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PeterWar

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About PeterWar

  • Rank
    Nebula

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  • Location
    Roses, Girona (Spain)
  1. Peter,

    Did you ever sort out the issue with your 16 inch Meade F8 ACF?  I am struggling to replace a RCX 14 which, being effectively open tubed, has a degraded main mirror which has defied successful re-coating. Whilst I prefer the optics in the RCX to the Meade 14 ACF F10, that I also have, the mirrors in the ACF have not deteriorated, are not much younger than the  ACF and live in the same dome as the RCX. I conclude the closed tube may be better for keeping the (un-recoatable) optics in good shape and so am looking at the 16 inch ACF F8 as a replacement for both.

    I originally intended to replace the RCX with the F10 ACF but the star images are smaller in the RCX and the field of view flatter. I have kept the ACF just in case the RCX totally dies.

     

    Regards

    Ian B

  2. PeterWar

    Perfect TSA-120 Setup

    My TSA-120 in on its way and will arrive tomorrow! I've spent a fun time doing a lot of research and I'm about to finish this project. I know I want to mount my TSA-120 in a Berlebach (Uni 24 or Planet) tripod, but I'm undecided about which mount to choose. Here's the short list of the final candidates: 1- Free-Turn X V2 Mount (don't know why unfortunately out of production, so not a choice apparently ). 2- Discmount Dm-6 3- Discmount Dm-4 4- Giro Ercole mount 5- Universal Astronomics UniStar - 7 lbs (also apparently out of production) The Dm-4 ranks first in aestetics and lightweight (both very important factors), but performance on high magnification planetary viewing with the TSA-120 and the Mark V binoviewer concerns me...
  3. PeterWar

    Perfect TSA-120 Setup

    Nicos, I'm leaning towards buying the Berlebach Uni 18 tripod as I think the Planet would be a bit overkill, it has a load tollerance of 55kG which is way bigger than my planned load (about 14Kg tops). Indeed FS-128 is a great scope!
  4. PeterWar

    Perfect TSA-120 Setup

    I'm now trying to ascertain how much of a field curvature would I have on the TSA-120, and if it would be noticiable for visual use under 1.5 arcsecond seeing. My idea was to buy the TOA35-FL for visual use, it's even advertised as an improvement in views on wide angle 2" eyepieces. I'm concerned however that this might introduce vignetting in the 31mm Nagler. The Nagler has a 42mm field stop and Takahashi specification for both the TOA-35 reducer and flattener account for a 40mm image circle (I presume this to be equivalent to the field stop).
  5. PeterWar

    Perfect TSA-120 Setup

    I wish feather touch focusers would come at a similar color palete than the TSA-120, honestly the only thing that's keeping me from ordering one is the thrown together look of the feather touch version.
  6. PeterWar

