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Saturday: 45F gales and showers. Much too windy and far too cloudy for solar. So I worked on the friction wheel, dome drive. Just tidying up the reinforcing plate and the counterweight fixing. I gave the dome a spin and there is slightly more friction and noise from the plastic underskirt rubbing on the rubber skirt. As I descended the stairs I noticed a spare sheet of 4mm birch ply. I realised could have used that as an upstand instead of the plastic, lawn edging. Though it would have needed joints at regular intervals. So would have been more work.
Going back to the need for a "mid strength" 2x GPC I have found a 2x William Optics Barlow/GPC nosepiece. Whether it pushes the power up as much as the TS 2.6x GPC I have no idea until I give it a try. It looks identical to the TS 2.6x in the sales images. In others it looks more midway in length. I shall know when it arrives.
What a shame they never put a standard 1.25" filter thread on the front of the TS binoviewer! It would have reduced the amplification factor of any GPC or Barlow fitted directly to the binoviewer body. Or, the binoviewer nosepiece could be left in place. Allowing it to increase the amplification power of GPCs, Barlows and eyepieces when so desired. Double the fun for the same price. All for a simple change in body thread diameter of only a couple of millimetres.
All this talk of GPCs versus Barlow lenses raises some serious questions. Or should do. GPCs are supposed to compensate for the long glass path length of their host binoviewers. While Barlow lenses [supposedly] know nothing about binoviewers.- Simply because they have never been told. In fact we [the punters/consumers] have frequently been told that Barlows simply aren't good enough in this specialized role. The William Optics nosepiece is sold as a multi-purpose device in the sales literature. It should not go unnoticed that William Optics makes [or offers] a binoviewer of their own. So they should know what they are talking about.
Sunday: Woke to find last night's roaring gales had opened the shutters by about a foot. I have two sliding bolts to secure them in the open and closed positions but made the locating holes exactly the right size. Which means they are quite hard to locate and are just above eye height. This is not a good idea! I shall have to shove the drill into each hole and open them out enough to ensure the bolts can slide fully home without any effort or doubt. I'd better go over and see how wet it is in there! I was lucky that it hadn't rained overnight. Not even a drop of dew.
9.20 H-alpha: Had to reset the adjustments to confirm focus at 300mm from the back plate. The PST etalon group is slightly negative at 330mm from the back plate when set at 200mm inside focus. Should I compensate for this in some way? BY adjusting the etalon position? My fuzzy logic suggests I pull out the etalon to refocus at 300mm. I'm using 100mm of total extension from the back plate.
Several disturbed areas on the sun's disk. On my left using the binoviewers "straight through." [32mm with 1.6x GPC] A nice, dark filament at my 8.00. Several dark pores scattered around the disk. Two fairly large prominences opposed at my 2.00 and 8.00. These are reversed on Gong. So I need to reconfirm my solar orientation with the binoviewers used straight on. I have always used a diagonal until now.
All this talk of GPCs versus Barlow lenses raises some serious questions. Or should do. GPCs are supposed to compensate for the long glass path length of their host binoviewers. While Barlow lenses [supposedly] know nothing about binoviewers.- Simply because they have never been told. In fact we [the punters/consumers] have frequently been told that Barlows simply aren't good enough in this specialized role. The William Optics nosepiece is sold as a multi-purpose device in the sales literature. It should not go unnoticed that William Optics makes [or offers] a binoviewer of their own. So they should know what they are talking about.
Sunday: Woke to find last night's roaring gales had opened the shutters by about a foot. I have two sliding bolts to secure them in the open and closed positions but made the locating holes exactly the right size. Which means they are quite hard to locate and are just above eye height. This is not a good idea! I shall have to shove the drill into each hole and open them out enough to ensure the bolts can slide fully home without any effort or doubt. I'd better go over and see how wet it is in there! I was lucky that it hadn't rained overnight. Not even a drop of dew.
9.20 H-alpha: Had to reset the adjustments to confirm focus at 300mm from the back plate. The PST etalon group is slightly negative at 330mm from the back plate when set at 200mm inside focus. Should I compensate for this in some way? BY adjusting the etalon position? My fuzzy logic suggests I pull out the etalon to refocus at 300mm. I'm using 100mm of total extension from the back plate.
Several disturbed areas on the sun's disk. On my left using the binoviewers "straight through." [32mm with 1.6x GPC] A nice, dark filament at my 8.00. Several dark pores scattered around the disk. Two fairly large prominences opposed at my 2.00 and 8.00. These are reversed on Gong. So I need to reconfirm my solar orientation with the binoviewers used straight on. I have always used a diagonal until now.
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