Enter Earth, Stage Left.

Here is a gif I made from Nasa apollo 17 photos
AS17-134-20385
AS17-134-20387

both taken from www.lpi.usra.edu....

I assume that is the Earth in the backround, although for the life of me I can't get my
head around how and why it should appear so small. The Moon's diameter is given
as 3474 km and the diameter of earth is 12800 km, making the Earth nearly 3.7
times as large across. Yet it appears roughly the same size in the background, as the
moon appears to us from Earth.

Now how the heck did it enter into the scene so quickly? There can only have been
a couple of seconds between the two photos.
Now I know you may say that the photographer has moved position a little, but relative
to all the weird smudging in the backround (what the heck accounts for this?), the
movement doesn't appear so drastic as to be able to account for the sudden appearance.
Note the strange smudging around the Earth also.

Also, what accounts for the spherical reflection seen in the spacemans visor?

So maybe it really is a picture taken on Earth and what we see in the sky is the moon!

My take...

The reflection in the visor is the astronaut's helmet/visor opposite him taking the picture.

As for the other observation...the earth's size particularly...I have taken photos of extravagant full moons that to the naked eye appeared massive but on the photo looked like a pea in the sky. I presume it would be something similar.

Moving in the frame so abruptly, I think you already nailed it.

Originally posted by OutonaLimb

Here is a gif I made from Nasa apollo 17 photos
AS17-134-20385
AS17-134-20387

both taken from www.lpi.usra.edu....

I assume that is the Earth in the backround, although for the life of me I can't get my
head around how and why it should appear so small. The Moon's diameter is given
as 3474 km and the diameter of earth is 12800 km, making the Earth nearly 3.7
times as large across. Yet it appears roughly the same size in the background, as the
moon appears to us from Earth.

Now how the heck did it enter into the scene so quickly? There can only have been
a couple of seconds between the two photos.
Now I know you may say that the photographer has moved position a little, but relative
to all the weird smudging in the backround (what the heck accounts for this?), the
movement doesn't appear so drastic as to be able to account for the sudden appearance.
Note the strange smudging around the Earth also.

Also, what accounts for the spherical reflection seen in the spacemans visor?

What you need to be asking is why the Earth looks so small.. It looks to be the size of the moon as viewed from earth yet the earth is a lot larger then the moon, it should be at least 4 times the size it's shown in the photo.

reply to post by OutonaLimb


I've been through this before.

It's the camera lens that alters the perspective. If you search there is a good thread about it.

Yet it appears roughly the same size in the background, as the
moon appears to us from Earth.

The image is taken with a 60mm lens. On 70mm film that is a wide angle lens. Wide angle lenses make things look smaller.
www.flickr.com...

Now how the heck did it enter into the scene so quickly? There can only have been a couple of seconds between the two photos.

About 6 seconds actually. You can see that Jack has lowered the camera in order to get Earth in the shot by comparing how the mountain behind Gene changes it's alignment with Gene's arm. Here's another shot.

You can read the transcript about it here: www.hq.nasa.gov...
Here's the video:
www.hq.nasa.gov...

Also, what accounts for the spherical reflection seen in the spacemans visor?

The surface of the visor is spherical.

Originally posted by UberL33t
My take...

The reflection in the visor is the astronaut's helmet/visor opposite him taking the picture.

As for the other observation...the earth's size particularly...I have taken photos of extravagant full moons that to the naked eye appeared massive but on the photo looked like a pea in the sky. I presume it would be something similar.

Moving in the frame so abruptly, I think you already nailed it.

Fair point about the camera versus eye discrepancies. I have experienced this myself.




Maybe the 'sphere' is supposed to be the lunar lander.

But what is with the artifacts and pixilation around the solid objects
and the dark smudging seen throughout? Are not these indicators of
cut/paste inserts and/or photo manipulation?



These photos are taken from an official NASA site!

reply to post by OutonaLimb

These photos are taken from an official NASA site!

There are better quality scans available.

Here. Use this.
www.hq.nasa.gov...

Originally posted by RocksFromSpace

Originally posted by OutonaLimb

Here is a gif I made from Nasa apollo 17 photos
AS17-134-20385
AS17-134-20387

both taken from www.lpi.usra.edu....

I assume that is the Earth in the backround, although for the life of me I can't get my
head around how and why it should appear so small. The Moon's diameter is given
as 3474 km and the diameter of earth is 12800 km, making the Earth nearly 3.7
times as large across. Yet it appears roughly the same size in the background, as the
moon appears to us from Earth.

Now how the heck did it enter into the scene so quickly? There can only have been
a couple of seconds between the two photos.
Now I know you may say that the photographer has moved position a little, but relative
to all the weird smudging in the backround (what the heck accounts for this?), the
movement doesn't appear so drastic as to be able to account for the sudden appearance.
Note the strange smudging around the Earth also.

Also, what accounts for the spherical reflection seen in the spacemans visor?

What you need to be asking is why the Earth looks so small.. It looks to be the size of the moon as viewed from earth yet the earth is a lot larger then the moon, it should be at least 4 times the size it's shown in the photo.

It's about distance and perspective. That's why the earth looks the size it does. Size much like time is all relative to ones perspective of it. Hope this helps

Originally posted by OutonaLimbBut what is with the artifacts and pixilation around the solid objects and the dark smudging seen throughout?

