CS178 Assignment 4 - Architecture and Interiors
Kneeling figure, Humayun's Tomb. Photo by
Good photography often shows us the familiar in an
unfamiliar way. Taking macro photographs last week, we
made small things larger on our computer screens, and saw
a level of detail not usually visible to the naked eye.
For this reason, it's not too difficult to take a macro
photograph that makes a non-photographer gasp. Capturing a
compelling imace of Architecture can be much harder. This
week you'll be looking at the spaces where people live and
work and trying to fit them into a frame.
Architecture is typically more geometric than natural
scenes, so this week is a good week to think about the
geometry of your scene. Consider repeating elements, size
relationships as they change under perspective, the lines
induced by vanishing points, and the texture and
weathering of man-made objects. One way to surprise people
with architecture and interior photography is by using
clever composition to highlight the geometric aspects of
structures that are subliminal or even overlooked. The
requirements this week will help you play with geometry
and think about the practical concerns of people who need
to represent an interior space in a photograph.
By now you should have a good handle on the controls
of your camera, so put your extra effort this week
into making your photos visually compelling. Go beyond
simply meeting the letter of the requirements and try
out some of the rules of composition that were
discussed in lecture last week.
There are five requirements in this assignment that you
should meet by taking 5-10 photographs.
- Requirement 1: Vertical vanishing point In at least one of your photos, vertical lines in the world (e.g. corners of buildings) must visibly converge to a vanishing point either within or nearly within your frame. To do this, look up and use a wide field of view (a short focal length).
- Requirement 2: No vertical vanishing point In at least one of your photos, vertical lines in the world must appear parallel in your photograph. You can do this by looking straight ahead when you take the picture and fixing the composition by cropping later. Alternatively, as demonstrated in lecture, you can use Photoshop's perspective warp tool (found under Edit->Transform->Perspective) to make these lines parallel. You can also use the lens correction tool found in the Filter->Distort menu.
- Requirement 3: Frame your shot At least one of your photos should be shot through a door, window, archway, or other physical man-made frame. The frame should be visible in the photograph, but is not necessarily the subject. The frame need not be rectangular.
- Requirement 4: Repeating patterns Find some
interesting repeating patterns in a building or other
man-made architectural object and use them as the
focus of a photograph. Try to be creative here --
don't just take a random photo that happens to have
some repeating elements. Instead, make the repeating
elements the obvious theme of the image. So while you
should certainly explain your choices in your
comments, the repeating patterns shouldn't be so
obscure that the viewer would need to read your
comments in order to ascertain the repeating theme of
the photo. To keep things exciting, you may not use
windows or Main Quad arches for this requirement!
- Requirement 5: Interior Panorama As
real-estate agents know, it's hard to capture the
interior of a room without making it look small, and
it's usually impossible to fit the entire room in the
frame (where would you stand?). We're going to solve
this with an interior panorama. Stand in the corner of a
small room, or at the center of a large room, and take a
sequence of photographs that captures the entire room,
rotating the camera about its center of perspective
(somewhere in the middle of the lens). Make sure your
photographs overlap by about 25-50%. Then, convert your
set of photographs into a single panorama that better
shows off the interior of the room. We want to see the
panorama, not the source photographs. Try to find an
interesting room to do this in. Interiors are often dim,
so pay attention to your camera settings and the
In Photoshop you can make a panorama by going to
the File menu, selecting Automate, and then
Photomerge. A cylindrical layout usually works best,
but you should try the other ones too to see what they
do. If the resulting image has obvious artifacts (eg
edges that don't line up), you probably didn't rotate
the camera about the center of perspective, and need
to try again. For this reason, you may want to make
multiple attempts at capturing the source photos for
the panorama before you take your photos back to
You can also use some other panorama stitching
tool, such as
if you like.
Upload your photos and add comments.
Upload your photos using the Picasa account you created in the first
week to a public Picasa album titled "CS178 Assignment 4 - Architecture and Interiors".
