What really is EEVA

[vlaiv]

Just now, Moonshed said:

Curious as to what you mean by a night vision eyepiece that you class as just another eyepiece.

Military / hunting night vision gear like this:

it is used to amplify even small amounts of light. It is placed on regular eyepiece and it amplifies light that you would otherwise struggle to see...

[GavStar]

6 minutes ago, Moonshed said:

Curious as to what you mean by a night vision eyepiece that you class as just another eyepiece.

Here’s a link to the Televue section on night vision which I think is a good starting point for this approach

https://www.televue.com/mobile/TV5_page.asp?id=36

 

[bomberbaz]

There are these classed as a full HD eyepiece camera

bresser eyepiece

Although to me it is simply the same as any other off the shelf bits of kit; eg zwo 120mm/mc.

Although that said, it's a cracking price but i guess it's performance might not be great compared to other options. 

[vlaiv]

15 minutes ago, bomberbaz said:

There are these classed as a full HD eyepiece camera

bresser eyepiece

Although to me it is simply the same as any other off the shelf bits of kit; eg zwo 120mm/mc.

Although that said, it's a cracking price but i guess it's performance might not be great compared to other options. 

Yes, be careful about those as these are not very suitable for EEVA / live stacking.

This is the same as your regular full HD web camera with 1.25" attachment. Issue with such cameras is that they are capable of full HD video stream at USB2.0 speeds - which means that they use heavy compression and can't record raw data. Such image/video compression causes artifacts and both degrades image quality and does not let you exploit stacking properly (which needs raw data to work the best).

Here are examples - first done with modified web camera (which cost me half the price of that HD eyepiece - I just added piece of 1.25" (or rather 32mm OD sanded a bit down) PVC pipe as nose piece):

vs

This one is done with ASI120 equivalent (QHY5IILc)

Same telescope, same capture and processing style, less than month apart - different camera - both are best samples achieved. Due to compression, detail is missing in the first and when I tried more wavelet processing - I could clearly see Jpeg style artifacts popping out in the image.

Edited December 23, 2020 by vlaiv
added proper image

[PeterW]

EEVA is visual observers looking to see more using electronically means... could be rapid CCD stacking, could be intensifiers.... too many people get hung up about the details or too narrowly define things..... if you want to observe more than one object in a session then you’re in EEVA territory,  if it  takes weeks to observe one object and then you spend a week fiddling in photoshop then you’re probably an imager.....
If you want your “eye to an eyepiece” then the intensifier is probably the way to go, if you don’t mind waiting a few minutes and have tracking then using a camera and software are your tools. 
Lots of options to explore, lots of options people haven’t fully explored yet, but both are fairly mature and close to physics limits, so don’t expect huge improvements.

Each to their own..... vive la difference!

 

Peter

[saac]

8 hours ago, Moonshed said:

Hi vlaiv, thank you for supplying that information, it’s a big help.
It seems to me though that unless we stick with eyeball to eyepiece observing then as technology continues to improve we are, step by step, moving further and further away from reality. What we see on screen is enhanced, yes, we can see more detail, but what actually is it are we looking at? (This could get a bit deep). The difference in seeing an object sharp and crisp in the eyepiece is far removed from that very magnified and detailed image on the screen. 
Both have their place obviously, it depends on what you want to achieve, but if it is only to observe I feel that you can’t beat the experience of looking through the eyepiece. 
We are at the stage where some members do all their observing remotely, the scope is out in the observatory and they are indoors in the warm watching the images on a screen. Yes, it does have a certain appeal, but apart from selecting your own target I feel you may as well be watching a television program about astronomical images, there being no connection between you and your telescope other than electronically.

Maybe it’s just me, I don’t know.

