With all the stunning Lunar images produced by our resident experts and shown here. I was wondering if two imagers many miles (the futher the better) apart imaged the same region of the Moon at the same time and at the same conditions, the two images when viewed together should give a stereo view. Has this been attempted? Or is the distance to the Moon too large to get enough difference.
People were using Lunar libration to achieve this. I have some Moon stereo (anaglyph) pics somewhere, when I find them I will post them here.
Of course, you have to wait for the same ilumination but different libration, to see the Moon from differeent view point. This may take quite a while.
I talked with Chris Go from the philippines about trying this some time, but we haven't managed to synchronise, due to weather and other challenges :-)
The time difference is only about 1 or 2 hours, so it's possible. It would give an "up-down" stereo pair due to images coming from different latitudes, rather than a "left-right" stereo pair from libration.
The Moon is ~60 Earth radiuses away from us.
If we have two observers at the opposite points of the globe (that means the other one should be somewhere in Europe or USA or south America), the distance of view points will be less than 1/30, which may just be enough, besuase for good stereo effect humans need at least 1/20 [5cm (eyes distance) over 1m of distance from eyes].
So, libration is still the way to go, I believe, to produce significant enough result without relying on other people which adds to the uncertainty of the outcome...
It may be intersting to try stereo on some big feature like Clavius... It is not hard to calculate the times when photos must be taken but with weather conditions etc it is a bit hard to predict the completion date of the project :-)
However, someone may try to do images of the terminator during the one whole lunar cycle, and then wait for good conditions to take another one of the pair.
The project is doable, it only requires a careful planing. But one should not expect too much from it: The terrain on the Moon is very smooth, so even the maximum libration may not be sufficient to show the 3D effect properly..
Maybe one day (night) when I am retired... :-)
Petra, for this kind of image to see in 3D you need glases with red and blue filters..
Polarized 3D glasses (used in cinema theatres) can not be used here...
However, some time ago there were stereo adapters around to be used with classic monitors (Tube type)
They worked like this (the same method is used in cinemas):
There was polarized filter in front of monitor, which can change the polarization every frame (must receive sync signal from computer or TV)... so with polarized 3D glasses each eye receives its own picture (because the left and right filter on glasses are polarized differently)
Of course, to display the stereo images, computer was supposed to alternate display of "left" and "right" image between each frame.
With LCD monitors widely available today, this scheme can not be used (because polarizers are used in those monitors to display individual pixels, so passive polarized glasses are in the way). I think some big manufacturers are working on develpment in this direction... Computer games will be the first to use them, I am sure (if they are not here already, but I am not into games.. so I do not know :-)
Bojan
