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  • Mike_mds

    Active Member
    Oct 11, 2020
    159
    Ceciltucky
    I hate to be the IT nerd, but this is really cool.

    More pics please….


    Sent from my iPhone using Tapatalk
     

    ToolAA

    Ultimate Member
    MDS Supporter
    Jun 17, 2016
    10,500
    God's Country
    I hate to be the IT nerd, but this is really cool.

    More pics please….


    Sent from my iPhone using Tapatalk


    Ok since you asked. These two were both about 5-6 NM from shore.

    4bf61cdd178f9fd0e52a93e0440a151b.png


    2ffe0000e72fac8ac35667a6d41bcc12.png
     

    ToolAA

    Ultimate Member
    MDS Supporter
    Jun 17, 2016
    10,500
    God's Country
    Same beach location this year and this has been my first chance to attempt to spot cool wildlife or anything else interesting with the spotting scope.

    Here is a ship leaving the port. 176m length 2.9NM from my location.

    a77b658595f893e10d53eeb1c367297d.jpg


    The with the whether sort of hazy off shore the furthest ship I could make out is this one. 16NM (29,632 meters) off shore. Because it pretty windy 15mph with 20-25 gusts the scope and camera are shaking too much to zoom in any further than 20x on the scope and 2x from the camera. 40x total.

    10f61c551728ee4b410b411cfda35591.jpg


    I was able to find the name by using the bearing S85E and distance from the scope and determined the ship is named Titan.

    8e1d30c2f04cfab2baa86eda155211a4.png


    f70388e0a179da00a46bf3a8d7662b89.jpg



    So since I’m board and my mind is wandering, I was curious to see how accurate the ranging reticle is on the theodolite app I’m using as an overlay. From the earlier photo the ship appears to be 240 mils. So time to do some math.

    Ship Size is 369m. It looks like from my vantage point I’m almost perpendicular to starboard side.

    Actual Length x 1000 / measured mils = distance.

    360m x 1000 / 240mil = 1500m (so that’s not correct) but then I realized the app’s digital zoom works like a first focal plane reticle, but the optical magnification of scope does not. So I have to take the 240 mils measured in the app and divide by the magnification to determine the actual measured mils, which is 240/20=12 mills.

    Redo the formula again 360x1000/12=30,000 meters away. Convert to nautical miles 1km ~ 0.54Nm so 30x.54=16.2Nm which is pretty spot on according to the distance reported by the Marine Traffic App.

    Going a step further I wanted to see if I could determine how high the ship was above the waterline, but at 16Nm the curvature of the earth obscures the lower half of the vessel from my perspective. Also I don’t know if the ship is loaded with full or empty containers which would also effect the draught depth and height. However I can see that the top of the containers appears to be about 70mil above the horizon line. Doing a bit of math to work out that apparent hight is just plugging in the known values into the formula to determine the distance.

    Distance / 1000 x mil = height in meters.

    cd275c9b0e4ed3517e13152b21c41a69.jpg



    30,000/1000 x (70 mils / 60 magnification in the above photo) = 35m height (114ft). I couldn’t find any info online to confirm the height, but I was able to find the beam 51m and then scale a photo to come up with a close approximation of the height.

    a8e5c5b05bac31e39e0bd7606d84391a.jpg


    So scaling the photo using the known beam width, I was able to estimate the height from the deck to the top of the bridge at about 30m. I can see the shipping containers stacked 9 high in the photo, and those range from 8.5 to 9.5 feet tall so about 81ft (24.6m) plus about another 15ft clearance to the top of the bridge gets me to 30m. That means the proportions of the photo don’t really have any significant perspective distortion. Measuring from the deck to the waterline comes in at about 22m (72ft).

    So if the reticle measurement calculations of hight above the waterline is accurate at 35m and my estimated height of the ship above the waterline is also close at 52m that means that 17m of the ship are obscured by the curvature of the earth.

    To check that we need to some more math that’s above my normal pay grade.

    x = √(a² - 2ad + d² + r²) - r

    a = distance to the horizon
    h = eyesight level
    r = Earth's radius (6371 km)

    x = obstructed height of an object below the horizon line.

    I’m on the 3rd floor of a beach condo which is also above sea level about 8ft so I place the height of my scope at about 45ft (13.71m)

    If you are lazy like me (im on vacation) just plug in the known values into this online calculator. https://physicscalc.com/physics/earth-curvature-calculator/

    The result from the online calculator is 22.1m of the horizon is obscured at a distance of 30km. That varies from my previous estimate of 17m. But considering all of the fuzzy math I’m doing here I say it close enough for my nerdy afternoon.

