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I've been reading with interest the other PST thread and have looked at a few options available. The basic PST and Lunt 35 are very similarly priced but which is the better option for visual and imaging. I like the idea of the PST mod but don't fully understand its benefits yet and when it gets to the stage 2 mod it looks to be getting expensive. If it is expensive then why not buy a bigger Lunt or is the mod even better.

Questions, questions. and more questions.

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You'll have people happily and firmly entrenched in both camps.

I have a Lunt ls35 and really like it. It is very nice for visual and I think I have been down to an 8mm eyepiece and it held a very decent image. It has been very good for imaging with a high frame rate DMK camera and I was able to get focus with and without a Barlow. I have owned a PST years ago but did not use it enough nor do I remember it well enough to be able to make a valid comparison between the two other than to say that the Lunt sweet spot was far more generous. On both scopes though you are peering around a rather small blocking filter (mine is a B400 and the B600 would be better).

There is lots of info on the PST mod available and people are really pleased how it turns out. I think that you still need to invest in a decent ERF and maybe get a bigger blocking filter. I have a feeling that the current crop of PSTs are harder to disassemble but do not know how much this affects the ability to mod.

I went down the "replace with a bigger scope" route and have taken delivery of a Lunt LS60. The clouds have not parted yet to allow me to report on it!

The PST and Lunt are great introductions to Ha solar astronomy and I am sure you'd be happy with either.

Google "Solarchat" (a solar forum) I recently starting using this forum and found it to be a great help in my decision making.

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On both scopes though you are peering around a rather small blocking filter (mine is a B400 and the B600 would be better).

Google "Solarchat" (a solar forum) I recently starting using this forum and found it to be a great help in my decision making.

Not sure I understand the blocking filter bit.

I have been looking at Solarchat, but have not joined them yet.

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Hi Allan,

I owned a PST and then bought a Lunt 60. It was quite a step up in price and performance, but I don't regret buying the PST first. I did briefly consider the PST stage-x mods but decided that I would spend the best part of the cost of the Lunt and I would still have a relatively small Etalon, although everything else would be upgraded.

The B400 and B600 refer to the blocking filter size. A small blocking filter, like those fitted to the PST is fine for visual and small CCD, but for larger chip cameras you really need a bigger blocking filter.

I am interested to hear that the Lunt 35 can get focus both with and without a Barlow on a DMKx1 camera. Some PSTs can get focus without a Barlow, but most seem to need it or a mod. From that point of view the Lunt 35 might be the better option.

There is a good review of both here although there isn't a clear winner.

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I got a secondhand LS35 and am very pleased. Visually it is a stunner. I use my Pentax XF8.5mm EP in it almost exclusively, and the view is just wonderfully sharp. I have tested it briefly (before clouds rushed in) with my new ASI130MM camera, and it reaches focus without barlow. Now if all this cloud would buzz off, I could take a few pics as well.

Mine also has a B400 blocking filter (which means a filter 4mm in size). This is suitable for a scope with a focal length of 400mm (which the LS35 has). The B600 has a 6mm diameter filter, and can be used on scopes up to 600mm focal length. This gives you a wider "sweet spot" in which the solar image is good. On a good tracking mount like my Vixen GP, the smaller diameter of the B400 filter is not an issue.

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Been doing a bit of research and the pst mod doesn't seem impossible, and sounds like it has benefits, but what is the cost. You obviously need a donor scope or buy one, and then there is the modding kit and ERF etc. Does anyone have a figure for a pst mod so that I can compare with a new scope.

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I am interested to hear that the Lunt 35 can get focus both with and without a Barlow on a DMKx1 camera. Some PSTs can get focus without a Barlow, but most seem to need it or a mod. From that point of view the Lunt 35 might be the better option.

I did not have much in-focus to spare and I think there may well be variance between scopes where it is normal for focal length to be stated as 400mm but in practice vary by a few mm between scopes.

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How about imaging with a dslr. is this possible with a Lunt 35 or a Pst, or is it just video with ccd cams that are used. I have a Spc900 on the way, but mainly use my Canons.

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The larger sized blocking filters give a wider field of view and are mandatory with longer focal lengths ( the sun's size is roughly 1/000 the focal length ie a 400mm fl gives 4mm diameter, a 1200mm fl gives 12mm diameter)

The cost of the PST mod can vary very much depending on your DIY skils and the bit's and pieces in your "junk box". Excluding the cost of the PST, I could be up to 1000gbp for a 102mm aperture/ D-ERF/BF15 Stage 2 mod.

( I have a write-up on PST mods available - just drop me an email address for a copy)

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I have been pondering using the 35mm etalon of the LS35 in a setup in which it becomes an internal etalon for a larger solar scope, but find the costs add up so rapidly, that I might well start looking for a secondhand LS60. For the time being I am content with the little LS35.

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