True Planets

16 Agosto 2009

The “True Colors” of the Moon: a “colourful” abstract by Marco Faccin & Paolo C. Fienga

Filed under: Articoli — info @ 16:28

Premises about the light and colors’ perception:

the so-called “Subjective Primary Factors”

The general premise (from both a factual and logical point of view) to our work is related to the idea that, from a human – and therefore subjective – perspective, the perception of the light and color is not (we should actually say “is never”) a constant.

It is not a constant on Earth, as well as it is not a constant on the Moon or anywhere else in the Solar System and therefore in the whole Universe (as we know it).

The perception of light and color is a variable: a very complicated and sometimes even wavering variable that, in our opinion, is a direct function of the combination of several factors (hereafter referred to as “Subjective Primary Factors”).

Here are the four (4) Subjective Primary Factors that we believe are the most important to consider when talking about the abovementioned human perception of light and color:

1) the Age of the observer;

2) the Visual Capacity (or Acuity) of the observer;

3) the existence or non-existence of a specific lesion and/or illness, either inborn or arisen out during the life of the observer, in his/her eyes or in his/her part of the brain that is dedicated to the capacity and acuity of the vision;

4) the so-called “Seeing Habits” of the observer, which can be related to and/or determined/influenced by either “physical places” or “lifestyles”. (consider the following examples:

a) people who are spending or spent their lives living on the mountains (let’s just say from 1000 meters on the Sea Level and above), usually develop – or developed – a substantially different visual capacity and acuity as to people, having of course the same age and physical characteristics, who are spending or spent their lives living on the plains and/or near the sea;

b) it is a fact – also medically proven – that people who are living in places that are generally well illuminated have a substantially different perception of light and colors as to people who are living in environments which are less illuminated (and the same can be said if we refer to people who mostly use artificial illumination in comparison with people who use, as a main source of illumination, the sunlight).

The “point” is, however, that people who are used to live and work in places characterized by a strong and diffuse artificial illumination – let’s think about offices, laboratories, schools and so forth – show, in time, a perception of light and color that is SUBSTANTIALLY DIFFERENT from the one of people who are used to live in places which are illuminated naturally (such as by Sunlight) and DRAMATICALLY DIFFERENT from that same perception of people who are used to live in places where the electrical or chemical illumination does not exist or is not (regularly) available.

Premises about the light and colors’ perception:

the so-called “Objective Primary Factors”

From an objective point of view, instead, there are a few more factors (to be considered as Objective Primary Factors anyway) to be considered when we talk about the human perception of light and colors:

1) the distance of the celestial body where we assume the Observer is standing on (which can be, for example, the Moon, or Mars, or some of the moons of Jupiter or Saturn etc.) from the so-called “Main Source of Illumination” (such as the Sun). This first Objective Primary Factor is obviously not an opinion or a speculation; it is just a fact: the closer we are to the Sun, the more light we get;

2) as a direct consequence of the above, the second Objective Primary Factor to consider can be found in the so-called “average illumination” of the environment where the Observer stands. (For example: the “average illumination” of Mars is much lower than the one of Mercury, while the “average illumination” of the Moon is certainly higher than the one of Ganymede). It must be highlighted that this second Objective Primary Factor can also be greatly influenced by other secondary factors, like the season that is current on the concerned Celestial Body and the latitude where the Observer stands at the time of the apprehension of the data;

3) the third Objective Primary Factor in the perception of light and colors is to be found in the presence or the absence of an atmosphere around the celestial body where the Observer stands. Furthermore, if in fact such an atmosphere does exist, there is an Objective Secondary Factor – the Medium Opacity (or “Tau”) of the atmosphere – that must be carefully evaluated. Of course, even the absence of an atmosphere (and therefore the lack of atmospheric-related optic phenomena like light reflection, diffusion and diffraction) is a key factor in the understanding of the perception of light an colors. The Moon can be the perfect example in this regard;

4) the last, but not least, Objective Primary Factor to be taken into account is the Geology and Meteorology (if existing) of the Celestial Body that we are considering. The perception of light and color will, in fact, be greatly influenced by the circumstance that such a world can be, in its very Nature, either dark, dusty and basically colorless (like, for example, the Saturnian Moon Iapetus), or white and shiny (like Enceladus), or covered by a perennial blanket of thick clouds and fogs (like Titan).

