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GavStar

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Posts posted by GavStar

  1. More clear skies in London tonight 😀


    I’ve been enjoying using my 85mm refractor with my night vision kit recently. However the image scale is a bit small (only 10x or so) so tonight, for a change, so got out my 11 inch sct in my back garden in south west London.


    With Orion shining in the south, it was lovely to have more magnification on some very well know objects such as the horsehead, flame, monkeyhead and Crab Nebula as shown in the phone pics attached here. Some great views despite the light pollution!!

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    • Like 3
  2. 5 hours ago, Highburymark said:

    These are incredible shots from London Gavin. Can’t imagine they could get much better with current technology.


    For newcomers to night vision, with extreme filtration for light polluted environments (from Chroma 3nm Ha filters), only the very best NV systems can pick up such detail and clarity, particularly with only a small refractor. Still lots to enjoy with less sophisticated systems, but for example, with my (very decent) FOM2150 Photonis 4G tube, the pictured objects are still ‘faint fuzzies’ observed from my Bortle 8-9 skies. 

    Yes that’s a good point Mark. 

  3. One of the key reasons that I bought my first night visio monocular was to observe DSOs from my London back garden (sqm 18). A few years ago, Jupiter and Saturn were low in the sky at opposition and so DSOs were a key part of my observation targets.

    It quickly became clear that although night vision was good from light polluted skies it is even better from darks skies like those in the Isle of Wight that I visit on an infrequent basis (sqm 21).

    Over time, I’ve aimed to improve the views I get from my London back garden. My latest kit test was last night with my little fsq85. Some great nebula objects in the sky and I’m really pleased with the views I can get from London of these wonderful DSOs. Now just to get to those dark skies on a more regular basis…😀 It’s a lot of fun to see the horsehead so clearly with my little refractor from London back garden as shown by the phone pic below.

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    • Like 10
  4. Unsurprisingly it’s my night vision monoculars - saying they have revolutionised my observing is rather an understatement. 
    Last week I was involved in the filming of a short segment on urban astronomy for the forthcoming January episode of “Sky at Night” discussing how my nv monoculars allow me to see the invisible 😉

    This photo was taken from the top of BBC Television Centre - definitely an urban location! 🤣

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    • Like 15
  5. I use the 0.7x edge reducer with my c11 edge. The required distance is 146mm so it’s straightforward to use a 2?inch diagonal. This is for visual only with my nv monoculars. Works very nicely in conjunction with my 55mm plossl. I also use a standard c11 with AP 0.75x photo visual reducer and 55mm plossl. Visual views are shown in the phone images in the linked thread (about 1 degree fov)

     

    • Like 1
    • Thanks 1
  6. Here is the latest iteration of my eyepiece cases. As you can see I like my peli cases.

    Front left: planetary and lunar set with tec turret and delites

    Front right: binoviewing set for solar and planetary 

    Back row: Various night vision monoculars with suitable Televue eyepieces for afocal viewing and ha and other filters 

     

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    • Like 11
  7. 14 minutes ago, apaulo said:

    thanks gav for clearing the ir filter up for me. so am i right in thinking that theres no filter  for observing that will  blacken the sky.

    Maybe I’m not answering your query, but For standard visual observing, depending on the object to be observed, there are various filters that can help to some extent like uhc, oiii (for emission nebulae) and Baader moon and sky glow (for planets). But these filters have nowhere near the impact that the night vision device plus appropriate filter has for light polluted skies. In this case bigger prices really do have a massive positive impact on what you can observe live.

  8. 16 minutes ago, apaulo said:

    will this ir  filter  work for general observing. i have realised very quickly that bigger prices very often dont mean bigger improvements in astro gear in general. thanks for the advice and input.

    I use my night vision monoculars primarily for live visual observing, not imaging. However I do like taking quick phone shots of the views as a record of my observing sessions.

    With respect to the ir filter this should be used in conjunction with a night vision device for live observing. 

