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Preferred ‘scope and eyepieces for NightVision?

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#1 StarAlert

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Posted 02 December 2019 - 06:19 PM

I purchased a used TV76 a couple weeks ago. After it arrived, I had a couple questions about this beauty, so I called Televue. I talked with a technician for about 20 minutes about a problem I was having with the focuser, and then I asked him about TV eyepieces.

 

He put me on hold to find someone who could answer the EP questions. To my pleasant surprise, Al Nagler picked up the line.  He first wanted to know my full name and where I was calling from. Then, after answering my eyepiece questions in great detail, he told me about the TNVC night vision equipment that Televue was partnering with. He said the white phosphor was a “game changer” for astronomy. From my light polluted skies in LA (he knew where I lived), I think he has a good argument.

 

So after doing a bit of research, I’m still intrigued. I’m wondering what kind of OTA and eyepieces the PVS-14 is designed to work with. I have the NP127 and the TV76. It sounds to me, after some initial research, like it would work better with the TV76. If that’s the case, I’d seriously consider selling the bigger scope and trying the NV. It would be about a wash in $. 

 

I’d like to hear your thoughts. 

 

Thanks


Edited by StarAlert, 03 December 2019 - 12:55 PM.


#2 Gavster

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Posted 02 December 2019 - 06:26 PM

I think both the tv76 and np127 would be great with nv due to their fast speed. With a 55mm plossl, 0.75x gso tv reducer and nv monoculars plus 5nm ha filter (for nebulae)  and 642 astronomik pass filter ( for clusters and galaxies) the views would be excellent. I have a Tak fsq85 which I use with nv and gives spectacular real-time views.



#3 StarAlert

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Posted 02 December 2019 - 06:39 PM

If you had to choose between the two scopes, which one would you pair the NV with? The 76 gives wider views. Is there a big benefit to more aperture when using NV?  



#4 Gavster

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Posted 02 December 2019 - 07:09 PM

If you had to choose between the two scopes, which one would you pair the NV with? The 76 gives wider views. Is there a big benefit to more aperture when using NV?  

I’d choose the np127 since I think it would cover a wider range of objects better ie with the 55mm plossl

it would have around 3.3 degree fov which would cover both large and smaller objects compared with the tv76. Aperture does matter with nv imo since it allows you to pick out more fine detail.



#5 wtd1114

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Posted 02 December 2019 - 07:39 PM

I personally think that aperture does play a role in NV.  I took a PVS-14 to a star party this year at a pretty dark site (21.7 mpas).  I put the PVS-14 behind a 56mm Meade plossl.  I used this combination on 3 different scopes.  I brought a WO ZS61 and an ES ED102.  The ZS61 is an f/5.9 and the ED102 is f/7.  Using the PVS-14/56mm combo and an NPB filter,  the view in the 102 had more definition and was a bit more contrasty and bright, even though it was a slower scope.  The 61 did have a wider view but kind of darker.  Personally, I felt the view in the 102 was bit more satisfying even though it had a narrower field.  This comparison was with the North American nebula.

 

The third scope was a star party camp neighbor's scope.  He was very inquisitive about NVD and I offered to put my PVS-14 on his scope for him to try.  He had a sub f/4 20" dob.  I think it was something like an f/3.3.  OMG the views in that monster was breathtaking.  Using the same PVS-14/56mm/NPB combo we could see crazy detail.  Soon we had a small crowd wanting to take a look.  People with many years of observational experience were blown away.  It was a very  memorable night.

 

Once you get your NVD put it on both your scopes and see which one is more pleasing.  For me it is the 102 over the 61.  However, normally, I put the PVS-14/56mm on my 10" astrograph reflector which is an f/3.85 when I am in my red zone home...

 

Best-

 

Willis



#6 GOLGO13

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Posted 02 December 2019 - 07:44 PM

That 127 would be really great for night vision. Actually both scopes would be good. Don't forget it can be used at 1x also. You would be in great shape for observations.

#7 slavicek

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Posted 02 December 2019 - 09:38 PM

I purchased a used TV76 a couple weeks ago. After it arrived, I had a couple questions about this beauty, so I called Televue. I talked with a technician for about 20 minutes about a problem I was having with the focuser, and then I asked him about TV eyepieces.

