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Struggling to get Averted Vision to Work

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#1 WheezyGod

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Posted 29 November 2021 - 12:16 PM

I’ve asked about averted vision before when viewing DSOs. A few of you explained how to go about figuring it out so I took a couple of the suggestions and tried with M42.

I tried both techniques, one was keeping M42 centered and moving my head around a bit at the eyepiece but unless I was only slightly off looking at M42 directly I was looking at the inside of the barrel of the EP (used Svbony 68deg 6mm EP). Is this what you guys refer to as blackouts?

The other was moving M42 around in the eyepiece and keeping my eye centered and using my peripheral vision which I was expecting to get results from, but after 15min of moving it around the EP I didn’t notice any difference no matter where I looked. I also tried doing this with my direct vision with no luck either.

Is seeing something in my peripheral vision the right way to go about this? If so then what’s the advantage to seeing something more brightly if it’s blurry? I’m guessing I’m missing something here.

Is there some way at home I could practice this and then apply it to my night sky viewing?

Tapping my scope does seem to flush out more details, although of course it makes it a bit more difficult to focus on them.
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#2 sevenofnine

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Posted 29 November 2021 - 12:28 PM

Averted vision is a technique to see objects or details that are invisible when looking directly at them. Very simply, visualize a 12 hour clock face around the object. Now, instead of looking at the center of the clock (direct vision) look at the 2'oclock position. Stare intently at that position and sometimes more detail will pop out that you didn't see before. Some people find other positions on the clock work better for them. You just have to see what works for you.

 

At first, I didn't believe in this. I thought it was "averted imagination" blackeye.gif But when I tried it on the Blinking Nebula, I was convinced it's real waytogo.gif



#3 WheezyGod

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Posted 29 November 2021 - 12:45 PM

Averted vision is a technique to see objects or details that are invisible when looking directly at them. Very simply, visualize a 12 hour clock face around the object. Now, instead of looking at the center of the clock (direct vision) look at the 2'oclock position. Stare intently at that position and sometimes more detail will pop out that you didn't see before. Some people find other positions on the clock work better for them. You just have to see what works for you.

At first, I didn't believe in this. I thought it was "averted imagination" blackeye.gif But when I tried it on the Blinking Nebula, I was convinced it's real waytogo.gif


Yea I’m convinced it’s real, maybe it only works on the faintest DSOs and not ones that are bright. I remember finding M57 or M27 initially in a low power eyepiece and seeing it disappear sometimes which was probably due to looking at it precisely in the center of my vision.

The “sweet spot” has been mentioned many times, but the fact that I could see it versus not sometimes must mean that looking at something faint even a little off center (no matter which direction) will provide a bright view.

Maybe M42 was too bright of a DSO for averted vision to work well? It’s not as if I’m viewing at dark skies, but maybe it’s more subtle if the object is brighter? Or more maybe my expectations for what averted vision can do are too high?

Your response is making me think I should try M27/57 again to test averted vision.

I can only hope my averted vision works best slightly off center rather than way off in my peripheral vision where everything is more out of focus.

#4 astrokeith

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Posted 29 November 2021 - 12:49 PM

......Edited to get it right! (its put the object towards your nose, not your centre of vision)

 

As sevenofnine says, its  for seeing stuff fainter than direct vision can see. M42 is too bright.

 

Position the object in the centre of the field. Using your right eye, with your 68 deg ES EP, centre your stare at half way between the centre of the field and the righthand edge. Don't move your head, just your eye. You shouldnt be looking at the barrel of the EP, just to the left of the field. Whilst staring at this point, you will, with practice, get better acuity on what ever object is at the centre. Try it on a small galaxy at the limit of what you normally can see.

 

If you use your left eye, then stare to the left of the object.

 

Once you have got some practice, you could try staring at other directions in the EP, but NOT to the left with your right eye, or to the right with your left eye. This is because the retina has a blind spot in this direction.


Edited by astrokeith, 30 November 2021 - 03:58 AM.


#5 astrokeith

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Posted 29 November 2021 - 12:51 PM

Your response is making me think I should try M27/57 again to test averted vision.

I can only hope my averted vision works best slightly off center rather than way off in my peripheral vision where everything is more out of focus.

