FAR SIDE OF THE MOON

[raven]

Doubtful. They'd just say they were planted sometime between then and then.

Oh the "secret" launches, you may be correct.

I thought the same thing, but if conspiracy theorists thought through the consequences of their claims, they would not be grawlix-ing conspiracy theorists.

[ka9q]

Large advances in imagery in 50 years

Mainly in digital imagery. The Apollo Hasselblad photos still look amazing for having been taken nearly 50 years ago; they rival even good digital cameras today. But they required the exposed film be physically returned to earth and processed.

The big advance today is that we can get the same image quality (or even better) without having to physically return anything to earth.

[onebigmonkey]

While on the topic of the lunar far side, I though this comparison between the historic Luna 3 image and LRO fascinating. https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4109

AS I've been trawing through Apollo Panoramic camera images I have been astonished at the level of detail they contain - particularly in the very very very high resolution scans (see my thread on Hadley Rille from orbit) - quite often from higher altitudes than the LRO.

Likewise Lunar Orbiters's data, which seems only to have been let down by image processing at this end.

[raven]

Zond 5-8 are also quite amazing, being also photographs returned as film.
Modern reprocessing of Luna 3 images shows improvements, though the choice of time of lunar day did not help.

[Dalhousie]

Large advances in imagery in 50 years

Mainly in digital imagery. The Apollo Hasselblad photos still look amazing for having been taken nearly 50 years ago; they rival even good digital cameras today. But they required the exposed film be physically returned to earth and processed.

The big advance today is that we can get the same image quality (or even better) without having to physically return anything to earth.

Even 35 mm slide film was pretty good - remember that they were meant to be projected on large screens 5 m across with minimal loss of resolution. 

I seem to recall a large format positive film has a resolution in the giga-pixel range.

[Dalhousie]

Zond 5-8 are also quite amazing, being also photographs returned as film.
Modern reprocessing of Luna 3 images shows improvements, though the choice of time of lunar day did not help.

The justification I guess was that they wanted to capture as much of the unseen hemisphere as possible.  Most people see the image as poor reproductions, copies of paper copies.  The original was much better, though still poor by modern standards. And of course the image was revolutionary, showing that the far side was very different to the near side, fewer maria and all highlands.

[raven]

Zond 5-8 are also quite amazing, being also photographs returned as film.
Modern reprocessing of Luna 3 images shows improvements, though the choice of time of lunar day did not help.

The justification I guess was that they wanted to capture as much of the unseen hemisphere as possible.  Most people see the image as poor reproductions, copies of paper copies.  The original was much better, though still poor by modern standards. And of course the image was revolutionary, showing that the far side was very different to the near side, fewer maria and all highlands.

Heck, it could have been largely the same, and it still would have been revolutionary, as it was something no one had seen before. As far as we know and very likely so, nothing ever. Given the tech at the time, a startling and stunning achievement.

[Dalhousie]

I remember getting excited over it when I was five.  Would have been 1963 or thereabouts.

[smartcooky]

I seem to recall a large format positive film has a resolution in the giga-pixel range.

Film resolution is usually expressed in lpm (lines per millimetre) but that is not quite a direct equivalent of digitial image resultion. Its an expression of the best possible level of detail that film can show, wheras digital resolution just says how big the image is. A typical good quality professional film has a resolution of around 100 lpm, but each line needs two rows of pixels, one dark and one light so the equivalent digitial resolution of the film will be 200 pixels per millimetre. A 35mm film frame is 36 x 24 mm, so at 200 ppm

(36 x 200) x (24 x 200) = 7,200 pixels x 4,800 pixels = 34,560,000 pixels, or around 35 MP

Medium format film has several aspect ratios, 645, 66, 67, 68, 69 and (rarely) 610 but as near as I can figure, most of the Apollo surface photography was on 66 (60mm x 60mm format)

(60 x 200) x (60 x 200) = 12000 pixels x 12000 pixels = 144,000,000 or around 150 MP

Large format film usually comes in three formats 5 x 4" (125mm x 100mm) 7 x 5 (175mm x 125mm)  and 10 x 8" (250mm x 200mm)

5 x 4 = (125 x 200) x (100 x 200) = 25000 pixels x 20000 pixels = 500,000,000 or arounf 500 MP

Its not until you get up to the 10 x 8 format that "gigapixels" kick in

10 x 8 = (250 x 200) x (200 x 200) = 50000 pixels x 40000 pixels = 2,000,000,000 or around 2 GP

However I cannot see any advantage in using large format film on space missions. The advantages of better resultion will surely be outweighed by the disadvantages. The film base itself is much thicker than a 120 or 135 film (adding weight) and the photographic equipment is much larger and heavier. Also, the film is so physically large that at anything approaching short focal lengths, you have to start taking into account the "petzval field curvature" and that gets very complcated.

[Sus_pilot]

I looked up the Lunar Mapping Camera, which was maid by Fairchild.  The image taken by the terrain cameras was 4.5"x4.5", with the film width being 5 inches.  The magazine held 1,500 feet of film.  The images had a resolution of 80 lines/mm using Kodak EK3404 film (apparently the stuff is still made - does anyone know if film is still the primary source for arial applications?).

So, for a case where someone didn't have to carry a large camera (I can just picture Neil Armstrong wielding a Speed Graphic and 4x5 sheets of Ektachrome while wearing a space suit), NASA deemed the weight penalty (275 pounds) worth the effort to get the high-res images on large-format film.

http://history.nasa.gov/afj/simbaycam/fairchild-lunar-mapping-camera.htm

[bknight]

And to think all this film wasn't fogged by the deadly VARB and by the space radiation that would have rendered any astronaut, ill/dead

[Abaddon]

I looked up the Lunar Mapping Camera, which was maid by Fairchild.  The image taken by the terrain cameras was 4.5"x4.5", with the film width being 5 inches.  The magazine held 1,500 feet of film.  The images had a resolution of 80 lines/mm using Kodak EK3404 film (apparently the stuff is still made - does anyone know if film is still the primary source for arial applications?).

So, for a case where someone didn't have to carry a large camera (I can just picture Neil Armstrong wielding a Speed Graphic and 4x5 sheets of Ektachrome while wearing a space suit), NASA deemed the weight penalty (275 pounds) worth the effort to get the high-res images on large-format film.

http://history.nasa.gov/afj/simbaycam/fairchild-lunar-mapping-camera.htm

I think they stopped a year ago. I could be wrong, but a bell is ringing.

[ka9q]

Don't forget that image resolution is limited by lens diffraction as well as the imager/film. LRO has an objective mirror roughly 200 mm in diameter, and its pictures are nearly as good as its diffraction limit.

How big were the Apollo SM camera objectives?

[Sus_pilot]

And to think all this film wasn't fogged by the deadly VARB and by the space radiation that would have rendered any astronaut, ill/dead

Well, that is a pretty dense bunch of polyester for a particle to drill through.  I've accidentally exposed bulk film to light and only the sprockets and outer couple of layers have been light shot.   But your point is well-taken, anyway.

[Abaddon]

And to think all this film wasn't fogged by the deadly VARB and by the space radiation that would have rendered any astronaut, ill/dead

Well, that is a pretty dense bunch of polyester for a particle to drill through.  I've accidentally exposed bulk film to light and only the sprockets and outer couple of layers have been light shot.   But your point is well-taken, anyway.

You have to realise that most of these people have no clue what a sprocket might be.