 

He put me on hold to find someone who could answer the EP questions. To my welcomed surprise, Al Nagler picked up the line.  He first wanted to know my full name and where I was calling from. Then, after answering my eyepiece questions in great detail, he told me about the TNVC night vision equipment that Televue was offering. He said the white phosphor was a “game changer” for astronomy. From my light polluted skies in LA, I think he has a good argument.

 

So after doing a bit of research, I’m still intrigued. I’m wondering what kind of OTA and eyepieces the PVS-14 is designed to work with. I have the NP127 and the TV76. It sounds to me, after some initial research, like it would work better with the TV76. If that’s the case, I’d seriously consider selling the bigger scope and trying the NV. It would be about a wash in $. 

 

I’d like to hear your thoughts. 

 

Thanks

First, what do you want to look at with NV? What FOV do you need?



#8 StarAlert

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Posted 02 December 2019 - 10:01 PM

First, what do you want to look at with NV? What FOV do you need?

Good question... I’m new to all this. Bought my first scope about a year ago and have been looking at whatever I’m able see in Bortle 7 skies, not much DSO observing for obvious reasons. Andromeda would be a good start. Would NV allow me to get a good view? How about other galaxies? Clusters? 
 

There is a lot of talk about nebula on this forum... never seen one in my scopes.

 

Scanning the Milky Way would be nice. I grew up in North Dakota in the 70s and 80s and never thought twice about looking up at the dark sky. 



#9 StarAlert

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Posted 02 December 2019 - 10:06 PM

I personally think that aperture does play a role in NV.  I took a PVS-14 to a star party this year at a pretty dark site (21.7 mpas).  I put the PVS-14 behind a 56mm Meade plossl.  I used this combination on 3 different scopes.  I brought a WO ZS61 and an ES ED102.  The ZS61 is an f/5.9 and the ED102 is f/7.  Using the PVS-14/56mm combo and an NPB filter,  the view in the 102 had more definition and was a bit more contrasty and bright, even though it was a slower scope.  The 61 did have a wider view but kind of darker.  Personally, I felt the view in the 102 was bit more satisfying even though it had a narrower field.  This comparison was with the North American nebula.

 

The third scope was a star party camp neighbor's scope.  He was very inquisitive about NVD and I offered to put my PVS-14 on his scope for him to try.  He had a sub f/4 20" dob.  I think it was something like an f/3.3.  OMG the views in that monster was breathtaking.  Using the same PVS-14/56mm/NPB combo we could see crazy detail.  Soon we had a small crowd wanting to take a look.  People with many years of observational experience were blown away.  It was a very  memorable night.

 

Once you get your NVD put it on both your scopes and see which one is more pleasing.  For me it is the 102 over the 61.  However, normally, I put the PVS-14/56mm on my 10" astrograph reflector which is an f/3.85 when I am in my red zone home...

 

Best-

 

Willis

Thanks for the insight, Willis. That’s very helpful. 
I think comparing NV in the two scopes is probably the way to go. But it’s not like the 127 doesn’t have a wide FOV. 



#10 StarAlert

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Posted 02 December 2019 - 10:12 PM

I’d choose the np127 since I think it would cover a wider range of objects better ie with the 55mm plossl

it would have around 3.3 degree fov which would cover both large and smaller objects compared with the tv76. Aperture does matter with nv imo since it allows you to pick out more fine detail.

Gavster,

How do you come up with 3.3* FOV with a 55mm Plössl? Televue says that a 55mm Plössl will give a 4.0* FOV in the 127. Does NV reduce the FOV? 



#11 Jeff Morgan

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Posted 02 December 2019 - 10:34 PM

So after doing a bit of research, I’m still intrigued. I’m wondering what kind of OTA and eyepieces the PVS-14 is designed to work with. I have the NP127 and the TV76. It sounds to me, after some initial research, like it would work better with the TV76. If that’s the case, I’d seriously consider selling the bigger scope and trying the NV. It would be about a wash in $. 

 

 

The PVS-14 is designed for neither. It was designed as a piece of military hardware used in various roles.