Again, these are a bit bright really (unless you have a small scope?)

 

the sweet spot is about 12-15 degrees from the centre of your vision. So using a 68 deg AFOV EP, that is about 1/3 to1/2 way between the centre and the edge. Don't go too far!


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#6 Napp

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Posted 29 November 2021 - 12:57 PM

Averted vision takes practice.  You are simply trying to use a more sensitive part of the eye to see fainter objects or details.  Simple - not if you haven't done it before.  Try looking at a small, faint object - not a big, bright object like M42.  Position the object off to the side of the center of view.  Direct your vision at the center of the field.  Now try to see the faint object without changing your direction of view from the center of the field of view.  Try for a little while and if you don't have success position the object in a different part of the field of view and repeat. 

 

Yes, you can practice averted vision at home. Look at some object on a shelf and keep your eyes pointed directly at it.  Without moving your eyes try to see what is on the shelf off to the side using your peripheral vision.  This doesn't help you find the most sensititve part of your eye but does give practice to seeing to the side without moving your eyeball.

 

Tapping your scope is using a capability that may go back to when humans had to be on the lookout for predators.  Our vision is sensitive to movement.  So tapping the scope uses this to detect faint objects we might not detect otherwise.  It's not a way to see detail - just a way to detect something is there.  Once you know it's there you use averted vision to try to see it.



#7 Frugal Astronomer

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Posted 29 November 2021 - 01:06 PM

You shouldn't have to look far from the object to use "averted vision".  As mentioned above, the "blinking nebula" is a great illustration of it working.  In my experience, the increase in visibility is subtle, but real.  It works best for me with fainter objects and smaller objects that you can center in the eyepiece.  But you shouldn't have to move your head around to do it.  M42 is not the type of object I would use it for.  I would use it with a small and faint galaxy, planetary nebula or galaxy.  



#8 WheezyGod

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Posted 29 November 2021 - 02:01 PM

Thanks guys I was under the impression that using averted vision would allow anyone to see more detail for all DSOs as a way to maximize the detail you can see. Now I know it’s more about being able to detect objects, or see some detail from objects that you can barely see with direct vision.

Unless there’s some here that get an abnormally high boost in what they can see. I’ve seen phrases such as “I was able to see a ton of detail with averted vision.”

Edited by WheezyGod, 29 November 2021 - 02:02 PM.


#9 WheezyGod

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Posted 29 November 2021 - 02:03 PM

Again, these are a bit bright really (unless you have a small scope?)

the sweet spot is about 12-15 degrees from the centre of your vision. So using a 68 deg AFOV EP, that is about 1/3 to1/2 way between the centre and the edge. Don't go too far!


Thanks this is quite useful. I’ll remember this if I can get out tonight.

#10 kathyastro

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Posted 29 November 2021 - 02:44 PM

Thanks guys I was under the impression that using averted vision would allow anyone to see more detail for all DSOs as a way to maximize the detail you can see. Now I know it’s more about being able to detect objects, or see some detail from objects that you can barely see with direct vision.

Unless there’s some here that get an abnormally high boost in what they can see. I’ve seen phrases such as “I was able to see a ton of detail with averted vision.”

You will not see more detail with averted vision.  You are moving the target off the high-resolution, low sensitivity part of the retina, called the macula, onto the more sensitive but low-resolution periphery.  You will see less detail, but you will see dimmer objects. 

 

I suppose you could say that low resolution of a dim object you can see is "more detail" than high resolution of an object you can't see.  But if you can see the object in central vision, that is the best view you will get of it.  Averted vision is only for detecting objects that are otherwise undetectable.

 

Be sure to look away from your nose when using averted vision: look to the right with the right eye and to the left with the left eye.  Looking towards the nose will put the object in your blind spot, where you won't see it at all.


Edited by kathyastro, 29 November 2021 - 02:45 PM.

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#11 belliott4488

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Posted 29 November 2021 - 03:05 PM

As sevenofnine says, its  for seeing stuff fainter than direct vision can see. M42 is too bright.

