15 inch dob and 8 inch with night vision

[TBRHussaR]

Hey guys… just a quick report / comparison.

I have been using an ovni bino night vision device for about 8 months now. It has really blown me away. I have always loved galaxies, especially finding structure in them. Of course, the hassle of moving larger dobs always holds me back. Night vision has changed everything- it makes my 8 inch scope more powerful than my 15 inch obsession. Here is my report on a few objects with comparison. I observe in my bortle 3 skies in Basingstoke, and sometimes at exmoor.

m51 - 8 inch with night vision - amazing structure seen!! Better than obsession 15. Interestingly - the night vision on the 15 inch does not enhance the image much.

M42 - gorgeous- I can see the structure of the nebula, not just the shape. Again - not much better view from obsession scope.

 

night vision has changed how I observe. I have attached pictures through the eyepiece - using iPhone . What can’t be seen is how the stars twinkle and seem “alive “ in the night vision device. I don’t think I need a massive dob anymore.

Clear skies everyone!

[faulksy]

are you sure your 15 is colimated correctly ?

i can see it visualy equal to that if not a bit better on a good night.

ace what you say about the stars twinkling 👍

[TBRHussaR]

Yeah , I’m amazed too. The 15 inch is definitely collimated correctly. I’ve checked a dozen times. Others in the USA say the same thing. Night vision is the great equaliser!

Edited June 6, 2022 by TBRHussaR

[Kon]

Very interesting. Could you share what kind of night vision equipment you use with your Dob please? Is there much benefit if you are observing from a fairly dark sky?

[TBRHussaR]

I have the ovni-b (bino) NV. Yes dark skies help, but honestly not by much. 

[Mike Q]

There seems to be a growing number of people who are now using NV here in the States, particularly out west where they have very dark skies.  On YouTube there is Dakota Starry Nights, that guy uses night vision with big scopes and the results are just amazing.

[TBRHussaR]

Yes I follow that guy. What has surprised me is how much my 8inch view is improved. I may even sell my obsession. 

[vineyard]

I'd echo the step change that NV makes - I use it in Bortle 8/9 skies with a 7" Mak, 5" Mak and 3" frac.  It's a complete game-changer for visual.  I haven't had a chance to run it on any galaxies yet (mostly globs & some nebulae) so your report on M51 w an 8" is v encouraging.  Can I ask what f/ratios you were effectively running your NV at (ie, the native f-ratio of your scope & if you were doing this afocally, which EP you were using?)?

Thanks

[niallk]

Holy moly the Ovni NV Binoviewer is expensive!

I've had one particularly spectacular view of M51 with my 15" from my local Bortle 4ish skies - transparency makes a huge difference along with good seeing: wonderful knotty detail in the spiral arms ...literally breathtaking.

Sounds like you are getting fantastic results with you 8".  Interesting to hear it doesn't make so much of a difference in your 15"!  I wonder why??

[TBRHussaR]

8 hours ago, vineyard said:

I'd echo the step change that NV makes - I use it in Bortle 8/9 skies with a 7" Mak, 5" Mak and 3" frac.  It's a complete game-changer for visual.  I haven't had a chance to run it on any galaxies yet (mostly globs & some nebulae) so your report on M51 w an 8" is v encouraging.  Can I ask what f/ratios you were effectively running your NV at (ie, the native f-ratio of your scope & if you were doing this afocally, which EP you were using?)?

Thanks

Afocal - so no eyepiece used...

[TBRHussaR]

On 06/06/2022 at 12:56, niallk said:

Holy moly the Ovni NV Binoviewer is expensive!

I've had one particularly spectacular view of M51 with my 15" from my local Bortle 4ish skies - transparency makes a huge difference along with good seeing: wonderful knotty detail in the spiral arms ...literally breathtaking.

Sounds like you are getting fantastic results with you 8".  Interesting to hear it doesn't make so much of a difference in your 15"!  I wonder why??

Don’t get me wrong - the view in the 15” is amazing, but what surprised me is that the 8 “ is so so close. It’s made me rethink owning the larger dob and will likely sell it now. The 8 inch is so convenient!!

