Yes, math is useful sometimes. And when I say “math” I do not mean simple arithmetic. I mean math. Real math. Calculus, and things like that – such as Fourier transforms.
I learned about FFTs (Fast Fourier Transforms) as an undergrad in university. And today I discovered a use for them in my photography practice. Namely, to remove unwanted repeated patterns from scans of old photos, printed on textured paper.
But let’s start at the beginning. What is a Fourier transform? Well… think about transforming a time-domain picture to a frequency-domain picture. (or, as Wikipedia puts it, “The Fourier transform (FT) decomposes a function (often a function of the time, or a signal) into its constituent frequencies. “. A picture full of repeated lines thus become two dots, for example.
And this (detail from a) picture, full of a repeating pattern due to the original photo paper…:
Becomes this, when transformed through an FFT:
But now I can remove the dots:
..and then I can do a inverse FFT, to end up with this:
And if that isn’t magic, I am not sure what is. There you have it: Magic through math.
Incidentally, the app I use is ImageJ, a free Java-based app from the US National Institutes of Health (NIH). Your tax dollars at work, here: https://imagej.nih.gov/ij/.
I hear this a lot: students almost apologizing for “only” owning, say, a Digital Rebel camera, or a similar “starter” model. Because, they say, “of course you need a pro camera for pro results”.
Pro lenses, maybe. But pro camera? Not always, not at all. And even the lenses: this, for example, is student Veronic this morning, using a Yongnuo 50mm lens for Canon (a clone of the cheap Canon 50mm f/1.8, but cheaper):
If you were to see this at full size, you would see it competes very well with photos taken with my pro equipment.
Those of you who take my lessons learn all about this; for the rest of you: be a little skeptical with regards to what you read. Yes, equipment is important. But no, it is not always needed for a quality picture.
To emphasize what I wrote yesterday, look here. My grandparents, in 1928 in Tilburg, the Netherlands. In other words: just before they were to set sail to the Dutch East Indies, or “Ons Indië”, as they called it at the time: “Our India”.
They were headed to the city of Batavia, where they settled down, both teachers, and had a family, namely my father and his two younger sisters.
Batavia is now called Jakarta, and the entire family has long since passed away. None of them made it to a very old age, all dying in their 60s or early 70s, probably at least in part due to their experiences for a number of years in several of Batavia’s Japanese concentration camps, including the infamous Camp Tjideng “hell on earth”. The entire family survived, which was not all that common, but they were marked. They never talked about it much: the little I know, I heard from my father’s younger sister Chris.
43, 13, 11, 9
In the photo, they were of course unaware of what was to transpire. The line above shows their record in concentration camp Tjideng in April 1944: mother and three children. (A couple of months later, at age 14, my father was transported alone to the “men’s camp”.)
After the war, they were held in the camp by the British for “security purposes” – my father always resented this, almost as much as he resented the Japanese and in particular Emperor Hirohito, in whose name all this was carried out. Not being one to listen to authority, he escaped and walked back to Tjideng–not a very safe thing to do at the time. Shortly after they were eventually released, they were all put on a ship to The Netherlands (which my father had never seen, of course) and handed 25 Dutch guilders and told, basically, to get lost.
In any case, the photo.
First, of course old photos are an invaluable way to travel back in time, and they should be valued as such. Priceless. And they should be preserved (the above version is my restored version of the original, where I fixed scratches, fading, sun discolouration, and so on. If you have old photos, have me restore them.
Second, the actual portrait. A fabulous professional work. Perfectly lit (the technical terms are “Rembrandt Lighting” and “Broad Lighting”. Great expressions. And they are not standing there posed military style, smiling at the camera. They are looking out, to we know not what—their future in the East, perhaps? Or are they looking back at the first half of their lives? She seems more apprehensive than he, pensive, perhaps a little sad, even. He is more “bring it on”, but is holding back somewhat at the same time.
This is what a great portrait should do. So while I understand the liking for “stand there and smile”, it is also a great idea to consider some more artistic portraits, that bring out the subject’s personality. Posterity will be very grateful.
Today, I was reminded of how I should not let you all down – the many people who read this blog. Like one reader, Dr Jason Polak, who kindly dropped by in the studio today to have a chat.
(Hint: anyone near Ottawa, feel free to come say hi. The store is open 9:30AM–9pm weekdays, and slightly shorter hours at weekends). So anyway… I promise I’ll write more. Starting today.
One thing to write about is portraits. And how I love doing them. And how I like doing not just the “stand there and smile” pictures, but also slightly more creative pictures. You do not need to look at the camera smiling, not in every picture!
So here’s one I took this weekend—one of a series:
A simple shot; I used two speedlights with Honlphoto grids, driven by Pocketwizards; and one strobe in a softbox, also driven by a Pocketwizard. Took two minutes to set up.