducer whereas I would also need a 30-40mm for the 2" (150-200€). Other accessories (e.g. filters) would be pricier in 2". The want to try EAA would mean an extra 130-160€ for the reducer if I've gone the 2" route.

So, scaling it down like this basically brings it to: is the 2" 30-40mm view ~200€ better than the R/C 1.25" 20-25mm view? On top of that 200€ I would also be ~150€ poorer (the cost of the reducer) when looking at cameras for EAA.

*The non-Zeiss T2 would save an additional 100-120€ compared to the Zeiss T2. 

 

This was just the economical view. The initial post still has some questions about optics only, e.g. prisms at f/6.3.



#3 Viktorious

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Posted 14 October 2019 - 08:12 AM

Never mind, went the "economical" way. The T2 Zeiss is ordered. I will find out how it works with reducer myself :p. Can report back in the future if some poor soul is wondering the same thing in a year grin.gif .



#4 Viktorious

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Posted 21 October 2019 - 12:42 PM

Can update that the package has arrived (last Friday), within the promised 5 days. Checking microglobe now the diagonal is not reported to be in stock, so might be that I have the last T2 Zeiss that was available for now, pretty cool! 

 

On other notes I can recommend microglobe (was my first experience with them). Fast delivery within EU (UK company) and most importantly the lowest price on Baader equipment! I also got the Celestron f/6.3 reducer/corrector there and that price must be the cheapest in the world (£97). So that's a tip for UK/EU residents (EU for 10 more days?). 

 

Now I'm just waiting for my mount so I can use all my new stuff. Had to send the mount back due to some wobbly clutches.. 

 

Clear skies, 

Viktor 



#5 Spikey131

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Posted 22 October 2019 - 07:57 AM

I think you will find the T2 Zeiss prism, reducer and 1.25” EPs will work out very well in your C9.25.

 

All you need is a 24 Panoptic and you can forget about eyepieces for a while.


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