Visual DOF calc as a learning aid in photography

Prehistory

During my learning curve in understanding how my lenses behave in landscape photography or in closed 4 walls environments I've used some online DOF calcs, entered lots of numbers and thought how it would be nice to have something interactively do that for me, with one or two easy moves.

It turned out that I had to write my own app to do just that. So now I have an app on my iPad and iPhone that can do like this: I slide zoom and aperture like on a real lens, and see how field of view, dof and size of a photo model changes inside a projected frame:

Lens geometry view with distance, aperture and zoom sliders.	DOF, angle of view, and 35 mm equivalent focal length displayed

LensTutorial is a free app that allows to manipulate a photographic lens in a virtual environment.

You can play with new zoom values to investigate photographic opportunities and see how lenses in different focal ranges behave in reality. Visual and interactive style simplifies learning for beginner photographers. Experienced photographers will find use for hard numbers that LensTutorial provides in a classic dof calculator fashion. Large font/hi-contrast mode will work well in studio or outdoor environments.

Experiments I've set up with LensTutorial so far

• See how much larger is DOF for small-sensor cams e.g. point'n shoot compared to my SLR
• What lens to take to a 6ft ambient light room to get angle of view for shoulder portrait in shallow focus
• What zoom and aperture values I need on my wide-angle lens to have foreground flower and mountains in focus
• How DOF is changing from wide to tele
• What will happen to my lenses on a full frame DSLR
• How that magic f/0.75, f/1.2 or f/1.4 superfast lens would project a view at different focal lengths

Lens Tutorial can calculate and visualize the following parameters

• DOF (depth of field)
• Near and far DOF range
• Horizontal angle of view
• photo model size in units of your choice (metric/imperial)
• 35mm equivalent focal length (compensates for digital camera sensor size)

Highlights

• Standard range of 18-135 mm f/2.8-f/16 for any camera setup.
• 3400+ cameras in database storing Crop Factor and lens mount information
• 2400+ built-in lens specifications for point’n shoot, DSLR-like and other models with no interchangeable lenses
• Upgrade of Aperture from f/0.75 superfast lens to f/64 present in telephoto and macro lenses
• Upgrade of Zoom from ultrawide 14mm to super telephoto 1000 mm range
• Upgrade of Distance from macro-like 2 ft (50 cm) to extreme distant 115 ft (35m)
• Large font scheme with hi-contrast for outdoor use
• Ability to share photographic setups on Twitter, Facebook, email and more

App info

App size: 8 MB

Version: 1.4

Pricing: Free. Has in-app upgrades that can be purchased.

Minimum iOS requirements: iOS 5.0 or later.

Compatible with iPhone/iPod touch, iPad.

Optimized for iPhone 5.

Supported languages: English, French, Russian

AppStore direct link: https://itunes.apple.com/us/app/lenstutorial/id500543869?ls=1&mt=8

Website: www.lenstutorial.com

Twitter: @LensTutorial

Facebook: https://www.facebook.com/LensTutorial

What's next?

Some people that I talk to about this app say it is useless junkware, but some people even show it to their students in photo classrooms. The latter people inspire me very much to continue. There are many nuances I think photographers need to learn about lenses, but they are tricky to visualize intuitively. Maybe dpreview's happy community can advise me on that.

About the author:

Denis is an amateur photographer, a professional software developer and a bit of scientist.