  9. 53 minutes ago, apaulo said:

    i was out last night with my gear at a local dark site. a passer by with his dogs stopped and chatted. he had a night vision viewer with him that he asked me to look through. wowwww what a bit of kit. i always knew about them but never looked through 1. it raised an immediate question within me. if they can turn dark into light why not a reverse item for the sky. maybe in my ignorance they do exist and ive never seen or heard of 1. we seem to get offered bits of glass that work with 1 thing and not another and seemingly quite useless. does anyone know of anything affordable that does work to make milky skies dark.

    With night vision astronomy we use strong filters to remove the “milky ness”. Eg for viewing stars and galaxies in my London back garden I use a Baader 685 filter which filters out the visible wavebands just leaving the infrared which can  be seen by the night vision device. Works very well and with the manual gain adjustment you can get really quite black skies but retain lots of stars.

    It’s expensive though unfortunately.

    Here’s a thread I posted recently about how light pollution does affect night vision astronomy. For the observing discussed in this post I was using a narrowband ha filter to observe the emission nebulae. Some light pollution does sneak in hence the more milky views but night vision still allows you to see stuff you would have no chance otherwise.

     

    • Like 3
  10. On 06/11/2021 at 00:52, Highburymark said:

    Possibly Stu. A couple of nights ago I was out looking at various nebulae with my 120mm frac and night vision. When I finished I saw the Pleiades and Hyades had just crept over the top of the adjoining houses (for the first time this year), so I swapped the NV monocular for a more traditional eyepiece, and spent the next 30 minutes completely absorbed with the views. Although you can see many more stars with night vision, there’s simply no contest on prominent open clusters, even from London - give me a ‘normal’ set up every time. Night vision doesn’t do planets, the Moon (obv), reflection nebulae, double stars, high magnifications, and many planetaries are better without NV too.
    I see night vision as a tool to transform views of particular objects, but there’s vastly more to see with a standard scope. If a beginner sampled NV first and then found views underwhelming with a conventional set up, then it’s probably not the right hobby for them anyway. 

    An experienced nv user posted the following comment on CN recently…

    Acting solely as a facilitator, offering up memories to last a life time, is incredibly rewarding in and of itself. 

     

    The most impactful encounters, have all been with those who will likely never have the inclination to buy an NVD nor a telescope. 

     

    The least impactful and joyless encounters, have been within the astronomy community itself, particularly with the "experienced " amateur.  

     

    Rough heathen outreach is rewarding, doing it to convert, not so much.  

    • Like 3
  11. 1 hour ago, Highburymark said:

    Didn’t realise Astrograph had stopped selling NV. So no UK retailers?
    Must say, when I was buying I researched the market in Europe and got an excellent tube with great service from Nighttec in Germany. This was for a PVS-14 with Photonis 4G tube, before OVNI - no history of selling to astronomers - but I spoke to them about what I wanted and they came back with a choice of options. Kept me fully informed throughout.

    Agreed Mark. Most European sellers of nv equipment are happy to provide options that meet the requirements of astronomers.

    • Like 1
  12. One of the key benefits of night vision astronomy is the ability to observe many DSOs from a light polluted site which would otherwise be invisible (or virtually invisible ) with normal glass eyepieces.

    However, light pollution still has quite an adverse impact on the views with night vision compared to observing from a dark site. I was pretty impressed with the nebulae views I got from London earlier this week. But I still get significantly more enjoyment from night vision when observing at a dark site. 

    In June this year, I observed several of the same nebulae from a dark site on the Isle of Wight (sqm 21+) using a reasonably similar setup (effective speed, aperture, image scale).

    I attach the London vs Isle of Wight night vision comparison of the North America, Butterfly, Veil, Pac-man, Soul nebulae. Quite a difference I think!!!

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    • Like 8
    • Thanks 1
  13. 1 hour ago, Stu said:

    It’s funny, I had a chat on messenger last night with @GavStar about the fact that I said that I’ve never seen the Horsehead nebula in a recent post.

    Of course I HAVE seen the Horsehead a few times through Gavin’s NV gear and it is amazing to see. I guess though that there is a ‘rite of passage’ which is about having the right kit, location, conditions and skill to see these targets visually because it is tough even with an Hb filter. With NV it is just ‘there’, so I did also say to Gavin that NV was cheating 🤣🤣, but despite this being a dagger to his NV heart I hope we are still friends 😆😉🤣.

