Anyone Else Have This Problem With The Moon?

[refractordude]

Hello there


Craters turning inside out. Is there a way to stop this? Perhaps a certain time of year or when the Moon is at a certain angle. Thanks all

[Dave882]

Hmm not quite sure what you mean…. Can you post an image?

[GUS.K]

Happens more when I'm really tired, I just look away for a couple of seconds and it usually reverts back to normal. If it keeps happening, it's time to pack up. I notice it happens more frequently closer to the terminator. See 'Crater illusion' on Wikipedia.

[Stefan Buda]

It is a well-known optical illusion. The brain interprets the sideways illumination as coming from the opposite direction than it really is. The easiest remedy is look at the image in a different orientation.

[leon]

I have never really liked the Moon, not for that reason, but it always interfered when the sky was clear and crisp and I wanted to do some imaging.:sadeyes:

Leon:thumbsup:

[refractordude]

terrible

[refractordude]

please explain

[refractordude]

[QUOTE=Stefan Buda;1607575]It is a well-known optical illusion. The brain interprets the sideways illumination as coming from the opposite direction than it really is. The easiest remedy is look at the image in a different orientation.

Thanks

[Stefan Buda]

Ok, here's the image rotated 180 degrees.

[EpickCrom]

I have only ever experienced this once so far, while observing the moon using a red wratten filter.

The effect was quite trippy!

[refractordude]

This is what I come up with and will try next time out observing the moon. Still learning how to respond to replies of what I post. So I am kinda all over the place.

[Stefan Buda]

So, have you looked at the rotated image? If yes, do you still see domes?

[Peter Ward]

Echoes of my undergrad years....

this is a well known illusion.

This one is very similar.

https://youtu.be/pH9dAbPOR6M?si=aj_1zLKdEt_Ee0_G

[refractordude]

Stefan Buda

Thanks for all your help. The image you posted did not work at 180 degrees. I snipped another image of craters from the WWW that worked. The original image shows the crater at the 6 o'clock position which creates the illusion. When I rotated it to the 9 o'clock position the illusion does not appear. It seems the way to deal with this illusion problem is to move the telescope diagonal. What say you?

[refractordude]

I Thank you all for your help.

[Stefan Buda]

Have you tried it this way?

[refractordude]

Stefan Buda

That second angle of your image did not work for me. The reangled image below worked. I will be out Thursday night with my scope aimed at the Moon. Will report back with findings. Thanks

[refractordude]

Stefan Buda


Nothing like traveling to the moon with my grab and go Mead LX70 R5. Sky conditions were good for 250 mag with a 90mm aperture mask. I experienced no crater illusion at several angles. Perhaps the Moon's angle prevented the illusion. Here is the position the Moon was in during my observation.

[Stefan Buda]

Interesting, but I'm curious why. Both have similar direction and angle of illumination, only the contrast is different.

Can you please have a look at the combined image and tell us if the illusion persists?

[refractordude]

Stefan Buda


Which two combined images and did you see a crater illusion with the two you are referring to? I am thinking crater illusion effects people differently.

[refractordude]

Going to let this topic rest until my next visit to the Moon. Here is the Wikipedia link referred. https://en.wikipedia.org/wiki/Crater_illusion