17 August 2014
How “Perspective” changes what we can see for example take our Field of View (FOV) of the camera lens or a telescopic sight on your favorite firearm. Simply stated the wider the field of field the father away your subject (target) appears to be from you. Appears is the operative word here. A 1 power (1X) power lens of scope is approximately equal to the normal vision of the human eye, and in camera terms that is a 40 to 50 MM lens for a 35MM camera or it’s modern digital equivalent. Len’s less than the standard focal length give you a larger field of view but the subject appears further away and conversely a longer more powerful lens brings your subject closer while reducing the field of view (narrowing the width of your vision range). Of course this is assuming that both you and your subject/target are not moving.

The following photos taken at Mount Rushmore provide a great visual presentation on the effects of perspective as it relates to your field of view and the magnification power of your optical instrument be it a camera lens or your favorite scope. The photos below were taken with my Canon 70D with the Canon 18-200 MM zoom lens.

From the Grand Viewing Plaza 18MM Lens

From the same location at 50MM or normal viewing.

Now at 100MM

At this point I changed to the Super Telephoto lens  my Sigma 150 to 500 MM Zoom lens these were shot from the same location as before using the Canon 70D and below are the photos as I zoomed up close and personal on George.

Same location but now at 300 MM

Really 500 MM or a 10X scope.

Now you notice that you get a real close up of George Washington’s carved face but the Field of View is now reduced to the point his face is all that you can see. The photos went from the width of the mountain down to just a little more than the width of George’s face. But how big is his face really. Tune in again tomorrow to find out.

Take care out there in Cyberspace and here in Reality.

S3