9.12.11no notes Camera Obscura Lab due tomorrow Today:Recap for lab Optical Illusions
Data calculations Hi is negative –upside down Ho positive M negative--<1, has no units Di = 23 cm All of the numbers in the same units
hi ho di do M = h i = - d i h o d o Rays are straight lines of light Notice that the rays from each edge of the object cross exactly at the pinhole when it is very small Be sure to draw in the image in the diagrams!!
hi ho di do M = h i = - d i h o d o When the pinhole is larger, More rays enter the pinhole from each spot on the object, What effect does that have on the image? Would the image be more or less clear? Would the image be more or less bright?
Conclusion..3 parts of purpose Confirm the linear propagation of light Calc. Magnification Calc. the Height of object
Floating finger illusion The Floating Finger Hold together the ends of a finger from each hand about arms length in front of you. Look under your fingers at some distant object. The fingers will now appear in three sections. Separate the fingers slightly and a finger with two fingernails will seem to be suspended between your two fingers
At first, there doesn't seem anything unusual about this picture.
Skewed lines All these tracks look as though they've come from a broken down railway track, but in actual fact, they are perfectly parallel! To prove they really are parallel, watch the small 'hairs' gradually disappear. You will see the lines as how you would expect them to be.
All of the red lines are completely parallel would you believe?
You should see a negative version of the square and word. Note that the image does not show up instantaneously but emerges out of the gray in a fraction of a second or so. Then it slowly fades away.
HERE is a chromatic diagram with roughly equal luminance in all the squares (except yellow). Look for its afterimage the same way, by staring at one place in the middle of the pattern for 15 seconds and then shifting to the gray.
Rapid-eye-motion Stare fixedly at the black dot for 30 seconds, and then look at the white dot. The black squares should seem stationary, but the white afterimage will flicker about, revealing your rapid-eye-movement. The afterimage is "burned" into your retina, while the new image is flickering about on the retina due to the REM.
Flickering Fog illusion stare intently at the red dot in the center of the left block for about a couple of minutes.Once you've done this, look over to the center of the right block. It should act weird - by fading out and 'flickering'. If you move your head closer and further from the monitor (while focusing in the center), you should see some interesting interference effects too.
Wheel of Confusion Which way is the wheel turning!? it appears to be rotating anti- clockwise. However, if you follow the yellow dots round instead, the whole wheel will be turning the other way! - clockwise!
Rotating dot whirlpool Wow! Try staring at this for more than 5 seconds without going crazy. Then try following it round! =) Curves constantly die out and then re-evolve as part of another curve.
Primrose's Field : This checkered background consists of squares but appears to wave. In addition, this figure shows a great amount of anomalous motion illusion.
The Rotating Dots : Follow the movement of the rotating pink dot with your eyes and the dots will remain only one color, pink. But if you stare at the black + in the center, then the moving dot will turn green.
Vanishing Dots : If you stare closely at one yellow dot for a while the other dots disappear.
Magic Zoomster This cool optical illusion has been seen before, but I've spruced it up by adding colour, multiple layers, and making it bigger!! The idea is to focus on the dot in the centre and then move your head constantly towards and away from the monitor. You should see the circles rotate spookily! Press the F11 key in your browser to see the illusion at full screen!