Apollo photogrammetry

[BertieSlack]

There haven't been many new topics started lately, so here's a really obscure one to get your Apollo geekery into gear. It's a quick question for any Apollo photography experts out there:

I've seen lots of documentation showing that the optical properties of each EVA camera was carefully measured pre-mission. For example, here's a document from March 1969 called "Photogrammetric calibration of Apollo film cameras":

https://www.hq.NASA.gov/alsj/NASA-cr101363.pdf

Try this link as the above seems to be broken: http://www.lpi.usra.edu/resources/USGS-Reports/Astro-0015.pdf

On Page 2 it is stated that ".........These rays can be regenerated from picture images if the following are known: (1) Orientation of the camera in object space at the time the picture was taken..........." but doesn't say how this information was acquired. Since the 70mm Hasselblad used on Apollo had a square format, it's not obvious which way the camera was orientated for any particular photo - which you'd need to know if you wanted to take proper advantage of your pre-mission calibration work. For example, it seems that most the photos taken with the 500mm lens were done with the camera on its side (presumably the astronauts found it easier to do it that way). I've seen photos of Apollo Hasselblads with magazine removed, and the exposed reseau plate has two marks on the edge (top left and bottom right) - and these marks are seen on many Apollo EVA photos (depending on the cropping). For example:

http://www.hq.NASA.gov/alsj/a17/AS17-139-21194HR.jpg

Are these orientation marks? Looking through photos for all the missions, it looks like each EVA camera had marks that could distinguish it from any other camera. Did NASA photo technicians modify the marks so they could identify which camera body took each photo? Presumably this would not be obvious if magazines were swapped between cameras. On later missions each camera was identified by a number etched into the glass of the reseau plate, but the marks are still there.

Hope that makes sense. Any ideas? Thanks in advance................

[Edited for typos]

[bknight]

The first link is broken, the image came through alright.

[BertieSlack]

The first link is broken, the image came through alright.

Try this one: http://www.lpi.usra.edu/resources/USGS-Reports/Astro-0015.pdf

[ChrLz]

First up, I ain't a photogrammetry expert, but I pretend to be one on the Interwebz..!   So you should probably wait for the likes of Jay (and others who I am now insulting by not naming them!) .. however .. a few comments:

That pdf goes on to say "Items 1 and 2 vary with each picture taken. They are computed by various photogrammetric
methods, which will not be discussed here."  The clue is that it requires further photogrammetry and computations... which I would guesstimate means:
- the use of 'knowns' in the image, eg the LM/astronaut/equipment/flagpole etc, the peak of a hill/mountain, the horizon, a notable rock, and so on..
- the use of other images, eg lining up that hill peak or flagpole or horizon and comparing to the image in question.

I know that the astronauts took many 'stereoscopic pairs', ie two or more images from not-quite the same location but of the same scene - my understanding is that they simply stepped slightly to one side to do that, rather than do anything precisely measurable.  They also took sequences of multiple images while rotating their viewpoint, to allow creation of panoramas...  However, given that it can be quite hard to locate a portable camera like the Hasselblad in space, as of course you not only have its position (x-y-z) in 3D space, you also have the roll/pitch/yaw aspects to consider also.

And no, I don't think those 'bumps' that are visible at the extreme edges are any sort of device to help with this - I can't see how anything in the camera could help more than just the fiducials.  What you need to locate the camera precisely is maybe a ridiculously accurate GPS, gimbaled gyroscope, a team of surveyors and leveling devices....


Were you trying to do something specific, btw, or is this just to satisfy your curiosity?  I'm just not sure just how much use was made of the potential for photogrammetry to create 3d models of the surface, apart from the stereo pairs and panoramas and some basic distance and size calculations (and of course there was also that famous verification that was first done with Jaxa/Selene...).

Other than that ...... ?  I'd certainly be interested to take a look if there are any examples of exactly how they went about it back then, online.  I know *how* it can be done, but I've always taken the easy route and used panorama programs and the like to do the hard yards...  Nothing I've had to do has required precise knowledge of lens distortions, and of course most panoramas are relatively easy to align and level, without having to measure anything..

(sorry about major editing - accidentally posted it before I was done..)

[BertieSlack]

Were you trying to do something specific, btw, or is this just to satisfy your curiosity?

There's an article on the Aulis website which claims that the black marks were part of some sort of nefarious post-mission compositing process. I posted a 2-part YT video about this a couple of years ago, but never got round to making the final part which would completely nail the Aulis nonsense. Here's the link:

http://www.aulis.com/composites.htm

[ChrLz]

Were you trying to do something specific, btw, or is this just to satisfy your curiosity?

