There are occasions when the iPhone camera is not wide enough. A handful of companies (Moment, olloclip, Schneider, Zeiss – just to name  a few) realized that this is an issue, and started making converter lenses that let you shoot wider. These lenses fall into two categories: 1) well corrected for distortion – like the Moment or Zeiss, and 2) uncorrected.

With the latter group you have severe barrel distortion. We started experimenting with these lenses for use with the Mark II Artist’s Viewfinder back in 2013. The barrel distortion basically made them unusable for simulation purposes, so we came up with a solution that’s unmatched even five years later. Maybe because it needs a lot of effort and is quite costly to implement.

The technology behind the solution is real-time distortion correction, and the associated thing in both Artist’s Viewfinder and Technical Camera is Wide Mode.

Let me show it in action before going deeper (veteran Artist’s Viewfinder users can skip this, as it’s exactly the same thing you’re used to in that app).

The top/left half of the image is what you get when attaching an uncorrected converter lens. The lower/right half is what you’ll end up after turning on Wide Mode.

This kind of correction is really important if you want to take architecture or real estate pictures – it may separate an amateurish looking image from a professional looking one.

Since distortion correction is done in software, edges of the resulting image may become soft. This is more pronounced with wider (0.5x-class) converter lenses. One possible mitigation (depending on planned image use) is using JPG Half or JPG Quarter image size for your album.

To use a converter lens with Technical Camera, you need to tell the app which lens you are using with the Wide Converter item in the menu. This will select the appropriate correction profile and conversion factor. We make dedicated profiles for each supported converter/phone combination (this is why it’s a costly endeavor). The list of profiles is continuously expanding, so if you miss something, please let us know.

We also measure the exact conversion factor for the profiles (which is usually more conservative that manufacturers tend to advertise). In Technical Camera this number is used for displaying Framing Previsor corners correctly.

But since we can’t cover every single lens on the market, there’s another neat thing: you can create a “custom converter” yourself. Since the process is exactly same for both apps, I’m not going to replicate here what I wrote about this feature when it was introduced in Artist’s Viewfinder – but I recommend you to read that post.

Ok, you have a converter selected. The lens is already attached to the phone. What’s next?

You have to activate Wide Mode. This is done with either the WIDE icon among camera options (accessed by tapping the circle icon in the corner – shown below).

Wide Mode icon on Camera Options

Or by assigning the Toggle Wide Mode (W) function to a Smart Function Key and operating that key.

That’s it. Until you turn Wide Mode off, the viewfinder, saved JPG images, and even preview images saved in RAW files will be distortion corrected.

All functions (exposure, focus, etc) operate the same way in Wide Mode, with the exception of digital zooming, which is disabled.

Technical Camera is available for pre-oreder now on the App Store, at a 30% discounted price. It will be released tomorrow.