Adventures in iPhone photography from tap tap tap, the creators of… Camera + MagiCam Filters

A Beginner’s Guide for Manual Controls in iPhone Photography: Focus

November 7, 2014 by 15 Comments

About Jack Hollingsworth

Jack Hollingsworth, a denizen of Austin, TX, is an award-winning, 30-year career veteran in commercial photography. Jack has fallen in love with his iPhone camera as his primary capture tool. He is also an avid Camera+ devotee and has been since day one. He deeply believes that, when all is said and done, the iPhone may just be remembered as the most influential capture device ever in the history of photography.



Welcome to the first feature in our series of Beginners Guides for Manual Controls in iPhone Photography. You can find the other installments here:

  1. Focus (this post)
  2. Exposure
  3. White Balance
  4. Shutter Speed
  5. ISO

Don’t Take Focus For Granted

Besides Exposure, Focus is probably the second most important part of the iPhone photography experience. Viewers will tolerate almost any technical difficulty with your photography, except focus. If your picture is not in focus, then all the rest of your technical and creative efforts are for naught. Also, there is relatively precious little you can do to salvage an ‘out of focus’ photograph. Get your exposure and focus taken care of first, then the rest of the creative process will be more enjoyable.

1.0 don’t take focus for granted

Technology and Art

I feel compelled to say this – most experienced photographers know quite well that the technical and mechanical aspects of photography need to become almost reflexive or ‘second nature’ before the creative part of the equation kicks in. Creating focused photographs is a tech skill and one you need to learn right at the onset.

How Exposure Works

Degrees of Sharpness

Focus and Sharpness are somewhat relative terms and concepts. There are degrees of each. It all depends on the clarity of detail you want in your finished photograph. Some photographers will insist on nothing short of ‘tack sharpness’. Others will be somewhat forgiving with their focus points. Still others will prefer a more ‘artful’ approach and have intentional ‘out of focus’ elements in the frame. You, the photographer, will be the ultimate judge of focus and sharpness.

How Exposure Works

Autofocus Points in Smart Phone Cameras

Let’s briefly talk about the iPhone camera’s handling of autofocus. All mobile camera devices have built-in autofocus (AF) systems, the majority of which are powerfully accurate and dependable (as is the iPhone camera). All these systems rely on one or more ‘focus points’ to properly set focus. The precise number of ‘focus points’ depends on the device you’re using (Apple doesn’t disclose this information for their iSight cameras). Generally speaking, most mobile AF systems are set up to maintain optimum focus in the center of the frame and less around the edges:

How Exposure Works

Pixel Peeping

The retina display, as awesome as it is, can sometimes be a little deceiving when it comes to properly evaluating focus. If I’m unsure whether my photo is properly focused or not, I will try a technique called ‘pixel peeping’. This is a simple matter of opening the photo up in the camera roll and either ‘double tapping’ or ‘pinch zooming’ to look at the shot at a higher magnification. If the images look ‘focused’ at higher magnification, then move on. If not…try again. Yes, this does significantly slow down the creative shooting process, but it’s worth it for those special shots you want full focus detail in the final image.

How Focus Works

The iPhone camera, or any camera for that matter, can only focus on a single point at a time, but there is an area that stretches in front of and behind that single focus point called the ‘zone of sharpness’ or more commonly referred to as ‘depth of field’ (DOF). This DOF is described as either ‘shallow’ (not much) or ‘deep’ (a lot).

What’s important here, when shooting with your iPhone camera, is to make sure you draw the viewers attention to that primary focus point in the photograph, then use DOF techniques to either accentuate or minimize the overall ‘zone of sharpness’.

How Exposure Works

Four Factors That Affect Depth Of Field

Truth is, getting the camera to focus properly on a single focus point is relatively simple. My suggestion would be to primarily use your ‘tap focus’ reticle and specifically tap on an area of the frame that you want to be the central point of focus in your photograph.

The more challenging and fun part is learning to control ‘depth of field’. Generally speaking, with almost all cameras, you control your DOF via:

How Exposure Works

The iPhone 6 and 6 Plus cameras have a fixed lens aperture of f2.2 and a fixed focal length of lens at 4.15mm (approximately a 30mm lens) so for shooting with your iPhone camera, the first two will be ‘non-factors’. Let’s concentrate on the second two:

Light Levels
When I talk about ‘light levels’ in photography, I’m talking about how much light you have to capture an image. If you are shooting indoors at night, the chances are pretty good that your light level is low. If you are shooting outdoors, on a bright day with full sunshine, your light level is high. The iPhone camera, in bright light, has ‘deep focus’ (where everything is in focus). In order to get to get ‘shallow focus’ (where subject is in focus and background is out of focus) it is better to shoot in low light.

