A Photographer's Interface to a Point and Shoot Camera

a product/business idea by Philip Greenspun in June 2013

This is a product design ready for a team of young engineers (or a master's thesis student!) to build.

The Market

Roughly 100 million cameras are sold every year worldwide. Most of these are compact (also called "lens-shutter" or "point and shoot") cameras, such as the popular Canon ELPH or the Sony RX100.

Everyone has a mobile phone that can take pictures, but the image quality indoors is generally terrible. The default camera application on a smart phone typically does not offer much control over shutter speed, aperture or focus. The compact digital camera, on the other hand, has literally hundreds of controls, but most of them don't relate to the photographer's image creation task. Even people who are expert users of digital SLRs, such as the Canon EOS and Nikon D-series cameras, don't want to use the same types of settings on a compact camera due to the cumbersome nature of the menus.

The task

Given an ISO sensitivity, there are only three camera settings that affect image formation: aperture, shutter speed, and focus. The hundreds of modes and menu items on a typical point and shoot camera are all directed at coming up with a combination of these settings. Put the camera in "sports mode"? That favors a higher shutter speed and therefore wider aperture (and/or higher ISO). "Portrait mode"? The camera uses the widest aperture so as to achieve a blurred background and a correspondingly faster shutter speed.

When a picture fails to turn out as hoped, the problems generally fall into one of the following categories:

camera set exposure based on a dark part of the scene, rendering the overall picture too light (because the important subject was in a lighter area)
camera set exposure based on a light part of the scene, rendering the overall picture too dark (because the important subject was in a darker area)
scene has too much contrast to represent in a single JPEG from a single exposure; multiple images need to be combined
subject was moving too fast for the shutter speed and therefore the image is blurry (e.g., sports, children running around)
image quality is poor due in low light due to camera setting high an ISO and relatively fast shutter speed despite the fact that camera is braced.
camera's autofocus system picked out an irrelevant part of the scene on which to focus (e.g., background is sharp while subject is fuzzy)

The focus challenge is too hard, is being actively worked on by existing camera software developers (e.g., facial recognition), and is not part of this business/product idea.

How to build it

This should be buildable simultaneously as a smartphone application (probably easier for Android due to its open-source nature; perhaps use a Google Nexus device, whose source code has not been modified by the manufacturer) and for a standard compact camera, which will offer much higher image quality.

Do you have to write all of the code for the camera? No! Samsung has published the source code for two very high quality cameras, the NX300 and NX2000 (see opensource.samsung.com). Both have APS-C sensors, the same size found in most digital SLRs (Canon Rebel, sub-$2000 Nikons) and in a lot of "mirrorless" system such as the Sony NEX. The NX2000 is probably the better choice because it is not already cluttered with physical buttons on the back. You can make the touch screen offer any interface that you program.

What to build

Essentially the camera should be locked into "green idiot mode" but the photographer should have the ability to provide a few hints via dedicated buttons (not deep menu items!) on the back of the camera. Even experienced photographers don't want to make fine-grained adjustments on a point-and-shoot camera. They would have pulled out their digital SLR system if they wanted to make a -1/3 f-stop exposure adjustment. Here then are the buttons...

"Highlight Priority" / "Darker"

Cameras set exposure by measuring how much light is reflected off the subject. If a lot of light is coming back to the camera it could be because the room is very bright or because the subject is white in color. If not so much light is coming back, it could be because the subject is black or because the room is dark. The result is generally a scene that is "18 percent gray" in the final JPEG. When the scene has some dark and some light areas the camera needs to choose which part should be given priority for determining exposure. Without full artificial intelligence (AI) there is no way for the camera to figure out that the foreground is more important than the sky, for example. And, ultimately, even two human photographers might disagree about which part of the scene should be used to determine exposure.

If the previous image was too light that's probably because the camera looked at a dark area of the scene and set the exposure based on it. The result will be a loss of detail in the brighter or highlight areas. The soultion is for the photographer to tell the camera "Use the bright parts of the scene when determining exposure". This could be labeled "Expose for Highlights" or simply "Darker" (on the assumption that the button isn't going to be touched unless a previous exposure attempt was unsuccessful).

"Shadow Priority" / "Lighter"

This is simply the opposite of the above button. The photographer tells the camera that the important part of the scene, the portion in which it is important to record detail, is in the shadows or darker area.

Subject is Moving

This is similar to "sports mode" on a current camera. ISO is boosted to allow higher shutter speeds. The camera is set to record bursts of images.

I'm Braced

In twilight and indoor photography, a standard camera shake-stopping shutter speed of 1/60th of a second results in too high an ISO for good image quality. With image-stabilized lenses, a static subject, and the photographer bracing the camera against furniture or a door frame, good results can be obtained with shutter speeds as slow as 1/4 second.

HDR

Due to the usage of "HDR" for "high dynamic range" in existing mobile phone camera interfaces, the button to tell the camera to take multiple images and merge them can be labeled with the standard name of the process, i.e., "HDR". The camera will take three pictures at different exposure settings and combine shadows from one file, for example, with highlights from another. This results in a (potentially unnatural-looking) image that holds detail in all portions of the image.

Additional Buttons

The camera still needs the following additional buttons and/or controls:

shutter release in traditional top-deck location
zoom (if equipped with zoom lens and no zoom control on lens barrel); traditionally this is a switch surrounding the shutter release
start/stop video recording (could be touch-screen switch; would be nice if this could be a gesture with the shutter release insead, e.g., hold it down for more than 1 second to start a video (which would create a spurious still photo for every video and possible some unwanted videos as well))
create a panorama (touch screen switch)
switch to playback mode
the dreaded MENU switch (required for things such as setting date-time, turning GPS on/off, formatting memory card); can probably get away with limiting this option to playback mode

Total buttons when in use to create pictures:

shutter release/zoom on top deck
start/stop video
panorama
playback
darker
lighter
subject moving
I'm braced
HDR please

Conclusion

That's it! A point and shoot camera needs fewer than eight buttons on a touch screen to be far more useful than current cameras with their deep menus.

The people who make digital cameras never seem to learn anything about user interface. The people who make smart phone cameras never seem to learn anything about image quality. That leaves a big market opportunity.

philg@mit.edu