There's an article on the Aulis website which claims that the black marks were part of some sort of nefarious post-mission compositing process. I posted a 2-part YT video about this a couple of years ago, but never got round to making the final part which would completely nail the Aulis nonsense. Here's the link:

http://www.aulis.com/composites.htm

Forgive me but having been to Aulis just once, I would rather keep my remaining brain cells intact...  I think the less hits they get the better..

Photogrammetry is after all, just basic geometry..  It is 'complicated' only by the fact it:
- is in 3D, with all the perspective issues that entails
- usually involves lenses which introduce various extra distortions
.. those issues just mean a bit of extra geometry, sometimes involving curves...

So it makes no sense to me at all for the aulis-numpties to suggest the marks (be they the fiducials or those extra notches, whatever they might be) were in some way nefarious...  Did they explain this rather silly claim, or was it just the usual handwaving bull-excrement and quoting of unsupported views of someone without a clue, who they call an 'expert'?

You probably don't need to answer that.. 

[Kiwi]

Were you trying to do something specific, btw, or is this just to satisfy your curiosity?

There's an article on the Aulis website which claims that the black marks were part of some sort of nefarious post-mission compositing process. I posted a 2-part YT video about this a couple of years ago, but never got round to making the final part which would completely nail the Aulis nonsense. Here's the link:

http://www.aulis.com/composites.htm

I wonder if Aulis and others have taken into account that many of the Apollo photos we've had access to since 1969 were made from duplicate films, not from the original films.  However, the very latest scans have indeed been taken from the original films, but the ones we usually see are reductions of those high-resolution scans, so things like the reticules over a white subject can almost disappear due to the reduction getting rid of very fine lines that are parallel to the edges of the photo.

So who knows exactly how those duplicates were made, and whether such marks were introduced in the duplicating process, and are they or are they not on the original films?

One other thing regarding the black-and-white photos is that the duplicate negatives (and perhaps even the originals) were numbered with ink, usually between the frames. I usually did my numbering with a simple nib and Indian ink in the early 1970s, but later invested in a Mars draughting pen and the ink that was intended for use on plastics. This worked better because a sharp nib could dig into the film and when it freed itself, splash ink over the film.

Another effect of this numbering is that occasionally some of the people who did it got a bit sloppy and wrote partly in the picture area, or used too much ink and it flowed into the picture area.

Then there's the issue of duplicating transparencies or negatives onto positive or negative film. When something blocks light reaching positive film, the result will be dark, and with negative film it will be light on the film and dark in a print, so it depends what process was used and what we're looking at.

A few years ago an HB thought he had seen evidence of studio lights in an Apollo photo (Apollo 15 IIRC) but I was able to show that, no, it was just numbering ink. From old posts at the Bad Astronomy Bulletin Board (don't click on the links, they are so old that it will take about a fortnight before you are told they are long dead).:--

Kiwi
Post 186
Apollohoax question
11 Aug 2004 22:32
http://www.bautforum.com/showthread.php?p=262827#post262827

Does anyone know what this is in this image, top center?

My guess is that it's writing on the edge of the negative that, in this case, has crept into the picture area.

I recently bought the CD version of the ALSJ and many of the small black and white images show parts of the borders. One clearly shows the entire AS??-??-??? number on the right-hand side, and most of them show on the left just the tips of letters written in a slanting hand. Sometimes this encroaches on the picture area and some photos have writing between the frames too.

Most of we professional photographers identified our negatives with Indian ink in a similar way.

I believe that Harald is right about the light area within the picture -- sun strike, but not related to the markings on the edge.


Kiwi
Post 192
Apollohoax question
12 Aug 2004 21:09
http://www.bautforum.com/showthread.php?p=263265#post263265

I'm asking the experts. I don't know what it is. And I'm thinking no one else here knows what it is either or isn't saying.

Drat! I thought I'd explained it in my post above...

Looking at the picture upside-down, it seems to me that we could be looking at, in the first two symbols, the tops of the letters "AS". The extra bright spot at the top of the downstroke in the "A" is typical of the clumping that sometimes occurred when inks were used on film. I eventually got around the problem in the 70s by using a draughting pen and Pelican drawing ink instead of an ordinary nib with Indian ink. This had the added bonus of preventing splashes of ink onto the picture area which sometimes occurred when a nib got stuck, then freed itself.



Kiwi
Post 196
Apollohoax question
13 Aug 2004 07:37
http://www.bautforum.com/showthread.php?p=263534#post263534

We don't tend to post "I concur" or "Me to" on the board. We mostly answer to arguments we consider wrong.

Oh, I dunno about that. Sometimes we'll signal our agreement when someone writes a brilliant line like: "...Twinkies often refer to pretty bad prints or scans to do their rorschaching"
 
:-)

If you can provide examples of this, it could be helpful.

Some people like to have their research done for them. Here are a few examples -- I had to search through black and white Apollo photos just the same as you could have, starting with the ones around AS15-84-11348.

