Right away I must admit that this is not my idea. I know that is true of many photographic tools but I once saw someone do something just like this and I wanted to try it out myself. The question was how to go about it. I improvised a bit and trusted the camera to do what I wanted which it didn’t always do so I have learned some lessons already.
The idea is to take multiple exposures of aircraft on the approach and then combine them into one image in which the aircraft appear multiple times. I would set myself up in a position and then take a sequence of shots as the aircraft moved through the frame. My first mistake was that, because I was taking the same shot each time, I thought the exposure would not change. Not true! The camera will make some minor tweaks and this will make the whole thing less easy. White balance may also vary but I shoot in raw so syncing that afterwards is no problem.
Since I was not using a tripod, the shots are not all perfectly aligned. I took all the images in Lightroom and used the Open as Layers option to Photoshop. Then I used the auto align layers option to get everything perfectly in place. It is surprising just how much you move doing something like this! I originally thought I could just set every layer above the base one to Difference blending mode and everything would pop right out. However, that didn’t work as I had hoped. The aircraft all had an odd color cast.
Instead, I put a layer mask on each upper layer and then painted in the aircraft one layer at a time. This is more time consuming but it did the trick. Of course, if the exposures are perfectly matched, you don’t have to paint too accurately. if not, the sky color is different so a far more accurate painting on the layer mask is required.
This was a fun thing to experiment with. SFO is a great spot since you can get parallel approaches in one direction and parallel departures on the cross runway. This puts lots of aircraft in a single shot which makes it more interesting. Another time, I will take the lessons from this time and try and get them a bit better.
My day out shooting with Hayman was mainly an aviation themed event. One of the things I was interested in was looking for something more head on as the heavier jets launch out of SFO. Most aircraft depart off 01 and head out across the bay. however, the heavier widebodies launch off 28 and climb out towards South San Francisco. A head on shot of them coming off the runway is what i really want.
Hayman had a location which was halfway to what we wanted. You are a bit further from the airport and so they rise out of the surrounding landscape rather than seeing them come off the runway itself. The location has a lot of promise. Sadly, on this day the weather was not nice and, as the day was moving along, what light there was after the clouds had taken their share was fading fast. however, it was rather fun to see the 747s and A380 climbing out over us. Definitely something to try again some time. As for the runway shot, we shall have to keep exploring to find the right spot for that!
