Jump to content

Narrowband

Deadlake

Members
  • Posts

    1,506
  • Joined

  • Last visited

Everything posted by Deadlake

  1. The motorised goto mount seems to of been pulled, any ideas why?
  2. Is that fabricated by Long Perng? Even so just because it’s the same factory different specs, happens a lot with EP’s and scopes.. Wonder what the back focus is, 96 mm, very short…
  3. This model was also an option https://www.365astronomy.com/apm-telescopes-super-ed-apo-astrograph-107-700-apochromatic-refractor-telescope-with-3-apm-focuser is F6.5, it’s been discontinued due to SharpStar quality control issues. However there is a Long Perng 104/650 built model for APM in the pipeline with an optional Starlight FT focuser option. Not LZOS but half the price.
  4. Any idea what the modern day equivalent of the Vixen ED102SS (F/6.5) would be? I'd imagine the weight would be similar to the SD103S.
  5. What mount do you use with say a Ethos 21 and Vixen ED102SS (F/6.5)? When I use my SD103S on a ScopeTech Zero with an APM XWA EP the scope will move any time I change an EP due to the larger then usual weight of the EP.
  6. With your dark skies @jetstream you can see quite a lot due to the contrast you have. Even with your TSA-120. However with portability in mind to get to a dark sky a smaller scope might be the answer. I’d imagine a Mewlon 180 would be very good which @Fedele already has. Presume that’s not portable enough???
  7. Interested to hear what the differences are between standard and uprated version. It’s not although I’ll be able to order one anytime soon, given the availability of lens cells…. Next year, however the FT and rube adds a thousand to the price… In addition what it performs like once barlowed if possible. You can always add focal length but cannot take it away, without cutting the tube. 😃 I know Takahashi Q extender might be an option, works with AP scopes as well.
  8. Are you saying get a FT for it? 😃 GPC aren't hat bad, needed for correcting the prims in the bino originally? Is it the F6.2 or the F8? Thanks
  9. An NP101 did cross my mind as well..... Genesis no longer available. An FSQ-106 from RO is around £4000, a little cheaper then the LZOS mark II and you can actually buy....
  10. @Stu Thats a good idea. Additional requirement is to have 220 mm of focus range to support Bino's as well without a GPC. A DF or DZ could do this if FT? Cheaper then a LZOS, which will not be available until sometime in 2022...
  11. SW Esprit 100 has a back focus of 183 mm, not enough. What about your APM 105? 😃
  12. For portability reasons I'd like a 4" refactor (Doublet or Tripet) that can support 2" eye pieces. I have at present a SD103S that I can use with APM 5, 13 and 17 mm XWA's by using them with a 1.25" fitting to a Baader T2 prism diagonal. However when trying to use the above EP's with a Baader 2" dielectric diagonal there is not enough infocus. A 2" Baader prism diagonal has an optical path of 100 mm, that saves 12 mm over the 2" dielectric optical path of 112 mm. This will not be enough, the issue is the scope. I'm looking for a scope which will support the 20 mm APM XWA and an APM 30 UFF. These need a 2" diagonal. I suspect a Takahashi 100DL would have the same issue of not enough infocus either. Is this correct? The only option I've come up with is a LZOS 105 mm/F6.2, focuser will have the range to support the EP. Any other ideas or options? I'd need to cut the tube for the SD103S to work. I like the Vixen SD103S however I like the wide field views more. Interested in 100 mm scope, not smaller or bigger. Also supported Bino's without a GPC would be good, back focus of around 220 mm. Thanks
  13. How much wide field viewing would you imagine doing with the scope, e.g. with an Ethos 21 mm or APM 20 XWA? My SD103S does not have enough infocus for either of these EP’s so I need to use another scope and I suspect the 100DZ has the same limitation. The APM 140 will not had the focuser has the range to accommodate these EP’s.
  14. I believe the 140 mm has got a poly-Strehl around 0.92, so how many nights of the year will you be able to make use of a scope with a higher Strehl? Note, TMB defined 0.95 Strehl as a limit where a scope would be seeing limited most nights of the year, so why engineer more? I’m sure your SXD2 would be able to handle the 140 mm, so unless portability is a requirement I’d go with the larger aperture. Also how much overlap with you Mewlon 180? Always good to have a 4” for flexibility, does it need to be a DZ?
  15. Surprised no NV intensifier attached. 😄
  16. It’s a good idea, the Amici is not listed here in comparison with the other available 2” diagonals: https://www.cloudynights.com/articles/cat/articles/mirror-vs-dielectric-vs-prism-diagonal-comparison-r2877 Not sure if this is enough infocus.
  17. As discussed Stu, several sites 30 minutes from Walton Green that are > SQM 20.69. When I arrived home after the meet-up a couple of weeks ago you could tell the difference in sky brightness. I was tempted to keep on viewing but school night. "..the one I’m not supposed to mention by name..." I thought you took the dob 😃
  18. Did the moonlite focuser you outfitted your Vixen with reduce the optical path length? Another valid approach?
  19. Revising this thread. I have a APM XWA 17, 20 mm and 30 mm UFF EP’s. I find using a Baader 2” dialectic not enough in-focus available to gain focus. I note that the Baader 2” dialectic and BBHS mirror diagonals have an optical path length of 115 mm whereas the 2” prism has an optical path length of 100 mm. I’m hoping the 15 mm decrease in path length of the prism diagonal will be enough to gain focus with the XWA and UFF EP’s. Does anyone have any experience of this?
  20. Can be bought separately from a flight case: https://www.vanguardworld.co.uk/products/supreme-46d
  21. It's one of these: https://www.vanguardworld.co.uk/products/divider-bag-46 Sold on amazon or most camera shops, around £70.
  22. A camera bag is very flexible and at night easy to find which EP, filter you are looking for. This bag also fits it side a hard flight case.
  23. @GavStar Has written a good comparison between OVNI and PVS-14 based intensifiers which will save you having to wade through the CN threads on the subject. While the OVNI does have the cherry picked harder tubes and the prime feature, I think its up to OVNI to respond with a better lens Matches the PVS-14 Envis lens A little more adaptable on the filter front. Jonathan @OVNI does know this limitation and has responded on CN he intends to offer an Envis type lens if/when he can source one. Well done Gavin and PeterW
  24. You mean where someone get a better number and they send the scope back? Which forum could that be on. 😁 However as you know from another thread on this forum, you can publish RMS, PV and Strehl and those scopes are still third division due to Abbe number for the glass. 😉
×
×
  • 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.