In general we will penalize photographs with insufficient
comments, and starting this week we will be stricter than we've
been so far. You should write at least two paragraphs (ie two picasa
comments) below each of your photos explaining what camera settings
you used, why you used the camera settings you did, how you composed
your shot and why, any interesting story behind the photograph, and
any image processing done afterwards. As always, be sure to note
which requirement the photograph meets. Show that you are being
mindful of your camera settings while taking photographs. It's true
that Picasa will show these parameters in the top right of the
window, but we want to hear from you why you set them to what
you did. Here are some examples of the types of questions we'd like to
see answered in your comments.
- What did you focus on? Why?
- What aperture and shutter speed did you use, and why did you choose them?
- What settings did you let the camera determine automatically? Why?
- Why did you choose a particular focal length (zoom)?
- Why did you take the photo from where you did and include in the frame what you did?
- Did you color correct the image afterwards? Crop it? Sharpen it?
Note that there's no need to include all of these for every shot;
just choose questions that are the most relevant to each
composition. You can look at the example solution for more
As usual, we've post an
solution to this assignment to let you know what we expect. For
additional inspiration, you may want to peruse the best CS178
photographs (as selected by the TA's and instructor)
and 2010. However,
you do not need to meet the assignment requirements in the same way as
these solutions do - in fact, you should challenge yourself to come up
with creative, unique compositions. There are plenty of possibilities
out there. Surprise us!
Please remember that the photographs that you submit for each
assignment must be taken by you specifically for this course. Do not
reuse old photographs that you may have laying around, even if they
perfectly meet one of the requirements!
If you have questions or comments about the photos we used in the
example solution, feel free to add them as comments below the
corresponding photograph in Picasa Web, or to email us.
We will assign grades based on whether you met the
requirements of the assignment. For each requirement, you'll be given
a check for meeting the requirement, check-minus for not quite meeting
the requirement, or check-plus if you do something spectacular that
makes your grader's jaw drop.
Finally, here are some practice technical problems related to recent material. You do not turn these in; they're just for your educational benefit.
Note: answers have now been marked in bold.
- Problem 1 If sampling an image or scene leads to aliasing, what could you do to get rid of it (check all the apply):
- a) Downsample the image in Photoshop
- b) Pre-filter the light before it reaches the sensor
- c) Blur the image in Photoshop
- d) Upsample the image in Photoshop
- e) Nothing
- Problem 2. According to sampling theory, what should be your minimum sampling frequency, when trying to record a signal with maximum frequency 'f', to avoid aliasing?
- a) sqrt(f)
- b) f
- c) f^2
- d) f/2
- e) 2f
- Problem 3. An image convolved by the following kernel will (circle all that apply):
0 0 0
0 0 2
0 0 0
- a) be shifted
- b) become more blurred
- c) become sharper
- d) become brighter
- Problem 4. This question is not directly related to this week's material, but is meant to show you what the third type of question on exams - short answer questions - look like. You have purchased a 100mm lens and you are eager to see how well it performs as a close-up lens for macro photography. After reading the specifications online, you learn that the maximum image distance (between the sensor and the equivalent thin lens) is 120mm.
(a) For this lens, what is the distance between the equivalent thin lens and the sensor when the camera is focused at infinity?
(b) Given it's maximum image distance, what is the closest object distance that will produce an in-focus image?
600mm. The maximum image distance (s_i) is given as 120mm and the focal length is given as 100mm. Using the Gaussian lens formula (1/s_i+1/s_o = 1/f), we compute that the object distance (s_o) is 600mm. From this, we can conclude that this telephoto lens cannot focus any closer than 0.6 meters.
11:59PM, Sunday, April 29, 2012
Assignments are generally due on Sunday at midnight at
the end of the week in which they're assigned. This leaves
you free to start thinking about the next assignment
during your next section. Sometimes lateness is
unavoidable. In such circumstances, be sure to read the
lateness policy from
outline, or contact your TA.
Marc Levoy, Andrew Adams, and Jesse Levinson