Which Coronado ?

[glowingturnip]

So next on my shopping list for the school observatory (from this thread: http://stargazerslounge.com/topic/211216-equipping-a-school-observatory-from-scratch/#entry2255443) I'm starting to look at Coronado solar telescopes.

I guess I'm looking at a 60mm Meade Coronado, like the ones on this page (http://www.f1telescopes.co.uk/product-category/solar-telescopes/coronado-solar-telescopes/).

There seems to be quite a price range on those though, depending on a) the diameter of your blocking filter and whether it's 'doublestacked' or not

Anyone know what these are, and what the best value for money mix is likely to be ?

Cheers,

Stuart

[alanjgreen]

I would have a good look at Lunt scopes before deciding on a Coronado ?

[alanjgreen]

For me, the first question is

how many kids do you want to be able to see the sun at the same time?

* do you want one scope and a queue of kids waiting to look through it

* or several scopes and several kids all looking at the sun

therefore several lunt 35mm scopes would get my vote

[glowingturnip]

no, it'll be in an observatory, only room for the one scope, so one kid at a time, or stream the view through a Watec ( possibly ?) camera so they can all see it

[alanjgreen]

ok - whats the budget?

[alanjgreen]

take a look at Dr.Robin at his village show (in attached thread) - you may be onto something similar to use at school

http://stargazerslounge.com/topic/194401-calling-all-imagers-today-is-the-day-please-submit-a-photo-of-the-sun/?hl=%2Bsolar+%2Bvillage#entry2036786

[glowingturnip]

budget would be around £2k for the scope only, with a little flexibility either way in that.

Had a look at that thread, that's the kind of thing - it mentions doublestack again, what is that and do I need it ?  And how important is the blocking filter diameter ?

Cheers

[alanjgreen]

key point is that "Budget will likely be an issue" - £2000 feels a little low.

lets take scope diameter first

* larger diameter will let you use more magnification. typically 60mm or 80mm is a good useful diameter for the sun (at it is not too far away & there is plenty of light coming to earth from it)

now doublestack

* solar scopes use an "etalon" to filter the suns light, double stack means a second "etalon"

* single etalon lets us see the suns surface (as opposed to just using white light where you cannot see the surface)

* double etalon lets you see "more" surface detail - if you want to see the suface then double is better than single stack but the cost is roughly x2 (double!)

now blocking filter

* if you intend to use camera and image then BF diameter is very important

* with the Lunt's 1200mm is usually the one to go for

With your budget of £2000 then double stack lunt is probably out of the question, I would go for the pressure tuned LS60 with B1200 blocking filter, just slightly over budget and you can add a double stack later (if you want to see more of the surface)

* however, the views are great (don't get hung up on double stack - solar is a bit like cars - "there's always a faster model"

Obviously, as I have a lunt - "i would say that" - so I suggest that you let others come in with their opinions - it would also be recommended to go visit a supplier and take a look through some of the scopes (before you commit)

[Peter Drew]

At the 60mm aperture and with your budget I would second the Lunt with a B1200, even though I've got 6 Coronados!.  The video option for group viewing would be ideal. 

[glowingturnip]

a consensus vote, love that !  I'll have an investigate, thanks

[Merlin66]

I have and use an SM60 (single and double stacked ) with either a BF10 or BF15 blocking filter.

The DS significantly reduces the light throughput, and for the casual observer with limited time at the scope can be counter productive.

The 60mm aperture is a compromise between $$$ and detail.

I can't comment on the Lunt scopes - I only use Coronado (and a 102mm PST mod)

[Macavity]

no, it'll be in an observatory, only room for the one scope, so one kid at a time, or stream the view through a Watec ( possibly ?) camera so they can all see it

Great! I suppose you'll have to check re. Watecs? The 120N+ is now superceded. The latest one £700...

I sense there would be enough "light" available to perhaps save a bit, with a slightly cheaper Camera?

[Merlin66]

Many of the solar imagers use TIS DMK21/31/41/51 cameras.....

These can present a "live" video on the screen which you can capture to prepared a stacked image, if required.......

[Pig]

Stuart,

I have a Lunt 60mm single stacked with a B600 blocking filter. The views are quite stunning even with this basic set up    I must add I do not use it for photography.

[glowingturnip]

thanks vm for the info all, think I have a good handle on what I shoudl be looking for now. 

I've not really looked into the camera aspect yet, will come round to that, and will check the cameras mentioned, tks

Stu