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The ultimate solar imagers filter?? The ultimate visual?

Posted: Fri May 11, 2018 12:09 pm
by Astrograph
Solar Spectrum filters tend to go unnoticed, probably because you can never buy one normally without waiting for a very long time!

Well a few have quietly slipped out of the factory and are waiting patiently for new homes.

For the imagers among you, we have access to 6 (six - in case you missed it) 0.3A Solar Observer 1's. These have a 19mm etalon and active heating and cooling. Uniformity on them is apparently superb. Yours for £3665+VAT.

How about something for the eye's? We currently have access to 3 (three) 0.5A Research Grade 46mm Etalons. Again they are actively heated and cooled. With a 55mm Plossl you can experience a full disc with over 4000mm of focal length! Little bit more than the SO1 filter at £9415.83+VAT but hey, nothing else comes close.

Re: The ultimate solar imagers filter?? The ultimate visual?

Posted: Sat May 12, 2018 5:10 am
by mdwmark
Hi group,
Being in this group I try to explain and I don't try to get free advertising or talk down about other systems.

The SO-1, 0.3A (name change to RG18 but the same price) are all Research level uniformity. They all have three cavity hard coated blockers, (so the blockers are very unlikely to ever fail). With the extra sharp side bands there is no lost of contrast do to the next peak leaking through.
I use TEC controlled ovens with enough power to hold the CW where you set it. Non TEC control will always allow the CW to drift into the red wing regardless what ERF you are using.
The HW's of the SO-1's are in the .25Ang. range. They were selected for this reason.

The RG46's have that same design blockers. The TEC oven's are designed with a high current TEC to give it the power to hold the large optical stack at +/-.1C. These filters are the ideal HW when used in a F/27-F/30 systems, like the SCT solar scopes.
I hope this gives a better understanding how they are different from the other systems out there.
Mark W.

Re: The ultimate solar imagers filter?? The ultimate visual?

Posted: Sat May 12, 2018 12:38 pm
by Astrograph
There you go folks, you now have the inside info one what makes these filters special. And to make them a little more special there are then some dedicated accessories.

- All the filters come with SC threads that feature T2 inserts so you have two, well supported ways to attach them. No need to order adapter plates.
- To make them work there are 2x, 3x and 4x dedicated T2 threaded solar tele-centrics that are as good as it gets
- To give you options for field of view, there are dedicated tele-compressors (reducer) with corrected image fields in 0.7x and 0.4x. With different spacing its possible to use the 0.4x at 0.3x. These tele-compressors are designed to work with a tele-centric (unlike a regular reducer) and screw straight in to the back of the Solar Spectrum Filter.

Go on,you know you want one.... :)