By Graham K. Rogers

A local user contacted me at the weekend reporting a problem with output from his iPhone 5 camera. My experience with the iPhone 4S suggests that images should be sharp and clear unless of course there is something wrong. With the help of input from the user, I analysed the problem and pointed him in the right direction.

For a lot of photographic work I will reach for my Nikon cameras, but sometimes convenience has me using the iPhone. The pictures are usually good enough for the end output I am aiming for: an email, web pictures, or perhaps Facebook content. There is no point taking a 16 mp RAW image of 17 MB or more, if all that is needed will be a 640 x 640 JPEG.

An email from a local user who sometimes asks for advice, initially had me a bit worried. He reported that the images he was taking with the iPhone 5 were just not up to par. They were not in focus, or were blurred. As the iPhone 5 has a better camera setup than the iPhone 4S I use, he felt he had a problem. I started by making some suggestions to try and find the possible cause.

The iPhone 5 has an 8-megapixel iSight camera as does the iPhone 4S that I use. However, the 5-element lens used in the newer iPhone with its sapphire crystal covering is better and Apple goes to great lengths to match the lens to the camera. Mark Crump, reporting on GigaOm comments that he now uses his point and shoot camera less, in favour of the iPhone. While he did not see a marked improvement with the camera and lens, the software now used is a major improvement, he writes.

My first comments, without having seen any images, concerned the source of the problem: physical or software. I asked him to confirm that there was no cover over the lens (either the original protector or a cover added since), and that the lens was clean. Camera shake can be a problem in some situations, but I needed more information. However, I did suggest putting the camera on its side on a table or some other flat surface and taking a photograph.

In case the problem was software, I suggested a reset of the iPhone: hold the off button at the top and the Home button together. Do not let go until the Apple icon appears on the screen.

My main concern for him was that there was something that could not be easily fixed and that a trip to the shop might be needed. As the iPhone is under warranty this might not be a problem (I believed) if the camera installation itself were faulty: not that I had heard any reports of this so far.

Later in the day, he sent me a couple of shots that he had taken and, indeed, these were fuzzy. I was in Siam Discovery so I took a shot of the mall, ust holdiong the iPhone in one hand, and sent it by email (slow because of poor DTAC connections there). The image was crystal clear.

As the images he had sent were faulty, I asked for some metadata: the information about the shot that a digital camera embeds in the file. Images sent by email have this data stripped out, but I thought this would be useful to compare the faulty images, my image and also another photograph he sent later that was crisp. His iPhone 5 certainly could take photographs, but not all the time.

The metadata, when it arrived enabled me to narrow down the problem. As can be seen using the metadata image I have here (taken from iPhoto on the iPhone 4S), the image size is usually the same, as is the exposure control (the F-stop) which on the iPhone 4S and iPhone 5 is 2.4.

The lens size is also fixed. In Aperture this is reported as 4mm for the iPhone 4S, while the metadata in iPhoto reports 4.3mm. The information that I was sent about the images from the iPhone 5, showed that the focal length of the lens for that device is 4.1mm.

The software changes the other settings, such as ISO (the theoretical film speed); and the time, usually in fractions of a second. The image I had taken in fairly good light conditions shows an ISO rating of 50 (higher quality) and a time of 1/24 sec. The good image from the iPhone 5 that he had sent, also had an ISO of 50, with a speed of 1/401 (the software produces unusual figures that a DSLR camera would not). However, when I looked at the metadata from the three images (he sent one more later), I saw the following:

• ISO 800 - speed 1/15
• ISO 500 - speed 1/15
• ISO 400 -speed 1/17

Then I remembered advice I had read in an old book on film photography that I had kept for many years (Michael Langford's 35mm Handbook. Knopf, NY; 1993 - still available on Amazon), that taking a photograph at a speed of below 1/30 is likely to produce camera shake. While the iPhone software was able to compensate for my image taken at 1/24, at the slower speeds of 1/17 and 1/15 the iPhone would probably not. The lesser light conditions needed flash or some form of camera stabilisation.

While I have the Glif tripod mount and a small tripod for some situations, it might be just as easy to lean against a wall. When I had taken the photograph at 1/24 I was seated which may have been enough. Most people stand when taking photographs.

Additional Note

While I have all settings on English, including Locations, because reading Thai is really limited for me, the data was probably taken from local sources, in the same way that the Maps app data shows all locations (not labels) in Thai. GPS settings in Aperture were reported correctly, but these are numbers anyway. Google Maps also displays information this way.

Most local users will be able to read the Thai characters, but there are many non-Thai iPhone users here while it is also a major tourist destination. Few visitors to the country will be able to read Thai, so (apart from major destinations) the maps are confusing. Settings for English would be better.

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs.