Apollo 14 photos of LEM on surface experimentation

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  • Henry_J
    Blossoming 3Dflower
    • Jul 2021
    • 2

    Apollo 14 photos of LEM on surface experimentation

    Hi, I am a complete nubi in photogrammetry. Simply out of curiosity I thought I'd try to see what could be done with the photos from the Apollo 14 landing images. I was particularly interested to see if the various packages could extract distances as the dimensions of the LEM are known.

    The astronauts used a Hasselblad 500 El. On the lunar surface the photos of the LEM and surrounding adjacent were taken with a Zeiss Biogon 60 mm lense whose focal length is given as being 61.1 mm. The Field of View is said to be 49.2 deg side, 66 deg. diag. The film negative of the images was on 53 mm X 53 mm negative. The only info I knew how to use was the focal length which I put into the image EXIF.

    Here is where I found the images, https://www.hq.nasa.gov/alsj/a14/images14.html#Mag65
    The LEM was photoed from two different sides. The first such sequesnce of images where the LEM is seen starts with - AS14-66-9252.jpg. The second, astronaut is much further away, starts with AS14-66-9274.jpg.

    What I wanted to share here is my observation about 3DF Zephyr. IT IS VERY GOOD !!!!!

    The photos available are very limited. But I nubi managed to get a fairly good 3-D model only with Zephyr. I tried this with Meshroom, Agisoft Metashape and Reality Capture with dismal results, basically no results. I realize that I was using the free incomplete versions without control/marker point usage. Additionally being a nubi without deep knowledge I was probably not getting optimal results. But using 3DF Zephyr straight out of the box with near auto guiding and little sophistication by the user, gave me results that simply are impressive. Zephyr was able to resolve the angular shape of the LEM from just a few photos taken by the astronaut JUST ROTATING his body, hence he was not moving around the craft. Whatever is the algorithm picking tie points/markers, well it must be super good.

    If anyone has the energy to try out this project I would just love to see what a really good user could do with 3DF Zephyr and these limited number of images.

    Again, Great Software !!!!

    Ciau
  • cam3d
    3Dflover
    • Sep 2017
    • 661

    #2
    Hi Henry_J - Welcome to the forum! Thank you so much for your kind words - I'll be passing them on to the developers who will be delighted I'm sure! All our technology is coded in-house and if you want to read a little bit about what goes on in the engine then check out these resources here: https://www.3dflow.net/technology/

    I hope you continue to enjoy using our software, and feel free to reach out at any time with any questions you may have regarding 3DF Zephyr!

    Comment

    • Henry_J
      Blossoming 3Dflower
      • Jul 2021
      • 2

      #3
      Hi cam3d

      Thank you for the reply. It's no hyperbole from my side to say that your software kicks *ss.

      I do have one question that I am not all clear about despite digger around. I understand that masking the images helps during Image Alignment so as to eliminate background information from the images that may confuse the algo as to ?Caption
      what is the object of interest to focus on. What I am not clear on is whether or not it is possible to tell the software "This point and this point and this point on these images are the same points. Focus on them !!!"

      I as this because several images I used to my human eye said, "There is no way to reject this image", yet the software did. How can one diagnose to find out what caused the problem and is there a way to direct the software to specific points in the pictures ?

      Cheers

      PS: Just for illustration I include some screen captures. Please don't be horrified as I was ONLY using 8 photos with minimal lateral movement. The four red lines in the 3D model nearly perfectly are as in reality. What was most surprising for me was the correct placement of the flag. Flag which appears as nearly nothing yet was located in the right place with +- a meter or two from the correct position. That blew me away, as NONE of the other software could handle this small data set. I suspect they are geared for high density imaging.

      Click image for larger version

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      Click image for larger version  Name:	Zephyr_Model_2.jpg Views:	0 Size:	200.0 KB ID:	7508?Caption
      Last edited by Henry_J; 2021-07-19, 09:17 AM.

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      • cam3d
        3Dflover
        • Sep 2017
        • 661

        #4
        "...What I am not clear on is whether or not it is possible to tell the software "This point and this point and this point on these images are the same points. Focus on them!!!"

        This kind of thing is possible using the full version of 3DF Zephyr by making a bundle adjustment: https://www.3dflow.net/technology/do...ment-tutorial/

        If I have weak data I'd definitely prefer to re-shoot and refine my image acquisition approach. Avoid control points for long enough and you get pretty good at taking photos :-) Obviously in this case taking new photos is not an option so it might be beneficial to place some control points and use them to drive the camera solve.

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