Recent blog posts


I bought the excellent OM System’s OM-1 camera in may 2022. Since then there have been two firmware updates for the camera. There have been a few reports of people failing to update the firmware, resulting in a camera that won’t even start, and which needs to be fixed by OM System’s support. So I was a bit apprehensive of doing it, but it went fine for me. This blog article describes how I did my firmware update, and should also be of interest to those OM-1 owners who only use Linux.
Read more

In a previous post on recording birds with a camera or mobile phone, I described how you can make quite decent recordings just using your camera or mobile phone. In this post I will discuss how I decided on buying a Sony PCM A10 recorder. You can read more about the technical details of digital recording in my longer article The Basics of Sound Recording for Birders. Going into the equipment jungle of sound birding is a challenge!
Read more

As part of my decision to start recording birds this year, I also decided to try start recording migrating birds over my apartment in central Stockholm. Yeah, I know I should have better things to do, but this is fun. Bear with me! This summer I bought a small Sony PCM A10 recorder, which I think is an excellent lightweight recorder, to have with me in the field. In mid July I started to leave it outside my window over the night, recording for the entire night.
Read more

Recording Birds With a Camera or Mobile Phone
This year I decided to start recording birds more seriously. My decision was driven by a desire to learn more about bird songs and calls, but also to see what I could do digitally with sound recordings. I have, for a long time, been intrigued by Fourier transforms and spectrograms and how they could be used for machine learning and identification of bird songs and calls. Yes, we all have strange interests deep down in our souls.
Read more

Fact 1: HTTP stands for Hypertext Transfer Protocol. It does not stand for Hypertext Transport Protocol. Fact 2: HTTP is not a transport protocol in the sense of a computer or network communication protocol, despite it being used as such by SOAP. It is an application-level protocol for distributed, collaborative, hypermedia information systems. Fact 3: HTTP is a protocol, i.e. a specification. It can be implemented in software. Fact 4: REST is a set of software architectural principles and constraints for characterizing a certain class of systems; those that consist of distributed and independently developed and continuously evolving applications that need to collaborate.
Read more

More posts

New and updated odds & ends


This is a simple overview of the basics of sound, human hearing and the workings of digital audio recording, with particular focus on the recording of bird songs and calls. There will be almost no mathematics, but enough of the important concepts, so you will know a little bit about what to consider when buying a recorder and also so you will understand the important recording parameters that you can control and how to set them.
Read more

Introduction This article describes how to set up a website www.example.org with nginx and Let’s Encrypt HTTPS certificates on Ubuntu 20.04. I also describe how to make sure that the same website is served at https://example.org The domain example.org is a reserved domain name for use in illustrative examples in documents. and https://www.example.org and that HTTP requests to the server’s IP-adress are redirected to https://www.example.org. The article is based on notes from when I set up this website on a Digital Ocean droplet.
Read more

More odds & ends


Blog and Article Tags




I am Paul Cohen, and this is my personal website. I live in Stockholm, Sweden. I am also CTO at Feelgood, a partner at Seibo Software Studios, a software engineer by education and a tech lead, programmer and digital craftsman by trade, with a voracious and eclectic interest in science, culture and society. Oh, and birds too. Opinions are entirely my own and not the views of my employer.
I believe openness and transparency are essential to our digital freedoms. Sharing and copying are signs of compassion and intelligence and are also vital to innovation and prosperity. I support and sponsor, and I think you should too, the Free Software Foundation, the Electronic Frontier Foundation, the Free Software Foundation Europe and Wikipedia and the Wikimedia Foundation.