Meade a 6" f/8

[Viktor Z.]

This story started with a 6" Meade refractor. I loved that scope for deep-sky and had mixed feelings when I observed planets with it. Therefore I decided some improvement. It was a very long process of decision making, mainly because of budget considerations. After three years, I chose to purchase a 150/1200 R30 objective and counter cell from Istar. This meant the end of life for my Meade refractor, because I basically kept only its tube. The focuser end of the tube got a moonlite focuser. When I received the package from Istar, I painted the Istar counter cell with matte black inside and outside. The next step was the installation of the lens and counter cell. Instead of using the collimating option on the side of the counter cell, I had a matching ring machined so that the counter cell exactly centered and tightly fitted on the Meade tube. I still have the options of lens alignment on the front of counter cell and the adjustment on the moonlite focuser. When the objective lens was installed, I noticed right away that the tube became very heavy. Well, the counter cell and objective lens weight at least 14 lbs. The first test of the scope did not go very well, because I was short of in-focus path with a 2" diagonal. However, my friend had a 2" 2x barlow that helped with the issue, and I have to tell you that Jupiter was amazing! I did not have focusing problem using a 1.25 diagonal. Even though, a tiny violet fringing was apparent using either a 1.25 diagonal or the straight view with different eyepieces, the image quality of the planet was very satisfying. Interestingly, there was absolutely no colouring issue around Jupiter when the image was barlowed with a 2" barlow. Probably that barlow corrected the rays somehow. Continuing the topic of telescope building, I had to shorten the tube. My preliminary testing of the shorter scope in very cold conditions turned out to be a great experience! I and my friends spent a few hours out in -40 celsius in the cold Yukon weather in December 2012, three different nights. It was not just to break our "observation in cold" personal Guiness record but to be amazed of the views this telescope is capable of. We observed different deep-sky objects, the Moon and the Jupiter. The scope continued to give beautiful tackle sharp images of all. Eventually my Istar 150 mm f/8 R30 is much better corrected than a regular f/8 Fraunhofer (my old Meade 6"). My further plans are to properly collimating the lens and having a sturdier mount within a year or so. To sum it up, I wish the scope had a bit lighter weight but I love this scope a lot because its performance is stunning! It is a keeper!

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[Viktor Z.]

I add some more pictures

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[Viktor Z.]

one more picture

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[Viktor Z.]

And the last picture. Should I get an Astrozap dew shield?

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[mikey cee]

Hi Viktor....Nice to have you aboard. Yeah those R30's do put up a great image. They are also heavier than a like sized Fraunhoffer. You'll get used to the weight. Just like working out....after awhile the 100 pound barbell feels like only 80 pounds. Now when the Raycorr 6 comes to market we will both have apo like scopes for next to chicken feed! Later Mike

[Viktor Z.]

I hope Raycorr will be available soon, I can't wait to feed it in my focuser.

[bn1777]

Nice Viktor , I have done the same thing using an Istar 127mm f/8 achro .
Brian.

[leon]

Very nice Viktor! I also have an ar6 I'm thinking of converting, by chance you have any more pictures of the lens cells? Specifically how the counter attaches to the tube?

[Viktor Z.]

Leon, I don't have more photos of the disassembled lens cell. I will return home at end of the month and surely I can take photos then. The lens cell I have is a couple of millimeters larger diameter than the tube. Instead of collimating option I chose to use a tight fit. so I had a ring machined that exactly fits between the counter cell and the tube. I used the screw holes on the side of counter cell to tighten the counter cell to the tube. And I do not even have holes drilled through the tube itself because every 90 degrees there are double screws on the counter cell that are tight holding it to the tube. I don't know if this explanation makes sense , I tried to describe due to the lack of a photo. however, I would recommend you to talk to Mike @ Istar, who knows he may be able to offer you solution for a lens cell. (?) I had to shorten the tube by one inch to make 2" diagonal work with my setup. If you also plan to change the focuser to an expensive one, then you may consider buying a complete refractor OTA from Istar.

[bn1777]

Viktor , have you used this scope yet with the new Istar lense in place ? if so how does it compare with the origonal Meade lense ?
Thanks mate .
Brian.

[Viktor Z.]

I can just say: Oh boy, oh boy it is amazing view that I saw couple of nights ago through my Istar 6" R30! Finally the Yukon had a warmer weather, just about -4 Celsius. I took the scope outside well before dusk. A little ice-dew shattered on the tube and the 2" diagonal. but when it became dark, I was ready for observing my favorite Jupiter. I can tell that the planet's stripes were amazing in my 16mm Zeiss eyepiece (75x)! I was so excited about the view that I started to push the magnification quickly and gradually to 120x, then to 200x, then even to 300x! Well, far better images than in my meade. In other words, they are not even comparable on planets. I have actually never seen the Jupiter so crisp and detail in my meade refractor compared to my new r30 anastogmatic lens! In addition, the sky was partially cloudy, so that the Jupiter got faint frequently because of the high atmosphere cirrus clouds passing by! Can you imagine what this scope can do in an actually excellent night? The same night I tried to put in my 5x powermate in the focuser then I slid my 25 mm orthoscopic eyepiece in it. The image of the planet did not fell apart, however the sky conditions limited my useful magnification to 250x. I am very satisfied with this lens. In addition, using the scope in warmer temperature yielded way less colouring than in minus 40 degrees temperature. I did not see ANY false colour using the 16 mm eyepiece. When I pushed the magnification higher, I started to notice some faint violet colour around Jupiter but it was so insignificant and faint that it did not even bother me at all.

[mikey cee]

You can say that again! Istar lenses are super duty. I echo the same type of sentiments about my 10" F/11 R30. I sure hope this Raycorr Pro6 thing doesn't bomb. I'm keeping my fingers crossed. Mike

[Viktor Z.]

My build project finally finished after a year! I can't be happier for my great Istar optics that is hiding inside the telescope tube! My 150 mm f8 R30 sits very comfortably on my newly acquired AP900 mount on the light polluted balcony. By the way, I only observe the Moon and the aurora borealis from my balcony. This setup travels to dark observing sites:)

A big thank you to every person at Istar Optical who contributed to the make of this great refractor objective lens!

But life is boring without challenges, therefore this year's plan is to build another Istar scope on "cloudy nights", and I am so excited about it!



Viktor Z.

[astromanuk]

Hi Victor,

That is a lovely outfit you have there. My record cold weather observing was one January Quadrantid meteor watch where the temperature before dawn got down to -15°c. Towards the end I was spending as long in the house as out observing in 15 minute sessions. -40°c is real arctic conditions.

I think your AP900 is the ideal mount for your telescope - solid as a rock!

[boomboom]

Jan 16, 2013 21:11:41 GMT -5 leon said:

Very nice Viktor! I also have an ar6 I'm thinking of converting, by chance you have any more pictures of the lens cells? Specifically how the counter attaches to the tube?

Hi Leon,
At the risk of being boring and repeating what is in my build thread here is my solution to fitting an Istar Objective onto an aluminium tube.

This is low tech stuff that needed a jigsaw, exterior wood glue, a drill press and JB Weld to glue the aluminium to the wood. It works great.

Nice retro fit Viktor!

Matt