Thursday, October 28, 2010

iPhone 4 Camera, surprisingly good, needs raw.

I'm guessing there is no application that can be written for the iPhone that will allow me to capture the raw file from the little 5 megapixel camera.  Too bad!  I find the tiny camera to be a gem, with a sharp lens that focuses quite close to the camera. (See photo below)

A "Horselubber" grasshopper eating one of its own kind on an asphalt road.  I just set my iPhone on the road next to it and used an application with a 3 second timer to fire the shutter.

As many have said, sometimes the best camera is the one you have with you.  When I bought my iPhone 4, I was looking at the latest model iPod touch but the specifications for the camera on the touch were so much worse than the iPhone, I decided to ditch my old cell phone and switch to the iPhone just to get the better camera.  I find the back illuminated CMOS sensor on this camera performs well, giving reasonable shutter speeds in dim light (in spite of the auto ISO adjustment) and sharp JPEG files with good pixel to pixel resolution.  Of course I'd like more control over the shutter speed and ISO settings but these can be worked around, sort of, by carefully picking the part of the image the meter sees.

A sculpture found at La Entrada and River Road in Tucson.  I picked a bright point in  the center of the image for both focus and metering, keeping the sky dark and not blowing out the highlights.  I made the sky darker when I converted to black and white.

I have found there are various useful applications for the iPhone camera.  One that I like is "Camera Plus" which has a timer setting that delays the shutter for a few seconds after I touch the screen to take a photo.  This allows me to better use the "Blur" tripod and mount I bought for the phone from Mobile Mechatronics Inc. (  The "Camera" app that comes with the phone provides a setting for in-camera High Dynamic Range (HDR) photography which sets the camera to take 3 photos at varying exposures and merges the three into a final image that covers a wider range of exposures than a single photo could.  Of course, the camera and subject must stay fairly still for this to work.

On the left is the "normal" image taken with the iPhone camera, on the right is the HDR version of the same image taken at the same time.  Notice the blown highlights and darker shadows in the first image.

The fixed aperture of f/2.8 on this camera means the depth of field is always the same. I find this compromise to be acceptable for the small size of the camera.  Given the tiny sensor size and the 3.85mm focal length of the lens the depth of field is quite deep even for macro shots.

Vines on a slope.  Even a couple of feet away from the camera the depth of field is a couple of feet.  For closest focusing distance, it is only an inch or two (see first image in this post).

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