Not sure about  being a step further removed from reality unless we view at the eyepiece. The brain after all enhances the image, photons being converted to electrical signals and then processed by the brain.  We may well argue that what we see with our "eyes" does not itself reflect reality.  That said , it is our reality so I guess such a debate is academic.   I can argue though that having spent time setting up, calibrating, configuring and tweaking my setup then I do feel a genuine connection with the image I view on a screen remotely  just as I may if I look through the eyepiece.  In the professional world I'd be surprised if many professional astronomers have ever used telescopes that even have eyepieces.  I guess it really depends on what you want to take away from the pastime and that is the great thing about the hoby it offers such a range of different levels of interaction.

Jim 

[Moonshed]

1 hour ago, GavStar said:

Here’s a link to the Televue section on night vision which I think is a good starting point for this approach

https://www.televue.com/mobile/TV5_page.asp?id=36

 

Okay, thanks for the link. “The night vision eyepiece” that you “class as just another eyepiece” is in reality an entire night vision system similar to that used by the military and requiring a power source and image intensifying tube, it’s a lot of gear, not just an eyepiece. This is what I was expecting and was confused by your description of it. I get it now thanks.

[GavStar]

6 minutes ago, Moonshed said:

Okay, thanks for the link. “The night vision eyepiece” that you “class as just another eyepiece” is in reality an entire night vision system similar to that used by the military and requiring a power source and image intensifying tube, it’s a lot of gear, not just an eyepiece. This is what I was expecting and was confused by your description of it. I get it now thanks.

Is it a lot of gear? I can literally just put it into my diagonal and off I go like any other eyepiece. The actual in use experience is identical.

Edited December 23, 2020 by GavStar

[Moonshed]

10 minutes ago, saac said:

Not sure about  being a step further removed from reality unless we view at the eyepiece. The brain after all enhances the image, photons being converted to electrical signals and then processed by the brain.  We may well argue that what we see with our "eyes" does not itself reflect reality.  That said , it is our reality so I guess such a debate is academic.   I can argue though that having spent time setting up, calibrating, configuring and tweaking my setup then I do feel a genuine connection with the image I view on a screen remotely  just as I may if I look through the eyepiece.  In the professional world I'd be surprised if many professional astronomers have ever used telescopes that even have eyepieces.  I guess it really depends on what you want to take away from the pastime and that is the great thing about the hoby it offers such a range of different levels of interaction.

Jim 

My point about being a step further removed from reality is actually a very basic observation. When we look through the eyepiece we are seeing reality, I think that is clear enough and unarguable. When we look at a screen we are not seeing reality, what we are seeing is an electronic representation of reality, I think that is also obvious and unarguable.

As I have already said a number of times each has its uses.

[Moonshed]

26 minutes ago, GavStar said:

Is it a lot of gear? I can literally just put it into my diagonal and off I go like any other eyepiece. The actual in use experience is identical.

I understand it attaches to the telescope just like an eyepiece, but my point is that it isn’t just an eyepiece, and I have already explained why I say that. However, if clarification is needed, an eyepiece is a lens or number of lenses  that are used to magnify the telescope image.  (I do not claim this to be the definitive definition of an eyepiece). Eyepieces do not contain power packs and image intensifying tubes.

I think that in your original comment you were trying to make the point that you pick it up and plug it into your scope in the same way as you do with any other eyepiece, not that it was an eyepiece? Anyway, I think we have sorted that one out and can move on to other things.

Edited December 23, 2020 by Moonshed

[saac]

1 hour ago, Moonshed said:

My point about being a step further removed from reality is actually a very basic observation. When we look through the eyepiece we are seeing reality, I think that is clear enough and unarguable. When we look at a screen we are not seeing reality, what we are seeing is an electronic representation of reality, I think that is also obvious and unarguable.

As I have already said a number of times each has its uses.

When we look through the eyepiece we see a representation processed by the brain. I accept that this is the common definition of reality.  I agree each, and every form of observation has its uses.

Jim 

Edited December 24, 2020 by saac

[saac]

1 hour ago, GavStar said:

Is it a lot of gear? I can literally just put it into my diagonal and off I go like any other eyepiece. The actual in use experience is identical.

