Median Stack

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.