March 28, 2015: Awesome first light of Solar Spectrum H-alpha 0.3Å filter

[michael.h.f.wilkinson]

Managed a brief first light with the Solar Spectrum 0.3Å (!) filter I managed to get from ABS-UK (great thanks to Pete Larkin). It took a while to get focus with the APM 80 (stopped down to 64mm, with Thousand Oaks ERF), requiring an extreme amount of outward travel with the 4x PowerMate (and ultimately a variable extension tube), and warm-up time was around 5-8 minutes, but the detail in the big AR near the centre of the disk was absolutely stunning. The contrast was way beyond anything I have ever seen. I later managed a peek with the SM-II 60. The contrast at 0.7Å was nowhere near as good as with the APM Solar Spectrum combination. No time for imaging, but did make a few snaps of the rig.

The SolarMax did show a nice filaprom which I did not spot in the restricted FOV of the other combination. Clouds have now cut the fun short. I am REALLY looking forward to imaging with this new rig, but I do hope a Baader TZ4 4x tele-centric that is underway doesn't need the insane amount of outward travel as the PowerMate does. This outward travel does little to keep the focuser slop down.

Still very excited!

[jabeoo1]

0.3Å 

[Qualia]

Lovely set up, Michael and glad you caught the Sun today. The contrast and detail with the new filter must be spectacular   

[michael.h.f.wilkinson]

Cheers guys. I only got to see the sun for about 5 minutes with the 0.3Å but it looks like an absolute winner for detail shots (or a new class of mega mosaics ). Once I get a new chance to test the system more thoroughly,I might try how the system works if the scope is stopped down to F/6.5 (74mm) so the filter works at F/26 rather than F/30. If it works well at that focal ratio, I might well look for a bigger F/6.5 or so achromat to increase the aperture available. I have an 85mm dielectric ERF which should allow use as internal ERF for something like an Explore Scientific AR-127 or even an AR-152.

[Pig]

Great result Michael  Sounds like another useful piece of kit to buy.

[michael.h.f.wilkinson]

Great result Michael  Sounds like another useful piece of kit to buy.

As you have a Quark already, I would not put this high on the list of priorities. My Solar Spectrum/PowerMate combination is very much like a Quark, albeit with a slightly smaller image circle, but much narrower bandwidth. Normally these filters are extremely expensive (we are talking 3.5-4x the price of a Quark). I got mine, including the ERF (100mm with a clear aperture of 90) for little over the price of a new Quark. That was an offer I couldn't refuse.

[Pig]

All the same it still sounds awesome Michael, I will take your advice and put the cash toward a campervan