Thursday, September 20, 2012

Mobile Phone Photography - Part 1: HDR

 
Mobile phones are getting better and better at taking photos, especially outdoors in good light, they are usually in our pockets all the time, they have a huge DoF, they focus reasonably quickly and they shoot good quality 1080p 30fps videos with stereo sound.
This will be the first part of a series discussing mobile phones photography, and how they fit in the usual DSLR workflow, in this post I will discuss built-in HDR capabilities. HDR is short for "High Dynamic Range", it usually indicates a technique to get a picture with very light and very dark tones apparent at the same time. You will find lots of stuff on the Internet labeled HDR that looks like technicolor vomit with lots of halos, these pictures are usually overdone.
 
However, there are sensible pictures that uses this effect cautiously to get clear darks and highlights at the same time, the usual technique is to take several photos for the same scene at different exposure values to record all highlights and darks in detail, then you'd take these images and combine them using software like Photomaix or Photoshop. There are lots of other ways to get more dynamic range out of your photos.
 
Recently several cameras, phones and even DSLRs (ex. Canon 5D Mk III and Nikon D600) featured built-in HDR creation, this makes it much easier than having to use software later to process images, especially if you're as lazy as I am regarding post processing.
 
I have bought a Samsung Galaxy S III when it was available (I have owned the original S and the S2), it has a real nice 8MP camera, it also has two excellent features that I didn't have on the S2, can you guess? Correct, HDR is one feature, and the other is a burst mode that takes 20 shots at 6 frames per second and lets you choose the best one, it can even choose it for you.
 
Have a look at this example, I was sitting in a car with bright daylight visible through the windshield, I looked at the dashboard and it looked very dark in comparison, then I thought to use the HDR feature and test it out, I didn't need that picture, just wanted to test HDR, when you choose HDR, it gives you both the standard image and the HDR one, here's how the original looked like straight out of the camera:
 
Original image straight out of camera
 
Then I took an HDR shot of the same scene, the extremely fast burst rate doesn't make you feel that it took any time to shoot three photos (correct exposure, under-exposed and over-exposed), here's how it looked like:
 
HDR photo
 
Much better than the original shot, but how about tweaking the original in Lightroom? My phone doesn't shoot RAW, but I gave it my best shot, and here's what I was able to do:
 
Original shot tweaked in Lightroom
 
Which one do you like better? I certainly like the sky better in the original shot, it seems to have some halos in the HDR version (look around the tree top), more complicated masking in Photoshop can solve the issue, but I am no Photoshop user.
 
Mind that you're seeing a resized version of the pictures, the tweaked shot has a lot of noise and artifacts (caused by pulling shadows in a compressed JPEG), and It doesn't have enough details in the dashboard.