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GavStar

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Everything posted by GavStar

  1. I have both a c11 and a 16 inch goto dob. I note that several people have said go for the 16 inch dob, particularly for visual, due to the extra aperture, and I understand why. But I think it’s also worth restating the obvious ‘the best telescope is the one that you actually use’ comment. I think this should be emphasised since a 16 inch dob is not easy to transport around imo. Ideally you would store it fully setup and then just wheel it out on wheelbarrow wheels. I use my c11 on a lovely panther TTS alt az mount and I find it very easy to transport and setup. In particular, the c11 ota is not that big or heavy and the mount packs away into conveniently sized packages. However, my 16 inch dob is a bit of a beast even though it’s a ‘compact’ version. With the mirror in place, the mirror box weighs around 30kg which is quite heavy to move around carefully - I now tend to move the mirror box without the mirror in it. And the footprint of the dob is pretty large - it’s not straightforward to pack into my Discovery Sport (and the back seats have to go down). For my preferences, the c11 is much easier to setup and observe with (I also like the seated observing position of the c11 compared with standing for the 16 inch dob). As a result, my c11 gets used many more times than my 16 inch dob and for this reason I prefer the c11. I also enjoy taking phone images with the c11 as per the attached. (Not proper imaging but I enjoy it)
  2. It was a wonderful experience and a great one to share with my dad. Lovely clear skies in Bella Vista, Argentina. The moon was inky black at totality - blacker than most according to the experienced eclipse observers. Although low in the sky it certainly seemed higher and was lovely set against the Andes. Quick phone pic attached as I was concentrating on just enjoying the views.
  3. I had always assumed that the Travel Companion objective was made by Canon as well John. I know that Gerry ( @jetstream ) asked Baader directly the source of the fluorite lenses and they declined to supply this. However, I decided to do a did more research this morning to see whether I could find out more. Firstly I note that Roland Christen of Astro-Physics has confirmed that there are a number of suppliers of fluorite lens as per the following quote from the AP yahoo groups: "A lens cannot use two of the same type glasses. I am quite familiar with the design of the Aries doublet. It is nothing especially difficult as far as design. It is very similar to the design of the original Takahashi doublet fluorites that were offered some 20 years ago in 4" and 5" sizes. Front element KzFSN2, rear element CaF2. Straight forward, all-spherical airspaced. The variable here will be how well the optical company fabricates the fluorite element. It can be notoriously difficult to make this without fine sleeks and scratches. CaF2 is ultra-soft and hard to polish to a high degree. Oiling it between tow outer glasses eliminates all this - the sleeks and even scratches disappear, and the lens becomes ultra-clear and of high contrast. Fluorite can be purchased today from a number of sources, and I have actually made a number of fluorite triplets in the past (the 90mm F5 Stowaway being the most famous example). I have made other sizes in experimental numbers, up to 6.8 inches. Fluorite is used today in specialty optics, in stepper lenses and in UV transmitting windows in scientific instrumentation. It is mostly very expensive, and can be variable in quality if you happen to be unlucky in your choice of supplier and batch. It is a heavy risk for a small company like AP to make such a huge financial commitment without knowing how the material will work out." Then I found this CN post from the late Per Frejvall (who was one of the first purchasers of the Baader Travel Companion back in 2014), who states that it has the same glass and basic design as the Zeiss APQ 100 and that the optics are made in Germany. https://www.cloudynights.com/topic/477858-anyone-have-the-baader-apo-95560-caf2/?hl=%2Bbaader+%2B95mm#entry6240163 The Zeiss APQ fluorite lenses were made in house, Zeiss had a specialist subsidiary, schott lithotec who made the fluorite blanks. https://www.laserfocusworld.com/optics/article/16558307/schott-lithotec-delivers-calcium-fluoride-lens-blanks I found the glass list for Schott in an excel spreadsheet which shows caf2 (fluorite) being removed as an offering in 2010, and I thought that was it. But then I found out that In April 2010, the Hellma Group took over Schott Lithotec´s calcium fluoride production. It continues its business, now called Hellma Materials, at its site in Jena. Hellma states in its website that it does supply fluorite for astronomical instruments. https://www.hellma.com/en/crystalline-materials/optical-materials/caf2/ So maybe, just maybe, the fluorite objective for the Baader Travel Companion is made in Germany with the fluorite supplied by Hellma. I guess we won’t ever find out!
  4. Ok, as a European owner of one of the new AP Stowaways I’ll give you some thoughts on it. @nicoscy also owns one so he may also have some useful info for you. Please note I am visual only, no imaging done. First of all regarding portability here’s a shot of mine against my televue tv85 and baader travel companion 95mm. Dimensions wise it’s just a tiny bit longer than the tv85 (not obvious from photo) but it’s about the same weight as the tv85 and in hand seems just as portable. I also have a Tak fc100df and that is a significantly bigger scope and definitely feels in a different category size wise. In summary the Stowaway is a very portable and light scope. My az gti mount works beautifully with it. It’s also superbly made. I have several top class refractors (another Ap, a 160mm tec, the Tak and tv85) and I would say this is the best made of them all (even beating my tec!). I love the feather touch focuser that comes with it and not heavy at all for my visual use. The screws don’t worry me at all - I just ignore them . I notice you are from Italy - I got mine from Skypoint in Italy and Mauro gave me fantastic service. I had a small issue with the felt on the tube rings and Mauro sorted it out AP very quickly and efficiently. So any downsides? Well I think it’s 99% certain that the lenses are made and coated in China unlike virtually any other AP scope. There is a reasonable amount of evidence for this (obvious green coating on the lenses, font and wording on lens ring being the same as many Chinese scopes and different to previous AP scopes etc) Roland was asked the question directly on the AP yahoo group and was evasive and didn’t answer the question. Since this scope is fully air spaced the likely situation is that Roland manually tuned the lenses by adjusting the positions to give the excellent characteristics he was after. He did give lots of detail on the yahoo group about how this was done - seems quite a complex process! But if the results are great, does it matter where the lenses are made and coated?? Also I have done a side by side test against both my tv85 and baader as described towards the end of this thread. https://www.cloudynights.com/topic/633270-baader-travel-companion-or-ap-stowaway/ In summary the AP beat the tv85 noticeably (as it should given the extra aperture) but came second in contrast to the Baader at high mag on things like the Plato craterlets. However, as you can imagine the differences are marginal and I’m very impressed with the optics of my Stowaway. I intend to test my Stowaway and Baader against the Tak fc100df in the next few months. I’m expecting all three scopes to have very similar (excellent) views. If I was given a choice between the Stowaway and the Tak, I would choose the Stowaway since it’s noticeably more portable and can be taken on an aeroplane more easily. (But I’d take my Baader above both!!) So my advice is get the Stowaway or give Baader a call/email direct to see if they can supply you with a travel companion 95mm.
  5. I thought so too Robert, hence I posted this report in the visual deep sky observing section. However after a day it was moved by a mod to the EEVA section and I was informed by pm not to post in the visual observing sections from now on.
  6. Well Matthew, I won’t be making any more posts since I’m now not allowed to post my reports in the visual observing sections (which is where I’ve been posting them for the last 18 months and where I originally posted this report). But I hope you do try night vision. It was fun when we had a go at Regent’s Park a few months back and great from my London back garden but it’s truly amazing from dark (sqm 21+) sites....
  7. Iain, I was genuinely not meaning to demean UK based astronomers, I apologise if my comment gave this impression. I was rather complimenting Gerry’s skies (and observing skills) which I understand give excellent seeing and transparency.
  8. I haven’t thought about higher mags with NV giving darker skies and higher contrast - not sure but maybe... The bigger image scale is the key factor but thinking about it the contrast did seem better as well. I think you’d need to take your 15 inch dob to Canada as well Robert ? I think jetstream’s skies are rather special!
  9. It really depends on what objects you want to view. For smaller objects such as galaxies aperture is king since you can get higher mag (all of 40x ?) and still run at the fast (sub f4) speeds that NV thrives on. For larger objects (eg North American, heart and Soul, California) then the smaller refractors are better since you can frame the object much better. For the largest objects (eg Barnard’s Loop) using the monoculars on their own at 1x is the best and really breathtaking. On Saturday night scanning Cygnus at 1x with the Ha filter attached was amazing. The NV monoculars on their own run at a super fast f1.2 so really bring out faint nebulae. Cygnus was just a mass of fluffy nebulae hound out all other the place. I just scanned from one end of the Milky Way to the other watching the nebulae pop out as I moved the monocular. So in summary, the c11 and refractors are complementary for NV, I need both. But at the moment I’m preferring the c11 since I can view more objects (more smaller objects to see than larger ones) ?