 

Fortunately for us, it adapts well to astronomy. Both of your refractors would be fabulous with it.

 

The 55 Plossl is currently the best Tele Vue option for widest/brightest views. Lots of guys like the 41 Panoptic. Somewhat less field and speed, but better edge correction.

 

You will also want two more choices for smaller targets that benefit from more power and are not as speed-sensitive, which is primarily star clusters (open and globular). Something shorter than the focal length of the NVD eyepiece itself (27mm).

 

Al Nagler is right about the Game Changer thing. IMHO, more significant than the Dobsonian Revolution.



#12 outofsight

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Posted 02 December 2019 - 11:13 PM

Good question... I’m new to all this. Bought my first scope about a year ago and have been looking at whatever I’m able see in Bortle 7 skies, not much DSO observing for obvious reasons. Andromeda would be a good start. Would NV allow me to get a good view? How about other galaxies? Clusters

Andromeda is a gimme, with no magnification. I showed a bunch of people Andromeda, last Saturday night. It's not that spectacular, except for the idea that you can immediately see another galaxy. Galaxies are a mixed bag because of the way they present. Clusters are the bomb, haha, cluster bombs. But really, clusters that I can barely figure out where they are, because of light pollution, show up like the pictures you see, except it's all instantaneous. 

 

There's nothing as nice as a dark sky, but these are the only devices that approach the immediacy of a dark sky. Good luck with your search. 

 

One more thing, you don't have to spend a $3K or $4K to check it out, I have some units that cost only $600 to $700 that are still Gen 3 and they are kick A! Those are hard to find, but you can pretty easily find a PVS-7 for less than $2K, and I'd rather have a PVS-7 than just about anything else. 


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#13 StarAlert

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Posted 03 December 2019 - 12:03 AM

You will also want two more choices for smaller targets that benefit from more power and are not as speed-sensitive, which is primarily star clusters (open and globular). Something shorter than the focal length of the NVD eyepiece itself (27mm).

There isn’t much choice if over 20mm eye relief is needed. Maybe a 40mm or 32mm Plössl with a 2x Barlow? 



#14 Gavster

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Posted 03 December 2019 - 02:56 AM

StarAlert, on 03 Dec 2019 - 05:03 AM, said:

There isn’t much choice if over 20mm eye relief is needed. Maybe a 40mm or 32mm Plössl with a 2x Barlow?

Delites work well.

#15 Gavster

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Posted 03 December 2019 - 02:58 AM

Gavster,

How do you come up with 3.3* FOV with a 55mm Plössl? Televue says that a 55mm Plössl will give a 4.0* FOV in the 127. Does NV reduce the FOV? 

The night vision monoculars have a tfov of 40 degrees compared to the 55mm plossl of 50 degrees so the resulting fov is reduced a bit by this from 4 to around 3.3 degrees.



#16 bobhen

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Posted 03 December 2019 - 07:51 AM

1. If you are just using a scope (your 76 and 127) for deep sky observing ONLY and you want to purchase an intensifier, you could sell both scopes and get an 80mm F5 and 120mm F5 or 150mm F5 fast achromat or an inexpensive 4 to 6” fast Newtonian and a C8 or C9. The point is, with Night Vision you don’t need really high quality optics. There are other attributes that you want to consider: Speed, Size, Image Scale, Portability, and ect.

 

So you could sell both TV scopes and pick some scopes from the above to help offset the cost.

 

2. If you want to look at the moon and planets and also have a small, high quality telescope for travel and daytime use, then keep the 76, which should be great with NV. Sell the 127 and use the proceeds to get an intensifier AND a C8 or C9.25 or 8 Dobsonian, as all of those scopes will be fine for the moon and planets and will work really well with an intensifier giving you more image scale than the 76 which should be great for wide fields.

 

A TV 76 and a C8 or 9.25 or 8” Dob is a nice combination for visual observing in its own right and would also be a nice combination for Night Vision and would also help offset the cost of an intensifier.

 

3. If money is no object, keep the TV scopes and add an intensifier and a C8 or larger for image scale.

 

To learn more start HERE

 

ALSO: Nice to see that Al has seen the light! I think I’ll start WWIII and post Al’s quote over in the eyepiece forum.