 

Position the object in the centre of the field. Using your right eye, with your 68 deg ES EP, centre your stare at half way between the centre of the field and the lefthand edge. Don't move your head, just your eye. You shouldnt be looking at the barrel of the EP, just to the left of the field. Whilst staring at this point, you will, with practice, get better acuity on what ever object is at the centre. Try it on a small galaxy at the limit of what you normally can see.

 

If you use your left eye, then stare to the right of the object.

 

Once you have got some practice, you could try staring at other directions in the EP, but NOT to the right with your right eye, or to the left with your left eye. This is because the retina has a blind spot in this direction.

Are you sure you don't have the directions reversed? I just did the old test of putting a dot on a piece of paper and aiming each eye to the left or right until the dot disappeared. With my right eye the dot disappeared when I looked around 5 - 6 cm to the left of the dot, and the opposite for my left eye.

 

Based on that, I would say that you should aim your right eye between the center and the right edge of the FOV, or your left eye between the center and the left edge.


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#12 BoldAxis1967

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Posted 29 November 2021 - 03:32 PM

"Be sure to look away from your nose when using averted vision: look to the right with the right eye and to the left with the left eye.  Looking towards the nose will put the object in your blind spot, where you won't see it at all."  Kathyastro

 

Kathy you mention some good points.   However, I think with the left eye the blind spot (where the optic nerve bundle or optic disc, begins) is in the left part of the visual field, thus you want to move your eye ever so slightly to the left (away your nose as you indicated above.  the image below was taken from (http://www.cns.nyu.edu). And the right eye follows the same relationship between the right eye and the location of the optic nerve.

 

Slide3.jpg

 

Also check-out WebMD (https://www.webmd.co.../eye-blind-spot)

 

L.


Edited by BoldAxis1967, 30 November 2021 - 12:45 AM.

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#13 Tony Flanders

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Posted 29 November 2021 - 05:07 PM

Maybe M42 was too bright of a DSO for averted vision to work well? It’s not as if I’m viewing at dark skies, but maybe it’s more subtle if the object is brighter? Or more maybe my expectations for what averted vision can do are too high?


M42 is a very unusual object because it has a vast range of surface brightness. The innermost section, right around the Trapezium, is intensely bright. I've seen photos of it taken during broad daylight, and it's readily visible through a telescope even in the worst conditions imaginable.

Next come the "batwings" that extend perhaps 1/4 degree each side of the central region. The batwings may well require averted vision from an urban site, though they should be obvious to direct vision from a good suburban site.

And then there's all the rest -- probably 90% of the total area -- which fills in the batwings to form a giant circle about one degree wide. Parts of it are visible only with averted vision even from pristine sites.

Likewise, M27 has a bright dumbbell generally obvious with direct vision from all but the worst sites. Averted vision might show the fainter glow that fills in the dumbbell's cavities and turns it into a giant ellipse.
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#14 kathyastro

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Posted 29 November 2021 - 05:30 PM

"Be sure to look away from your nose when using averted vision: look to the right with the right eye and to the left with the left eye.  Looking towards the nose will put the object in your blind spot, where you won't see it at all."  Kathyastro

 

Kathy you mention some good points.   However, I think with the left eye the blind spot (where the optic nerve bundle or optic disc, begins) is in the left part of the visual field, thus you want to move your eye ever so slightly to the right (toward your nose).  the image below was taken from (http://www.cns.nyu.edu). And the right eye follows the same relationship between the right eye and the location of the optic nerve.

 

Slide3.jpg

 

Also check-out WebMD (https://www.webmd.co.../eye-blind-spot)

 

L.

You are correct that the blind spot is in the left part of the visual field in the left eye and in the right part of the visual field in the right eye.

 

So, with the left eye, if you looked right, towards your nose, you would be placing the target, which has not moved, in the left part of the visual field, right on the blind spot.  I just tried it, with the "Post" button right under the box I am typing in.  Using my left eye, when I look about 15 degrees to the right, the button disappears.

 

So, to avoid the blind spot when using averted vision, you should look away from the nose, not towards it.
 


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#15 BoldAxis1967

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Posted 30 November 2021 - 12:22 AM

Kathy, yes I agree with you. I expressed myself poorly and incorrectly. Thanks for clarifying and I corrected my mistake in my earlier post.
 

