Monday, 12 September 2016

Median Stack

War Memorial, Victoria Park

Not the world's most interesting photograph and not helped by dull grey light, but pretty damn sharp for an iPhone. That's because it's not a single image but a median stack of 12 shots. This is a technique which is used a lot in astrophotography to boost sensitivity and reduce image noise. After alignment of all the frames, Photoshop is used to calculate what I understand as the median value of each pixel. My interest is in boosting the quality of images from small sensors in phones or compact cameras. And I was pleased with this result. But there's a problem. This was my first attempt, worked pretty good. All the subsequent attempts ... not so much. Which is very frustrating. I suppose I can't expect a complex technique such as this to have high reliability. I just need to be happy when it works.

War Memorial, Victoria Park. Apple iPhone 5s f2.2 4.2mm 1/595 ISO 32, 12 image median stack.