Grab and go scope for Night Vision

[PeterW]

The BorenSimon is just an f5 newt with a special reducer-corrector in it. I use an f4 imaging newtonian and a 0.5x reducer and run around f2.5.... cheeeper still.

tue 67mm afocal reduction turns any reasonably quick system into  a decent NV system. (Mike Lockwood has shown this still works if you star with an f3 system!) I wouldn’t fret about trying to have a “perfect system”, there are many good options, start with what you have. Check SGL or CN to see if anyone has tried specific things before.

@Highburymarkyou’ve been lucky on your trips, I’ve seen crap skies in dark locations before. Always best to have a few “test nebulae”, see what they look like, then you know if it’s a special night to go after the really challenging stuff.

 

Peter

[Highburymark]

43 minutes ago, Space Hopper said:

I'd love to have a go at NV someday, but know fairly little about the pros and cons.

Eddgie, On CN (NV & binoviewer guru)  uses a Boren Simon Astrograph to good effect, i believe.

Maybe worth a look and doing a bit of research on. A bit cheaper too !!

They are listed at the bottom of the linked page...

https://www.teleskop-express.de/shop/index.php/language/en/cat/c221_TS-Optics-ONTC---UNC-Newtonians.html

Indeed Rob - Boren Simons are very nice night vision telescopes and wickedly fast - they are just a bit big for my needs. Was also a little concerned about collimation as a Newt newbie. The Epsilon seems to have rock solid collimation. 

[PeterW]

As long as the newt is reasonably well made it is easy to collimate with a laser, NV is low power so slight errors won’t show.

Peter

[Highburymark]

4 minutes ago, PeterW said:

As long as the newt is reasonably well made it is easy to collimate with a laser, NV is low power so slight errors won’t show.

Peter

Easy for you experienced Newt users to say Peter. I struggle to even read the collimation instructions in the Epsilon owners’ manual, never mind carry them out.

Useful message that isn’t always communicated in night vision threads - it is not a panacea for all astronomy problems - particularly poor seeing. 

[GavStar]

37 minutes ago, Highburymark said:

 

Useful message that isn’t always communicated in night vision threads - it is not a panacea for all astronomy problems - particularly poor seeing. 

Mark, I think it’s poor transparency that nv struggles with rather than poor seeing?

Edited November 4, 2020 by GavStar

[GavStar]

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

 

[PeterW]

Show off! More better, but lower spec stuff will still show plenty.

mark, the epsilon instructions may be have to read as they might be a bad translation... Japanese commonly makes for hilarious or incomprehensible translations. If the views are ok then leave the little screws alone!

Peter

[Highburymark]

37 minutes ago, GavStar said:

Mark, I think it’s poor transparency that nv struggles with rather than poor seeing?

Fair point Gavin - though looking at open clusters sometimes I struggle to get clean stars - while other times they’re pinpoint. 

[Deadlake]

For the newbie here I was googling around and found this site:

https://www.falconclaw.eu/monocular-night-vision-buying-guide/

A lot cheaper than the ONVI products. What the difference in products for the same FOM level, ONVI is almost EU2500 more? The FOM is a lot lower than the harder digital, what a good starter one that I will not to upgrade immediately?  

Edited November 4, 2020 by Deadlake

[PeterW]

The Photonis uses a different photocathode to the harder, Gav has compared and the harder Gen3 is the way to go. I thought the photonis cost more than the harder for similar FOM? There are secondhand options for Gen3, which will cost a good deal less, but then you don’t know what the specs are, though thewy should still work plenty well. Don’t be tempted to go for Gen2/2+ as they won’t perform as well.

Peter

[Space Hopper]

@PeterW thanks for the message.

This hobby certainly leaves a hole in your pocket doesn't it....?? 😀 (or it can do if you're not careful)

[joko]

15 hours ago, Deadlake said:

For the newbie here I was googling around and found this site:

https://www.falconclaw.eu/monocular-night-vision-buying-guide/

A lot cheaper than the ONVI products. What the difference in products for the same FOM level, ONVI is almost EU2500 more? The FOM is a lot lower than the harder digital, what a good starter one that I will not to upgrade immediately?  

Hi @Deadlake, you have very good questions.

Before speaking about the tube, let's speak about the body (monocular).