L.


Edited by BoldAxis1967, 30 November 2021 - 12:46 AM.


#16 gnowellsct

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Posted 30 November 2021 - 01:05 AM

Any good things here. You can think of averted vision as having evolved to help you see that snake which is about to strike your ankles while you are busy looking at something else. You can also think of it as the non-color receiving part of your eye which allows you to see vague shapes and forms in a dark room with minimal illumination. But you won't see color and you won't be able to make out the patterns on blankets and curtains and that sort of thing.

With averted vision you're looking to catch the elusive detail, the hidden snake as it were, with the parts of your eye that are most sensitive in dim light but least sensitive to color. You can get glimpses but if you look directly at it, it's not there.

But sometimes you can catch specific features that are otherwise elusive. Things that stick out in particular, or companion stars that you can't see looking straight on.

I am personally of The view that the more light polluted your sky is and/or the more invisible clouds obscure the star background, the less useful averted vision is. It is a means to detect a subtle contrast that essentially defines something which is from all the space which is not. When there is too much light pollution or even when you are in a dark area but there's too much moisture between you and the Stars, I've heard it vision is not going to save the day.

Incidentally m57 is a very bright object you can see it in binoculars with direct vision and it's great in a 3-in telescope. But it greatly helps to know what you're looking for. And no matter how much you know what you're looking for pretty much not worth the effort under a light polluted sky. Look at the Moon and double stars and other more rewarding objects.

#17 Bill Weir

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Posted 30 November 2021 - 02:07 AM

And don’t just stare in that off centre direction. As we are a different pieces of meat we all have different sweet spots. You will need to find yours. Also as you slightly move your vision in and out of that sweet spot those fainter objects or details will reveal themselves from behind the curtain. 

 

Practice, practice, practice and eventually it will all make sense. 

 

Bill


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#18 astrokeith

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Posted 30 November 2021 - 03:59 AM

Are you sure you don't have the directions reversed? I just did the old test of putting a dot on a piece of paper and aiming each eye to the left or right until the dot disappeared. With my right eye the dot disappeared when I looked around 5 - 6 cm to the left of the dot, and the opposite for my left eye.

 

Based on that, I would say that you should aim your right eye between the center and the right edge of the FOV, or your left eye between the center and the left edge.

My bad, I know how to do it but when writing it down I confused myself. Put the object towards your nose, not your stare.


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#19 Asbytec

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Posted 30 November 2021 - 04:10 AM

Yea, I never think much about what direction I am looking. Maybe I could use a more methodical approach? I believe we all find our way.  I pretty much sample in more or less random directions around and near the object. Sometimes a bit further away than other times, and occasionally directly at the object just to see what's up. I occasionally find a good view. Sometimes not so good, other times pretty good. After a pass or two through the eyepiece, I take a moment to recharge in the dark under the hood then hit it again. Usually the first averted look after recharging is pretty good. Then I do it again. And yet again until I am sure I have noticed everything. That can take a while. 


Edited by Asbytec, 30 November 2021 - 05:00 AM.

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#20 BoldAxis1967

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Posted 30 November 2021 - 01:15 PM

My bad, I know how to do it but when writing it down I confused myself. Put the object towards your nose, not your stare.

I made that mistake as well, it is easy to do.  KathyAstro caught my mistake.

 

L.


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#21 Jon Isaacs

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Posted 30 November 2021 - 01:43 PM

My two cents:

 

I recommend the double cluster as a target for practicing averted vision.  There's quite a range of stars, some are quite bright, some are less bright, some are dimmer than those... etc.. etc.

 

What happens when you get it right, the cluster just lights up as your averted vision turns on those fainter stars.

 

Another virtue of the double cluster is that it's large so some of it lights up, some doesn't. There's room for error and you can also investigate just where you averted vision is most sensitive.

 

Jon


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#22 WheezyGod

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Posted 30 November 2021 - 07:12 PM

My two cents:

I recommend the double cluster as a target for practicing averted vision. There's quite a range of stars, some are quite bright, some are less bright, some are dimmer than those... etc.. etc.