I was correct in guessing that the marks are the AS numbers written in ink. They only appear on certain black and white films and always in the same hand, so I guess that one particular lab worker always wrote close to the picture area.

Go to the ALSJ
 
and look up the following under Miscellaneous Images:

AS14-64-9053, 9058, 9066, 9115, 9152, 9158, 9175, 9190, 9198
AS14-68-9441

They have part of the number visible on the left, but 9175 is the best – it shows most of the entire number on the right side.

These show tiny blobs of ink at the top:
AS15-84-11292, 11299, 11316

These show parts of changing ID details on the side:
AS15-82-11088 to 11097 and 11111 to 11123

**************************************
AS14-64-9053 -- 20149467
AS14-64-9058 -- 20149472
AS14-64-9066 -- 20149480
AS14-64-9115 -- 20149529
AS14-64-9152 -- 20149566
AS14-64-9158 -- 20149572
AS14-64-9175 – 20149589 Most of number
AS14-64-9190 – 20149604 Good
AS14-64-9198 -- 20149612
AS14-68-9441 -- 20149633
AS15-84-11292 -- 20147259
AS15-84-11299 -- 20147266
AS15-84-11316 -- 20147283
AS15-82-11088 -- 20147661
AS15-82-11089 -- 20147662
AS15-82-11090 -- 20147663
AS15-82-11091 -- 20147664
AS15-82-11092 -- 20147665
AS15-82-11093 -- 20147666
AS15-82-11094 -- 20147667
AS15-82-11095 -- 20147668
AS15-82-11096 -- 20147669
AS15-82-11097 -- 20147670
AS15-82-11111 -- 20147684
AS15-82-11112 -- 20147685
AS15-82-11113 -- 20147686
AS15-82-11114 -- 20147687
AS15-82-11115 -- 20147688
AS15-82-11116 -- 20147689
AS15-82-11117 -- 20147690
AS15-82-11118 -- 20147691
AS15-82-11119 -- 20147692
AS15-82-11120 -- 20147693
AS15-82-11121 -- 20147694
AS15-82-11122 -- 20147695
AS15-82-11123 -- 20147696

**************************************

JayUtah
13 August 2004, 07:47
Join Date: Oct 2001
Posts: 5,925
Post 27
Apollohoax question
http://www.bautforum.com/showthread.php?p=263558&post263558

Since none of the other experts corroborated your explanation, I didn't give it too much consideration.

I did, but I didn't write about it.

When Kiwi first mentioned the possibility of it being writing, I considered it seriously. Unfortunately at the time all I had time to do was look at the original picture again with that hypothesis in mind. I noticed immediately one of the things he pointed out: the "pooling" of density at the bottom of what may be a pen stroke. That's consistent with a felt-tip marker.

When I got back here, I saw that Kiwi had already done everything I would have done to confirm his hypothesis, including finding clearer examples.

Oh, I looked for them. But I looked in the LPI archive, not the ALSJ archive. That's important for two reasons. First, the archives were created from different dupe masters. The ALSJ pictures come from the older dupe masters; the newer ones won't have been used so extensively. And second, LPI crops their photographs. The double edge you see on the ALSJ pictures confirms that their digital images go all the way out to the edge of the frame and then some. The double edge is an artifact of the camera, not something in the scanning process; it exists on the negatives/transparencies. If the double side edge is missing in a digital version, it means the image has been cropped. The frames Kiwi cites as examples have no writing on them in the LPI archive, which is why I didn't find them. Kiwi simply did better research than I did.

So any writing in the margins of the LPI dupe masters would be cropped out, unless it intruded significantly into the frame, as it did in your example. It makes sense for the archivers to label the dupe masters in this way. The photos are not otherwise self-identifying. The role of the dupe master is to satisfy the requests for reprints and copies, which are ordered by ID number, so labeling each individual frame with its NASA ID number is prudent. This doesn't work for the color film, whose margin is black.

The camera leaves about 2 cm of space between each frame, so the natural place to label the frame directly is in the generous margin between the frames. However that could lead to some question of whether the label goes above or below the frame. So it's less ambiguous to label it along the side margin. I'm not surprised to see both methods used.

So yes, I concurred with Kiwi yesterday, even if I didn't have the time to say so.

[bknight]

Were you trying to do something specific, btw, or is this just to satisfy your curiosity?

There's an article on the Aulis website which claims that the black marks were part of some sort of nefarious post-mission compositing process. I posted a 2-part YT video about this a couple of years ago, but never got round to making the final part which would completely nail the Aulis nonsense. Here's the link:

http://www.aulis.com/composites.htm

I remember the videos, and I agree with the premise you presented against Percy.  From browsing the document, it seems like the marks were used for orientation and amount of distortion at the edges of each image.