Round Earth

There are clear pictures of the earth from space that depict the earth being round... so this website is completely inconsequential.

There are pictures from Earth that show a curved horizon.  It's called a wide angle lens. 

There are pictures from Earth that show a curved horizon.  It's called a wide angle lens.

A wide angle lens does NOT change a straight line into a curved one. Nice try.

correction.

Simple Solution I'm surprised I haven't seen it before.

Quote from: jroa on January 16, 2014, 10:24:05 AM

There are pictures from Earth that show a curved horizon.  It's called a wide angle lens.

A wide angle lens does change a straight line into a curved one. Nice try.

Yes, it does.  Nice to finally meet an REer who admits this. 

Quote from: inquisitive on January 16, 2014, 10:47:52 AM

Quote from: jroa on January 16, 2014, 10:24:05 AM

There are pictures from Earth that show a curved horizon.  It's called a wide angle lens.

A wide angle lens does change a straight line into a curved one. Nice try.

Yes, it does.  Nice to finally meet an REer who admits this.

I don't think RE have ever failed to admit that this is what fish eye lenses do. Its just that FErs don't acknowledge the details of how this works.

There are pictures from Earth that show a curved horizon.  It's called a wide angle lens.

By a "wide angle lens" I'm assuming you mean something in the order of 8mm to 10mm focal length?

If so, you'll be interested to know that a "normal" focal length lens of 55mm will also produce an image with a slightly curved horizon—just not as pronounced as with a WA lens.  And a 55mm lens also approximates the field of view of the human eye.
 
 
 
[EDIT:  spelling gremlins... grrrrr]

Quote from: jroa on January 16, 2014, 10:24:05 AM

There are pictures from Earth that show a curved horizon.  It's called a wide angle lens.

By a "wide angle lens" I'm assuming you mean something in the order of 8mm to 10mm focal length?

Actually, whether or not 8-10 mm would be considered "wide angle" would depend on the film/sensor size.  For a 35mm camera, then yes.  For a 1/1.7" point and shoot camera, it would be considered a "normal" lens.  For a 1/2.3" phone camera, it might be considered telephoto.

See correction above.

Quote from: jroa on January 16, 2014, 10:24:05 AM

There are pictures from Earth that show a curved horizon.  It's called a wide angle lens.

A wide angle lens does NOT change a straight line into a curved one. Nice try.

correction.

Actually, it can:

Quote from: jroa on January 16, 2014, 10:24:05 AM

There are pictures from Earth that show a curved horizon.  It's called a wide angle lens.

A wide angle lens does NOT change a straight line into a curved one. Nice try.

correction.

I wonder how these cows live on such a small planet, then?

Fish eye lens.

ps. How does satellite tv work?

Fish eye lens.

ps. How does satellite tv work?

I don't think anyone meant fisheye lens when talking about wide angle lenses. Jroa seems to assume all wide angle lenses are fisheye lenses.

Quote from: inquisitive on January 20, 2014, 02:49:33 PM

Fish eye lens.

ps. How does satellite tv work?

I don't think anyone meant fisheye lens when talking about wide angle lenses. Jroa seems to assume all wide angle lenses are fisheye lenses.

If you can tell people a better way, then do so,

Fish eye lens.

ps. How does satellite tv work?

Static Satellites...

Whether or not 8-10 mm would be considered "wide angle" would depend on the film/sensor size.  For a 35mm camera, then yes.  For a 1/1.7" point and shoot camera, it would be considered a "normal" lens.  For a 1/2.3" phone camera, it might be considered telephoto.

For the purposes of this exercise, I should've clarified that I was talking about a 36mm x 24mm sensor, or so-called "full frame" sensors, or a 135 film frame.

I don't think anyone meant fisheye lens when talking about wide angle lenses. Jroa seems to assume all wide angle lenses are fisheye lenses.

Agreed.  Fisheye lenses and wide angle lenses are two totally different things.  Admittedly, it's a subtle difference though, and possibly lost on non-photographers.

The image curvature caused by wide angle lenses (and particularly zooms) is known as "barrel distortion", and can be determined by the amount a reference line is bent (in pixels) as a percentage of the image height (in pixels).

Here is the distortion chart for one of the widest full format Canon lens, namely the 14mm f2.8 L II
It has a field of view of 114°, considered as a very wide lens on a 24x36 sensor.



You may note the moderate distortion, and the absolutely rectilinear rendering of the chart's center lines.

(credits: photozone.de)