  10. Panther TTS-160 - great mount, takes the c11 with ease when using 8kg weights.
  11. Thanks Gerry. It was at an sqm 21.0 site so dark but with some light pollution. The galaxies were taken earlier in the evening when it wasn’t fully dark and as mentioned in my reply to Stu, the exposures were much less than the nebulae - at the eyepiece the views were better - m51 was definitely in form last night - my personal favourite ever observation of any galaxy. Ive found NV can struggle on the Veil at lower magnifications but last night at 40x it was just immense. The western side is never as good as the eastern with NV but even so there was just so much to look at. It has transformed my approach to observing this object. Its great that the views are very similar even though I’m looking at ha and (I’m guessing) you’re using an oiii filter. Thank you for giving details about the comparison.
  12. The c11 has been a surprise - due to the slow focal ratio its not an obvious NV scope but with the reducer and 55mm plossl it gets down to a respectable f3.3 and still has around 40x magnification. Typically with my 4 inch scopes I’m running at around 10x mag so the jump from 10 to 40x in terms of detail on say the Veil is very large I think. I also find the c11 reasonably easy to setup and portable compared to my 16 inch dob. Regarding the actual visual views I got versus the images shown in my post, as we’ve discussed I try to make the phone images as representative as possible. I find galaxies harder to image and in fact the visual views were better than shown in the images. I could only do 6 second exposures before the sky background got too light. For the nebulae shots, the exposures were 30 secs (50 iso) and can be longer due to the aggressive filtering used. The low iso and longer exposure time do bring out the small detail well in the images but at the eyepiece the details (eg the elephant trunk and the pillars of creation) are still clear but maybe not quite as sharp. At the eyepiece the Veil close ups were really cool, something I haven’t experienced before.
  13. This new moon period seems to me to be the last opportunity to have a good DSO observing session before the nights become too light. And as the forecast was suggesting clear all night, I decided to have a bit of a bumper session. My plan was to start with a few galaxies then move onto Cygnus which would start appearing after midnight. I thought I may even get a shot at the lovely nebula in Sagittarius despite being a bit low. I also wanted to target some smaller objects I haven’t seen with night vision before, so I needed to get a bit of aperture and therefore decided to use my Celestron c11 sct with a 0.75x focal readucer. It actually turned out to be one of the best observing sessions I’ve ever had. I’ve observed a lot of galaxies recently. I think my favourites are the whirlpool and the needle. So I started with these... It was clear immediately that transparency was rather good since the eyepiece views of these two objects were the best I’ve seen. I then went for the black eye galaxy which showed the central eye well. By now Cygnus was beginning to appear in the east. I switched to an Ha filter and went smallish nebulae hunting. First up, another favourite of mine, the Crescent. I hadn’t seen this at a darkish site before and it was very impressive... Next up other small nebulae in Cygnus that I haven’t seen very often before. So in order Tulip, cocoon, bubble, wizard and the cave nebulae. With extra image scale and aperture, I thought it would then be fun to go for some familiar objects to see what extra detail I could get compared with a smaller scope - quite a bit as it turned out.. So here are some alternative higher magnification views of the Veil, the North American nebula and the elephants trunk. It’s been a looooong time since I’ve looked at the Dumbbell - too long, it was lovely last night... I now noticed the Milky Way was arching nicely overhead and had a nice scan with the NV monoculars at 1x. This was fantastic with the good transparency and it also showed me that the Sagittarius nebulae were visible to the south just high enough to see through two houses... So I switched back to the C11 and wrapped up on the lagoon, triffid, eagle (with pillars of creation clearly visible) and swan. I think that’s given me a good setup for August when these objects are available at more accessible times...
  14. I would love to show you the views through a white phosphor NV monocular attached to, say, a 4 inch refractor. It sure feels like the real thing to me. ?
  15. Yes there is some sophisticated technology within the NV monocular ?. What matters to me are the end results and the ‘feeling’ in use of being just like an eyepiece. I guess that was what I was trying to convey (not very well ?)
