Despite some googling, I can't find any information on the hardware limits of the camera in the iPhone 4S. What ISO and shutter speeds are possible from the still camera?
I know the exposure is programmed and you can't choose ISO or shutter speed, but I'm looking to at least know what the ranges the phone is capable. I have a lot of iPhone 4 images and can scrape the minimum / maximum values from EXIF data, but lack this resource for the iPhone 4S.
What ranges are possible with the iPhone 4S hardware? I'm most interested in the shutter speeds, but anything will help since at f/2.4 the two are linked to exposure in an understandable manner.
Best Answer
You can scrape that information off photos on flickr taken with an iPhone 4S:
http://www.flickr.com/cameras/apple/iphone_4s/
Here are a few examples of extremes. The dark end seems to show a max ISO of 800 and max shutter of 1/15, which several dark photos agreed with, and none of the ten I looked at went further, so here are two examples:
http://www.flickr.com/photos/funinthegym/6328079422/in/photostream/
0.067 sec (1/15)
800
http://www.flickr.com/photos/matthewthecoolguy/6534661585/in/photostream/
0.067 sec (1/15)
800
Looking at very bright photographs, I saw a few claiming very high shutter speeds (1/9259 and 1/2600) but none of them matched the same exif format for the shutter speed field as the rest of the iPhone 4S photos I reviewed, suggesting that these fields were modified in post processing. The lowest shutter speed I saw that matched the format of the other 4S exif files was 1/1842, and the lowest ISO was 64:
http://www.flickr.com/photos/67660035@N04/7110241863/in/photostream/
0.001 sec (1/1842)
64
http://www.flickr.com/photos/xiahou/6298147263/in/photostream/
0.001 sec (1/1842)
64
This should answer your question for highest and lowest ISO, and highest and lowest shutter speed. Keep in mind I only sampled a few dozen photos on flickr, it's possible I missed the ends of the ranges.
A random sampling from the "interesting" section, showing the mid range of shutter speed and ISO combinations:
Shutter speed ISO
0.008 sec (1/122) 64
0.05 sec (1/20) 200
0.008 sec (1/120) 100
0.002 sec (1/550) 64
0.025 sec (1/40) 64
0.002 sec (1/464) 64
0.004 sec (1/242) 64
0.042 sec (1/24) 64
0.059 sec (1/17) 800
0.067 sec (1/15) 640
0.006 sec (1/170) 64
0.067 sec (1/15) 640