What happens when you get it right, the cluster just lights up as your averted vision turns on those fainter stars.

Another virtue of the double cluster is that it's large so some of it lights up, some doesn't. There's room for error and you can also investigate just where you averted vision is most sensitive.

Jon


Your explanation is similar to what I’ve read previously which gives the impression that averted vision enhances views of DSOs rather than simply allowing you to detect DSOs not visible with direct vision. Different from all the other posts.

Unless you’re suggesting the one exception are star clusters where using averted vision can enhance the view just because faint stars and invisible ones become brighter. If so, have you found this to work on globular clusters?

Or your averted vision works better than most others here.
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#23 JHub

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Posted 01 December 2021 - 12:37 AM

Yes, it works on globular clusters.

 

John



#24 radiofm74

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Posted 01 December 2021 - 07:47 AM

Your explanation is similar to what I’ve read previously which gives the impression that averted vision enhances views of DSOs rather than simply allowing you to detect DSOs not visible with direct vision. Different from all the other posts.

Unless you’re suggesting the one exception are star clusters where using averted vision can enhance the view just because faint stars and invisible ones become brighter. If so, have you found this to work on globular clusters?

Or your averted vision works better than most others here.

Jon will reply in his own time but I think that you're labouring under the false notion that "detecting" and "seeing finer detail" are two unrelated things. They're not. Averted vision allows you to detect fainter objects than direct vision. These "fainter objects" may be the whole astronomical object you're trying to see (e.g. a small and faint galaxy such as M74), or fainter detail in an object that is already plainly visible in direct vision. Example: the Pleiades are so bright that they're visible naked eye most anywhere. But the nebulosity around some of the individual stars is very faint and I've never been able to spot it. I would not be surprised if even under a very good sky it required averted vision to be identifiable at all. 

 

Back to suggestions… Jon suggested the Double Cluster. I never tried that but I can see how it makes perfect sense. The objects that taught me averted vision are however globular clusters as you yourself suggested. You pick a bright one – my "teacher" was M3 –, identify it without problems, and look at it with direct vision… you'll see a bright core, a halo, and may or may not already resolve a few individual stars. When you use averted vision, at some point (and it's very sudden and very evident) you start seeing a myriad individual stars shimmering where you only saw uniform or grainy light. It's so sudden and evident you can't have any doubts as to whether averted vision is working or not, and it will teach you where your sweet spot(s) is/are as well as the measure of patience it takes for averted vision to work out.

 

M15 is still high in the sky and I cannot think of a better candidate. M2 is great too and perhaps a little more challenging for resolving individual stars.

 

Once you have this firmly in hand, you may try objects that are invisible with direct vision (it's always relative to your circumstances). This requires some preparation because you must know precisely where to look… you're literally focusing your attention on a patch of void expecting for an object to "emerge". M1 is a good candidate for this exercise, M77 from a city might also be good. But first use easy objects and start squeezing out more detail from them. 


Edited by radiofm74, 01 December 2021 - 07:47 AM.

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#25 Tony Flanders

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Posted 01 December 2021 - 08:03 AM

Your explanation is similar to what I’ve read previously which gives the impression that averted vision enhances views of DSOs rather than simply allowing you to detect DSOs not visible with direct vision.


That cannot be. If averted vision allows you to see DSOs not visible with direct vision, then it must necessarily enhance the views of most DSOs that you can see with direct vision.

The only exception to that would be a DSO where direct vision shows you absolutely everything that there is to see. An example of that would be a bright, coarse open star cluster like the Coma Star Cluster (Melotte 111) or IC 4665 in Ophiuchus.

But if parts of a DSO are too faint to see with direct vision -- which is almost always the case -- then averted vision will inevitably bring at least some of those faint areas into view.

 

Note, however, that averted vision does not usually add detail to the brightest part of a DSO -- though that's not completely unheard-of.
 

Unless you’re suggesting the one exception are star clusters where using averted vision can enhance the view just because faint stars and invisible ones become brighter. If so, have you found this to work on globular clusters?


The effect of averted vision on any partially-resolved star cluster is particularly magical. Ultrafaint stars spring into visibility in the vicinity of the spot where you're looking, and disappear again if you look straight at them.


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