Lens Slate is a free photography app for iOS and Android to help you keep track of the configuration of manual lenses as you shoot.

What is it for?

When you use a digital lens on a digital camera body, information about the lens model, focal length, and focal ratio is typically recorded in the image file.

When you use a manual lens, this information is not recorded. Later, you might remember which manual lens you used for a particular photograph, but you often won’t remember the focal ratio or, for zooms, the focal length.

Lens Slate helps you keep track of this information.

How do you install it?

Open the app web page in

and follow the instructions.

How does it work?

On the main screen of the app you select the lens model, focal length, focal ratio, adapter model, and whether the configuration applies to the previous images or the next images.

You end up with a screen that looks something like this:

After choosing the lens, focal length, and aperture from menus, you take a screenshot:

The screenshot will be saved in the camera roll on your device.

After shooting, you import the photos from your camera and the screenshots from your iOS device into your catalog software (Lightroom, Photos, or similar).

If you sort by capture time, the configuration screenshots will be interspersed with your photos:

You can now match the lens configuration to your photos.

If you want to take this a step further, you can then add the lens configuration to your photos using, for example, exiftool or the Lens Tagger plugin for Lightroom.

© 2016, 2018 Alan WF