Coronado PST

[Rob63]

After attending an open day at the local observatory and having the chance to try out an Ha Solar telescope, I am thinking of buying a Coronado PST.

Would any owners out there recommend it or would I be better holding off for a while and going for the SolarMax II 60 (which is twice the price)?

Also is it possible to do DSLR imaging with the PST? would I need adapters (I already have a T-Ring)

[JamesF]

More aperture is always good

DSLR imaging with the PST will be quite awkward.  I think someone has done it, but you need to hack things about a bit to get the camera to focus.  Also, because the image is only in a single wavelength red light you won't be using three quarters of the camera sensor.

Mono imaging makes much more sense with Ha scopes.  The main problem is the size of the image and the size of the camera sensor you need to capture it.  Or you need to accept that you have to use mosaics.  The longer focal length you use the larger the image at the focal plane, so this becomes more of a problem.  Camera choice is made even more tricky because not all models will reach focus.  Some can be fixed using a shorter nosepiece, but not all.

James

[JB80]

DSLR imaging is possible but it is a faff, I never quite managed to nail it but Photosbykev did a pretty good job of it and has some stuff on his website.

Basically the easiest option is to use a zoom eyepiece that has a t-ring connection, I used a baader hyperion but I can't see why another wouldn't work. Then it's a matter of getting your exposures right before processing the pictures which is the hardest part as you need to isolate the Red channel.

It is a hassle but if that's all you have at your disposal then I say have a go at it until you feel the need to move up to a ccd which you will want to do.

Hopefully Kev wont mind me linking his page....

http://www.photosbykev.com/wordpress/photography/pst-solar-imaging/

[keithatrochdale]

Do you know about this site?

http://solarchat.natca.net/index.php/en

[mitchelln]

Do you know about this site?

http://solarchat.natca.net/index.php/en

That's a really useful site. Thanks for sharing

[michael.h.f.wilkinson]

On my LS35 I only use monochrome planetary cameras. MUCH easier and does not need to cost the earth, especially if you go down the second-hand DMK route, as I did.

[Rob63]

Do you know about this site?

http://solarchat.natca.net/index.php/en

Thanks for the link, looks like a great resource.

[Merlin66]

The PST is a great little Ha scope!

Unfortunately it was designed for visual use and fitting a camera can sometimes become a real PITA.

There are many solutions.....

[Naemeth]

On my LS35 I only use monochrome planetary cameras. MUCH easier and does not need to cost the earth, especially if you go down the second-hand DMK route, as I did.

I think this is the best solution. The Lunt 35 is about the same price I believe, perhaps a little more.

[keithatrochdale]

Sometimes all that is needed on a PST is to turn down the eyepiece holder so that is just a little shorter and use a short camera nose piece.

[michael.h.f.wilkinson]

I think this is the best solution. The Lunt 35 is about the same price I believe, perhaps a little more.

My point was really about the planetary camera, not the LS35. The LS35 does have a larger sweet spot, but the PST allows modding.

[Rob63]

Hmmm, the general opinion seems to be that DSLR imaging is posible but can be tricky.

I am not ready for the CCD imaging route yet but I am sure that day will come.

The main use would be visual so if we put imaging aside how does the PST rate as an Ha solar scope against the likes of the SolarMax 60 ? or the Lunt 35

(current UK prices are PST =£659 SolarMax 60= £1300, Lunt 35 = £640 )

[Merlin66]

I've had a few PST's over the years - they generally perform very well and give good to excelent Ha results.

I also have a few SM60 etalons - no comparison! The SM60 is head and shoulders above the PST. Aperture and resolution...

I can't speak for the Lunt 35 - I've never tested one. It's an external etalon and should give good results......

[AndyWB]

Might be of interest: http://stargazerslounge.com/topic/66401-lunt-35-v-coronado-pst-shootout/

[keithatrochdale]

For me a PST is the route to go, allowing a stage1 conversion once the bank has recovered and if you were going to afford a SolarMax 60 then you could afford a TAL/PST conversion (100mm).

With the other scopes I believe (correct me if I am wrong) you cannot upgrade them.

[michael.h.f.wilkinson]

I have been toying with the idea of modding the PST, and it should in theory be possible, but now I am aiming simply for a pressure-tuned LS60. That can be modded "Franken-scope" style, and is a lot better in its own right.

[keithatrochdale]

I have been toying with the idea of modding the PST, and it should in theory be possible, but now I am aiming simply for a pressure-tuned LS60. That can be modded "Franken-scope" style, and is a lot better in its own right.

How much will this route cost to say get a 100mm dia?

Going the TAL/PST route will cost about £1200 IIRC, less if you can buy second hand.

[michael.h.f.wilkinson]

My aim is to buy a LS60PtHa without blocking filter (I have a B400 and B1200), and sell the LS35 with B400. That would cost roughly 1200 euro if I get a decent price for my LS35. This would give me a much better result that modding the LS35 (if at all possible) with my ST80. I might be able to "franken-scope" the LS60 with a fairly fast 80mm and arrive at a far more compact 80mm H-alpha scope than would be possible with the PST, which really needs F/10 optics for the mod. I might later alter that to a 100mm, which again could be based on a shorter tube frac. The advantage of this kind of set-up is a much larger etalon is used, so I may even get full-disk images at the larger aperture.

Having said that, I will first play with the LS60 itself, before getting the tool box out.

[jonathan]

I have the Lunt LS60 with pressure tuner, it's all I want from a visual solar scope at the moment.  Every time I view the sun through it I love it, there's usually something funky going on to see, and as it's during the day time the whole family can come and have a look too.  If you can afford it, go for the B1200 blocking filter.

I think the PST pleases those who love to tinker and modify their equipment, I'm not interested in that side of things really.  The pressure tuner is a wonderfully simple device, it literally has only one moving part - a large threaded handle - which you can't really do anything to mess up.

The price of the LS60 is quite high compared to a PST, maybe you could achieve something close to the LS60 with several PST modifications, I don't know, but it certainly wouldn't look as elegant or be as simple, wouldn't come with a custom storage / carry case, and you may end up spending almost as much unless you get some second-hand bargains.  You need to be really careful with solar scope modifications - get it wrong and it could be disastrous not only for the scope, but also for your eyes.

I started out umming and arring about the cheap end of solar scopes, looked at the SolarMax II for a while, but then decided I really liked the look of the LS60 with pressure tuner and haven't regretted it.  I believe the LS60 can accept an 'extension' to improve it, not sure what that is exactly or how much better it would be, it's a case of diminishing returns once you start spending more and more on solar scope equipment.

[Merlin66]

Jonathan,

The internal etalon in the Lunt 60 is about the same size as the one in the PST.

The Lunt pressure tuning is neat - the PST appears to use a version of Mechanical compression tuning to achieve the same result.