Focusing Distance
In iPhone photography, the real ‘secret sauce’ to getting your main subject sharp and the background out of focus is understating ‘focusing distance’ – which is the distance from the lens to the subject. The closer your camera lens gets to the object you’re shooting, the more ‘out of focus’ (or softer) your background will become, especially if you are shooting in low light.

How Exposure Works

The iPhone 6 and 6 Plus Lens

The iPhone lens is small in size but mighty in performance. The more I shoot with the iPhone camera, the more I’m impressed with what this tiny lens is able to deliver in terms of picture quality. Amazing! For you ‘techies’ that are taking notes, here is a nice snapshot of the iPhone lens:

How Exposure Works

3 Ways to Focus Your iPhone Camera

There are 3 simple ways to focus your iPhone camera:

How Exposure Works

How Exposure Works

How Exposure Works

How Exposure Works

Focal Length and Field Of View

When talking about manual focus, it’s hard not to also talk about:

  1. Focal Length
  2. Field (Angle) Of View

The Focal Length is the distance, measured in millimeters, from the optical center of the lens to the sensor. The Field of View (or angle of view) is what that lens sees in ‘degrees’. The iSight camera in the iPhone 6 has a focal length of 4.15mm (or a 30mm equivalent) and a 73˚ field of view.

How Exposure Works

Interestingly, the human eye has a focal length of about 20mm with a field of view around 95˚ (wider than that of the iPhone lens).

How Exposure Works

Stay Focused

One of the biggest differences between a DSLR and an iPhone is the way the two cameras handle and control focus and depth of field. Obviously, with your DSLR, you have significantly more control. However, now that certain photo apps like Camera+ 6 are building in manual exposure, focus and white balance controls, it’s possible for your iPhone photos to take on the look and feel of your big camera.

Stay focused!

11.0 stay focused

Who Linked To This

15 Comments

  1. If there are four factors that affect depth of field, please tell us about them. There is no number of factors that “effect” depth of field (bring it into existence).

  2. Mr. Hollingsworth, what is your opinion of using Clarity? Could you please make an article about its use?

  3. Eddie, I love and use Clarity quite a bit. But generally at very small settings (like 10%). For my kind of photography, Clarity, at full strength, is just too overwhelming an effect. But doing a video on Clartiy is a very good idea. The development team at taptaptap has put in a lot of time and resources on making Clarity great and popular.

  4. Jack, I liked your video. I don’t mind to get a longer video with all the details as you suggested (Director’s Cut). A video on the use of Clarity will be welcomed.

  5. I would like for you guys to have an app for this website. That would be awsome and very convenient for me. Please and thank you.
    xoxoxo

  6. Thank you for this tutorial! Clear, concise, and with great examples. Would you mind sharing what app and any post-processing you did for the black-and-white “8” photo in the “Don’t Take Focus for Granted” section?

  7. I learn so much from your tutorials. Great site to keep referring back to. Thanks for all your work to make the iPhone work as a great camera easy to use.

  8. Thanks Jack for your movies and tutorials. Love watching them over and over, and pick new points of learning every time. You are not only an excellent photographer but also an excellent teacher. Those two do not always go hand in hand. Thanks for trying to educate us! I am learning so much from you…

  9. I am new to iPhone. I do have the the iPhone 6+s. Trying to learn about it. I agree that focus and exposure are critical and I prefer manual control to auto. I do not know how to find the settings on the iPhone that allow me to control focus. I am especially interested in a camera app that helps me with manual settings. I assume some apps are better than others with regard to exposure, focus, capturing action, and macro. I shoot a lot of photos of animals and nature. I have seen there are a lot of apps. Wow.

    Thanks

  10. Great series of tutorials, but please correct your misuse of the word “effect” which is a noun. You need to use the verb–affect. Here is a mnemonic device to help you. RAVEN = Remember Affect is a Verb Effect is a Noun. (I am a former English teacher, can you tell?)

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