We're all photography lovers at Realmac Software and occasionally a few of us like to dust off our Holgas, Polaroids and LC-As (my personal favourite is an old Olympus XA2), to shoot off a few rolls of analogue film.

The effects of using these vintage and toy cameras, along with techniques such as cross processing, are often unpredictable and fun. Light leaks and other imperfections are part of what gives analogue photography it's 'soul' and it's what we love about it.

The thing about shooting analogue though, is that it's actually quite a hassle (sorry die-hard fans - it's true). Getting good film stock, loading and unloading the camera, developing, printing, scanning, it's all stuff that gets in the way of the end result. So we wanted to produce an app that would take your high res, digital photos and give them the artistic qualities that our much-loved analogue cameras do.

The problem is: capturing the very spirit of a camera or film type and then making sure that it will apply to pretty much every photo you throw at it is tricky business. I spent a good many hours trawling over analogue film groups on Flickr and reading forum posts from camera fanatics to try and work out which were the most important qualities for each type of filter. Why is the Diana regarded a 'toy' camera? What are the exact colour shifts made by C-41 cross processing? How does ISO noise differ from digital noise? These are all important questions!

Once we had decided on the definitive qualities of our favourite analogue cameras and film types, we started mocking up filters in Photoshop that would take our ordinary digital photos and make them as close to the analogue examples as possible.

Keith, the lead developer on Analog, had built in a way for us to transpose the lessons we had learnt from building filters in Photoshop layers straight over to Analog. However, once a filter had been built in Analog using a particular photo as a starting point, it didn't guarantee that all photos would look great with the same effects applied. We quickly learnt that we needed to test each filter against an enormous number of photos with varying contrasts, colours and subject matter and then tweak the filters accordingly.

After a lot of fine tuning and continual research, we finally developed a set of filters that we feel are as close to real analogue cameras and film as possible. And with more filters and borders on the way in future updates we think it's only going to get easier to give your digital photos the analogue soul that they deserve.

Analog is available now on the Mac App Store.