     

    Nope you’re off the Christmas card list now @Stu 🤣🤣

    • Haha 5
  14. 18 minutes ago, Stu said:

    You made the most of the clear night Gavin 👍. The forecast was wrong here so I wasn’t expecting it to be clear.

    A very capable setup despite being so ‘grab and go’, although amazing to see the different image scale between this and your C11 and 16”.

    Thanks Stu. As you know I was going purchase a Sharpstar 13028 as a larger aperture grab and go. But after last night I think I’m going to stick with the easy setup, pinpoint stars and lovely flat field of the fsq85 (night vision is notorious for exaggerating any fc exhibited by the scope).

    And you’re right, the fsq85 and c11/16 inch dob work in great partnership for big and small objects respectively…

  15. It was a lovely clear night sky in London tonight and also no moon so I thought it was about time for a decent night vision astronomy session.

    I went for my grab and go setup, ie az gti mount and Takahashi fsq85. First up was a bit of experimenting with my Televue 67mm and reducers and also my Televue 55mm in afocal mode with my pvs-14. Given the light pollution I only used my chroma 3nm ha filter. The reducers gave relatively disappointing star shapes tonight so I quickly just focussed on the eyepieces only. The 67mm is nice with good stars to the edge but it does suffer from some vignetting - not really noticeable for visual but quite obvious when I take some phone pics through it. The 55mm didn’t have the vignetting but the edge stars were pretty yucky (lines not points!).

    I then dusted off my Televue panoptic 41mm to compare with my experiences with the 67mm and 55mm. Although a bit dimmer, the 41mm didn’t vignette and also had nice sharp round stars right to the edge. As a result it stayed in the focuser for the rest of the session. I started with Cygnus (North America, Veil and Butterfly) and then gradually made my way across the rest of the sky taking in the Pac-man, Heart, Soul, California, Monkeyhead, Rosette and then finally the Flame/Horsehead. Phone pics attached and bearing in mind this is from an sqm 18 (light polluted) London back garden, I really want to get this setup to a dark site soon. The fov of around 4 degrees frames many showpiece nebulae very nicely.

    I think November is one of the best times to observe with night vision - there are loads of showpiece nebulae all over the sky - and nebulae are what night vision really excels at. I’d definitely recommend grabbing your nv kit and scope at the next clear night to do a “Grand nebulae tour”.

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    • Like 8
  16. 2 hours ago, joko said:

    What do you mean by "something else is making a bigger difference…" Because there is something else you do not explain, the PVS-14 is just the housing, you have an OVNI Night Vision Astronomy grade tube designed for astronomy in your PVS-14.

    And knowing you have an OVNI Night Vision Astronomy grade intensifier tube in your best PVS-14 housing, tube that i supplied to you, it means you have the same tube performance in your OVNI-M. And there are absolutely no other parts between the tubes and the SLR/Camera lens. So the only difference is this SLR/camera lens. Nothing else can explain the difference you get.

    As you explain, there are a lot of positive comments on CN, (i never read any negative) so there are obviously something that makes the difference. For sure, it is the lens.

    I already tried a lens at f/2 and the view was really bad, close from your Fujinon f/1.8. And it was incomparably better with the Cosmicar f/1.4 (close to your f/1.5 lens). Like most OVNI users have.

    So the difference is due to the lens and nothing else.

     

    What I mean is that the difference in f ratio between the lens of f1.5 and f1.8 is not the key reason for the major differences I am seeing when observing nebulae. C mount lens like the fujinon and cosmicar are not designed for use with an nv monocular - it’s just that they have a c mount thread and so can be attached straightforwardly. The afocal 3x lens is specifically designed for use with a pvs14 - I think this a key reason why I am getting better results with it (using either my actinblack pvs14 or my Carson/ovni pvs14) than than ovni with fujinon lens.