It is our firm opinion that the light and color perception of a human being standing on any of these worlds would be dramatically influenced by this fourth Primary Factor.

The pictures taken from the Surface of the Moon

Given that there are situations where the human vision is and/or can be influenced/altered by a series of both Subjective and Objective Primary (and Secondary) Factors in the proper/true perception of the light and color (meaning that “what the human being sees is not/may not be what the reality actually shows”), there are also several situations – with their relevant causes – where the light and color shown in a picture could have been influenced and/or altered, thus making the picture a “partially untrue” representation of the reality.

This factors that might alter a picture – as far as the genuine representation of the brightness and colors of the environment that has been photographed is concerned – can occur in a very high number of moments and instances but, just for simplicity, we have assumed that all the possible situations can be basically traced back to three (3) specific “moments”:

1) the moment when the picture was taken, for reasons related to the environment;

2) the moment when the picture was developed, for reasons related to the developing technique;

3) the moment when the picture was additionally processed (for example, during the “analogic acquisition” of the data and/or afterwards, during the “digital conversion” and “compression” of the frame – given that these processes can be the cause, as they often actually are, of alterations and artifacts).

However, in this Abstract we are particularly interested in the so-called “Environmental” causes of alterations and therefore these will be the ones that shall primarily be investigated.

First of all, we believe that it should be considered the fact that the illumination characterizing the Space Environment is in itself capable not only to cause the Space Photographers (such as the Astronauts) to commit a number of “human errors” (going from the time of exposure, to the position and choice of the most appropriate lens and filter for the specific kind of target that was chosen etc.), but it is also fit to cause/induce specific stress on the optics of the camera and, as far as the “Moon-Apollo Pictures” are concerned, on the film itself.

For example: the illumination of the Lunar Environment during the “Lunar Daytime” is so sharp and intense that it reasonably tends to saturate any and all visible surface details (visible at least to a human eye!), thus making such environment basically, even though just apparently both for the human eyes and in the final picture, monochromatic.

If this consideration is correct, the first consequence is that to a “human eye”, no matter how good and perfect it could be, the Lunar Environment shall always appear – we repeat: in FULL DAYLIGHT – as an environment largely and basically monochromatic: such as mostly white, with subtle nuances of light and dark gray and, maybe in the penumbral areas only, with subtle shades of light and dark brown.

Of course, that fact that a “human eye” (like the eyes of the Apollo Astronauts) would see the Lunar Environment as dominated by whites and greys (with some “dash” of browns), does not certainly mean that such an environment is actually an environment made by whites and greys only.

However – and this is the nice part! –, on every kind of picture we might have and regardless the place where it was taken (on the Moon, in our home or during a Space Walk), we can ALWAYS find (of course within the limits set for the camera that was used) any and all necessary information that, at the time of the click, were available in the imaged environment.

It is just matter of time and technique, but the “reality”, whatever it was, can be reconstructed, even when the picture was “bad”.

Furthermore, let’s not forget that during the conversion of the “Lunar Frames” from analogic to digital, a lot of the original information contained in the film lost their true “intensity”, while other information were added in the process.

Given all that and since we are now working in a “digital” environment, the first thing we have to do in order to reconstruct the “Original Information” contained in each picture, is to enter in the so-called LAB Space – which is nothing else but the digital extension of the “Human Vision”.

In this LAB context, we shall try to enhance the feeble “color information” contained in each frame that we wish to restore, by taking into account its medium-brightness.

Where we realize that the environmental brightness (also known as “diffuse luminosity”, such as the brightness of the place where the picture was taken) is fit to both cover and/or alter the color information contained in the picture, we intervene and remodel it.

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As we said before, it must be taken into account the fact that also the conversion of the image data – from analogic to digital – is a source of noise and artifacts.

The trickiest one (which is probably also the most recurrent), can be found in the tendency of the diffuse luminosity (such as, we repeat, the actual brightness of the environment where the picture was taken) to cover the colors contained in the original picture with a monochromatic component that is capable to wash away the subtle (and original) color shades and variations of the imaged target.

Some of the original color shades and variations that were washed out/altered by the presence of such a monochromatic component, however, can be restored (meaning that they can be brought back to their original value) if a specific and known color reference is available in the picture (for example: the colors of the American Flag, the colors of the Gnomon, some specific colored detail of the space-suits, the colors of the LM or the LR etc.).

