Advantages of Stage I and Stage II
Advantages of Stage I and Stage II
Since you are not changing the size of the etalon, what advantages are there to the Stage I and Stage II mods? Thanks.
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Re: Advantages of Stage I and Stage II
You're increasing the effective aperture which gives better surface resolution...
The Stage 2 mod also dumps the problematic penta prism, improves the backfocus to accommodate cameras and allows the introduction of larger blocking filter for a better FOV.
The Stage 2 mod also dumps the problematic penta prism, improves the backfocus to accommodate cameras and allows the introduction of larger blocking filter for a better FOV.
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Re: Advantages of Stage I and Stage II
Exactly what Ken says!
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Re: Advantages of Stage I and Stage II
I do not see any advantage between them if your PST is working well; it is another story if the PST is not giving of it's best.
Re: Advantages of Stage I and Stage II
I do not see any advantage between them if your PST is working well; it is another story if the PST is not giving of it's best.
There's one major advantage. It opens you up to the world of large aperture Ha telescopes.
There's one major advantage. It opens you up to the world of large aperture Ha telescopes.
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Re: Advantages of Stage I and Stage II
Ok let me rephrase it, I cannot see any advantage of a TAL100/PST stage 1 conversion over a Tal100/PST stage 2 conversion.
Re: Advantages of Stage I and Stage II
OK, there's a major advantage to getting rid of the Black Box of the PST and in particular getting that penta-prism out of the light train.
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Re: Advantages of Stage I and Stage II
OK, there's a major advantage to getting rid of the Black Box of the PST and in particular getting that penta-prism out of the light train.
And they are what exactly?
Having used both side by side and bigger scope conversions I would be interested.
And they are what exactly?
Having used both side by side and bigger scope conversions I would be interested.
Re: Advantages of Stage I and Stage II
If you used both and couldn't see the difference, I'll leave it to others to carry on.
Re: Advantages of Stage I and Stage II
If you used both and couldn't see the difference, I'll leave it to others to carry on.
Yeah a huge difference in practice
Yeah a huge difference in practice
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Re: Advantages of Stage I and Stage II
Having used both configurations I have to agree with Mlr Tom above , there is a huge difference . Personally I would not consider a stage 1 mod after seeing how the stage II opens up the view . The big advantage in my opinion is being able to use bigger blocking filters . Going from the 5mm BF in the PST to a BF 15 compares like looking through a straw to looking through a telescope . My next move is to try a Lunt 2" - 18mm straight through .
Re: Advantages of Stage I and Stage II
A BF15 is a direct swapover from the standard PST BF5, you just unscrew both for the switch. Both the PST BF5 and the BF15 use the same supplied 15mm ITF so there is no issue there.
Re: Advantages of Stage I and Stage II
Is there a detailed description of how to perform a stage 2 mod including the parts necessary and where to purchase them? It sounds like a stage 2 is the way to go. I already have a diagonal with a BF 10 blocking filter. Thanks.
Jim
Jim
Re: Advantages of Stage I and Stage II
I've only ever seen one person who swears there no difference between a stage 1 and a stage 2, I have better things to do than deal with that.
- keithatrochdale
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Re: Advantages of Stage I and Stage II
I've only ever seen one person who swears there no difference between a stage 1 and a stage 2, I have better things to do than deal with that.
Well JohnM some side by side testing was done with 2 TAL/PST stage 1 and a Vixon florite/PST stage 2 and the three testers favored the stage 1.
I hope some of the testers who visit this site will add their comments.
Well JohnM some side by side testing was done with 2 TAL/PST stage 1 and a Vixon florite/PST stage 2 and the three testers favored the stage 1.
I hope some of the testers who visit this site will add their comments.
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Re: Advantages of Stage I and Stage II
My testing was done with the same donor scope and the same PST . Celestron 102 OMNI XLT with stage I mod and followed by the same XLT scope using the sams etalon from the PST . The big difference was the Coronado BF 15 I used for the stage II . After comparing the views there was no desire what so ever to go back to the stage I configuration , in fact I plan to move up to a Lunt B 1800 2" straight through for this scope in the near future .
These are just my findings and opinions on what I have done . For imaging I actually prefer my stage II mod to my SM 60 II
These are just my findings and opinions on what I have done . For imaging I actually prefer my stage II mod to my SM 60 II
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Re: Advantages of Stage I and Stage II
Visually (with perfect aligned black box PSTs) I could 'see' no difference with the stage 1 and stage 2 mods, and in this context happily see the argument. However from a critical imaging point of view, with that penta prism in place sharpening soon shows the astigmatism it introduces and with it a relative lack of contrast and definition.
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Re: Advantages of Stage I and Stage II
Yes, probably important to emphasize the difference between visual and photographic uses.
The human eye is much more forgiving than a camera chip.
The human eye is much more forgiving than a camera chip.
- keithatrochdale
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Re: Advantages of Stage I and Stage II
Not having progressed to serious imaging yet, all my comments and the three tester were using standard
Mk 1 eyeball.
So I think we can agree that for visual there is little to justify the extra costs of stage 2, but there may well be advantages for imaging, which I have yet to do/assess?
Mk 1 eyeball.
So I think we can agree that for visual there is little to justify the extra costs of stage 2, but there may well be advantages for imaging, which I have yet to do/assess?
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Re: Advantages of Stage I and Stage II
Not having progressed to serious imaging yet, all my comments and the three tester were using standard
Mk 1 eyeball.
Mk 1 eyeball.
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