 

Bob


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#17 Eddgie

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Posted 03 December 2019 - 09:14 AM

I purchased a used TV76 a couple weeks ago. After it arrived, I had a couple questions about this beauty, so I called Televue. I talked with a technician for about 20 minutes about a problem I was having with the focuser, and then I asked him about TV eyepieces.

 

He put me on hold to find someone who could answer the EP questions. To my welcomed surprise, Al Nagler picked up the line.  He first wanted to know my full name and where I was calling from. Then, after answering my eyepiece questions in great detail, he told me about the TNVC night vision equipment that Televue was offering. He said the white phosphor was a “game changer” for astronomy. From my light polluted skies in LA, I think he has a good argument.

 

So after doing a bit of research, I’m still intrigued. I’m wondering what kind of OTA and eyepieces the PVS-14 is designed to work with. I have the NP127 and the TV76. It sounds to me, after some initial research, like it would work better with the TV76. If that’s the case, I’d seriously consider selling the bigger scope and trying the NV. It would be about a wash in $. 

 

I’d like to hear your thoughts. 

 

Thanks

You should know that the more popular device amount US CN members is the Mod 3 monocular.

 

The PVS-14 can only be used afocally. This means that to use it, you must use an eyepiece in the scope, an the NV device is either coupled to the eyepiece or attached with a Digiscoping adapter.  Now there are some advantages to afocal NV observing, but it lacks the flexibility of prime focus.  For example, you can't use a filter wheel with afocal, and you can't use SLR lenses with the PVS-14.  That does not mean it does not work well for NV, but most US CN members opt for the Mod 3.

 

Now the Mod 3 can work at Afocal as well as prime focus, though the Televue adpapter may not fit it, but that is just a piece of metal, and you can either have an adapter made, or you can use the Digiscoping adapter.  So, the Mod 3 does everything that the PVS-14 does, and much more. 

Both though will allow for very exciting views. 



#18 StarAlert

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Posted 03 December 2019 - 10:38 PM

What does afocal mean? Is is short for adjunct focal? That’s all I can come up with. 



#19 slavicek

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Posted Yesterday, 03:13 AM

Good question... I’m new to all this. Bought my first scope about a year ago and have been looking at whatever I’m able see in Bortle 7 skies, not much DSO observing for obvious reasons. Andromeda would be a good start. Would NV allow me to get a good view? How about other galaxies? Clusters? 
 

There is a lot of talk about nebula on this forum... never seen one in my scopes.

 

Scanning the Milky Way would be nice. I grew up in North Dakota in the 70s and 80s and never thought twice about looking up at the dark sky. 

For DSO you can use 127 Televue with NV. That will work as a nice enhancement. It's the nebulas which needs the wide FOV. And it's the nebulas where NV really rocks! So keep the 127 Televue (I'd never sell that) and, as suggested above, go for wide FOV telescope. But, with NV, be prepared to spent lot of $$$$! And buy MOD3 white phosphorus! Also, You will need narrow band filters, those can get expensive too. Etc, etc. For example, I am now converting Canon 200mm f/1.8 ($3000 used) for use with NV - it will have FOV of 5deg! And it will be very portable. But again it's $$$$.



#20 GOLGO13

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Posted Yesterday, 06:55 AM

I should point out that other than the actual NV unit you don't have to spend a lot of money. But it is easy to start doing so.

#21 StarAlert

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Posted Yesterday, 08:28 AM

You should know that the more popular device amount US CN members is the Mod 3 monocular.

 

The PVS-14 can only be used afocally. This means that to use it, you must use an eyepiece in the scope, an the NV device is either coupled to the eyepiece or attached with a Digiscoping adapter.  Now there are some advantages to afocal NV observing, but it lacks the flexibility of prime focus.  For example, you can't use a filter wheel with afocal, and you can't use SLR lenses with the PVS-14.  That does not mean it does not work well for NV, but most US CN members opt for the Mod 3.

 

Now the Mod 3 can work at Afocal as well as prime focus, though the Televue adpapter may not fit it, but that is just a piece of metal, and you can either have an adapter made, or you can use the Digiscoping adapter.  So, the Mod 3 does everything that the PVS-14 does, and much more. 