    Perfect TSA-120 Setup

    Gentlemen, thank you so very much for your very informative repplies. MarsG76, we almost have the same telescope setup, I have an Orion X14G and a Nextar 8 SE, an APO would be the totaly logical next choice for both of us. Michael, you seem to have an in-depth understanding of this subject. How do you think the TSA-120 would compare to the TeleVue127NIS? EDIT: Have you seen the Airylab reports? iPeace, you've been able to find just the right tripod for my needs, it's great that I can source it in Europe!
  7. Greetings guys, After many years happily owning Reflectors and SCT, I've decided to try to give me a threat and buy a nice refractor. Presently, I now run a professional observatory in Europe and I do plenty of outreach activities with most of my current equipment (except for my premium eyepieces, those I've kept at home). So the plan is now to leave all the scopes at the Observatory, that is located in an International Dark Sky Park and buy a new premium telescope to be used for visual observations at my sub-urban home. Contrast and perfectly corrected optics do take preference over aperture in this situation, the scope would sit in the living-room, just a few meters away from the terrace, so aesthetics need to be considered as well. A grab-and-go telescope is most preferable too, I don't need goto. The scope will be used for visual for moon, planets and some wide fields. After many candidates reviewed the Takahashi TSA-120 is my prime candidate, It's ahead of the Astrophysics and TeleVue refractors in any strehl rating I've found. I would appreciate help on deciding the following: 1- Optional flatteners The scope is intended for visual use, would eyepieces like my 17mm Nikon NAV-SW benefit from using the TOA35-FL flattener? would the flattener vignette the 31mm Nagler? 2- Focuser: Should I order it standard or with the feather touch focuser? I've heard that the feather touch would be preferred when it comes to holding heavy eyepieces like my 31mm Nagler, but my understanding is that if I choose to go this route I won't be able to screw in the Takahashi TSA-120 flattener or the focal reducer if I ever decide to buy them, is that correct? 3- Mount and Tripod I'm leaning towards using a DM-4 mount. I would like a grab-an-go alt-az mount that doesn't look ugly and would be enough to carry the TSA-120 with heavy eyepieces or a binoviewer. I think I would prefer wood over metal, although I like the looks of the T-Pod tripod. Any input you may have on this would be greatly appreciated. Thank you very much for your time!
  8. Thank you for your input! we tried both locking and unlocking the mirror to no result. The scope is mounted inside a 4M scopedome, come to think about it, yesterday we opened the dome shutter much before 11pm, it was actually 9pm, so naturally the scope should have cooled down by 3am, even without fans.
  9. The book page 27 of the book Star Testing Astronomical Telescopes states that a common tube current appearance is the squeezed or herniated lobe on one side of the disk, and a flattened look on the other. In this case unfortunately the lobe is herniated on both sides of the focus, as seen per the images, I don't thinks it's a tube current issue.
  10. Peter what cable are you using to power your fans? the OTA came without instruction manual and without a cable to power the fans.
  11. Hi Lockie, The scope should have been in thermal equilibrium as those pics where done last night at 3am and I opened the dome at 11pm. Oddly enough, this wave effect that you describe switches from lower left to upper right when I move from infocus to outfocus. ronin, we ended up performing all testing at primary focus, without other optical elements to narrow down the error.
  12. Hello everyone, A couple of months ago I bought a 16" Meade ACF F8 OTA from a dealer in Europe to be used in my observatory. I'm now concerned that this OTA has a severe optical issue, as stars won't come completely to focus, I've tried time and repeatedly and the lower FHWM I've been able to measure in Maxim DL is 8.0. I've also tried to use it visually at magnitude 90x and I could not get sharp stars at all. This week I used a newly acquired artificial star and a ronchi ocular to do some tests an to check for collimation. Using the Atik Infinity camera, I've detected what seems to be a rough edge with its own diffraction pattern. This asymmetry is present both in focus and out focus on opposite edges respectively. All testing has been done with the scope acclimated to the outside temperature, no diagonals nor other optical elements are present. Also, the ronchi test shows potential spherical aberration and some zone aberrations, although we lack the experience to make a definitive diagnostic. I'm attaching some pictures below in the hopes that someone could tell me what's going on: Some pictures of the aberration infocus and outfocus. A picture using Maxim DL of a star at the "sharpest" point of focus, notice the tails of the star on the right hand side. A picture of M13 showing the sharpest point of focus. As always your input is much appreciated.
  13. Thank you for the great feedback so far. Has anyone tried PixIndight wavefront analysis tool to assess their optics?
  14. For my 16" Meade ACF F8, I'll be buying a Moravian G4-9000 camera with KAF-9000 chip. The KAF-9000 chip is 36.7mm square, a big chip! on paper the Explore Scientific 3" 0.7 reducer/field flattener could work well right to the edge, but has anyone tried it with Meade ACF telescopes? Also, I'm wandering what is the light cone of the Meade 16" ACF F8, will I get a lot of vignetting with that chip? I have a friend who has tried a KAF-9000 with his Meade 12" ACF F8 with very acceptable results. Thank you for your time.
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