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GavStar

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Everything posted by GavStar

  1. Thanks Stu, as you know it’s taken me a while to get the dob set up to how I like but I think I’m there now, it’s almost grab and go . It’s the needle galaxy, one of my favourites and spectacular through the eyepiece of my dob.
  2. No taken a few weeks ago with much less moon!
  3. Some more phone pics with my 16 inch dob and new night vision monocular, taken recently with ovni-m (rather than my pvs-14 which I used for all the pics above). I think the ovni-m in prime mode gives sharper stars to the edge visually.
  4. I think some night vision discussion on sgl even with the existing few practioners on a separate nv forum would be better than the current virtual zero nv discussion that happens on the eeva forums. A separate forum might also prompt more people to consider trying nv.
  5. Night vision is very different to EAA in terms of practical usage. Cloudynights has recognised this and now has separate EAA and night vision sections. This change has been a positive development for both EAA and NV users.
  6. Jim Unfortunately I don’t think gen 3 night vision monoculars will drop in price anytime soon, particularly in Europe where they are materially more expensive than the USA. (Europeans cannot purchase USA tech due to ITAR regs). I bought my first nv monocular over 3 years ago and prices have remained high since. It’s important to note that for astronomy due to the narrow ha filters used to view nebulae, you do need to get good quality gen 3 technology. Lesser gen 1 or gen 2 (with the exception of photonis intens tubes which also cost £6k plus) just won’t give good results. I think the best ‘cheaper’ option is to purchase secondhand. There is a Facebook group where secondhand gen 3 monoculars can be purchased legally. I recently saw a good spec gen 3 actinblack pvs-14 for sale for £3k there which would be great for astronomy. From a personal perspective and as a visual only astronomer, night vision has transformed the hobby for me - it’s a real shame that it’s so expensive. From my London back garden I was previously restricted to lunar, planetary and open clusters observing. Now I can see hundreds of other Dsos including many nebulae and galaxies. I don’t care whether it’s the original photons hitting my eyeball or not. The key thing for me is that it feels just like a ‘normal’ eyepiece when I’m visually observing AND that I can see so much stuff clearly. I’ve read about many starting in the hobby being disappointed with the ‘faint fuzzies’ etc and not really seeing much compared to astro photos. Night vision is fantastic as a visual observer aid. A few years ago there was a flurry of night vision posts on SGL but this stopped when the EEVA sections were introduced. I think many of us just didn’t think Night vision fitted into EEVA since it uses completely different techniques to EAA and feels much more like normal observing. Maybe in order to get more nv discussion, one of the 3 EEVA sections could be renamed to Night Vision Astronomy?
  7. Is it a lot of gear? I can literally just put it into my diagonal and off I go like any other eyepiece. The actual in use experience is identical.
  8. Here’s a link to the Televue section on night vision which I think is a good starting point for this approach https://www.televue.com/mobile/TV5_page.asp?id=36
  9. Ah now you are changing it from use of electricity to original photons etc...
  10. So is using a Quark for solar visual observing EEVA since it needs electricity? Defining an approach purely based on use or not of electricity is a poor definition imo since the various methods are just so different.
  11. What it’s not for me is night vision - night vision is just another eyepiece in my eyepiece case that can be used in the same way as my Televue, explore scientific eyepieces etc. Virtually all the discussion in this section is about EAA which uses cameras and computers.
  12. The figure I quoted for Celestron is at the 656 halpha band that is critical for nv nebulae observing. I haven’t seen anything specific regarding the Epsilon transmission but would think it would be similar to the other scopes. As Peter says the key advantage of reflectors is the ability to have large aperture to get the necessary image scale for smaller objects with nv, which is what I use my c11 edge and 16 inch dob for.
  13. Eddgie on CN estimates his Boren Simon has transmission in the order of 85% which is the figure Celestron gives for its latest coated scts.
  14. I still think refractors give a crispness of view with night vision that reflectors can’t match Also I believe that mirrors have some light transmission loss that refractors don’t have. The two mirrors in an imaging Newtonian f4 can lead to a light transmission loss of 80 percent meaning it’s actually operating at f5ish rather than f4...