Both though will allow for very exciting views. 

 

Eddgie,

It looks like you were an early adopter (2015?) of the NV technology. Have you seen prices for the NV unit come down at all over the past couple years, or has the unit cost been stuck at about $4,200? Do these vendors ever put them on sale? 



#22 Eddgie

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Posted Yesterday, 08:39 AM

What does afocal mean? Is is short for adjunct focal? That’s all I can come up with. 

Afocal projection is where you hold or mount a camera on to an eyepiece.  In this case, the Night Vision device with its objective would be mounted on to the end of a regular eyepiece rather than removing the objective and mounting the night vision device into the eyepiece holder and using it at prime focus just like any other eyepiece.  By using an eyepiece with a longer focal length than the objective on the night vision device, it is like using a focal reducer (or Barlow) in that you get the same magnification as the eyepiece.   If you used a 55mm Plossl, it would be like using a .5x reducer. 

 

If you remove the objective from the night vision device (if it is removable), you can put a 1.25" or 2" nose on the device and insert it directly into the focuser. Here you are working at prime focus, and the eyepiece on the NV device is about 27mm, so you would get the same magnification as if you use a regular 27mm eyepiece in that scope so in my 6" f/2.8, the 27mm eyepiece gives about 15x or so. Now there is no exit pupil limit when you use a night vision device so you don't have to worry about that.



#23 Eddgie

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Posted Yesterday, 08:44 AM

Eddgie,

It looks like you were an early adopter (2015?) of the NV technology. Have you seen prices for the NV unit come down at all over the past couple years, or has the unit cost been stuck at about $4,200? Do these vendors ever put them on sale? 

Prices on the older thin film tubes have come down (particularly PVS-7 tubes, both new and used), but prices on L3 filmless tubes have not.

 

If you think that time will cause the prices to fall, I would say that unless some new technology arrives on the scene, it is unlikely.  This is not a lack of volume thing.   The US has produced hundreds of thousands of image intensifiers.  This is a "if you want to see in the dark, how much is it worth to you?" kind of thing.  They charge a price that the market will bear and people are willing to pay $4400 for a top end unit.

You can get Gen 2 or PVS-7 tubes and devices for half the price but top end stuff has been in the $4K+ range for as long as I have been doing it with zero change. 


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#24 StarAlert

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Posted Yesterday, 08:58 AM

Afocal projection is where you hold or mount a camera on to an eyepiece.  In this case, the Night Vision device with its objective would be mounted on to the end of a regular eyepiece rather than removing the objective and mounting the night vision device into the eyepiece holder and using it at prime focus just like any other eyepiece.  By using an eyepiece with a longer focal length than the objective on the night vision device, it is like using a focal reducer (or Barlow) in that you get the same magnification as the eyepiece.   If you used a 55mm Plossl, it would be like using a .5x reducer. 

 

If you remove the objective from the night vision device (if it is removable), you can put a 1.25" or 2" nose on the device and insert it directly into the focuser. Here you are working at prime focus, and the eyepiece on the NV device is about 27mm, so you would get the same magnification as if you use a regular 27mm eyepiece in that scope so in my 6" f/2.8, the 27mm eyepiece gives about 15x or so. Now there is no exit pupil limit when you use a night vision device so you don't have to worry about that.

I was just wondering what “afocal” means... literally. Is it short for something? 



#25 StarAlert

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Posted Yesterday, 09:03 AM

Prices on the older thin film tubes have come down (particularly PVS-7 tubes, both new and used), but prices on L3 filmless tubes have not.

 

If you think that time will cause the prices to fall, I would say that unless some new technology arrives on the scene, it is unlikely.  This is not a lack of volume thing.   The US has produced hundreds of thousands of image intensifiers.  This is a "if you want to see in the dark, how much is it worth to you?" kind of thing.  They charge a price that the market will bear and people are willing to pay $4400 for a top end unit.

You can get Gen 2 or PVS-7 tubes and devices for half the price but top end stuff has been in the $4K+ range for as long as I have been doing it with zero change. 

So you’re saying there won’t be an After-Christmas sale? smile.gif


Edited by StarAlert, Yesterday, 10:10 AM.



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