Mariusz Milka is part of the team behind Seamagination, which creates a digital documentation of Croatia’s cultural heritage underwater and on land.
This allows them to produce photogrammetry of landmarks such as Maslovnik, an Ancient Greek watchtower on Hvar, and Kupinovik, an Ancient Roman villa rustica near Stari Grad on the same island.
But it’s their work underwater that most captures the imagination, exploring Ancient Roman shipwrecks and discovering Ancient Greek pottery, not to mention coming face to face with sea turtles.
Mariusz, 42, a UK national originally from Poland, also teaches underwater, terrestrial and aerial photogrammetry online. Here he speaks with Time Out Croatia about his unique work:
Time Out Croatia: When did you first become involved in photogrammetry?
Mariusz Milka: It was around 2015. Back then I was an enthusiast of these technologies, which were not yet so popular. There were no tutorials, there were only some blog posts, forums and often low-quality information. So, it was all experimentation and trying to get the best results. I started on land, but since I was already a diver, I quite quickly begun experiments with photogrammetry under water.
It is also important to note that back then there was plenty of discouraging information online that photogrammetry was very difficult under water and most certainly impossible with a GoPro camera… And all I had was a GoPro camera.
Quite quickly I realised that the only reason all those people wrote it was impossible was only because they did not succeed, but I did...
Over the years, with many projects and opportunities to learn, I became better at photogrammetry and from an enthusiast I became a professional. Also at one point I did postgraduate university studies in Digital Heritage Conservation and 3D visualisation in Archaeology, in Sweden.
TOC: What kind of equipment did you have at the start and how has it improved?
MM: The great thing about photogrammetry is that you do not really need any specialised equipment, if you know what you are doing. The technique requires good-quality photographs and today’s phones, cameras and action cameras take much better-quality photos than needed.
So, I started with a GoPro 4 action camera and now I have a GoPro 11. Yes, the quality has improved, but the old one would still do in many situations. I bought it, because it is waterproof to ten metres deep without protective housing, so once I put it in housing and it leaked, nothing happened to the camera anyway.
Of course, I have a few other cameras, but these are consumer-level models. I have a Nikon DSLR camera I bought back in 2012, and an Olympus TG-5, a tough camera from 2017. And for terrestrial photogrammetry, I sometimes use a DJI Mini 2 drone, which is very small, almost like a toy.
However, the other part of photogrammetry is the computer to use for processing. And in my case I have a gaming computer to be able to process huge models made of thousands of photographs. Luckily, the software I use, Agisoft Metashape, has evolved and I believe this is the only software I have ever seen that works faster with every new version. How do they do it?
So, the same projects that used to take days to process, now on the same computer can be processed in hours. Also, you need to understand that I do it professionally, but if someone is an enthusiast, like I was a few years ago, all you need to start is a decent laptop, which these days cost around €800 and will be good for photogrammetry for at least a few years.
TOC: What attracted you to Croatia specifically?
MM: It was coincidence that I ended up in Croatia. I was in Cyprus working at a local dive centre and a friend of mine called me from Croatia. He runs the Nautica Vis Diving Centre in Vis. He told me that local archaeologists had just found a 2,000-year-old Roman shipwreck with its cargo almost intact and they asked him to take photographs of it, but were also looking for someone to 3D scan it.
So, he called me, because he knew I specialised in scanning wrecks. Since then, I have been working at his dive centre and also working with Croatian archaeologists.
TOC: How did you choose which particular sites to focus on?
MM: Whether these are sites on land or under water, I either 3D scan what I like or what someone wants me to scan, like the underwater heritage sites I scanned for archaeologists. There is always something interesting to digitally preserve in 3D. You just need to really pay attention. And when you are paying attention, you can accidently find a treasure others have missed in a well-known place. It has already happened to me a few times and not during an actual underwater archaeology project, but when I was leading a group of recreational divers in the waters around Vis. Every year I find something there and it ends up at the local museum.
TOC: Which dive site was the most interesting or spectacular, and why?
MM: Although I have scanned a lot of interesting places on land and under water, still one of the most spectacular was the first scan in Croatia, the 2,000-year-old Roman shipwreck near the island of Šćedro. It felt magical to dive there and see all the amphorae in the sand and realise I was one of only few people who had seen them in the last 2,000 years. It was also interesting to see how marine animals adapted to live on this piece of heritage and converted it into an artificial reef.
And then when I saw the scan for the first time and for the first time I had time to really look at every detail and discover things that I did not notice when I was taking photographs. It is because the wreck was at a depth of 45m.
So, the time we could spend diving and scanning was very limited due to air consumption and decompression. Also, at this depth everyone experiences nitrogen narcosis, which slows down thinking and limits our perception.
TOC: Where else do you intend to explore?
MM: I am still in Croatia and I would like to explore more underwater heritage sites here. There are so many unexplored archaeological sites underwater, and also so many already explored but never well-documented.
I can document these sites in 3D. I like doing it. I am always open for cooperation and collaboration. Or I can teach someone to do it. Because my first background is actually in teaching. I have a Master’s degree in Pedagogy and Adult Education. Digital Heritage Conservation came later and now I combine the two.
For the last few years, apart from teaching diving, I have also been teaching underwater, terrestrial and aerial photogrammetry o -line to people from all over the world. And some of them are just enthusiasts, like I was back in 2015, others are professionals – archaeologists, surveyors, photographers, engineers, divers… They are all interested in doing what I do, so I teach them. And with some of them, I later collaborate on interesting projects.
For more details on photogrammetry tuition, see seamagination.com.