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John

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Posts posted by John

  1. One of my early scopes was a Vixen SP102M. I have very fond memories of it. My current Vixen ED102SS dates from around 2000 and is Japanese made. It looks like a shorter version of the SP102M but with a 60mm focuser. It's a fine scope too :smiley:

    I believe that some of the current Vixen scope range are still Japanese made or have Japanese optics and are of very good quality. They tend to have comparatively high prices in the UK though.

    • Like 1
  2. If I were in your shoes I'd get another Telrad. My 1st choice preference would be a Telrad and an RACI optical finder but with a budget constraint I could cope very happily with a 14" dob with just a Telrad (working !) mounted on it :smiley:

    Lots of the planetarium software and printed star charts have Telrad rings as an overlay and combining those tools with a decent wide field, low power eyepiece in the main scope will enable you to find your way to practially any target.

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  3. The Hyperions are nice eyepieces, well made and thoughtfully designed. They perform well in scopes from F/7 and slower. They do show astigmatism in faster scopes than this and really quite a lot when the focal ratio gets down to F/5 or faster. When they originally came onto the market they caused quite a stir. There is a lot more competition in the 60-70 degree eyepiece niche now though.

    • Like 1
  4. Nice Shane :smiley:

    Is that one of those simple cheshire's that I can see the top of ?

    I have one like that - dead cheap but it seems to do the trick so easily :smiley:

    If the Delite's come out in 4mm and 3mm focal lengths I'd be interested to see if they could oust the Radian's I currently have in those slots. From the reports on the current Delites I suspect they would.

  5. Haven't visited in a while. Some really great scopes here. I might be getting a 4" F/6.5 achromat some time soon, to make EVEN bigger solar H-alpha mosaics :D

    Thats the same spec as my Vixen ED102SS Michael, except that it's an ED doublet. I ought to try a Quark in it sometime, I believe it's the right sort of specification for that device.

  6. Nice pics of the scopes :smiley:

    In that last one of the moon, it looks like the CA around the limb varies in tint from the top (greenish) to the bottom (blueish). I've not seen that before. Usually you see it as per your other two photos, a consistent colour around the limb, changing colour, again consistently, as you rack through the focus point.

    Does the Antares show that visually or is it a photographic artifact ?

    • Like 1
  7. I think it was the field stop of that Kellner (if it is a true Kellner and not modified by Celestron somewhat) that intrigued me the most. It seemed so wide compared to the Plossls I had. It's objective lens does seem too far from the end of the barrel compared to the diagram to be a Kellner even though Celestron describe it as one....

    The field stop diameter of an eyepiece will increase as it's focal length increases so a 25mm Kellner (or similar 3 element design) will have a larger diameter field stop than, say, a 15mm Plossl. The Plossl will still have a larger apparent field of view through.

    The 25mm Kellner type eyepieces supplied as stock items are often labelled "Super Wide Angle" or similar because their field stop is a little wider than the a normal Kellner would be. So you see a little larger apparent field of view even though it's not going to be that well corrected, especially in a faster focal ratio scope.

    These are low cost eyepieces though (you can get them for £5 used) so thay don't do too badly considering that and they do get you started :smiley:

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