The 50mm ‘trick’

From the Telegraph:

Wind farm developers using ‘tricks’ to make turbines look smaller

Wind farm developers make turbines look smaller than they actually are when applying for planning permission in order to ‘trick’ councils into giving them the go-ahead, a leading architect has warned.

What is this nefarious trick? Using 50mm lenses to take pictures of wind turbines. 50mm lenses are also known as normal lenses (on 35mm cameras). Anything shorter than 50mm is considered a wide-angle lens and anything longer is considered a telephoto.

So the complaint seems to be that wind farm developers are using normal lenses. How awful! But when you run out of real controversies, I suppose a fake one will do.


Borehole item(s)

Comments:

  1. In 35mm format cameras, 50mm lenses produce images with a perspective that well matches what the human eye sees. So yeah, what a dirty trick to use such lenses!

    Here's the actual trick. If you download the image from the Telegraph article, you'll find that it's 620 pixels wide. If the bottom picture was really taken with a 75mm lens as claimed, and the top one with a 50mm lens as claimed, and neither was cropped, then the scene represented in the bottom frame should be about 413 pixels wide in the top frame. In fact, it's only 230 pixels wide.

    Close inspection of the images leads me to believe that both were taken with the same lens at slightly differing viewpoints, and that the bottom image was merely cropped to simulate the effect of a different focal length. The focal length being simulated is 135mm, not 75mm.

    • Another lifetime ago, I was attempting to be a documentary photographer -- of course this was before the digital age, and I have not caught up with all the facets of digital photography. How can the number of pixels in these photos be determined? In fact, how does one get to the meta data?

      Having looked closely at the two photos, I would say that they are one and the same. The only difference between the two is the shading of the clouds which are in the same position in each photo. This is most pronounced with the enlarged photo, in the upper left. Note that the clouds are in the same position, but are darker.

  2. very basic photography and basic optics, an example of this effect using a model isn't very succesful since we all know how tall average models are (DoF - Depth of Field): http://farm3.staticflickr.com/2650/3767022167_dc0cf3ee4f.jpg

    • hi jyyh,

      The two photos in the article were not taken with different focal length lenses. The photo was just enlarged and cropped. Check it out.


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