Photos from Apollo 11 film footage

[ka9q]

Are there any actual examples of filmed-for-TV footage shot at 30fps rather than 24?

I could be wrong, but that was the impression I got from talking to a producer who seemed to know these things. Many TV shows were shot on film at 30 fps, then converted to video and edited. Examples include Star Trek: The Next Generation.

I presume digital cameras have largely taken over by now, but I understand at the time they were encountering a lot of resistance from directors and producers, not sure exactly why. They would certainly be cheaper and quicker.

[cjameshuff]

Most material made for TV in the US has been shot at 30 fps (or rather, 29.97 fps). You'll have a hard time finding anything made for TV and shot with video cameras in 24 fps. Material made for PAL systems can be either native 24 or 25 fps, sometimes nothing's done to compensate for the 4% difference in playback speed.

Shooting film at 24 fps gives barely perceptible flicker that audiences have deemed acceptable, and uses less film. Adoption of higher framerates then had problems due to the lack of flicker, the "video look"...people expected the flicker and thought higher framerates looked "cheap" due to the association of smoother motion with TV, despite the objectively better quality. In some cases, especially recently, they've even converted from higher framerates to 24 fps to achieve the same "look".

[Glom]

Red Dwarf VII did that when they decided to do the whole single camera thing.

[JayUtah]

It doesn't work like that, the flag's height and the shadow's length lie in different directions across the frame...

Further there is photographic evidence that the shadow falls across uneven ground.  The effect of changing sun elevation upon the shadow length as seen from some line of sight is not a straightforward computation, especially at the tolerances being discussed here.

Fail.

[profmunkin]

Attached is Apollo 11 image.
30 degree angle on lens flare.
30 degree angle to horizon
30 degree angle on landing pod shadow.
30 degree angle on astronaut shadow.

[ka9q]

Attached is Apollo 11 image.
30 degree angle on lens flare.
30 degree angle to horizon
30 degree angle on landing pod shadow.
30 degree angle on astronaut shadow.

Among your other mistakes, the angle of the line through the lens flares depends not on the sun's elevation but on the position of the camera relative to the sun. Draw a line through the two flares and it will always intersect the sun, which in this case is out of the frame.  Had the camera been pointed, say, directly under (or over) the sun then the line through the flares would have been perfectly vertical. Would that have made it local solar noon? See the problem?

The actual sun angles during every Apollo EVA are readily available, so you don't really have an excuse for not knowing them. The Apollo 11 EVA began with a sun angle of 14.0 degrees and ended with a sun angle of 15.4 degrees. I've never seen anything to make me doubt those figures. Anyone familiar with Apollo photography can immediately tell from the Apollo 11 pictures that it's still very early in the lunar morning. The later missions (especially A15-17) remained on the surface for several days so their later EVAs were conducted with much higher sun angles -- and everything looks completely different.

[ka9q]

It really isn't that hard to do a lot better with these measurements.

The most direct way to determine the sun elevation during an Apollo lunar EVA is to find a picture that includes both the sun and the level horizon taken with a camera whose image size and lens focal length are known, and just measure the angle between the two. Yes, the sun will be vastly overexposed and its image will bloom enormously. But it'll remain reasonably symmetrical, and with lens flares and other artifacts as additional clues it is usually easy to determine the sun's true position in the frame.

The Apollo surface Hasselblad cameras used 70mm film with 60 mm focal length lenses. The fiducials inscribed on the focal plane are at 1 cm spacings, with a larger cross marking the center of the photo. Therefore, the subtended angle between two adjacent fiducial marks is about 10 mm/60 mm = 1/6 radian or 9.55 degrees. (I do not know about the behavior of the lens on off-axis points, but taking or not taking the arcsin has a minimal effect of only about 1/2% so I ignored it).

I can't find any Apollo 11 EVA pictures with the sun actually in frame, so I looked for the next best - a picture showing both the level horizon and the camera's shadow. The angle between these two will also be the sun's elevation.

AS11-40-5882HR, taken by Buzz Aldrin as part of a panorama, is one such picture. Although the camera's shadow is hidden in Aldrin's own shadow, I can accurately estimate its position from the brightness of the Heiligenschein surrounding his head and from the orientations of small nearby rock shadows. (see below)

Using The Gimp, I measure 448 pixels vertically between the two fiducials to Aldrin's left. That works out to 9.55 deg/448 = .02132 degrees/pixel.

Also using The Gimp, I measure 795 pixels vertically between the camera's shadow and the horizon (which isn't quite straight because of a crater rim). That's an angle of 16.9 degrees, not terribly far from the known sun elevation angle of 14-15.4 degrees during the Apollo 11 EVA and certainly a lot closer than the 30 degrees claimed by profmunkin with his erroneous methods.

