1. George Tasker

    George Tasker New Member

    One of the common claims of FEB's (Flat Earth Believers) seems to be that everything is CGI. One of the most frustrating claims though is that pictures of the earth curvature from on high are debunked as being a property of wide angle camera lenses showing curve where none exists.

    I recently asked myself if with the new digital cameras if a pin hole lens is viable now. It turns out that it is and as of about six months ago there are pinhole camera lenses that exist for some cameras from a crowd known as Thingify.

    https://petapixel.com/2017/05/31/heres-worlds-first-multi-aperture-pinhole-lens-dslrs/

    It appears to me that the pictures that one can gain from this lens are sufficiently sharp to be able to send on up on a high altitude balloon to settle the claim once and for all whether curvature of the earth is visible from those altitudes.

    So if someone has the means and the motivation to make this a goer then I'd be most interested in seeing the outcome. Heck of someone has the motivation but not the means then I'd be more than happy to toss a few shekels into a gofundme.

    I don't believe anyone would argue that light passing though a pinhole lens is in some manner being messed with in the same way they argue about it with glass lenses.
     
  2. Mick West

    Mick West Administrator Staff Member

    Those seem to be different claims. "Everything is CGI" and "curvature is a property of a lens". You seem to be discussing the second one.

    Pinhole lenses have never not been viable. I had one for my canon fifteen years ago. You can make one with a body cap and a soda can.
    upload_2018-1-13_7-49-37.


    The "Thingify" just has variable sized holes.

    Oh I think some would. After all they argue the sun stays the same size and sets, even though it's moving away and staying at the same height.
     
  3. Laser

    Laser New Member

    The pinhole lens has the advantage of not only being distortion free, but in particular, it is perfectly rectilinear. I find the pinhole lens to be a useful simplifying concept when calculating images of the horizon.

    Unfortunately, I'm not sure such a low distortion lens on a high altitude balloon will help the flat earthers, since Jeranism already reposted a video by flat earther Dwayne Kellum

    Source: https://www.youtube.com/watch?v=2RATP53l9MA
    who sent up a low distortion wide angle lens on a balloon and found the curvature. But bizarrely, the flat earthers considered that video as proof of flatness, even though there was clear curvature, even in the bottom of the frame! See for example around 1:40:15 in the video. I had not realized until reading the comments to that video that the flat earther's couldn't see the curvature even when it was plainly visible. I'm not sure now what's going on in their heads. I'm guessing they just expect far more curvature. Or maybe it's that their visual system is blind to small curvature, kind like those people who used to set their TV to stretch 4by3 aspect ratio video to fill their 9by16 widescreen tv, and even when you pointed it out, they couldn't tell that all the circles were ovals and the people were extra fat. There is a kind of art called naive art where works lack perspective. Probably most naive artists are just untrained in perspective, but it has been said that some may actually lack the faculty in the brain to comprehend it. Or maybe if you grew up outdoors with few straight lines, your brain might not learn the ability to recognize a straight line or deviation therefrom.
     
    • Like Like x 3
  4. Laser

    Laser New Member

    On Dwayne's discussion page, a commenter asks him about the curvature in one of his images and he says that is just clouds and that there is a lot of moisture in the air where he flies his balloons. At least he acknowledges the curvature. But a lot of flat earthers don't even see it. Of course you may need to hold a straight edge up to the image to clearly see the curve.

    From high altitude you can see hundreds of miles, so there will almost always be clouds on the horizon. Even if you see no clouds, you can't be sure there are none there that just blend in with the haze. So unfortunately if they are going to use the clouds make curvature excuse, then I don't see how any pictures showing curvature from altitude are ever going to be convincing to them. Nothing less than far up in space will do. At least we know what evidence not to waste trying to get for them.

    Of course this just brings us back to their problem that they keep saying we should go by our own observations, but whenever those observations show curvature, they tell us not to believe what we see because that's not really curvature, it's just distortion, perspective, clouds, or something.
     
  5. DavidB66

    DavidB66 Member

    A pinhole lens (which to be pedantic isn't a lens at all) could also be useful at lower altitudes. From a cliff or building a few hundred feet high, overlooking the sea, a slightly curved horizon should be visible if the field of view is wide enough. For example, from a height of 500 feet, and with a FoV of 130 degrees, the sagitta of the visible arc of the horizon would subtend an angle of about half a degree at the viewpoint. This ought to be detectable even to the naked eye, and even more so when enhanced by the methods Mick West proposed in an earlier thread. The problem with conventional lenses is that it is difficult to get such a wide FoV without distortion, and even if this could be achieved, the doubters would not believe it. A pinhole camera, with no refractive lens, should in principle remove this objection.
     
  6. Whitebeard

    Whitebeard Senior Member

    Pinhole photography is a fascinating discipline. This guy, Justin Quinell ( https://www.lomography.com/magazine/64615-justin-quinnell-the-pinhole-wizard ), is perhaps the worlds leading authority in the technique. His home made cameras range from the tiny, that can fit inside a human mouth, to a huge wheely bin (dumpster to our friends in the US). His work is amazing. He used to date a friend of mine and when he did his huge wheely bin camera pics of Bristol, our home city, I was his camera roadie!!
     
  7. Mick West

    Mick West Administrator Staff Member

    I suspect a pinhole camera at that wide an angle would have resolution problems. While theoretically it's a good idea, there's some practical problems. Look at this from "the world's widest digital pinhole", which is still only 22mm equivalent.
    https://www.popphoto.com/gear/2011/04/wanderlust-pinwide-pinhole-lens-micro-four-thirds
    3-cityscape.

    A selling point for pinhole lenses is their "dreamy softness". That generally means the pictures look crap, and they are just a novelty, producing blurry images you can reproduced and improve upon in post.
     
  8. DavidB66

    DavidB66 Member

    Thanks. The optics of pinhole cameras are more complex than I thought. There is a useful article here explaining some of the complications: https://www.wesjones.com/pinhole.htm Whether the disadvantages of the pinhole camera would outweigh the advantages, for the specific purpose of detecting the curvature of the horizon, isn't clear. Some of the problems are due to the dimness of the light entering the camera through a small aperture, but this might be offset by using a very long exposure time, as was often done in Victorian landscape photography. For many purposes this would be impractical, but when the object of interest is essentially static, like the horizon of the sea observed from a fixed viewpoint, it might not be such a drawback. It wouldn't matter if moving clouds, etc, appeared blurred, because we would not be interested in them.