Following is a picture of the sample of lenticular sheet that we got from
Microlens. The lenses are clearly shown in the picture.
The first experiment we did was trying to figure out how many time one
particular image will be shown. The setup is shown below.
The lenticular sheet is taped to the orange protractor so that the
pictures can be taken at different angles. After trying out many times, I
figured that each image will appear 3 times in the 180 degrees range. The
result is shown below:
From the resulting pictures, we can see that the same image repeats 3
times in this range of angles.
The Second Trial
After the first trial, Dr. Noe told me that I can use the multiple mode
of the camera to take a motion of the images of the lenticular sheet. The
camera will take nine pictures during the three seconds. The result is
below:
When put those pictures together, we can actually see the motion.
Imaging of a single cylindrical lens
Since the patterns on this sheet are convex cylindrical lenses, I went to
the Physics and Astronomy Instructional Lab to borrow one of those
cylindrical lenses. It appears to have this "flipping" effect when put on
to stripes of different colors. These pictures are the set up and the
results.
The lens was placed about 1 in. above the paper since that is the focal
length of the cylindrical lens. From the resulting multishot pictures, we
can see how the color we see from different angles is different.
The Color Changing A
Dr. Noe called this company called microlens to ask for information on
lenticular sheets. They are very kind and they decided to give us samples
of those sheets. Those samples came in all sizes. I decided to work with
the 15 lens per in. one to make an image for it. Since the company didn't
send us the program to make the image, I had to hand drawn our image. The
following picture is an A that I draw to try to let it flips to different
colors. From this trial I found out that the spacing between the two lines
of one image is the same as the arrangement of the lenticular sheet which
is 15 lines per in.
Following is the result
From the result we can see that the spacing actually worked and the A
changed from pink to blue at different angle.
Another Trial
After the A, I spend a long time on a larger piece of drawing which was
not as successful since its much bigger and requires much more precision
on the arrangement of the lines. Below is my drawing and the result.
An interesting Discover
After doing all that work by hand, I figured maybe we can use computer to
draw those lines since we know the spacing. Dr. Noe used this drawing
program to draw a sheet of lines with 1/15 spacing. Since the program does
not take integers while doing the spacing of the lines, there are errors
to the diagram of lines. It does not all turn black when observed at a
specific angle under the lenticular sheet. Following is a picture of it:
Since there are small errors on the spacing, the effect is not very well
shown. Then, we had this thought that lenticular sheet can be used to find
the precision of arrangement of lines. It can be used to find out whether
the lines are drawn precisely at that spacing. The lenticular sheet will
enlarge that error so tiny errors can be seen very easily.