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John

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Posts posted by John

  1. Is it an older C8 ?

    I had an older one and it suffered from mirror flop. When the scope was pointed at a certain angle, the weight of the mirror would cause it to shift a little throwing the collimation out.

    It was very annoying !

    I tried running through the full focusing range a few times to spread the lubricant out more evenly and that helped a bit but didn't make it go away. I believe the ultimate cure is to lock the mirror and to use a 3rd party focuser on the back of the scope.

     

     

  2. 1 hour ago, patsmnp61 said:

    Greeting. My scopes used the most are a 150mm f/6 Intes Maksutov-Newtonian and a 80mm TMB f/7.5 apochromatic with a LOMO objective. Both are used on a Losmandy GM811G mount. I use orthoscopic eyepieces from University Optics volcano tops and Zeiss Abbe Ortho II

    486349102_GOBStarParty2009.jpg.f43e7acf108bf82b0cdd8f19be1a44ed.jpg

    1088941701_80mmscope.jpg.fae084d79c66fa463ab06d27827ab54f.jpg

    Hi and welcome to the forum :icon_biggrin:

    I used to have an Intes 150mm F/6 mak-newtonian. It was a superb planetary scope :thumbright:

    Mine was branded "Orion". I think it was the first time that they had sold a Russian made product under their branding !

    orionmn61.jpg.a152b20c0d1de0eb8707a13edbb7439a.jpg

     

  3. I have seen this issue with refractors a few times and each time an over-tight lens retaining ring was the cuprit.

    Following the method that @vlaiv explains usually improves things a great deal. The lens retaining ring just needs to be tight enough to stop the lens elements rattling but no more than that.

    It should also be noted that you need decent seeing conditions, a cooled scope and a reasonably high magnification to see the airy disk and diffraction rings clearly. Poor conditions will cause them to be ill defined. Trying to interpret what you see when you star test under poor conditions can be very misleading.

     

  4. 4 minutes ago, Pixies said:

    Managed to get a quick look in the ST80.

    It's brighter now, than HD220819 (Mag 6.6) but dimmer than HR8894. The latter is a variable star though - AAVSO currently has it at Mag 5.5, but I can't find any recent observations.

    There aren't a lot of nearby stars with magnitude around 5.5 -> 6.0. 4-Cas is mag 5.0

     

    I'm going to stick my neck out and say the nova is around mag 6.0. I'd be grateful for any comments from more experienced observers.

     

    Nice report :thumbright:

    I'd love to supply one myself but I'm heavily clouded out tonight :rolleyes2:

    Your neck is very safe ! :smiley:

  5. On 23/07/2021 at 12:20, badhex said:

    If, hypothetically speaking of course, I were to consider buying another Morpheus, my choices would be between the 6.5mm and 4.5mm. Primary usage for now would be with a C5 at F10 and ZS73 at F5.9.
    Now the problem is as follows: 

    • 6.5mm would probably be useful in a wider range of potential future scopes, and definitely a better choice for a high power EP in the C5 at 192x / 39x per inch
    • 6.5mm only gives me 66x / 23x per inch in the ZS73
    • 4.5mm is better suited as my higher/highest power EP for the ZS73 at 96x /  33x per inch
    • 4.5mm would be really pushing the C5 at 278x / 56x per inch

     

    Thoughts?

    Anyone got specific experience and feedback using the 4.5mm  / 6.5mm in similar scopes?

    My 130mm refractor has a focal length of 1200mm and a focal ratio of F/9.2 so the basic specs are similar to the C5 but probably not a reasonable comparison in other respects.

    I find that I regularly use 5mm, 4mm and even 3mm focal length eyepieces with it.

     

    • Like 1
  6. Great report - nice to read :icon_biggrin:

    There is a nice galaxy right next to Mirach known as "Mirach's Ghost". It's NGC 404. Should be visible as a small pale misty circular patch of light in an 8 inch dob at around 150x or so.

    It's just above Mirach, in the same field of view. Just below Mirach through a dob of course !

     

     

     

    • Like 3
  7. 27 minutes ago, Malpi12 said:

    @John in another topic you have said

    "I've owned two 12 inch dobs and one was not a good choice because it was far too heavy but the 2nd one (my current one) was much lighter and much more practical all round."

    May one ask which is the lightweight one ?

     

    The Meade Lightbridge 12 inch weighed 80 lbs in total.

    My current 12 inch which is an Orion Optics 12 inch F/5.3 tube on a plywood dobsonian mounting made by an SGL friend weighs 58 lbs in total.

     

    • Thanks 1
  8. I ought to qualify my earlier post a little by adding that I've owned two 12 inch dobs and one was not a good choice because it was far too heavy but the 2nd one (my current one) was much lighter and much more practical all round.

    If I had not found the lighter 12 inch, I would have stuck with 10 inches. I need to move a scope around a bit now and then where I observe.

    So practicality should come into the decision as well I think.

  9. Transparency is really missing tonight - the skies are milky / soupy here with just the brighter constellation stars showing through.

    Not going to have a long session so I just took in a few double stars with the 100mm refractor.

    Had my first look at Mu Cygni this year. It's right at the tip of the Swan's lower wing - opposite tip to Delta Cygni. Mu is a nice multiple star system and the principle showpiece is the close pair of magnitude 4.8 and 6.2 respectively with just 1.51 arc seconds currently separating them.

    Interesting to compare Mu Cygni with Pi Aquillae which is a mag 6.3 and 6.7 pair at 1.4 arc seconds apart. Mu is a little easier but both a nice challenge for a 10cm aperture with tonights conditions.

    Not much in the way of DSO's going tonight but some nice binaries make having the scope out worthwhile :smiley:

     

    • Like 2
  10. 16 minutes ago, Sunshine said:

    Sometimes I feel like i'm the minority with my eyepieces at star parties, nobody wants to play with me. 😢

    Interestingly, when I've attended the SGL star parties, the visual side of the hobby has been really well represented. If anything I seem to recall more folks doing visual but that might be the sections of the meets that I hung out with :icon_scratch:

    With my club events and public sessions the majority seem to be doing visual observing.

     

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