The Math
Feel free to skip right over this part, this is the boring part, it’s so boring I thought of putting a picture of an artistic nude shot next to it just to keep people awake. Ok, so here we go. Before you can calculate the depth of field you first must know the circle of confusion for your camera.

Don’t get too lost on me yet, for most of us digital SLR users this is  one of two numbers. For most of us with APS/APS-C sized sensors this number is 0.019948, for full frame sensors (the big Pro cameras) and 35mm film the number is 0.02501. This represents the sensor size. Again, don’t get all lost on me yet, just remember the number for your particular camera.

The first thing we need to calculate is the Hyperfocal distance, for this calculation you will need to know the focal length of your lens. the aperture you are using and the CoC (circle of confusion) for your camera.

The math to calculate the hyperfocal distance is as follows:

HyperFocal = (FocalLength * FocalLength) / (Aperture * CoC)

Thus, the Hyperfocal distance of a 50mm lens at f/2.8 on an APS sensor (Canon 30D in my case) is 146.85 feet.

Next we need to calculate the near point which is the closest distance that will be in focus given the distance bdetween the camera and the subject. The math here (yes, it gets SO much worse) is as follows:

NearPoint = (HyperFocal * distance) / (HyperFocal + (distance – focal))

This is somewhat  complicated because the focal length is in millimeters and those of us in the US are better with feet and inches still so if you want the end value to be in feet you have to do some more conversions. If we are using the same 50mm lens, at f/2.8 on an APS sensor at a distance of 10 feet (3048mm) then our HyperFocal distance is 146.85 feet (44,749.23mm), giving us a near focus point of 9.37 feet (2,856.66mm). Are we following along still? Did I lose anyone?

Alrighty then, let’s now calculate the far point distance, this is almost the same as before but using slightly different math, so here we go.

FarPoint = (HyperFocal * distance) / (HyperFocal – (distance – focal))

Without changing our values that we used before, we now know that are rear point is 10.72 feet (3,266.81mm). Take note that the near point is actually closer to you than the subject is, typically the focus is 1/3 in front of the subject and 2/3 behind the subject.

The final step is to calculate the total amount of focal distance. This is one I can even do without a calculator, we simply subtract the far point distance from the near point distance.

TotalDof = FarPoint – NearPoint

Giving our example so far we have a total depth of field of 1.35 feet (411.48mm).

Let’s get practical
Why on earth would you want to know this? The simple answer is you may not, nor may you ever care to know it. When shooting portraits, weddings, events, and pretty much anything else it really isn’t going to matter much. However, if you are the type that wants to set up a shot and have it be EXACTLY what you want, there is simply no other way to know what the camera is going to do. This is important in macro, food, and product photography. By knowing exactly where you focus points begin and end you can more accurately design and execute precise shots.

Ok, how about the easy way?
This is kind of like taking a digital photography class and having to spend a semester cooking your own B&W film, its good to know the theory before taking on the practical application. So how can we do this easier than having to pull a scientific calculator each time you want to set up a shot?

• f/Calc Spreadsheet (download) – This is an Excel spreadsheet that will do all the math for you. This was development by me and is free to use.
• f/Calc Windows and Palm App (website) If you want a simple but powerful Windows or Palm based application, f/Calc does Field of View, Angle of View, Magnification, Spot Meter, f Numbers, Depth of Field and Hyperfocal distance
• PhotoCalc for iPhone (website) – Not only does it do everything for DoF, it also incorporates a sunrise/sunset function, flash exposure calculator, and Exposure Reciprocation calculator.
• CamCalc (Market) Android App for Depth of field, field of view, focal length equivalents, flash calculations, color temp. conversion, miniatures, and sunrise, sunset.
• PhoforPho (Market) Android App with Exposure calculator, Hyperfocal calculator, DoF calculator, Timer, and Exposure compensation calculation for multiple exposures.

I know this has been a doozy of an article to read through just to get to some free or almost free (PhotoCalc is $2.99) tools to make it dead simple to do these calculation. Hopefully this will help you perfect your images help you to use depth of field to its full extent.

• Two versions available: DSLR Camera Remote HD for iPad; DSLR Camera Remote for iPhone and iPod touch.
• Remotely fire & control your Canon or Nikon DSLR from your iPad, iPhone or iPod touch.
• Includes an intervalometer and auto-bracketing for HDR photographers.
• Start, stop and monitor video on supported HD DSLR cameras.

Continue reading for full press release

Portland, OR – February 21, 2011 - onOne Software, Inc., a leading developer of time-saving software solutions for professional and advanced amateur photographers, announced the immediate availability of the major update to it’s wildly popular application for remotely controlling Canon and Nikon DSLR cameras using Apple iOS devices. Specifically designed for the iPad, the new DSLR Camera Remote HD includes a redesigned interface that takes full advantage of the larger screen on the iPad, improved gesture-based preview functionality and the addition of starting, stopping and monitoring video from supported HD DSLR cameras from Canon and Nikon.

In addition to DSLR Camera Remote HD, onOne Software also updated DSLR Camera Remote 1.3 to version 1.4 by adding support for the Canon 60D and the Nikon D7000. The original DSLR Camera Remote (not the HD version) is designed to run on the iPhone or iPod Touch. Owners of DSLR Camera Remote 1.3 can add video start and stop functionality through an in-app purchase.

“DSLR Camera Remote has been very popular with professional and hobbyist photographers who value the ability to shoot remotely and we are extremely pleased to offer a new and separate version that adds iPad support and the ability to start, stop and monitor video in direct response to their requests,” said Craig Keudell, president of onOne Software. “We look forward to continuing to take advantage of new platforms in the ever evolving digital photography market to provide customers with tools that help them spend more time behind the camera and less behind the computer.”