Are not these indicators of cut/paste inserts and/or photo manipulation?

They are not. Those are digital compression artifacts caused by the .jpg format. Several years ago (posting as "Count Zero"), I wrote this exercise to demonstrate how .jpg artifacts are formed.

I hope that explains them adequately. Do some experiments of your own to learn more. Try compressing some of your own pictures and look for the artifacts. They show up most clearly on the border of areas with low contrast, such as the red background in my exercise, or the black space around the Earth in the Apollo pic.

reply to post by OutonaLimb


Well to all of you with NO understanding of photography the size of the earth will depend on the film format and the focal length of the lens.

Now we are in the digital age cameras are effected by the size of the sensor see link




On a full frame DSLR a 500mm telephoto gives approx 10x magnification on a camera with an APS-C sensor the crop factor is 1.5 so that 500mm becomes 750mm and 15x approx magnification.

You have to see the full frame of the negative and know the size of the lens on the camera to compare images.

Glad to be of help

Originally posted by wmd_2008
reply to post by OutonaLimb

 

Well to all of you with NO understanding of photography the size of the earth will depend on the film format and the focal length of the lens.

Now we are in the digital age cameras are effected by the size of the sensor see link




On a full frame DSLR a 500mm telephoto gives approx 10x magnification on a camera with an APS-C sensor the crop factor is 1.5 so that 500mm becomes 750mm and 15x approx magnification.

You have to see the full frame of the negative and know the size of the lens on the camera to compare images.

This.

The Lunar Surface Hasselblad had an f/5.6 60mm lense. The film was 70mm, though I do not yet know the frame-size. The image was square, instead of the usual rectangular.

Originally posted by RocksFromSpace
What you need to be asking is why the Earth looks so small.. It looks to be the size of the moon as viewed from earth

You determined that... how exactly? Let's see your calculations for the field of view of the Hasselblad camera and therefore the angular size of the earth in that image. Pardon the wiki quote, but this doesn't really warrant more detail than that:
en.wikipedia.org...
Given the 6cm film (www.photoethnography.com/ClassicCameras/index-frameset.html?Hasselblad500.html~mainFrame ), the 60mm focal length of their lens, the field of view was approximately 71 degrees. On this image that works out to about 46.72 pixels per degree:
www.hq.nasa.gov...
The earth in that image is about 105 pixels across, so just over two degrees wide. If anything it's too large, but it's reasonably close to the expected number - these are approximate calculations based on the theoretical field of view.

Originally posted by OutonaLimb
the
movement doesn't appear so drastic as to be able to account for the sudden appearance.

Sure it does. In the first photo he's looking almost straight on at the astronaut, in the next he's clearly looking up more.

reply to post by ngchunter


Hi ngchunter was it you or someone else who did the exact same on another thread when this same subject was brought up.

If people like the OP are going to make bold statements they should a least learn something about the subject.

Its amazing how many threads on here rely on photography but what's even more amazing is that the people who use it to try and back up theories of the Moon hoax etc have no idea about photography,cameras,lenses or digital imaging in general.

Originally posted by ngchunterThe earth in that image is about 105 pixels across, so just over two degrees wide. If anything it's too large, but it's reasonably close to the expected number - these are approximate calculations based on the theoretical field of view.

That's what I got, based on a 71-degree (diagonal) FOV. Actual visual diameter of the Earth on Dec 11,1972 was ~1.9 degrees. Part of the too-large answer is because the Earth image was out-of-focus, which of course causes a little bit of blooming. Asking around, someone pointed-out that the 60mm focal length number is for the lens focussed on infinity. When focused on a closer object (in this case, Gene Cernan with the flag), the lense extends, making the focal length longer and the objects in the image larger. This could account for the rest of the discrepancy.

I love learning new stuff...

reply to post by Saint Exupery


Thanks but I did already know that information.

Originally posted by Saint Exupery

Originally posted by ngchunterThe earth in that image is about 105 pixels across, so just over two degrees wide. If anything it's too large, but it's reasonably close to the expected number - these are approximate calculations based on the theoretical field of view.

That's what I got, based on a 71-degree (diagonal) FOV. Actual visual diameter of the Earth on Dec 11,1972 was ~1.9 degrees. Part of the too-large answer is because the Earth image was out-of-focus, which of course causes a little bit of blooming. Asking around, someone pointed-out that the 60mm focal length number is for the lens focussed on infinity. When focused on a closer object (in this case, Gene Cernan with the flag), the lense extends, making the focal length longer and the objects in the image larger. This could account for the rest of the discrepancy.

I love learning new stuff...

That's a very good point about the focus, I hadn't considered the effect of defocused blurring. Certainly though the exercise demonstrates that the claim that earth in this image is about as big as the moon is in our sky is dead wrong.

Originally posted by wmd_2008
reply to post by ngchunter

 

Hi ngchunter was it you or someone else who did the exact same on another thread when this same subject was brought up.

I've made the argument before, but this is the first time I went step by step laying out the calculations like that rather than simply showing what images of the moon look like from similar Hasselblads on the ground.

A friend of mine just ggot back to me. He found the original Hasselblad data sheet for the Apollo model biogon lense. It gives the diagonal FOV as 63 degrees, not 71. My calculations are now closer to the observed size, though slightly high. Measurement errors and the afore-mentioned focus issues still apply.