  15. Although I really enjoy the views through my Pegasus Binoscope, recently I've either been using my grab and go refractors for quick and easy observing or my C11 or 16 inch dob for more serious sessions. Since the WO binoscope is not grab and go (requiring my Panther TTS-160 mount) and also has relatively small aperture, I haven't had a proper outing with it since April. Weather conditions have been poor in the UK for the last month or so, but the forecast the other night was for clear skies from 2am, and with Orion nicely visible at that time from my London back garden, I decided it was about time to dust off the binoscope for a proper large nebulae session. I've also acquired 2x 67mm televue nv plossl adapters so it was a good opportunity to test these out for binoscope usage. With the 67mm, the setup has a nice fast f2.6 effective speed, 11x mag and 3.5 degrees fov, perfect for those famous large nebulae that grace the sky at this time of year. Due to the severe light pollution in my back garden (sqm 18.6 as measured), I use a very narrow 3nm chroma ha filter with each monocular. According to specialist nv binocular users I commit a cardinal sin by using very mismatched monoculars, in the left I use a Photonis 4G PVS-14 (actually gen 2 tech but top end) and in the right a Harder gen 3 PVS-14. The harder tube has nearly double the luminance gain of the photonis (the key drawback of gen 2 tech) but also has a materially higher sn. Having the monoculars side by side its extremely easy to do direct comparisons of the different tubes by switching from one to the other in mono mode. The lower gain coupled with the narrow 3nm ha filter resulted in the photonis being obviously visibly less good, the nebulae fine detail was noticeably less clear and distinct compared to the Harder. However, the brain is a fantastic thing and in bino mode even with the drawbacks of the Photonis tube, the views were a big jump better than the Harder mono mode (again easy to see, just by switching the photonis tube off and on!). I mentioned in my previous thread a number of advantages of bino nv observing, but the key one apparent to me was just how clear fine detail was in the nebulae compared to the mono mode. The brain really does some awesome stuff. I've decided that the next time I visit a dark site, I will be taking my binoscope with me - I've only used it in LP London and am itching to see the results at a dark site. The nebulae views I was getting were the best I've had from London (the 67mm televue eyepieces making a difference here also, working really well albeit with some vignetting due to the ~38mm image circle of the binoscope. The vignetting wasn't a particular issue for me as the vast majority of the fov wasn't impacted visually. M42 was the obvious first port of call given Orion was blazing bright in the southern sky and the full extent of the extended nebulosity was clearly visible. Then onto the horsehead and flame which were bright and the horsehead had a nice shape even at this low magnification. But the first wow moment really was the Rosette in which lots of intricate detail was visible which isn't the case usually from London. The bino mode really "smoothed" out the nebulosity and the fainter bits became much clearer, but it was the sheer fine detail shown that blew me away given the observing conditions. The fox fur nebula and cone were easy to see, something that hasn't happened for me from London before. The wide band of Barnard's Loop was very contrasty. Then I scanned around enjoying all the other nebulae highlights including seagull, monkeyhead, lowers (very nice when often it disappoints me at a LP site), monkeyhead (that's a bright one!), jellyfish, sharpless 254/255/257 (a bit small but all three clearly visible, first time I've observed these from home, I stumbled upon these by accident in Gran Canaria in a 16 inch dob in February), spider and fly nebula, and flaming star. To finish off a very enjoyable session, I scanned over to the California which provided another "wow" moment, the top and bottom bands were very distinct but also the fine nebulae detail within was fantastic. I did a quick comparison with mono mode and this object unambiguously showed how much of a difference two eyes makes on nv nebulae observing. A similar thing happened on the final objects of the night, the heart and soul, looking much like the views and phone images I have taken from dark (21+ sqm) sites, wonderful. Now I must getting planning that dark sky trip for the next new moon...
  16. At the start of this year I purchased a Williams Optics Pegasus 103mm Binoscope as discussed here I’ve been delighted by the views given by this Binoscope and in particular the ability to use 2 inch eyepieces. This enables wider fields of view but, importantly for me, enables me to use my 67mm Televue plossls (55mm plossl with Televue 67mm adapter attached) with my two night vision monoculars. Using two eyes is transformation for me for night vision observing in that the two separate images merged give significantly improved views of fine emission nebulae. However, when using the 67mm (40 degree fov) eyepieces I noticed that the bottom left and right of the fov was clipped off. I contacted Tatsuro Matsumoto directly by email and he promptly replied that he could do a bespoke modification to replace the mirrors with a bigger set to remove this clipping. I shipped the ems set to Japan and Tatsuro completed the modification this week. The ems mirrors are now on the way back to me and I’m looking forward to trying them out soon. Truly excellent service. Tatsuro has documented the modification on his website and I’ve attached some translated screen shots below.
  17. That’s a very good point - yes I think an echo would be very good for this task
  18. Regarding nv monoculars, unfortunately not. Even second hand you would need to pay £2-3k to get one good enough for the strenuous demands of astronomy.
  19. Pvs-14 is 300 grams and Televue 55mm plossl is 500 grams so 800 grams in total, materially lighter than a 21mm Televue ethos (which is about 1kg)
  20. Yes I’ve noticed a gradual switch in the USA, promoted by Televue introducing some innovative adapters for afocal night vision observing, from prime to afocal nv. Afocal enables extremely fast (ie bright) systems to be used (eg my preference for nebulae with ha filters is to get below f2 - not too many f2 reflectors or refractors!). For live visual observation with a telescope I think afocal beats prime. As you say there is a nice 3x afocal lens for the pvs-14 which can take filters (with some vignetting), so these systems are not limited to 1x or afocal telescope use. I have a photonis 4g intens (which is still gen 2 tech but better quality than photonis echo) nv monocular and it at least equals my harder tube for standard (not too black) nighttime use - very smooth detailed views of terrestrial observation (great for nocturnal animal observing). The photonis also has a noticeably smaller halo on brighter stars so for scanning the Milky Way, looking at star clusters, it provides a more attractive view than the harder. But where night vision really kicks is for ha nebulae observation which requires heavy ha filters and this really starves the photons getting to the nv tube. In this mode you need as much sensitivity and luminance gain as possible as that’s where gen 3 really trumps gen 2 tech. With heavy ha filtering my harder gen 3 comfortably beats my photonis. Regarding dark spots, I completely agree. My harder tube is completely clean but my photonis tube has two small dark spots towards the edge of the field of view. However, in astro use you just can’t see these at all and they have absolutely no impact. See these threads where I’ve taken some phone shots through my photonis nv monocular, I don’t think the two little spots have any noticeable impact on the views
  21. Congratulations. You will love it!! I love my TEC scope, amazing on planets and lunar
  22. I agree with Mark, c would work well with a 67mm eyepiece
  23. Here’s an old thread that gives some more detail on the various night vision tube specs
  24. Lots of good discussion here on what types of scope work well with night vision. But for astronomy you also need excellent quality night vision monoculars. Mark briefly touched on the various night vision tube specs earlier but to show a more specific example here’s the spec sheet for a gen 3 harder white phosphor monocular I’ve got arriving next week
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