[bomberbaz]

wow, great bit of kit but 5K 2nd hand and much more new. I would be expecting breath taking views at that much moula!

[TBRHussaR]

very expensive stuff....

However - my obsession 15UC cost 12000 after all said and done.

now if I'm getting the attached images below with my Celestron 8" , and I can use it even at home with light pollution, and its super easy to set up / move / transport, all for less than the cost of the obsession, I start to wonder...

[bomberbaz]

58 minutes ago, TBRHussaR said:

very expensive stuff....

However - my obsession 15UC cost 12000 after all said and done.

now if I'm getting the attached images below with my Celestron 8" , and I can use it even at home with light pollution, and its super easy to set up / move / transport, all for less than the cost of the obsession, I start to wonder...

what are the two pictures images of please?

[niallk]

Looks like the Needle Galaxy NGC4565 and the Black Eye Galaxy M64 to me!

I'd love to try NV 😉  I've seen 1x magnification shots posted here showing the Angel Fish neb and Bernard's Loop which were spectacular!

[vineyard]

On 06/06/2022 at 20:37, TBRHussaR said:

Afocal - so no eyepiece used...

Do you mean prime focus (I think afocal involves an EP)?  Great images of the most recent 2 galaxies too.  You're definitely motivating me to take the 7"+NV on a galaxy hunt   What f-ratio are those galaxy observations running at?  (If its a Celestron 8" with NV at prime focus then that suggests f/10?)  Thanks!

[Deadlake]

Prime is with no EP, afocal with an EP.

Back to the subject great photos. I know @GavStar tells me the C11 is close to a 16” SkyVision Dob in use. I’ve used Gavins C11 and it is very good.

What is the focal ratio of the 15”?

In afocal with a compressor the C11 with run at an effective speed of f3.

I think it comes down to ease of use, the C11 is a little more portable then the dob and requires less collimation. For me I can reuse a AZ100 for all my scopes and don’t need to get a second set of digital circles.

Did you use any filters at all?

Edited June 18, 2022 by Deadlake

[joko]

6 hours ago, Deadlake said:

Prime is with no EP, afocal with an EP.

Back to the subject great photos. I know @GavStar tells me the C11 is close to a 16” SkyVision Dob in use. I’ve used Gavins C11 and it is very good.

What is the focal ratio of the 15”?

In afocal with a compressor the C11 with run at an effective speed of f3.

I think it comes down to ease of use, the C11 is a little more portable then the dob and requires less collimation. For me I can reuse a AZ100 for all my scopes and don’t need to get a second set of digital circles.

Did you use any filters at all?

With your OVNI-M do you use a focal reducer or do you prefer afocal for wide FOV ? 

Edited June 18, 2022 by joko

[Deadlake]

17 hours ago, joko said:

With your OVNI-M do you use a focal reducer or do you prefer afocal for wide FOV ? 

Options with a 130/f6: 

• afocal TV 67 mm
• afocal TV 67 mm, with Riccardi reducer (0.7)
   

The reducer option does give a brighter image no doubt on that with a reduction of image scale. I've not tried the reducer option in prime only mode, which would give an effective speed of f4.2. Could be interesting. The afocal solution are around f 2 for reference.

The other issue with the reducer is the back focus is around 82 mm resulting in a short optical path. The AP tele compressor has a back focus of 150 mm which gives  more room in the optical path and maybe the prime mode might work. 

It should be noted that the TV EP 55 mm has a focal plane of -26 mm from the bottom of the EP, which make using a compressors in afocal mode easier and prime mode impossible in with the Riccardi.

Which do I prefer, I like the brighter image with. compressor however image scale is a little off for a lot of the showcase objects, I need to get a C11 or Dob to have enough light bright enough image) and the image scale required. 
 

Edited June 19, 2022 by Deadlake

[Stu]

1 minute ago, vineyard said:

What a farce.  Why does NIMBYism spring to mind (as in 'NV must be kept in its own ghetto & not allowed to mix with "respectable" folks').  Ah well.  

This subject has been talked to death. If more of you with NV posted in the EEVA section then it would be more active and get more attention.

It is highly confusing for new starters to see observing reports written using NV gear as it does not give an accurate impression of what you can see visually.