New Lunt Front 60mm filter

[armicheal]

I just got my new Lunt front 60mm stand-alone filter with B600 straight. I will be putting it through the paces tomorrow morning if all goes well. Clear Skyz,

[ollypenrice]

Looks good. Nice Pronto, too. The Sun is very lively at the minute so have fun.

Olly

[Albireo380]

Daft question:

So how does this work exactly Olly? This filter screws onto a normal refractor (what size?) and away you go, imaging prominences??

I had thought of buying a dedicated Solar Scope, but depending on your answer, this may be another possible route to go down.

Cheers

Tom

[Peter Drew]

Tom. You need the complete set, front etalon and rear blocking filter, you supply the in between telescope. In the past, good telescopes fitted up in this manner, to me, always seemed better than the bespoke solar telescope with the same Ha components. This of course does not neccessarily hold good for the latest offerings. The "add on" route does mean that you can still use your original scope for other astro objects.

[ollypenrice]

As above. The thing about a dedicated scope is that it can use a singlet lens because there is no need for colour correction. Light with a bandwidth of about 0.7 Nnanometers is monochromatic.

I don't think it much matters which you go for really, but I like not changing stuff around more than I can help because some days I seem to do nothing else!! So I went for the dedicated scope despite having a Pronto like the OP.

The Sun is wonderful at the moment so I'd say go for it.

Olly

[Merlin66]

Olly, correction Ha is only 0.7A which is 0.07nm ;-)

[ollypenrice]

Olly, correction Ha is only 0.7A which is 0.07nm ;-)

Thanks Ken. What a wally.

Olly

[armicheal]

Daft question:

So how does this work exactly Olly? This filter screws onto a normal refractor (what size?) and away you go, imaging prominences??

I had thought of buying a dedicated Solar Scope, but depending on your answer, this may be another possible route to go down.

Cheers

Tom

Hello Tom, For this setup I got a Lunt 60 front filter (non Doublestack type) and adapter to fit the filter to the front of the telescope, and a rear blocking filter. They make two types of front filter, one is for adding to an existing filter as a "double stack" filter and the other is a standalone type like the one I got. The single stand alone filter is rated by the Lunt group at <.75 angstrom. If you add a Double stack filter to the front of it the filtering is reduced to <.5 angstrom. These Lunt filters do not have a central obstruction in them like the Coronado filters do.

In the Coronado days the 60mm filters were matched to the threads of the Televue Pronto and TV76. They also used a T-max device behind the front filter. Lunt's filters have this function build into the filter housing. It basically tilts the internal etalon filter such that it detunes the band pass. This allows you to pick up fast moving detail like proms.

I got the Televue Pronto Used on a local (stateside) classified website called Astromart. I've always wanted a green one. I have a Lunt 152 scope and had called to get some warranty work done on it and started talking to Rikki, the nice sales lady at Lunt Solar Systems. She mentioned that they had a sale going right now for the month of June on these filters, 20% off. I had wanted one for my Pronto for a while so I jumped on the opportunity.

For the back of the scope you need a Blocking filter. I went with a straight type because they are easier to connect to a DLSR but they also come in diagonal types too. You have to match these to your focal length in order to see a full disk when you look through the eyepiece. The blocking filters come in different exit aperture sizes, the B600 is for scopes up to 600mm focal length, B1200 for scopes with focal lengths up to 1200mm and the B1800 for scopes with focal lengths up to 1800mm. I got the 600 for the Pronto since its FL is 560. I works really well for me. I took the images below yesterday except for the full disk which was taken the day before.

Clear Skyz,