    Enjoy.
     

    ToolAA

    Ultimate Member
    MDS Supporter
    Jun 17, 2016
    10,500
    God's Country
    It’s looking a like a perfect evening to snap some photos. The sky is almost clear with low humidity, low wind and the sun at by back.

    Here one cargo ship coming in to harbor. First photo is a out 5.5 Nm away.
    f08ee37da0d1d86b2e66979d80d1f4e8.jpg


    9e0b0d4992d0c918ec887c65717b85ba.jpg


    This is about 5Nm out
    c125e045476c71e1fd980a574096c640.jpg


    These three are 4.7Nm
    a66ad78ef0f1d3bec00fc34beaeceb90.jpg


    d4d95761a2323f4de335d73a9640c84d.jpg


    c1ce73caf6efebd8acf0bc4f1f60a938.jpg


    Here is the last one at 30x magnification about 2Nm offshore
    228da4505d178751ea2bf42e27764745.jpg



    What was cool was that in that 4th photo I could see another cargo ship anchored off in the distance.

    b67d87ab0e76171a46f939d1ff0aefad.jpg


    Are there any flat earthers in the crowd today? This ship is 18.9Nm away 38,279 yds. At that distance the horizon is blocking the bottom 136ft of the ship from view.
     

    ToolAA

    Ultimate Member
    MDS Supporter
    Jun 17, 2016
    10,500
    God's Country
    The SVbony digital eyepieces are decent for the money.

    So you suggested this SVBony eyepiece adapter last year and I brought one. Then I must have sat it on the project shelf and totally forgot about it, until last weekend when I was looking for some other project parts. I said “Hum…What’s this, and why do I have it?” It took a few minutes to recall why but I remembered that I had wanted to make an adapter for my Nikon D610. I had some time Saturday to do some designing and came up with a clamp on adaptor that holds the SVBony camera adapter to the Spotting Scope Eyepiece.

    39185a9f149a8d3c51fbc37df825aae3.jpg


    b2644813ffb4e6717a96f3df5fd6ad2e.jpg


    dfa107ea3b6112b04b9611f56143e8bc.jpg



    bdb42f7b7b79b45a63278dff1a7afd20.jpg




    Sent from my iPhone using Tapatalk
     

    rbird7282

    Ultimate Member
    MDS Supporter
    Dec 6, 2012
    18,537
    Columbia
    So you suggested this SVBony eyepiece adapter last year and I brought one. Then I must have sat it on the project shelf and totally forgot about it, until last weekend when I was looking for some other project parts. I said “Hum…What’s this, and why do I have it?” It took a few minutes to recall why but I remembered that I had wanted to make an adapter for my Nikon D610. I had some time Saturday to do some designing and came up with a clamp on adaptor that holds the SVBony camera adapter to the Spotting Scope Eyepiece.

    39185a9f149a8d3c51fbc37df825aae3.jpg


    b2644813ffb4e6717a96f3df5fd6ad2e.jpg


    dfa107ea3b6112b04b9611f56143e8bc.jpg



    bdb42f7b7b79b45a63278dff1a7afd20.jpg




    Sent from my iPhone using Tapatalk
    Man you make some really cool stuff. That's very cool.
     

    ToolAA

    Ultimate Member
    MDS Supporter
    Jun 17, 2016
    10,500
    God's Country
    Man you make some really cool stuff. That's very cool.

    Thanks man. It’s 9:15pm and I’m designing custom concrete dining room table for a customer right now.

    e3acb9298f82f321a3bc2b7f44b68df3.jpg


    Some days I hate my job and all the BS we have to deal with in construction, my favorite part is solving design problems. I don’t even feel like I’m working sometimes.


    Sent from my iPhone using Tapatalk
     

    ToolAA

    Ultimate Member
    MDS Supporter
    Jun 17, 2016
    10,500
    God's Country
    Man these would be the shizzle for glassing for working birds.
    I'm not currently a bird watcher, but I think I may start getting into it a bit more. When my wife and I are down in Savanna, there is a lot more species to look at around the marshlands, so this may be an activity that I learn to enjoy in the future.
     

    mpollan1

    Foxtrot Juliet Bravo
    MDS Supporter
    Sep 26, 2012
    6,559
    Мэриленд
    I'm not currently a bird watcher, but I think I may start getting into it a bit more. When my wife and I are down in Savanna, there is a lot more species to look at around the marshlands, so this may be an activity that I learn to enjoy in the future.
    My comment was directed at fishing in open water and searching for birds feeding but damn those optics have sooooo many cool applications.
     

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