GavStar out of interest is there any prospect of the cost of these units falling?  There was an NV unit advertised recently on Surplus Shed - not sure if was being made available outside of the USA though; the price was quite appealing though.  That said, not sure about the compatibility of it for astro use , it was part of a vehicle periscope setup. 

Jim 

[vlaiv]

1 minute ago, saac said:

GavStar out of interest is there any prospect of the cost of these units falling?  There was an NV unit advertised recently on Surplus Shed - not sure if was being made available outside of the USA though; the price was quite appealing though.  That said, not sure about the compatibility of it for astro use , it was part of a vehicle periscope setup. 

Jim 

There are like multiple generations of these devices and I believe some of older generations are safe to trade (but don't quote me on that one).

They should also be quite a bit cheaper than later (gen3, gen4) models.

Here is one example that I found that is less than £1700 (or there about):

https://tavcso.hu/en/productgroup/dipol-126pro

it is gen 2+ but it now seems discontinued?

[GavStar]

8 hours ago, saac said:

GavStar out of interest is there any prospect of the cost of these units falling?  There was an NV unit advertised recently on Surplus Shed - not sure if was being made available outside of the USA though; the price was quite appealing though.  That said, not sure about the compatibility of it for astro use , it was part of a vehicle periscope setup. 

Jim 

Jim

Unfortunately I don’t think gen 3 night vision monoculars will drop in price anytime soon, particularly in Europe where they are materially more expensive than the USA. (Europeans cannot purchase USA tech due to ITAR regs). 

I bought my first nv monocular over 3 years ago and prices have remained high since. It’s important to note that for astronomy due to the narrow ha filters used to view nebulae, you do need to get good quality gen 3 technology. Lesser gen 1 or gen 2 (with the exception of photonis intens tubes which also cost £6k plus) just won’t give good results.

I think the best ‘cheaper’ option is to purchase secondhand. There is a Facebook group where secondhand gen 3 monoculars can be purchased legally. I recently saw a good spec gen 3 actinblack pvs-14 for sale for £3k there which would be great for astronomy.

From a personal perspective and as a visual only astronomer, night vision has transformed the hobby for me - it’s a real shame that it’s so expensive. From my London back garden I was previously restricted to lunar, planetary and open clusters observing. Now I can see hundreds of other Dsos including many nebulae and galaxies.

I don’t care whether it’s the original photons hitting my eyeball or not. The key thing for me is that it feels just like a ‘normal’ eyepiece when I’m visually observing AND that I can see so much stuff clearly. I’ve read about many starting in the hobby being disappointed with the ‘faint fuzzies’ etc and not really seeing much   compared to astro photos. Night vision is fantastic as a visual observer aid.

A few years ago there was a flurry of night vision posts on SGL but this stopped when the EEVA sections were introduced. I think many of us just didn’t think Night vision fitted into EEVA since it uses completely different techniques to EAA and feels much more like normal observing. Maybe in order to get more nv discussion, one of the 3 EEVA sections could be renamed to Night Vision Astronomy?

Edited December 24, 2020 by GavStar

[PeterW]

What @GavStar means is that that it behaves like a normal eyepiece and with modern systems the view is pretty much as “natural” as you could get, meaning a high resolution grey monochrome with minimal sparkle/scintillation… only the bright stars are not coloured and the apparent field of view is a bit narrow compared to modern tastes.

 

Cost…. Depends on US politicians, one senator in the past blocked a loosening of ITAR. The US have much lower costs for second hand and new systems, secondhand systems are available outside the US with costs around half of the new. In the past few years a non-US source of suitable systems has come online, but the costs are rather high. Avoid everything but the “Gen3” level stuff as the cheap Gen1 stuff you’ll come across won’t work any better than a bag of carrots!

 

If people could view the sky with NV they might be  more proactive in wanting to fight light pollution. 

 

It’s not for everyone, just as huge dobsonians, monster binoculars, 6”Apos and some mounted imaging rigs aren’t, but amateurs are happy to share the views. I am never sure why one has to defend NV when it so obviously delivers such a huge visual benefit.

