Technical Camera : Focusing

Technical Camera provides there focusing modes: Continuous AF (the default), Single AF, and Manual Focusing.

In automatic modes focus is calculated for the AF point (the whitish circle, marked with 2 on the screen shot below), which you can move by tapping the screen at the desired position.

Focusing controls

In Continuous AF the app continuously updates focus. The focusing/focus lock key (indicated with 1 on the screen shot) displays FL in this case (as in Focus Lock). Tapping the function key will lock focus, which will be re-engaged again when the lock is turned off by tapping the key again.

In Single AF mode (which you activate by turning off the Continuous AF option in the menu) focusing is only engaged if you tap the screen to relocate the AF point; or tap the focusing/focus lock key (which changes its title to AF in this focusing mode).

You can hide the AF point when focusing is not in progress if the circle happens to interfere with your vision. Just set the Show AF Point preference in the menu to During AF Only.

Manual Focus is initiated by the vertical drag gesture. The gesture is described in the Exposure Control post, so if you haven’t done so, I recommend you to read it now. In Continuous AF mode it activates focus lock as soon as the beginning of the gesture is detected (that is you tap and hold the side of the screen assigned to manual focusing). You need to re-engage Continuous AF by turning the lock off.

There are two things that become active during the focusing vertical drag gesture: focus peaking and the focusing distance indicator. Both will turn off as soon as you lift your finger from the screen.

The screen shot above shows how the app looks during manual focusing. Black and white mode is also active, because it’s easier to see the colored peaking this way. In real life black and white mode is not turned on automatically during manual focusing.

You can choose the color of peaking via the menu, since no single color suits all situations. The available choices are green (the default), yellow, white and magenta. And of course peaking can be disabled completely.

The focusing indicator is the vertical bar displayed on the left side of the AF point (see the magnified screen shot on the right).

The white dot in the track indicates the position: the higher the point the farther the camera is focusing. There’s no scale, though. Apple warns developers that the distance values iOS provides can’t be mapped to actual distances in meters or feet, so a scale is missing for this reason.

As parting tip, let me share how I use manual focusing. Lifting your finger from the screen might change the device’s position and thus the focusing distance. To avoid this situation, you can take a picture while your finger is on the screen during manual focusing. I usually do the focusing with my right index finger, and tap the shutter button with my left thumb.

Focus Bracketing Comes in Kuuvik Capture 1.1

kc-focus-bracketToday I practically finished the focus bracketing feature in Kuuvik Capture. Of course it has to pass our rigorous testing procedure, but the features are considered final.

Speaking of the features. You can drive focus starting from either the closest or from the farthest point, in small/medium/large sized steps. What those steps mean is camera body and lens specific (a totally arbitrary value actually), so you have to test it before starting the bracket. Hint: Command + arrow in live view mode drives focus by small steps, while Command + Shift + arrow drives it in medium steps.

You can expose up to 30 images in a focus bracketed sequence. It can also be combined with mirror lock-up and the intervalometer, as usual. At the end of the sequence we try to focus your lens back to the starting position, but don’t rely on it if you need accurate positioning – some lenses are really crappy in this regard and are unable to drive focus by the same amount back and forth.

kc-15-bracketWe have also changed the maximum number of shots you can expose in other bracketing modes to 15. As you can see on the bracketing monitor, this number is usually more than the exposure range your camera is capable of, but some of you requested it, so we added it.

Version 1.1 is in private beta right now, and it is planned to be release early July. It will be a free upgrade for current Kuuvik Capture users.

How to Make Focusing a Tilt/Shift Lens Easier

The tilt movement is used in technical cameras as well as DSLR tilt/shift lenses to precisely adjust where the plane of focus is on the image. Focusing with tilt is a tedious process (described here and here), but the results always worth the time!

There was a big pain point in using DSLR T/S lenses: checking what you have done. The viewfinder isn’t enough for that with today’s high resolution bodies, so you have to zoom in and check different points on the image using magnified live view. The adjust either tilt or focus. Then check the points. Then refocus… I had some images where I spent more than half an hour on fine tuning focus!

I said “was” – as it was the case before Kuuvik Capture’s Split View feature came along. I’m using this since I was halfway into developing the first prototype, and man, it can save lots of time! No, it won’t think instead of you, but the ability to quickly and visually asses what you have accomplished is priceless. It is also a great tool for learning how to focus a tilt/shift lens.

So watch the video below, and if you are using a Canon EOS-1D X, 5D Mark III or 6D with any of Canon’s great tilt/shift lenses, then grab Kuuvik Capture’s beta now! It’s that good (OK, don’t believe me, try it for yourself ;)).