Convert a Refractor/Mak scope to a Solar scope with an Ha filtered eyepiece?

[collangm]

Apologies if this has been asked before, but basically as the title says. Is there and easy (cheap, but safe of course!) way of converting a standard 90mm refractor or mak type telescope into a solar scope by using an appropriate Ha filtered eyepiece? Do these things exist and if so what kind of cost are we talking about compared with a solarmax/coronado type scope?

Thanks in advance,

Gary

[Ibbo!]

Sorry it will not work

cheapest option PST or Lunt 35

Steve

[John]

It can be done with a refractor of the right aperture / focal ratio. The Vixen 80mm F/11 refractor is considered a good "donor":

First Light Optics - Vixen A80MF Refractor

But you need to sacrifice a PST (for the Etalon filter) and to purchase a suitable ERF filter (which are not cheap !) so the cost will exceed that of a PST or the Lunt 35. The prize is a larger aperture HA scope of course but you have to "do it right" - you can't take any chances or cut any corners when it comes to the sun.

One of our members, Merlin66, has a lot of expertise in undertaking such work.

Edited May 16, 2011 by John

[Merlin66]

Simple Ha filters for solar observing just don't exist!

The very narrow bandwidth required (<0.1nm) means that you need to use etalon type filter which costs $$$$$$.

The cheapest source of an Ha etalon is the Coronado PST. The etalon can be used with a suitable energy rejection filter (ERF) on the objective and the PST etalon positioned infront of the focus.

This set up say on an 80mm scope would cost around 800 gbp on top of the cost of the scope!

[Peter Drew]

There is no need to "sacrifice" a PST to convert it to a larger set up. If you cut off the "gold" tube a few inches in front of the tuning ring the back half becomes a Ha eyepiece. With a suitable sleeve, the front half can be rejoined to reconvert it to standard. I use this method to either fit to a range of larger refractors or provide a grab and go unit to determine whether there is sufficient activity to warrant setting up something better. You still have to have a suitable ERF for the upgrade.

[John]

There is no need to "sacrifice" a PST to convert it to a larger set up. If you cut off the "gold" tube a few inches in front of the tuning ring the back half becomes a Ha eyepiece. With a suitable sleeve, the front half can be rejoined to reconvert it to standard....

I stand corrected Peter - I did not realise that this could be done

[Abirsky]

Could the conversion work using a solar scout the type we're the etalon at the rear is fixed