Jump to content

Banner.jpg.b89429c566825f6ab32bcafbada449c9.jpg

Axunator

Members
  • Posts

    42
  • Joined

  • Last visited

Everything posted by Axunator

  1. Jeremy - quite a coincidence, my main rig is C9.25 and Tak FC100DF on AZ-EQ6 and Berlebach Planet, and I sit on Berlebach Nix II. I’m quite happy with Nix, and tend to use quite a wide range of seating heights. To avoid the eyepiece on the apo to get too low when looking near zenith, I keep the mount rather high on the tripod, which means that looking closer to horizon raises the eyepiece quite high, especially on the shorter SCT. FWIW, I’m pretty tall myself, 194 cm. It is true that Nix II is not very compact, less so with the optional foot rest installed (which I do have and like, but it’s in no way necessary of course). But it still fits sideways in the trunk of my old RAV4 with the rest of the gear (and even some bags). Fozzie, If you need me to get some measures from the Nix, just let me know!
  2. Focuser in FC-100D’s is easy to screw off and on without tools for ultra-compact transport if needed - that will shave appr. 10 cm off the length (don’t have my DF now at hand to measure exactly but that’s the ballpark figure), and I presume this will apply also to the DZ. However, with the dew shield screwed off the DF is even shorter than DZ due to its 6 cm shorter f.l. But then you have to protect the lens somehow and pack the dew shield safely to protect it from getting bent out of shape. So I’d feel safer to travel with the new DZ...
  3. Yes, it’s an insulation wrap: two layers of reflecting aluminized bubble wrap with a thin foam layer sandwiched in between. I added it last spring after lot of talk about SCT/MCT insulation on CN, and I have to admit it seems to decrease required cool-down time to effectively zero. Haven’t tried it during really cold winter weather yet, though. I still also use a corrector dew heater band under the insulation (at low power), if I don’t put a dew shield on, since I need battery power for the mount anyway. With an insulated dew shield, insulation is supposed to prevent the cooling of the corrector below dew point, making active dew heating unnecessary.
  4. Tak FC100-DF + C9.25 on AZ-EQ6 and Berlebach Planet:
  5. I see several advantages in these, as compared to standard SCTs: - easier thermal management compared to closed tube SCTs - way easier dew management (no corrector plate) - flatter field due to slower primary - much wider diffraction-limited coma-free field (standard f/10 SCT has coma-free field of ca. f/5 Newt, whereas f/12 Cassegrain equals ca. f/12 Newt, i.e. very wide diffraction-limited field. EdgeHD and ACF SCTs are of course a completely different story in this regard, but come with a price tag to match... yet still have that dew-magnet corrector plate). - no mirror flop during focusing (can be avoided with after market focusers in SCTs as well, albeit with a price) Of course, there are downsides as well: - a bit narrower FOV due to longer focal length (although diffraction-limited field is wider compared to standard SCT, see above) - diffraction spikes from the secondary spider - fixed focal length (back focus in 8" is reported to be 150 mm behind the 2" focuser), which may affect the use of some accessories, like binoviewers - more difficult to collimate because of hyperboloid secondary I guess you can tell that I'm excited ? And yet I'm still quite happy SCT owner as well ?
  6. Remains to be seen. I believe there are several visually oriented amateurs out there (count me in!) who fill find an open tube classical Cassegrain design - even at f/12 - very tempting and interesting... Especially at these prices. Whether it will be sufficiently profitable for GSO/TS/Astronomics, only time will tell. At least their RCs have been going on for years, and they are targeted to quite narrow audience as well.
  7. Piero, I know what you mean when you talk about bending of the MEF3 aluminum plate. In fact, after my mishap that eventually led me to fine tune the focuser tension helped me to get rid of that spongy feeling of aluminum plate bending! Another thing that I noticed affected the bending was the tightness of the screw (the one with two tiny spanner wrench holes) holding the aluminum plate and the green box - if it's loose, you experience more bending and sponginess. Another spot to adjust Tak focuser are the two tiny hex screws at the top of the focuser (the other one of these is hiding under the large focuser locking knob that you can remove simply by unscrewing it). From the factory, these screws are under a protecting drop of clear lacquer. To adjust, one needs to soften the lacquer e.g. with a tiny amount of acetone and puncture through the lacquer. I have not gotten around to adjust these, because I don't have exactly the right size Allen wrench (the one that came with MEF3 is not the right size for these). There are several threads on CN that discuss adjusting Tak focusers to perfection, that's where I learned about these upper screws. However, I was also able to adjust the focuser well enough for my liking with just the brass box screws underneath. Punching through the lacquer may also affect your warranty (not sure about that), so proceed at your own risk...
  8. Yes, under the green box there is a smaller brass box with two screws that adjust the tension of the pinion against the teeth on the focuser tube. Very tiny adjustments of these screws have quite a significant effect on the feel of the focuser. It’s an incredibly simple (you might even call it primitive...) mechanism, actually. The adjustment on mine became loose by itself during an observation night (a scary experience!), that’s how I learned it - had no choice but open it up and figure out what’s going on. Be very careful to not overtighten it - you may even bend the pinion! (Guess how I know that ? Luckily, you can get a new Tak pinion e.g. from Ian King for about 40 GBP).
  9. My Paragon 40 clone (SW Aero ED 40) was astigmatic enough at the edges in my FC-100DF that I eventually made the switch to Pan 41 - despite twice the weight and thrice the price. To me it was worth it, as the Tak + Pan 41 combo makes a truly splendid wide-field scope. But I can understand why someone would prefer the much lighter and more compact Paragon, especially since 90% of the field is really, really nice.
  10. Aahhh, those Tak unboxing pictures bring back memories
  11. Another recent Tak FC-100DF owner here... Sitting on HEQ5. Not exactly a grab and go with this mount, but very stable. -Aki
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.