  16. I think one issue in this discussion is that there are so few people (particularly in the U.K.) that have actually looked through a top quality white phosphor manual gain NV eyepiece (and it is an eyepiece!). Those that have looked through one are stunned at how similar the experience is to a standard glass eyepiece (apart from you can see so much more). There are no wires, no computer screens, just a glass lens with plenty of eye relief to look through. The stars, nebulae, galaxies etc are white in colour, very sharp and very natural looking. As I mentioned earlier in this thread, when I took mine to a London astro meet a couple of months ago, no one suspected it was anything other than a normal glass eyepiece until they were told. The actual experience with NV is virtually identical to just using an eyepiece. It is very different to video astronomy.
  17. Ok I guess we are just not going to reach agreement on this point. All the NV users are saying quite clearly that they would like to post on the main topic boards. If we label the posts clearly as NV, other posters can ignore it if they wish. I have reflected a good deal on this topic and hope I have expressed my opinion clearly and politely. But at the end of the day it’s up to you to decide.
  18. Ok, good questions. ? I think it’s very likely that NV astronomy is going to remain being very rare in the UK (it’s very rare in the US and it’s far cheaper and easier to get there!). So I think consideration of a separate SGL NV forum is not appropriate for many years due to so few users... On the idealogical issue, I have two observations: firstly my NV eyepiece sits along side my glass eyepieces since for all practical purposes they operate and feel like the same thing to me. This points me towards wanting to post about both types of observing in the normal observing sections. Second point, which sorry I have mentioned a few times already, both Alan and Mark would not have found out about NV if I had only have posted about NV in the EAa section. NV is so niche that the reality is for most people you just accidentally bump into it somehow and I really believe SGL should try to maximise the chances of this by allowing NV posts in standard sections. I was lucky, someone in my local astro club had a NV monocular already - most people won’t have that opportunity...
  19. Please could @Steve or @Grant clarify this comment? Does this mean that posts about night vision are still fine in the general observing and equipment sections (suitably labelled)? Or does this mean that nv users can post on the general sections but only on sessions where only standard glass eyepieces are used?
  20. From a purist definition, yes. But from a practical, in use, perspective, no - it’s completely different. (And from a practical ‘how it feels’ perspective NV is very very similar to viewing through normal glass eyepieces. This was shown very clearly by my recent outreach experience in Regent’s Park - the people looking through the NV eyepiece had no idea it wasn’t just a normal glass eyepiece!)
  21. I don’t understand the point you are making. @Highburymarkhas eloquently expressed the concerns that us (only 4) night vision (NV) users have, ie 1) half of us would never have heard of NV if it had only been discussed in the EAA/ video astronomy section, so would have missed out on getting this additional eyepiece tool in the box. Allowing night vision discussion in the main observing/equipment sections allows better communication for people who may be interested (but don’t know it yet ?) 2) there’s only 4 of us so nowhere near enough to have a separate section 3) NV is a very different approach from a practical perspective to EAa/video astronomy. There is very little overlap in terms of what each type can learn/discuss with the other. This is clearly shown on cloudynights where NV and EAa are grouped in the same section and there is no discussion between the two groups so it may as well be two different sections. (However CN is very happy for NV posts to be made in the general observing or equipment sections if we wish).
  22. I do really like my 100mm f7.4 doublet. But as an airline travel scope I prefer my 95mm f5.9 Triplet which is much easier for carry on, virtually the same aperture so good for planetary and has a nice wide field.
  23. We don’t want NV to have a separate section, just to be able to post in the ‘standard’ visual and equipment sections (with suitable title labelling as was agreed by the mods only a couple of weeks ago!). Are we ok to still do this? We believe what we do is much more like (in terms of experience rather than technology) normal glass observing than EAA.
  24. Excellent point @Highburymark. 3 NV observers on SGL have now commented that this change would be to the detriment of NV discussion on SGL (and @PeterW was very diplomatic ?). I really think SGL admin should reconsider.
  25. I have to admit I’m very disappointed with this development. I’m a visual observer not a EEVA observer. I hope my NV posts over the past 15 months have always been very clear about the equipment I’ve been using. I also hope that they brought this new approach a far greater audience by having the posts in the normal observing sections. I think having a separate EEVA section ‘hides’ away these new techniques and makes it more difficult for general users to find out about them. As you say, there has been a fair bit of discussion and conflict. It’s a shame that as a group we can’t embrace new approaches and change. It does make me feel unwelcome on SGL. I don’t think I will be posting much on SGL in the future as a result. ?
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