Lunt 50 SS vs. PST double stack.

[tico]

Hi,
I will try to be very clear in my question:
For visual observation which of the proposed instruments would provide me the  best visual image?
- On the one hand a new Lunt 50 / B600. or
 - I have the opportunity to get a second-hand double stack PST for 900 euro and I would like to ask you if it is really worth it on a visual level, is there much difference between the PST with or without double stack?

Both possibilities would have a similar price.
A greeting and very grateful.
Greetings.
Tico.

 

[Peter Drew]

It really depends on what represents the best image for your interest.  Double stacking enhances the contrast of surface features albeit with a dimmer image visually which detracts from prominence visibility, a hood or cover over the instrument improves this.  I personally find the prominences more dynamic and interesting.        🙂

[Highburymark]

So difficult to say. The more experience you have with solar scopes the more you realise each example is different. For me, double stacking transforms the views of surface features, but no doubt the Lunt 50 is a nicer scope than the PST. So if possible, I’d say get the Lunt 50 and save up for double stack. Even if it’s not affordable for a while, it offers that option for the future. 10mm is a lot of aperture difference at this level.

[Nigella Bryant]

I had a PST, wasn't impressed with the view. I much prefer the Lunt.bi had a Lunt 35m far outshined the PST so the 50mm Lunt in my opinion is the best.

[Paul73]

A PST Double stack shows slightly more surface detail than an unstacked Lunt 50mm, but as Peter points out the view is a lot dimmer.

An unstacked Lunt 50mm beats an unstacked PST.

I haven’t tried a double stacked Lunt side by side with a double stacked PST, but can vouch that a double stacked Lunt gives great views.

Paul

[Luke]

I'd go with the Lunt and maybe double-stack it at a later date.

For me it is aperture first, double stacking second for "best view". I like the more constrasty view double stacking gives you, which can make it easier to pick out details on the disc, but I like the finer detail you can see with larger aperture scopes more.

Edited December 1, 2020 by Luke

[Nigella Bryant]

1 hour ago, Luke said:

I'd go with the Lunt and maybe double-stack it at a later date.

For me it is aperture first, double stacking second for "best view". I like the more constrasty view double stacking gives you, which can make it easier to pick out details on the disc, but I like the finer detail you can see with larger aperture scopes more.

Totally agree, aperture first then double stack later. I also went second hand which was half the new price. 

[Mark at Beaufort]

I have the PST + DS and I can state that the image is dimmer but I also use a black out hood. I bought my PST in 2005 for the annular eclipse in Spain followed by the Total eclipse in 2006 (Turkey). 

I was really happy with my PST until I tried the double stack at a SGL star party. I then obtained a used double stack a few years ago. I usually start with just the single PST turning the wheel to get a white light view which you cannot really obtain with the DS in place. To obtain better surface detail I add the DS.

If I was starting out now I would most likely buy the Lunt 50, not because I am not happy with my PST, but I believe that the extra 10mm would improve the view. In saying that I have been told that the surface detail in a PST+DS is better than the single Lunt 50.

[Peter Drew]

Users of single stack units will probably have noticed the significant enhancement of solar disc contrast which occurs when thin cloud passes over the image.  This is very similar to the effect of double stacking in appearance.  Pity it's so expensive to achieve properly.      🙂

[Highburymark]

The challenge with single stack is to get a good example - whether Lunt or Coronado. Many only show faint surface activity, while the best examples can almost rival double stacks. It’s the luck of the draw unless you can test your purchase first. Adding a second etalon almost always transforms the views of filaments and ARs, even if the single stack etalon on its own was unimpressive. At least, this is my experience after many years of solar observing with 50, 60 and 70mm single and double stack Ha systems.

And the cloud trick Peter mentioned is spot on - it also further enhances double stack views! Of course the other great tool for solar observing is a binoviewer, which is a relatively cheap way of getting better views.

[Peter Drew]

This is the problem with entry level equipment, even at these prices!  There is a manufacturing tolerance which results in a variable example lottery.  The PST etalon used in my 150mm Ha telescope was the best one out of a dozen or so.  A friend once brought along a 60mm model which proved to be unexceptional, when fitted with a double stack unit, for someone noted for his low key persona, the outburst of expletives on looking through it said it all.       🙂

[tico]

Of course, this is the doubt, I also think that a <lunt 50, simply not because it is Lunt but because it is 10mm more, would show a brighter or brighter visual image, with higher resolution, but with lower contrast compared to the DS PST ... I imagine that the prominences would look better in the Lunt because of their higher resolution ... I don't know about the sweet spot anymore, if better or greater in the Lunt ... But I am clear that Lunt's after-sales service is light years away from Meade's. Something very important !! Nor am I clear about the problem of rust in the PST Coronado, I read that Meade said that it was already solved. Well these are my "solar" reflections..

Cheers,

Tico.

[tico]

I think it's a joke

[tico]

Sorry,

I meant that for the price of these solar telescopes ... that this is a lottery, this is what I mean,

I'm sorry if someone could feel offended but that's my opinion ... Tico.

[jonathan]

In case the views in any Lunt solar scope don't come near to showing surface detail or the bright patterns around a sunspot (I forget what it's called, spiculae?), the small blue glass filter (the one that can suffer from surface corrosion) is easily replaced.  They are available to buy quite cheaply from Lunt's website and Lunt will send one free of charge if it's one of their own scopes that has this problem.  It's a known problem with older blue glass filters, they are not a critical blocking filter.  Corrosion will be easy to see on the blue glass if the diagonal is closely examined, what the surface corrosion effectively does is diffract the light coming through a bit like when there's some thin cloud coming across, usually resulting in a red background around the sun as well (this can also happen if there's some haze or thin cloud around that the sunlight is lighting up, if the blue glass filter is not corroded then it should still be possible to see good surface detail through bright haze).

I've been impressed with the views through a PST for such a small scope, more aperture definitely improves the magnification and detail potential though.  Whatever you get, make sure you mount it on something solid, I've seen a PST mounted on a flimsy camera tripod which seriously diminishes the experienice in my experience, fighting against an overloaded tripod sag and trying to nudge the stiff joints trying to keep the sun in view.  A heavy duty camera tripod with smooth pan and tilt controls or an EQ1 is probably enough for a PST, I use a CG4 (EQ3-2) for my Lunt (I found it too heavy for my camera tripod).

The B600 part is in the diagonal and so should in theory be easy to upgrade to B1200 at a later date, whether it is worth while is another question.  I've never actually seen another Lunt in person so can't compare B600 to B1200.

Edited December 3, 2020 by jonathan

[Nigella Bryant]

Solar quest mount is what I use for my Lunt. Brilliant mount and track's the sun via light diode.

Edited December 3, 2020 by Nigella Bryant
Pic added