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Seeing moon craters inside out!

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#1 mike174

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Posted 17 February 2013 - 10:30 PM

Hi,

I was observing the moon and noticed that craters especially ones toward the south pole appeared inside-out like a wart on a smooth surface. I've never experienced this before. Has anyone heard of this before and can Lyme disease cause this?

I'm a bit concerned about this because it's affecting my observing and I enjoy looking at the moon more now.

Tnx,

MIke

#2 azure1961p

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Posted 17 February 2013 - 11:38 PM

It means your not schizophrenic. Apparently the image reversal that the moon can provide this illusion doesn't occur with people having that disorder - well so I've read. It's all in perception though it would seem. Show a person a photo of the moon whose never ever seen it before - whose to say which is correct and where the illusion would fall with whom?

Pete

#3 Carol L

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Posted 18 February 2013 - 12:20 AM

Yeah, it's odd to see an 'outie' instead of an 'innie'. :grin:
But there's nothing to worry about, Mike - it's just an occasional optical illusion.
Sometimes it happens when we're looking at lunar images, too.

#4 Mike B

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Posted 18 February 2013 - 02:40 AM

Yup, seen it too. Not recently, but i do recall the effect... it's actually kinda funny.

Then, once you get it visually back to "normal", i've tried making myself see it "reversed" again. Sometimes can do it, sometimes can't.

The trick i've found is to *blink* your eyes while viewing... sometimes this will pop things straight. That, or flit your vision across the cratered Moonscape, back-and-forth quickly... see if that resets your vision.
:grin:

#5 mike174

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Posted 18 February 2013 - 10:11 AM

Wondering if it's age related. Never did experience this until now. I think I first noticed it when watching a YouTube video of someone panning the moon.

MIke

#6 BigC

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Posted 18 February 2013 - 10:41 AM

I experience that often when looking at Moon photos but not with telescope viewing.

Sometimes turning the photo upside down reverses the illusion.

There are a few lava filled craters that really are like warts just to confuse things .

#7 Jim Nelson

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Posted 18 February 2013 - 12:43 PM

Check out this picture: LINK

Wefigure out whether something in concave or convex based partially on the assumption that any light source is "up", a pretty good assumption in our daily life. All bets are out the window for astronomical photographs, where light sources may be coming from darn near any direction.

This has nothing to do with aging. I swear that in relatively close-up photographs of the moon or of Mars from orbiters, it seems like I see things the wrong way at least twice as often as the right way, and this has always been true, since childhood.

#8 dan777

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Posted 18 February 2013 - 02:00 PM

to add to what Jim said...
This is an optical illusion that is a result of the direction of the sun and hence direction of shadows relative to what our brain expects the shadow's direction to be. We experience this with lunar observing because the sun is not overhead relative to the moon and it therefore can create shadows that seemingly point the wrong way.

Try this experiment, the next time you experience this, change the direction you look into the eyepiece at by 180°.

#9 Doc Willie

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Posted 19 February 2013 - 09:17 AM

I frequently see this in moon photos. One trick to get it to flip to normal is find a very small crater in the image. That will often "flip", then you gradually expand the field of view until the whole photo looks normal.

#10 Ed D

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Posted 20 February 2013 - 05:54 AM

A couple of nights ago I was observing the Lunar X and there was a crater off to the side of my view that was doing exactly that. Last evening I was looking at the same area again and it appeared totally different. The lighting can play tricks on what we see.

Ed D

#11 cpsTN

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Posted 20 February 2013 - 07:17 AM

I have seen it many times. Since I know it is not that way, if I concentrate, they will "go back in". Funny! I've seen it with street signs too. Sometimes, I see a sign and can't determine if it is facing me or angled away from me, especially if viewed from the side!

#12 Mark9473

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Posted 20 February 2013 - 07:20 AM

I used to see this often, but I'm under the impression I don't ever see it when binoviewing.

#13 Ruimteman

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Posted 20 February 2013 - 09:00 AM

I'm a fan of this illusion and can often see it in photographs of craters but have never been able to see it at the eyepiece. Funny brain.

#14 mike174

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Posted 20 February 2013 - 11:43 AM

It happened again the other night and while looking at a picture video. It's become a distraction now.

#15 kansas skies

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Posted 20 February 2013 - 12:45 PM

Up until now, I've never seen this illusion. After reading about it here, I pulled up a picture of the moon and wouldn't you know, the craters were reversed. I closed my eyes for a moment, then looked again and the picture was back to normal. After that, I couldn't get it to repeat. :scratchhead:

Bill

#16 rtomw77

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Posted 21 February 2013 - 02:11 AM

It happens to me occasionally at the scope, but I notice it more with photos.

Tom

#17 Unknownastron

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Posted 21 February 2013 - 02:18 AM

Yes, it is a completely normal and not rare optical illusion. Kind of like the classic illusion where we are asked if we see two faces in profile facing each other or a goblet. The brain chooses one shape as the figure and the other as background. It has happened to me and does not seem to increase with age. With me, the more fatigued I am the more likely I am to see it.
Clear skies and clean glass,
Mike

#18 jpcannavo

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Posted 23 February 2013 - 10:43 PM

This is in fact a very well know illusion used to illustrate aspects of visual processing. It is a consequence of our having evolved with natural light - the sun - typically coming from above. As such we tend to interpret a surface as having a raised vs. depressed region under the "processing assumption" that the lighting is from above. There are many, many references to this, simply google crater illusion. See image below to illustrate effect, and turn the screen upsidedown to reverse the effect.

Attached Files



#19 jpcannavo

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Posted 23 February 2013 - 10:49 PM

Check out this picture: LINK

Wefigure out whether something in concave or convex based partially on the assumption that any light source is "up", a pretty good assumption in our daily life. All bets are out the window for astronomical photographs, where light sources may be coming from darn near any direction.

This has nothing to do with aging. I swear that in relatively close-up photographs of the moon or of Mars from orbiters, it seems like I see things the wrong way at least twice as often as the right way, and this has always been true, since childhood.


Whoops!
Sorry about the redundant post. I didn't see this prior post by Jim.






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