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jetstream

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Everything posted by jetstream

  1. Mine open to at least 6.6mm or thereabout.
  2. More from Mel... "Exit pupil thoughts How to test for exit pupil without ruining dark adaption and causing the pupil to shrink? I test by slightly defocusing the star image so that it forms a disc. Since I can see the mirror's edge, I know that my eye's pupil is not truncating the mirror's aperture. I must place my eye exactly at the correct location centered and above the eyepiece using the rubber eyeguard. I also use the 17mm Ethos with its 3+ degree field of view at slightly higher power where my eye doesn't need to stay exactly centered. The 21mm Ethos eyepiece with this scope gives an exit pupil of 6.4mm. My eye opens to this size. But what would be the consequences if my exit pupil were smaller? If my eye opened only to 6mm then that's equivalent to stopping down the aperture to 5.6 inches, or a drop of about 10% illumination or about 0.1 magnitude. And keep in mind that both the object and the sky background are equally affected, leaving the ratio between the two or the contrast the same. I've not been able to observe this difference. Aperture is an important consideration seting the overall size and weight of the telescope. Field of view is equally important. Try considering field of view first. With this approach you determine the aperture based on the lowest power eyepiece in combination with your eye's pupil, giving the widest possible field of view. This makes the eye the limitation, not aperture, not field of view. That's as good as it gets."
  3. One limiting factor for f7ish refractors (or others) is the lack of Ethos quality hyperwide eyepieces in the 35mm-40mm range IMHO. There is a noticeable increase in contrast when using Ethos over Nagler/ES eyepieces, at least to my eyes. This is in respect to nebula.
  4. Yeah, I was sure fasting dancin when I told the wife the 24" was ready to be picked up
  5. None of us needs to justify our telescopes or projects IMHO- this looks like a fantastic telescope in the making.
  6. The Loop is huge! I can follow it from top to bottom under my best skies. The first thing to look for is the shade edge just off M78, the brightest section, one side brighter than the other. The 30ES in the f7 kills the Loop, the 42mm brings it out (for me). The 42mm not only gives more eye illumination but more FOV which is also needed. Before buying the 42mm LVW ask around- some don't like it, but I find it meets my needs. The big Pan might be better,not sure.
  7. Whats your f ratio? What the highest fl eyepiece you have? Forget all what youve heard about too big exit pupil Neil IMHO...I was stuck on that for years until a member here told how he had used very large ones with success. These days I just try everything on objects to see what works. The 30ES 82 works good for me at f3.8 for instance.
  8. It depends... in my experience the refractor used matters, for some unknown reason. My 90mm SV triplet shows it but the SW120ED is much better eventhough a smaller FOV.My VX10 does a nice job on it and the TSA120 is good on everything. Try them all Neil! ps the f7ish fracs love the 42mm LVW on Barnards Loop..exit pupil deal.
  9. Question: do you want future proof eyepieces? many buy/sell quite a lot which is fine but costly IMHO. Used is an excellent idea! Heres a few widefields, good ones that your F6 will like :30mm APM UFF, 30mm ES 82, 28mm ES 68, 24mm ES 82, all 2". in 1.25": 24mm TV Pan, 24mm ES 68 The Q Barlow will give you a multitude of mags with one eyepiece... as its 1.3x and 2.25x... a 12.5mm ortho will give: 12.5mm/9.6mm/5.55mm selection. the 18mm 18mm/13.8mm/8mm selection So, a 24mm-30mm 2" widefield and a 12.5mm-18mm ortho with Q barlow. Used Circle T volcano top orthos are very high on this list as is the Baader 18mm. Many like BST's too.
  10. Excellent and informative post Stephan.
  11. Its a combination of things that add up to seeing deep, including object recognition. After being seen once objects become easier for me even threshold ones. Along the same line, when trying to go for faint galaxies forget nebula viewing first and vice versa. Another hugely important thing to do is find the objects exact spot and then stare...trying to find very faint things panning is more difficult IMHO. The Sky Commander is helping a lot in my case. I've read some reports under lightish skies describing some faint objects as "easy" or bright"- I think setting realistic goals for the conditions is important regards of some of the reporting... One more- when trying a galaxy for instance, knowing its size and magnitude will help visualize what your trying to see instead of searching for a larger brighter object potentially.