For sake of clarity, it must be said that once a frame has been reconverted in its LAB version, the reconstruction work of its original contents – in terms of brightness and color – is still far from being complete.

Furthermore, if a specific attention to the details of each picture is paid, it will be relatively easy to notice that, in the frames taken on the Moon during the Apollo Days, the artificial components included in the Lunar pictures (such as the Space Helmets, the LM, the LR, the Gnomon as well as each and every other “man-made” tool) always appeared (at least slightly) colored (we could actually see hints of red, gold, silver and blue) even though the Lunar Surface that has been imaged with them appears always – and basically – grey and white.

APOLLO 11 AS 11-5927-29EvMHR.jpg

Why? Because the “true color” of the Moon is really made of greys and whites only?

We do not think so.

We believe that the Lunar Surface albedo (meaning the suitability of the Lunar Surface to absorb and/or reflect the Sunlight) was deeply different from the albedo of the man-made components that were pictured with it.

In particular, the albedo of the Lunar Equipment was DEEPLY different from the albedo of the Moon.

This means that while a small quantity of light (and therefore a short photographic exposure) was more than enough to make the color variations of the Lunar Equipment to emerge in the pictures, the Lunar Surface required A LOT MORE LIGHT AND LONGER PHOTOGRAPHIC EXPOSURE in order to truly reveal itself!

Such a difference – a HUGE difference, in fact – was a big obstacle to the correct development of the color pictures taken on the Moon and it almost totally impeded, as it should appears quite clear now, the execution of a precise and well balanced distribution of the brightness and color on all the frames during the development of the films.

Question: why did that happen? Answer: because, if – during the pictures’ development phase – the NASA Technicians in charge of the job had applied the exact and precise colorization of the “natural” Lunar Features, then the other (artificial) components of the Landscape (i.e.: the Astronauts, the LM, the LR etc.) would have resulted irreversibly oversaturated and unwatchable.

Solution: the right technique, at the time, would have been found in the separate development of each negative (a long process, in fact, because the phases and times of development should have been reset and changed for every frame) and not in the development of each film-magazine in its entirety (meaning “all the frames at the same time and with the use of the same parameters”).

As far as the “human vision” of the Lunar Surface is concerned – and here we are explicitly referring to the Moon Landscape that the Astronauts said they have seen – we believe that such a vision varies from eye to eye, from person to person and, therefore, from Astronaut to Astronaut.

This is just a general observation.

In particular, though, we must remember that the Astronauts were in a difficult situation of visibility because of the direct illumination of the Sun which, in the absence of a filtering atmosphere, must have been extremely white, bright, sharp and blinding.

In other words: the specific conditions of illumination of the Lunar Surface were ideal to alter the human perception of the colors and thus create an “illusion” of monochromatic landscape whose main colors was just shaded nuances of whites and greys.

It is possible, of course, that the Astronauts had different perceptions of the colors of the Lunar Surface: men with an extremely sharp and acute sight (like Alan Laverne Bean, for example) might have perceived some of the true Lunar colors, while other Astronauts whose eyesight was not that sharp, had the impression of the Moon as a generally monochromatic environment (exception made for those areas where the color was so obvious and strong that even a bad seeing condition was not suitable to alter its perception completely – see, for instance, the red-orange sands photographed in frame AS 17-137-20990).

A good experiment to prove the extreme difficulty to perceive the right colors of an environment when such an environment is flooded with light, can be done by asking a person whose eyesight is nothing less than excellent, to paint a simple color panorama on a white paper while the room where he works is being illuminated by extremely strong white lights.

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In conclusion: the Lunexit Coloring Technique of the NASA – Apollo Lunar Frames considers all the premises that we have examined (such as the so-called Subjective and Objective Primary Factors) plus a series of both technical and theoretical considerations related to the human perception of light and colors.

Our technique is extremely simple – conceptually – but, as you can easily understand, it requires extreme care and dedication. In other words, the frames must be colorized “one-by-one”, because it does not exist, in our opinion, a “Standard Coloring Procedure”.

As well as it does not exist, probably in the whole (known) Universe, a “Standard Way to See”…

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16 Agosto 2009

The “True Colors” of the Moon: a “colourful” abstract by Marco Faccin & Paolo C. Fienga

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