 

Peter 

[stash_old]

16 hours ago, Moonshed said:

Yes we are, but I don’t understand what your point is. For instance I could just as equally say it doesn’t matter if you are looking at the sat nav screen when driving or through the windscreen, we are using a common input method - our eyes.  The sat nav screen is only a digital representation of the road ahead, but is not the road ahead, that’s only seen through the windscreen 

 

Again, I fail to understand what you are saying here, of course it matters how the image is projected onto the eye. I would say there is a massive difference in seeing the Grand Canyon if I am actually standing there and the image that is projected into my eye is light reflected from the Grand Canyon itself, as opposed to having those images projected onto my eye from a tv screen in Norfolk.

It’s the same difference between looking at a screen or looking through an eyepiece. The screen is an electrical digital representation of the photons falling onto a camera’s sensor chip whereas looking through the eyepiece is seeing the actual, real photons coming from the object, not an electronic representation of it.

All that aside, as I have already said there are numerous ways we can observe the universe and technology is discovering different ways all the time, it is up to the observer which method they prefer to use, they all have their uses. My only point is that looking through the eyepiece is seeing the actual, real object, whereas looking at a screen indoors is far removed from that.

The brain is only making a model of what its "see's" - funny but thats a electronic representation via electrochemcal thru nerves . 

As for "seeing the Grand Canyon if I am actually standing" - but you are not standing next too , or any where close, to 99.99% of space objects you look at .

Its plain we are never going to agree so I will leave it at that.

EEVA users are quite happy with what we see and how we see it!

Each to is own.

[stash_old]

12 hours ago, saac said:

The brain after all enhances the image, photons being converted to electrical signals and then processed by the brain.  We may well argue that what we see with our "eyes" does not itself reflect reality.

Sorry I wrote my reply to Moonshed  including the reference to the eye's an brain before seeing you had already stated the same.

[vlaiv]

11 minutes ago, PeterW said:

It’s not for everyone, just as huge dobsonians, monster binoculars, 6”Apos and some mounted imaging rigs aren’t, but amateurs are happy to share the views. I am never sure why one has to defend NV when it so obviously delivers such a huge visual benefit.

For some strange reason people get defensive when talking about EEVA. In two different ways.

Some people feel like traditional observing is under attack from EEVA. I actually get this - too much in today's world is digitized and we have become heavily dependent on computers in one form or another.

I've also seen that people get defensive on the notion that night vision is EEVA. It really is - when using night vision device - you are actually looking at the screen. It is nicely attached in the place you expect eyepiece to be - but you are still looking at the screen. It has resolution - like 40 lp/mm and similar - which translates to DPI/PPI of computer screens by simply multiplying it with 25.4 (but is much higher res than regular computer screen at 96dpi).

In fact, I've written about this before in EEVA section. You could get exceptionally cheap night vision device for your telescope if you had higher density display on your mobile phone.

All you need to do is to connect everything up in this configuration:

And have some software to do the stacking / processing.

Problem is that you are going to get very low resolution device this way as most phones have displays that are at most 500-560ppi. With 40 lp/mm, night vision devices have 1000+ ppi - so double the resolution. This can be somewhat fixed with using very long focal length eyepiece like 2" 55mm plossl.

Alternative is to use some lens system that will project phone display onto focal plane of eyepiece. HD phone with 1920 x 1080 could easily have equivalent of 1000 ppi in that case as we could squeeze phone width (1080px) into 25mm field stop of 1.25" eyepiece - however such device would be at least 20cm long.

[Moonshed]

18 minutes ago, vlaiv said:

I've also seen that people get defensive on the notion that night vision is EEVA. It really is - when using night vision device - you are actually looking at the screen. It is nicely attached in the place you expect eyepiece to be - but you are still looking at the screen. It has resolution - like 40 lp/mm and similar - which translates to DPI/PPI of computer screens by simply multiplying it with 25.4 (but is much higher res than regular computer screen at 96dpi).