• In the link you posted, please note this monocular can only be used in afocal. Prime focus is not possible. So no way to use it like a glass eyepiece. 
• Also no way to use it handheld (like binoculars) with camera lens. It doesnt' have c-mount. Only 1x is possible with its front lens and no adapter to add h-alpha filter. To see Barnard Loop, all big nebulas (America, California, Rosette...) is breathtaking. There is no way to imagine how amazing it is without trying it. I use lenses up to 7 times magnification.
• Next, the product is « a non-manual gain version » as noted on the website. Please note manual gain control is a MUST-HAVE feature according most NV astronomers.

So with the monocular you talked about, only afocal (no prime and no camera lens), no manual gain control…

While OVNI-M is a 26mm eyepiece, very flexible as you can use it in prime, afocal, and handheld (it has c-mount). It also includes manual gain control.

 

Now let's speak about the tube.

• It's written on the website you mentionned "Please be aware that not all spots are visible on those pictures and in real life the spots appear to be bigger than on this picture." A GEN2 echot tube is a tube with dark and bright spots meaning you will have spots in your field of view. Not great at all for astronomy !
• About the performance, what can i say... GEN 2 ECHO tubes have much lower performance than GEN3 thin-film tubes (the best in the world). The difference is huge much more light and details for DSO with high sepcs tubes. Probably the most important aspects. 
• Also FOM is not the only important spec, there are much more specs that needs to be well balanced to get the best for astronomy. EBI is also very important, like gain, resolution…
• And i don’t even speak about warranty (only 1 year) and shop service is also imprtant (many questions before and after sales) …

Please note i have an agreement to use Photonis tubes, but ther is no way i sell a product with ECHO tube for astronomy.

Hope my message respect the rules of the forum. No advertisement here, only replying to questions. 🙂 

Edited November 5, 2020 by joko

[Trentend]

Some great responses here (but a lot to take in!). Looks like different scopes depending on viewing objectives.

a) Have big dob in back garden for DSO with/without NV goggles (and great with binoviewer for lunar and planets when in view) 

b) Have Mak127 for grab and go for lunar and planets (but not NV). Great views but small FOV so may have to add some fine tuning knobs or tracking (not fun nudging around).

c) Perhaps a lightweight refractor for grab and go NV. I’ve seen a lightweight apo (4kg) in the 102mm F7 range.  Is that the wrong speed for NV even if I’m using the 67mm Televue adapter? Guess this would be ok for lunar/planets but I’d need more magnification from the eyepiece (24mm in Binotron even at high power would be less than I’m used to in the dob and Mak).

Any thoughts on c?

 

 

[Highburymark]

7 minutes ago, Trentend said:

Some great responses here (but a lot to take in!). Looks like different scopes depending on viewing objectives.

a) Have big dob in back garden for DSO with/without NV goggles (and great with binoviewer for lunar and planets when in view) 

b) Have Mak127 for grab and go for lunar and planets (but not NV). Great views but small FOV so may have to add some fine tuning knobs or tracking (not fun nudging around).

c) Perhaps a lightweight refractor for grab and go NV. I’ve seen a lightweight apo (4kg) in the 102mm F7 range.  Is that the wrong speed for NV even if I’m using the 67mm Televue adapter? Guess this would be ok for lunar/planets but I’d need more magnification from the eyepiece (24mm in Binotron even at high power would be less than I’m used to in the dob and Mak).

Any thoughts on c?

 

 

I use a 100mm F/7.4 frac (Tak FC-100DC) for night vision and it’s great - also use 67mm Plossl and sometimes reducers to get speed up. If you PM me I can send you an article Gavin and I wrote on night vision for Astronomy Now magazine last year which featured this set up

[Deadlake]

On 03/11/2020 at 16:07, GavStar said:

Great spot. Before I got the fsq130, I was very tempted by that 121sdq and with the 67mm plossl it would give a effective f2.2, very nice for afocal nv! With a 5 lens refractor there is a risk of miscollimation (fsqs have this issue sometimes as well) but it’s a lot lighter (and cheaper!!) than the fsq130 - I like it!

Very tempting specs. Was going to say good weight 5.6 kg however this looks like the real specs:

https://astronomytechnologytoday.com/2020/09/30/sharpstar-121sdq/

weight is around 9 kg, but not that heavy.

