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Coronado PST question


lnlarxg
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Hope this is the right place to ask about the Coronado PST

i recently acquired this scope and I can’t get any surface details to show on the sun, I have played with the tuning ring but apart from being able to see some flares on the rim of the sun, no surface details came through. I was using my own 8mm and 11mm Explore 

what I saw was just a red blob, pretty much like white light viewing with a red filter. Turning the tuning ring only changed the intensity of the light coming through

is this what is expected of the PST? Or do you think I am doing something wrong or my PST may well be faulty?

 

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With the PST you should have a sweet spot where an area of the surface should show detail but never the whole disk at once. There are ways to adjust the tuning range which sounds like it might be your problem.

This thread has some usefull info.

 

Edited by johninderby
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Could be a couple of things:

 

There's not that much detail on the surface currently in Ha. I'd expect you to see an orange peel effect surface though. I suspect this is your 'problem'.

20181003120250Uh.jpg

Or your ITF / objective might be 'rusted'.

 

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There are several reasons that can result in initial disappointing results with a PST and most are common to all solar telescopes. It takes a while to get your eye "in", specially if you have been looking at processes images. Tuning, as you have found, is important for best results and can take time to perfect it. PST's, as with other makes, are not equal in performance for a given aperture, there is a reasonably wide acceptance level of specification such that although each is fit for purpose, some are "superfit".

If your instrument is pre-owned, there is a possibility that the filter between the prism and the blocking filter has deteriorated, a common and fixable problem that seems to be unavoidable given enough time. This situation impacts more on the visibility of surface detail than prominence limb detail. A good PST is certainly capable of showing obvious surface detail under good seeing conditions, transparency of the sky being one of the most important requirements. The Sun, being at its low point of activity, currently shows less surface detail than usual.   ?

Edited by Peter Drew
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The thing is, there’s not much to see at present. And, as Peter points out, if you’re new to Ha viewing it can be underwhelming at first.

Take some time to look and really ‘observe’, educate your eye. Most of all, you have to absolutely nail the focus.

Stay with it. It is worthwhile. ?

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I've done a bit of HA solar observing with a PST and also a Lunt 50.

One thing that I found was that it takes some time for your eye to adjust to observing in hydrogen alpha light. I've been observing for decades at night and also solar white light but I found that it took a few sessions and some careful selection of eyepiece focal lengths and experimentation with the tuning of the etalon filter to start to tease out detail in h-alpha.

Add to that the rather inactive solar surface presently and the vagaries of seeing conditions and it's a more challenging pastime than you at first think !

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Agree with everything said above. I have a somewhat underused PST and I too was initially disappointed, but the more frequently I use it the more I seem to be able to tease out. I tend to be able to tune it for surface detail or prominences, but rarely both at the same time. A dark cloth over the head helps enormously. But the biggest success factor is patience and perseverance!! 

Paul

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