 

You have nicely, and technically, summed up the point I was trying make before I came under a sustained double attack for stating the obvious. My point being that if it has a power source and a screen it really cannot be described as being “the same as any other eyepiece.”  That’s all.

[GavStar]

29 minutes ago, vlaiv said:

For some strange reason people get defensive when talking about EEVA. In two different ways.

Some people feel like traditional observing is under attack from EEVA. I actually get this - too much in today's world is digitized and we have become heavily dependent on computers in one form or another.

I've also seen that people get defensive on the notion that night vision is EEVA. It really is - when using night vision device - you are actually looking at the screen. It is nicely attached in the place you expect eyepiece to be - but you are still looking at the screen. It has resolution - like 40 lp/mm and similar - which translates to DPI/PPI of computer screens by simply multiplying it with 25.4 (but is much higher res than regular computer screen at 96dpi).

In fact, I've written about this before in EEVA section. You could get exceptionally cheap night vision device for your telescope if you had higher density display on your mobile phone.

All you need to do is to connect everything up in this configuration:

And have some software to do the stacking / processing.

Problem is that you are going to get very low resolution device this way as most phones have displays that are at most 500-560ppi. With 40 lp/mm, night vision devices have 1000+ ppi - so double the resolution. This can be somewhat fixed with using very long focal length eyepiece like 2" 55mm plossl.

Alternative is to use some lens system that will project phone display onto focal plane of eyepiece. HD phone with 1920 x 1080 could easily have equivalent of 1000 ppi in that case as we could squeeze phone width (1080px) into 25mm field stop of 1.25" eyepiece - however such device would be at least 20cm long.

Night vision is very different to EAA in terms of practical usage. Cloudynights has recognised this and now has separate EAA and night vision sections. This change has been a positive development for both EAA and NV users.

[barkingsteve]

31 minutes ago, vlaiv said:

For some strange reason people get defensive when talking about EEVA

People have in their minds different definitions and this will never change and cause conflict. If you know what happened on another astronomy forum when trying to define EAA, you know what i am talking about 😅

[Moonshed]

1 hour ago, stash_old said:

The brain is only making a model of what its "see's" - funny but thats a electronic representation via electrochemcal thru nerves . 

As for "seeing the Grand Canyon if I am actually standing" - but you are not standing next too , or any where close, to 99.99% of space objects you look at .

Its plain we are never going to agree so I will leave it at that.

EEVA users are quite happy with what we see and how we see it!

Each to is own.

Saying that “the brain is only making a model of what it sees” really doesn’t have any bearing on how we describe either an eyepiece or a screen or what we see looking at them; this is because in both cases, all in fact, we use the same two eyes which the brain models in the same way. I really don’t see the need to bring in how the brain models what we see as it’s the same for everyone completely regardless of what we are looking at!

I said that standing next to the Grand Canyon is actually seeing it, as opposed to viewing it on  tv screen in Norfolk, to respond by saying that “you are not standing next to, or anywhere close, to 99.99% of space objects you look at.” does not even merit a response. 

I have already said  that we have sorted it out and that we can now move on to other things responding to GavStar as quoted below so I really was not expecting yet another attack on my comments.

12 hours ago, Moonshed said:

I understand it attaches to the telescope just like an eyepiece, but my point is that it isn’t just an eyepiece, and I have already explained why I say that. However, if clarification is needed, an eyepiece is a lens or number of lenses  that are used to magnify the telescope image.  (I do not claim this to be the definitive definition of an eyepiece). Eyepieces do not contain power packs and image intensifying tubes.

I think that in your original comment you were trying to make the point that you pick it up and plug it into your scope in the same way as you do with any other eyepiece, not that it was an eyepiece? Anyway, I think we have sorted that one out and can move on to other things.

I do hope that is the end of the matter because it has become rather wearisome. I’m done with it regardless. 

Edited December 24, 2020 by Moonshed

[saac]

25 minutes ago, vlaiv said:

For some strange reason people get defensive when talking about EEVA. In two different ways.