    • Like 1
  17. 1 hour ago, joko said:

    I would like to clarify one very important point that was not explained in the review. The PVS-14 is just the "housing". The intensifier tube in the PVS-14 is an OVNI Night Vision "Astronomy grade" tube specially designed for astronomy. 

    Around 80% of the price of a Night Vision Device is dependant of the tube.

    There is some confusion here. To confirm I have two pvs-14 monoculars. One is a complete setup (ie pvs-14 body and harder nv tube) purchased from actinblack, the other is one I built using a harder tube purchased from ovni and a pvs14 Carson milspec body/lens kit purchased from nighttec in Germany. 

    The astronomy now review comparison was done before I received the Carson pvs14 kit and so the comparison was done between the actinblack pvs14 and the ovni-m.

    The full review is now available online here

    https://astronomynow.com/2021/07/29/reviewed-ovni-m-fom-2600-night-vision-eyepiece/

    • Like 2
  18. 1 hour ago, joko said:

    Fujinon is f1.8 while most OVNI-M users have Cosmicar 75mm f/1.4 and emission nebulae are amazing with h-alpha filter.

    I never heard any negative feedback with the Cosmicar lens. All feedbacks are positive like those you read on CN.

    Only about half an f stop difference between the Fujinon and the Cosmicar so wouldn’t be much of an impact. The 3x afocal lens is f1.5 and the difference I observed visually on emission nebulae with ha filter between the fujinon and afocal lens was more like 3-4 f stops rather than half, something else is making a bigger difference…

     

  19. 3 hours ago, stnagy said:

    Interesting. I haven't tried the specialist 3x afocal lens. It sounds like it is worth a try. Do you mind me asking where did you get yours? How do you use it with a filter? 

    Since I’m based in the UK I got from actinblack in Luxembourg. However if you are in the USA they are more freely available and there are multiple versions some of which are better then others.

    I used this adapter to put the 1.25 filter between the pvs14 and 3x afocal lens. There is material vignetting due to the adapter etc but the centre 70 percent or so is excellent…

    https://rafcamera.com/adapter-envis-3x-to-pvs-14?amp=1

  20. 3 hours ago, vineyard said:

    That's a great idea @Martin Meredith - many parts of the world with rolling powercuts get that already & civilisation doesn't collapse.

    Its dangerously addictive b/c now I'm imagining what a headset with binocular NV in a proper dark sky zone would be like!😂 

    Binocular nv is very cool - I think the jump up from mono to bino nv is noticeably bigger than the jump from mono to bino with normal glass. Bino is definitely my preferred way of nv observing but quite tricky to get aperture with this so I stay at 1x with the monoculars or 10x with the big binoculars as per these threads. It does start to get a but expensive though…

     

     

    • Like 1
  21. 48 minutes ago, stnagy said:

    Is it the computar f2.8 lens? If so, it's gathering about 1/4 the light intensity of a specialist 3x afocal lens (at f1.5), which might be why you're getting those results. 

    It’s the 75mm f1.8 fujinon c mount, so a bit slower than the f1.5 but not much. The difference was pretty embarrassing for the fujinon though…

  22. @vineyard

    1) Excellent re the tinkering. I think it’s very worthwhile since I read stuff like the 6-12 nm ha filters being best but after trying a 12,7,6,5 and 3nm filter it’s clear that for me the 3 is the best to bring out the most nebulosity with nv. So definitely keep on experimenting to work out what it best for your personal preferences.

    2) here’s a cn link that may help you?

    https://www.cloudynights.com/topic/730773-why-doesnt-a-camera-lens-work-a-focally/

    3) Finally, (and probably least important), I’ve been able to try a camera lens and 75mm c mount lens in prime mode with my ovni-m. Both approaches disappointed me particularly on emission nebulae where with an ha filter both lens really struggle to show the nebulosity compared with my specialist 3x afocal nv lens. So I’ve stopped messing around with the camera lens as I’m happy with my afocal 3x lens setup. It perplexes me quite a bit about the positive comments made on cn re using camera lens/c mount lens with ha filters and nv as I just couldn’t get them to work at all well…

    • Like 1
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