Hi Mak
OK, as you should realise all my knowledge is
only from research over several weeks, 99% web-based, but here is my take (and why I choose the PST).
First - very basically the angstrom (A) rating refers to how narrow the unfiltered light bandwidth is - with solar viewing, the narrower the Ha bandwidth is, the more detail that can be seen. H-alpha filters (
for solar viewing, there are other astronomy Ha filters) allow only a very narrow bandwidth of red light, blocking the brighter emisions, and thus we see the surface detail and prominences.
The PST has one Ha filter built in but it is only at < 1.0A (Angstrom)
The SM 40 can be added to your own scope and is rated <0.7A - you can see more surface detail.
Both have an adjustment wheel so you can widen/narrow the bandwidth slightly to focus on prominces (wide setting) or surface detail 9(narrower). You CAN see both at same time though.
Both show prominences very well. The SM40 shows surface detail better.
Doublestacking the PST allows you to tune both filters so the bandwidth can be ranged from <1.0A to 0.5A - VERY good.
The 2nd filter on the PST is just a SM40 but
without the Blocking Filter (BF) as it already has one - you don't need 2 BF's.
You
can doublestack on your own scope, ie 2x SM40, for even narrower bandwidth.
When you buy the SM40 (it will come with a seperate BF - all Ha filters must be used with a BF to stop things from heating up) then you can attach it to your choice of scope - usually/always you need an adapter plate.
The advantage of this is that you then are only restricted by your scopes own limitations as to magnifications, eyepieces, barlows, imaging equipment. But SM40 filter alone is more expensive than PST.
The PST suffers from more restrictive limits with regard to accessories, especially back-focus. It suffers from not being able to get to full focus when using CCD/webcams to image (but this can be solved though).
For imaging with PST there are still many options but you may need to do testing (although there is much published on forums as to what works well). Some have to modify the camera, others have to use a barlow (some barlows filt better than others and some need adaptions). It all appears to be usually simple stuff (which is why I have decided on the PST).
If you aren't doing imaging then no mods are really necessary to get the good stuff and you don't need the barlow.
I will be getting :
PST doublestacked -------- 2200
TV Powermate2.5x barlow --- 300 (still to do more research on barlows)
DMK camera ---------------- 600
EQ4 mount -alreay have one -
300
---------------------TOTAL $
3400
Seems very cheap for the amazing images you can capture. As I have said I doubt you can get better looks at nighttime stuff without spending a lot more or going bigger.
AND what you capture is also what you can actually see with your own eyes looking through the scope.
You can get away with a cheaper camera - but have a look at the link provided by Rumples and see the quality of his 2 solar pics (using DMK), then compare with what is shown at Coronado's
massive image gallery (& other places).
http://www.coronadofilters.com/QuickGal/index.php
All are great, Rumples are clearer, don't you think?
Also in the gallery, compare the PST with the SM40 images, not much difference, if any (although depends on skill and imaging equipment).
Later I may add an ED80 refractor - depending how the urges go.
Who will you buy your PST from?
Will you get doublestacked? You can stack it later on.
I hope this helps. I hope (although I am pretty sure) that what I have written is correct.
Craig
![[1ponders]'s Avatar](../vbiis/customavatars/avatar45_9.gif){kind=avatar}
). While the PST was good in it's native state and I enjoy looking through it and getting my first few images (a coupld of months ago now. ) I was amazed how much more detail I could see with the double stack. I can't wait to try it with a camera attached.