[GavStar]

Here’s an old thread that gives some more detail on the various night vision tube specs 

 

[GavStar]

1 hour ago, Trentend said:

Some great responses here (but a lot to take in!). Looks like different scopes depending on viewing objectives.

a) Have big dob in back garden for DSO with/without NV goggles (and great with binoviewer for lunar and planets when in view) 

b) Have Mak127 for grab and go for lunar and planets (but not NV). Great views but small FOV so may have to add some fine tuning knobs or tracking (not fun nudging around).

c) Perhaps a lightweight refractor for grab and go NV. I’ve seen a lightweight apo (4kg) in the 102mm F7 range.  Is that the wrong speed for NV even if I’m using the 67mm Televue adapter? Guess this would be ok for lunar/planets but I’d need more magnification from the eyepiece (24mm in Binotron even at high power would be less than I’m used to in the dob and Mak).

Any thoughts on c?

 

 

I agree with Mark, c would work well with a 67mm eyepiece 

[PeterW]

With a fixed lens you can still use a 3x lens though no ultrawide or slightly higher power options that camera lenses would enable. It is easy to make or buy (depending on threads) a 2”filter to the 1x or 3x options. For maximal focal reduction afocal is probably the best option, though it does lead to rather a long unit in the focusser.

Many commercial tubes have occasional black spots, there are specs that limit the size, location and number. I have a little spot off to one side, doesn’t bother me. I agree that the photonis gen2 are behind the Gen3 even for the best specs.

 

Peter

 

[GavStar]

4 hours ago, PeterW said:

With a fixed lens you can still use a 3x lens though no ultrawide or slightly higher power options that camera lenses would enable. It is easy to make or buy (depending on threads) a 2”filter to the 1x or 3x options. For maximal focal reduction afocal is probably the best option, though it does lead to rather a long unit in the focusser.

Many commercial tubes have occasional black spots, there are specs that limit the size, location and number. I have a little spot off to one side, doesn’t bother me. I agree that the photonis gen2 are behind the Gen3 even for the best specs.

 

Peter

 

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

 

Edited November 7, 2020 by GavStar

[PeterW]

I  do still wonder what level of tube coupled with a fast low power lens and a long pass filter could be used for outreach to show people the Milky Way… Wouldn’t need such high specs as we need for nebulae…. The public (even astro imagers) don’t get impressed by nebulae that much but get shocked by the abundance of stars that appear. Could be an Echo could work for this?? Of course if you want to dig up really diffuse nebulae you need all the gain and contrast you can get, which still costs more.

 

Peter

[GavStar]

15 minutes ago, PeterW said:

I  do still wonder what level of tube coupled with a fast low power lens and a long pass filter could be used for outreach to show people the Milky Way… Wouldn’t need such high specs as we need for nebulae…. The public (even astro imagers) don’t get impressed by nebulae that much but get shocked by the abundance of stars that appear. Could be an Echo could work for this?? Of course if you want to dig up really diffuse nebulae you need all the gain and contrast you can get, which still costs more.

 

Peter

That’s a very good point - yes I think an echo would be very good for this task

[joko]

Like @PeterW i would recommend the Boren-Simon 6" . 

At F/2.9 it seems to be the perfect grab and go scope for Night Vision. Mainly for very wide nebulas.

I don't have it but i will probably order it soon, i should write this in my letter to Santa Claus 😀

[Deadlake]

4 hours ago, joko said:

Like @PeterW i would recommend the Boren-Simon 6" . 

At F/2.9 it seems to be the perfect grab and go scope for Night Vision. Mainly for very wide nebulas.

I don't have it but i will probably order it soon, i should write this in my letter to Santa Claus 😀

Does anyone own a Boren-Simon newton and use it with NV? 

[PeterW]

One chap I the US has done so, but with a 67mm plossl and an f4 imaging newtonian you can get down to around f1.6, which should be fast enough (maybe not for @GavStar though)! An explore scientific coma corrector can avoid loss of speed if you wanted.

 

peter

[joko]

3 hours ago, Deadlake said:

Does anyone own a Boren-Simon newton and use it with NV? 

On cloudynights there are Mazerski and Eddgie who use the Boren-Simon 6" with NV.