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Sunshine

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Posts posted by Sunshine

  1. 4 hours ago, chiltonstar said:

    Algieba is a superb pair indeed, with an amazing gold colour.

    As Stu says, you get diffraction rings as well - you should see sharp diffraction rings around a bright star if your scope is fairly decent optically, and in focus. Difficult with some scope designs I believe which can be a bit mushy. The size of the Airy disk, and the brightness of the diffraction rings around can set practical limits to resolution of double stars.

    This is an example ring pattern.

    Chris

    diffpatt.jpg

    Great info from all above! chiltonstar, this image is exactly what I saw, thanks for posting!

  2. To be honest, airy discs were never on my list of things to look out for when looking at stars, I know little about said optical phenomenon or whether they occur in all three popular optical designs or not. Having said that, this night I was introduced to the phenomenon in the most pleasant way by way of an awful lot of magnification on the beautiful Gamma 1,2 Leonis. It would be an injustice to speak of this beautiful pair without a short introduction. They are a wonderful pair, a gold colored duo at a distance of 125 light years from earth. What really hammers home the incomprehensibly vast distances of celestial objects is the fact they're separated by 170 AU! to quote SkySafari, 4 times the distance between Pluto and the sun. It sure is mind boggling, the superlatives involved yet, these distant suns several times the mass of our star appear as two tiny dots which barely manage to excite a few cones and rods in our eyes. It seems there has been a planet discovered around Gamma A in 2010, a world approximately  9 times the mass of Jupiter though this is a very rough estimate as the mass of Gamma A is not accurately known.

    It's been a while since I have trained my gaze on this pair, my 9mm revealed them easily but, the magic happened with my 5mm at 163x. Both appearing as sharp goldish discs which were so well defined in fact, they reminded me of paper discs a hole punch produces. My 2.5x powermate was begging to be used on this pair but I really didn't expect much, thinking I would destroy the pair and turn them into mush with 408x. Seeing was pretty good, those two stars at that ridiculous power still looked etched, it was a treat for the eyes but, what are these two beautiful rings around them? both looking like targets. So this is what they really look like! each star with its own perfect ring with black sky between them, a pair of owl's eyes looking back at me came to mind. Many here are experts when speaking of these airy discs, I can only describe how neat these two stars looked with these rings round them, Are they typical in all designs or is it a refractor thing? I must say, rather embarrassingly that it is the first time I have ever seen them so well defined that they actually made me take note and enjoy them. Then again, never have I hit stars with so much power, it took for me to develop a love affair with doubles that I began really hitting stars with some serious magnification.

    • Like 6
  3. Last night was a night of great transparency although seeing wasn’t as good, it still allowed for some insane magnification of Lunar features. Using my 3.5mm for 230x I could see that I needed more power, it would have been nice to have a 2.5mm to avoid any softening but, I don’t have such an animal. What I do have is a 2.5x Powermate, surely this is insanity, I thought to myself, some quick math revealed a number of some 582x!! surely this was madness. 
     

    To my shock, I was floored to see that features held up nicely, a little soft and quite a bit darker but, I was still able to see fine detail, it was as though I was looking out a thick window of an orbiting lunar ship. Features raced past at a good clip, requiring me to keep my hands on those slomo controls non stop. 
     

    145x per inch of aperture lol, if someone had said that to me I would have thought they were bonkers. 

    • Like 5
  4. 2 hours ago, Tiny Clanger said:

    Yep, I didn't read that as a joke ... this written communication thing is a minefield isn't it ?! 🙂🙂🙂  *

     

    * multiple smileys just to be sure the light hearted tone of my reply isn't misread .. and have you noticed the number of people who call it a 'mindfield' instead ? Weird.

    In a way, I firmly believe that written communication as is so popular now either by text, email, forums and such has changed the manner in which I express myself. Growing up into my early teens I hadn't heard of Internet or smartphones (there were none) text message was far of still and, email was a fancy word on shows like "beyond 2000". When all this came about I found myself in a bit of trouble on occasion because what I was typing was so misinterpreted It left me beside myself.

     We were not designed to communicate this way, we are expressive creatures in our faces, hand gestures and who knows what other cues we give off that we may not even be aware of but, the receiver registers them subconsciously and can then understand exactly what we mean to convey. This is the part I hate about written conversation by text or the like, how many times have I been left glaring at my phone, mouth agape wondering what did they say? are they mad at me? how do I fix this situation? only to find out later that it was all in my mind. Sometimes I wish there was an audio communication tab we can click on when we’re  on a hot thread going back and forth, old fashioned lip smacking has gone the way of the dinosaur.

    • Like 2
  5. The effect in my Pentax XW's and, my Baader 9mm was such that it never crossed my mind, if there is it is not enough to catch my attention. My 18mm APM on the other hand

    was like putting my eye to a fish bowl, enough so that when I would scan around it made me slightly dizzy, who knows to what extent my own eye was to blame for it 

  6. Looking at the wealth of info on his website, I cant help to wonder if 6 of those 12 years were putting together the expansive website. The mosaic is stunning, the info provided on his site matches it.

    I would love to have this as a poster.

    000-GrandeMosaic120DegreesMAP.jpg (4984×1800) (bp.blogspot.com)

    There's a tab labelled "buy selected items" the vast library of images are stunning in their endless detail and beauty.

    J-P Metsavainio | All of my color photos (zenfolio.com)

  7. Hello! It looks like I will be selling this eyepiece due to the amount of field curvature which it displays with my TSA-102,  you read correct, my "ultra flat field" APM is too field curvy, understand the effect is more evident with longer FL eyepieces. Can anyone recommend an eyepiece in the 18-25mm range which is better suited to for my scope based on experiences with similar scopes? or can field curvature be remedied by way of an additional element somewhere in the optical train? maybe a corrector directly on the diagonal or such? the 102 is an 816mm f8.

    Thank you!

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