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Franklin

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About Franklin

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    Nebula
  1. Have a Baader 2" Neodymium in good condition. Am looking to swap it for a Baader 2" Contrast Booster in good condition.
  2. Large sunspot right now. Umbra and penumbra clearly visible. First I've seen in ages! Lunt solar wedge, SC filter and Evo150 stopped down to 100mm.
  3. Omni Plossls are ok in the longer focal lengths, wouldn't go below 12mm. I had an omni 4mm once and it was terrible, I wouldn't even sell it on so it got binned. If you need a reasonable 6mm the SW planetary is good. Longish eye relief and a 58 degree AFOV, not bad for around £35-£40. I prefer to use a 2x barlow with my 12mm BST for the same mag as a 6mm.
  4. Hi there,

    Sorry to see you selling up, you've got some good gear there. I would be interested in buying the SW 2" Dielectric diagonal as a long as it's in good condition, which it looks to be. £65 with p+p ? I can do Paypal, no fee's, or bank transfer your preference.

    Thanks,

    Tim.

  5. I have an Omni XLT120 which I recently upgraded with a Skywatcher dual-speed crayford focuser (Wow, what an improvement!). So I thought I would check the focuser alignment and the collimation of the objective lens. Using a laser collimator without the diagonal in the focuser and an aperture mask with a centre mark I was happy and relieved to see the laser beam pass directly through the centre of the objective, even when the new focuser is rotated. All good there. I then replaced the lens cap and put a small cheshire eyepiece in, again without the diagonal. Pointing the cheshire window at a light source the primary and secondary reflections revealed a figure of eight pattern through the peephole. Out of collimation. After a little experimentation tweaking the three sets of collimation screws on the lens cell I managed to get the cheshire reflections to be perfectly concentric through the peephole. Great, my focuser is square on and my objective is collimated. All is good in the world. Then I put in the diagonal. Now the laser is about an inch higher than the centre. My 2" mirror dagonal has no collimation screws so I placed a 0.2mm thick teflon shim along the lower edge of the diagonal mirror to tilt the mirror very slightly. Success, the laser is now central. But when I put the cheshire in the diagonal the figure of eight reflection is back. Now, my question is this. Do I re-collimate the objective with the newly tilted mirror in the diagonal or do I leave the collimated objective as it is? When using the cheshire without the diagonal the light source just bounces off the back of the lens but when in the diagonal the cheshire light source is reflected off the diagonal mirror then the back of the lens and then the diagonal mirror for a second time. As I have tilted the mirror slightly with a shim to centralize it, is it this misalignment that is causing the cheshire reflection to appear wrong, even though the objective is collimated? I'm starting to confuse myself now. Help!
  6. Unscrew the polarscope eyepiece and the reticule should come into focus. I have the same one and I need to make about 3 or 4 full turns anticlockwise to get focus on the reticule. From your photo the eyepiece seems to be fully in.
  7. I like the Neodymium as an all rounder, not tried the Contrast Booster yet but I sometimes stack a Minus violet (VR-1) with the moon & skyglow for nice views of the Moon through my achro.
  8. The Vixen SP102M is a classic scope. Keep it for what it was intended for, portable visual astronomy. The Super Polaris is an excellent bit of kit, light years ahead of any synta EQ3/2 mount. You can fit the synta R.A. & Dec motors to it but there is no cover for the R.A. motor and if your mount is an early one (1980's) it may not have the declination motor fixing bracket. I used to have an SP102M, what a fool I was to sell it on. Derr!
  9. I have an Antares ND13 filter (thanks Thunderstruck) and from what I've read it has a 13% transmission, hence the name. I also have an Explore Scientific ND0.9 filter and this also has a 13% transmission. The puzzle is, why is the ND13 much darker than the ND0.9 if they have the same 13% transmission? Are they labelled up wrong? Do the suppliers not know what they are talking about? I don't really mind because it will be useful to have two different densities, it just seems quite odd. Has anyone else noticed this advertising blunder?
  10. Same in Sheffield. Clear all day, clouds rolling in after sunset! I've been finding Jupiter at around 6.30-7.00 in twilight just to get half hour but the seeing has been terrible really. Last week was brill, best I've seen in ages.
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