Besides possible errors in locating the camera's shadow, it's also possible (probable, even) that the horizon was not level. If the horizon to the west rose above level, as I believe it did, my result will be too large. Another possible error is the apparent drop in the horizon with the height of the camera, but even on the moon this seems too small to worry about given Aldrin's < 2m height.

(Regarding determining camera position from rock shadows: a line drawn through a shadow and the object casting it will necessarily pass through the camera's shadow, whether or not the latter is in frame. Do this for a whole bunch of object/shadow pairs and your lines will all cross at the camera's shadow. It is very important to ensure that each line joins a particular point on a shadow with the corresponding point on the object that cast it. You can't just draw lines through the centers of rocks and their shadows, especially when the shadows are short. Pick distinctive points that are visible both on the rock and in its shadow.)

[Bob B.]

30 degree angle on lens flare - Irrelevant
30 degree angle to horizon - Please show your method and math
30 degree angle on landing pod shadow - Please show your method and math
30 degree angle on astronaut shadow - Please show your method and math

[Chew]

Attached is Apollo 11 image.
30 degree angle on lens flare.
30 degree angle to horizon
30 degree angle on landing pod shadow.
30 degree angle on astronaut shadow.

This explains why you can't measure angles the way you are trying:
Shrunken Shadows on the Moon

[Glom]

Attached is Apollo 11 image.
30 degree angle on lens flare.
30 degree angle to horizon
30 degree angle on landing pod shadow.
30 degree angle on astronaut shadow.

The angle of lens flares in a frame has nothing to do with the sun angle.

I'm not sure what you're basing the rest on other than wishful thinking.

[gwiz]

Attached is Apollo 11 image.
30 degree angle on lens flare.
30 degree angle to horizon
30 degree angle on landing pod shadow.
30 degree angle on astronaut shadow.

OK, use that picture.  Assume the astronaut is square on to the camera, so measure his height.  The square-on length of his shadow is longer than the distance from his feet to the edge of the frame, so measuring that length will give an upper limit on the sun angle.  What do you get?

Actually, the shadow isn't square on, it extends towards the camera so is considerably longer than the square-on measurement, making the angle smaller still.  From the angle of the LM in the photo, I'd guess the shadow is about 45 deg to the camera axis, making the shadow 40% longer.  On that basis, my calculation for the upper limit on the sun angle is 18 deg.  The claimed value of 14 or 15 deg is therefore consistent with this picture, but the exact value isn't measurable because the full length of the shadow isn't in frame.

[JayUtah]

Attached is Apollo 11 image.

Yep, the same one used by David Percy to "compute" sun angle -- comically wrongly.

30 degree angle on lens flare.  No.  The angle of a linear set of catadioptric elements is proportional to the angle between the light source and the optical axis.  Until you rectify the photo, you cannot relate that angle to anything in the scene.

30 degree angle to horizon.  No, this is very much the wrong way to measure an elevation.  The line of flares will change as the photographer turns to the left; it will increase.  If this observation can be manipulated by changing the azimuth, then it is clearly not a suitable measure of elevation.

30 degree angle on landing pod shadow.  You neglect to note the points on the lander and the points on the shadow you consider to correlate.

30 degree angle on astronaut shadow.  Again here you neglect to identify the point on the astronaut and the point on the shadow you consider to correlate.  Percy actually tried to draw a line to the shadow of the astronaut's head -- yes, the out-of-frame feature.  That fails on two accounts.  You can't guess where things lie outside the frame, and the mathematics don't let you generalize that to an elevation angle anyway.

There is a science to doing this sort of thing, and it's clear you don't yet understand even the most basic fundamentals of it.  You cannot simply draw lines on photos and pretend that it correlates to the 3D angles formed in the real world.

I suggest you look at some of the pages on my site www.clavius.org for some simple demonstrations and experiments you can do yourself to show how lighting and shadow vary depending on many variables.

[profmunkin]

If the height of the camera and its angle are considered, which they must be, you guys are right on.
Even though I do not believe Apollo landed on the moon, these pictures appear to be technically correct.

[gillianren]

Okay, follow that to its logical extension.  If the evidence is in favour of Apollo in every case once you examine it, will you still believe that it was faked?  Because the evidence is.

[Glom]

If the height of the camera and its angle are considered, which they must be, you guys are right on.
Even though I do not believe Apollo landed on the moon, these pictures appear to be technically correct.

What would convince you otherwise?