Some people feel like traditional observing is under attack from EEVA. I actually get this - too much in today's world is digitized and we have become heavily dependent on computers in one form or another.

I've also seen that people get defensive on the notion that night vision is EEVA. It really is - when using night vision device - you are actually looking at the screen. It is nicely attached in the place you expect eyepiece to be - but you are still looking at the screen. It has resolution - like 40 lp/mm and similar - which translates to DPI/PPI of computer screens by simply multiplying it with 25.4 (but is much higher res than regular computer screen at 96dpi).

In fact, I've written about this before in EEVA section. You could get exceptionally cheap night vision device for your telescope if you had higher density display on your mobile phone.

All you need to do is to connect everything up in this configuration:

And have some software to do the stacking / processing.

Problem is that you are going to get very low resolution device this way as most phones have displays that are at most 500-560ppi. With 40 lp/mm, night vision devices have 1000+ ppi - so double the resolution. This can be somewhat fixed with using very long focal length eyepiece like 2" 55mm plossl.

Alternative is to use some lens system that will project phone display onto focal plane of eyepiece. HD phone with 1920 x 1080 could easily have equivalent of 1000 ppi in that case as we could squeeze phone width (1080px) into 25mm field stop of 1.25" eyepiece - however such device would be at least 20cm long.

I've often wondered where the polarized passion comes from when things like this are being discussed and I do find it difficult to reconcile with my own approach to astronomy where I will use anything and everything to widen my enjoyment.  I'm an engineer by profession so I guess Im predisposed to use of technology and adapting it to novel applications - its just what we do.  I do agree with Peter and GavStar in that the use of NV in astronomy is as natural a progression as it was for Galileo to turn a terrestrial telescope to the sky.  To be honest, I'm not all that fussed what category of observation people chose to call it ; to me observation is observation.  If anybody is looking for the purest interaction then they would need to ditch even telescope itself so avoiding the enhancement that the very glass brings to the image (especially all those high transmission coatings). As for interacting with the "original" photons well I think we are now straying into the poetic;  the scientific account for what is happening may disappoint. I haven't yet put my eye to a NV eyepiece but I would love to, I was hooked on one of Peter's/GavStar's previous threads and a video of a 3rd gen white phosphor device - absolutely captivating.   If there is anything  behind the passion in these debates I think it is not so much concerned with the technology or hardware rather than the experience and that's understandable - we do this after all because we enjoy it.  Be a boring old world if took a Henry Ford approach to astronomy "one version only".   

Jim

 

 

[vlaiv]

Regardless of how we name things - I just had my first night vision session (EEVA style ) to prove above concept works.

Details:

- target is TV tower about 6.5 miles away

- scope used is 32mm F/4 finder/guider by Astro Essentials

- primary focus eyepiece - 17mm plossl giving magnification of about x7.5

- NV device - Xiaomi A1 with full HD display and 400ppi screen resolution

- observing eyepiece 32mm plossl - field stop about 27mm - FOV resolution about 425 points on diagonal (this needs to be as high as possible for smooth display - it is number of visible "pixels" on diagonal of AFOV).

Mind you - this is hand held setup so everything was rather shaky and not properly spaced / aligned

Anyway - here is image at observing eyepiece snapped with Canon 750D (don't ask how I managed to hold phone, eyepiece and camera together to do this )

You can actually see some screen around the eyepiece since camera was moving and I snapped the image as it was further away from the exit pupil - not whole eyepiece FOV is visible here and image is zoomed in comparison to what you see at eyepiece (and yes, I did look and you can see the pixels regardless the fact that it is not as zoomed in).

I also managed to snap image (well touch screen did as I accidentally pressed it while holding the eyepiece against the screen):

So above is what phone camera sees at the prime focus eyepiece (17mm one).

If you want to try this - remember to unscrew 1.25" barrel from the observing eyepiece as field stop needs to almost touch the phone screen (phone screen needs to be at focal plane of observing eyepiece).

[saac]

The divide seems to come from whether you define the activity by it's hardware or the experience . I'd be happy just to use it. 

Jim