New Features in DSLR Camera Remote:

NEW iPad Version: Taking advantage of the larger screen, a new, separate version of DSLR Camera Remote HD for the iPad features image thumbnails and larger previews in addition to faster access to options like the intervalometer and auto bracketing. DSLR Camera Remote HD for the iPad also includes the new Video start, stop and monitor mode at no additional charge.

NEW Video Mode: Start and stop video recording on supported cameras and even remotely monitor video on an iPad, iPhone or iPod Touch. Video mode is included with the new iPad version and is available as an in-app purchase for the original DSLR Camera Remote 1.3 for the iPhone and iPod.

More Cameras: Both versions of DSLR Camera Remote include support for the latest cameras including the Canon Rebel T2i/550D, 60D and the Nikon D7000.

Free Version: Introducing a DSLR Camera Remote Free version for those who want to try the application first. The free version allows photographers to remotely fire their camera. This is a no risk way to try the app before making a purchase as photographers can see exactly how to set up DSLR Camera Remote and try it before making the purchase.

Improved Previews:  Browsing images is now easier in DSLR Camera Remote through support for gestures which enable zooming and panning of preview images by pinching and swiping the image.

Save Local:  Photographs can now be saved as low resolution images to the connected iPad, iPhone or iPod Touch to enable quick remote sharing via email, MobileMe, Facebook or any other sharing service. Saved images can also be edited with other iOS applications.

Availability and Pricing

DSLR Remote Camera Remote HD for the iPad is $49.99 and DSLR Camera Remote 1.4 for the iPhone and iPod is $19.99 and are available in the Apple iTunes App Store. For more information visit http://www.ononesoftware.com/products/dslr-camera-remote/.

Owners of DSLR Camera Remote Pro 1.3 for the iPhone and iPod can get the updated camera support for the Canon 60D and Nikon D7000 at no cost with the 1.4 update. However, adding the start and stop video feature will be a $9.99 in app purchase to add this advanced functionality.

DSLR Camera Remote Free is a free version offering the ability to fire or release the shutter of the camera, for those who wish try the app before purchasing.

There is no upgrade path from the iPhone or iPod Touch version DSLR Camera Remote 1.3 to DSLR Camera Remote HD that is designed specifically for the iPad.

After purchasing any of the editions from the iTunes App Store, users will need to download a free application that runs on their supported Mac or Windows computer. This free application is required to communicate between the iOS device and the supported Canon or Nikon DSLR camera, connected via USB or Firewire to a WiFi enabled computer.

Supported Cameras and System Requirements

For the most complete list of supported cameras and system requirements, please visit the onOne Software website at http://www.ononesoftware.com/iPhone.

About onOne Software

onOne Software, Inc. is a leading developer of timesaving software solutions for professional and advanced amateur photographers. Our products allow photographers to spend more time behind the camera and less time behind the computer screen. They include a wide range of easy-to-use applications and plug-in enhancements for Adobe^® Photoshop^®, Photoshop Elements, Photoshop Lightroom^®, Apple Aperture and now the iPhone and iPad. Founded in 2005, onOne Software, Inc. is a privately held company located in Portland, Oregon.

Coming soon will be free additional content with enhanced tutorials and bonus material.

If you want your Dojo Mojo as soon as it is available, then you want the Camera Dojo iPhone App!

iTunes: Camera Dojo App

Android

Camera Dojo – Yup, there’s an app for that!

We are thrilled to announce that we have just launched a new application for the Apple iPhone/iPod Touch and iPad! The new Camera Dojo application will automatically pull in the latest podcasts that feature some of the top photographers and industry leaders in the business.  Coming soon will be bonus material such as tutorial videos and interviews that will be exclusively for Camera Dojo application.

Currently on the iPad it works great but doesn’t yet take advantage of the extra screen real estate, that will be coming in a future version.

If you want your Dojo Mojo as soon as it is available, then you want the Camera Dojo iPhone App!

Itunes: Camera Dojo App

Mike talks about the possible future for plugins and for OnOne Software and hints at possible tools for the Apple iPhone and for dealing with video from new cameras such as the Nikon D90 and the Canon EOS 5D Mark II.

Mike also is giving away a copy of the Plugin Suite 4 which contains the following plugins:

• Genuine Fractals 6 Professional Edition
• PhotoTools 1.0 Professional Edition
• Mask Pro 4.1
• PhotoFrame 4 Professional Edition
• PhotoTune 2.2
• FocalPoint 1.0

This is a $499.95 value!! To be entered to win we have a little scavenger hunt to solve. First off, go to http://ononesoftware.com and find the page for the Plugin Suite 4, Figure out why you need plugins, and from there, find the 10 word slogan. When you have found it, send an email to contest@cameradojo.com with the subject “OnOne Software Contest” in the subject and the answer and your name in the body of the email. Entries must be received by 5pm on Friday the 13th of March, 2009 and will be announced on the podcast that airs on March 17th.

Be sure and check out the OnOne Software blog (http://www.ononesoftware.com/blog/) and the OnOne Exchange (http://www.ononeexchange.com/)

OnOne Software: http://ononesoftware.com

Show Hosts

Kerry Garrison (http://kerrygarrison.com)
David Esquire (http://esquirephotography.com)

This podcast is also available on iTunes.

Links from the podcast:

Apple iPhone
http://apple.com

Lightroom Enfuse
http://timothyarmes.com/lrenfuse.php

Think Tank Photo
http://thinktankphoto.com

You can listen to this podcast now using our player widget in the right hand sidebar

This podcast is also available on iTunes.