  12. Not sure about the Docter, which is now called Noblex but they offer the Nikons and are excellent to deal with.
  13. https://www.kyoei-osaka.jp/SHOP/165261/165262/list.html
  14. Youre welcome John and yes it is logical to assume this. I base my opinion on comparisons with 2 very good zooms- the Zeiss 25.1-6.7mm and the Leica Asph- at the 14mm setting the Nikon "14"/EIC goes no deeper than these 2 excellent zooms to my eyes. The Docter is deeper than both zooms.... and my 12.5mm Tak ortho. Yes eye placement is a bit awkward. However, for some objects such as the Eagle and Swan nebs the Nikon 17/14 has no peer, at least in comparison to the EP's I own, mind you the Docter is pretty fri cken good here too lol! Have you considered a direct from Japan purchase?
  15. I have the Docter 12.5mm UWA which is my deepest widefield, it surpassed my Ethos and is an orthoscopic widefield IMHO. My 17 HW/14 Nikon does not go as deep as the Docter- some will say its because of the mag difference but no its just not as deep. Delos are VG and deep but the Docter was a bit sharper on lunar/planetary. My deepest eyepiece believe it or not is the Baader 10mm BCO with and without the VIP barlow.
  16. This cell also looks excellent, I'm wondering if all the nylon tips are supposed to contact the mirror, I see one, maybe two that aren't but they could be for something else? I had an OOUK that had some tips not contacting. Bresser put some thought into this scope IMHO.
  17. This scope looks excellent- the bearings in particular and the focuser looks vg too. Nice scope
  18. It sure can get expensive too! and then you realize the "best" we just bought is not exactly what you want and the pursuit continues. Also, sometimes the best is not expensive- my copy of the 10mmBCO is top tier being sharper with more color and transmission than eyepiece 6x more expensive..
  19. No issues with the reply Wes, sometimes I don't check for periods of time myself- thank you for the consideration. Yes I own the 18mmBCO, 10mmBCO and the 6mm BCO. I cannot recommend the 6mm- it has great color but is not as "sharp" as the other 2 and it seems to bloat stars a little bit. the 18mm and 10mm are excellent however. The BCO stands for "classic" ortho and it sends ortho purists into fits. It is another design from a Zeiss optician utilizing an opened up field compared to traditional orthos. They will show some edge distortion- but- 99% of eyepieces do, including TV Ethos, Naglers, Delos,Leica etc. Some distortion is to be expected as all eyepiece design is a tradeoff IMHO. I love orthos and use them every session, they do have tight eyerelief in the shorter fls- do you wear glasses? of so this can be an issue. I would hold off on the shorter fl widefields (ie 6mm) just yet as there are a few superb (expensive) choices and some run of the mill one you ewould most likely replace. Your scope is f6 right? If so and if it were me I would look at a 24mm-25mm something. A 25mm Televue plossl is superb, a keeper in any scope and will show nebs extremely well. The widefoield are expensive but the ES 24mm 68 is great and in 2" a 24mm ES 82. Have you considered the 18mm BCO/10mm BCO with the Baader "Q Barlow"? https://www.firstlightoptics.com/barlows/baader-classic-q-225x-barlow.html
  20. I hope you get this sorted out Mark! my motives are insideous though.... as I'm in the same boat lol! What distortion? just coma or other stuff?
  21. Nice scopes! Great that the 10BCO is working well for you and those ES eyepieces are really good and will serve you well. Glad you got out observing, can't wait for the clouds to clear here.
  22. After learning the night sky pretty well I purchased an AZ EQ6 for the 120mm and now a Sky Commander "push to" DSC for the 24". I must say that the tracking for planetary/lunar is a nice benefit and the Sky Commander finds very difficult, faint galaxies (& others) with amazing accuracy. There is no way I could even re-find some of this stuff after "bumping" the dob inadvertently without it. I can get back on objects with a .18 deg TFOV... and easily with the 12.5mm UWA at .5 deg TFOV. This allows for so much more observing time which really helps out. I have no regret, remorse, guilt or any other negative emotion over using Go To lol!- and I also love the "chase of the hunt" finding things manually. Both my GoTo scopes work very well.
  23. What scope do you have? If you can observe the planets/lunar under good seeing the TV's (well some TV's...) can pull away from ES eyepieces. IME, ES replicates Nagler performance but does fall short of the Delos for sharpness, contrast, scatter control and transmission. The Ethos will out contrast the ES/Naglers, not sure about Delites but they are supposed to be good, with a small spot size. ES makes VG eyepieces and our 24 ES 68 has a secure place in the case... Of course there is a bit of "status" owning TV and you have excellent eyepieces already- just curious what focal length are you looking at? btw the 10BCO is my deepest eyepiece and competes with some very expensive glass, I love this thing!
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