Tutorial: Advanced Focus Stacking

THE PROMOTE CONTROL NEW ADVANCED FOCUS STACKING MODE: REPRODUCIBLE AUTOMATIC FOCUS BRACKETING AT YOUR FINGER TIPS

When creating ‘focus stacked’ panoramas or time lapse videos (for instance, blooming of a flower), it is essential to accurately reproduce the focus bracketing sequences. The focus brackets must consistently begin and end at the same near and far focal points at each camera position. The Promote Control’s new firmware version 3.31 adds an Advanced Focus Stacking Mode that allows you to easily create precise and reproducible focus brackets.

To demonstrate the Advanced Focus Stacking Mode we will configure the Promote Control to take a series of shots that will later be merged into an extended depth of field landscape panorama. In this example, we will be using a 70-200mm lens at f/11 lens zoomed to 200mm. The focus bracket will start at 1.5m, the “Near Point”, and end at 120m, the “Far Point”, a distance slightly beyond the hyperfocal distance. This guarantees our depth of focus will extend from 1.5m to infinity.

Step 1

Connect the Promote Control to the camera with a USB and a shutter cable. Set the lens to AF Mode and the limiter switch to its maximum value 1.2m-∞. Navigate to Setup Option #35 and set the Pre-roll steps from the default value of “Disabled” to a value between 3 and 12 by pressing the Up and Down button on the Promote Control.

Step 2

Navigate to the Focus Stacking Screen and Select a Step Size of “Large”. The step size determines how far the focusing elements will move after each frame. Notice “ADV” is displayed indicating Advanced Focus Staking Mode is active.

Step 3

Manually rotate the focusing ring to the desired Near Point (1.5m) and note the position on the lens distance scale. Move the cursor to highlight the Range Start value (+000) on the Promote Control Screen.

Step 4

Press and hold the Center button and click the Down Button multiple times to retract the lens to its Near Stop Limit (< 1.2m). The Range Start counter will remain at +000. Note: It is essential to allow the lens come to a complete rest between each push of the Up or Down button. Continue clicking the Down button until the lens focus group stops moving and is firmly against its Near Stop limit (<1.2m). Click the Down button a few more times to ensure the Near Stop limit has been reached.

Step 5

Release the Center button and advance focus to the Near Point (1.5m) using the Up button.

Step 6

Move the cursor to highlight the Range End (+008) on the Promote Control Screen. Advance focus to the Far Point (120m) with the Up button (+029). The Promote Control is now ready to take 22 images in 22 steps. Press the Start button to begin the focus stacking sequence!

Lens Distance Scale: Set Up Sequence

Useful Tips

• When using the Up and Down buttons click, release and let the lens come to a complete rest before clicking again. Do not hold down the Up and Down buttons.
• Experiment with different values in “Step Sizes” and “Focus Stacking Step Delays”, Setup Option #34, to achieve the desired result.
• Canon users have the option of using Live View in steps 3 – 6.
• A useful online Depth of Field calculator can be found here: http://www.dofmaster.com/dofjs.html.
• For tutorials on Basic Focus Stacking please visit Promote Control Focus Stacking (2-part tutorial), Promote Control Focus Stacking with Nikon.

We wish to thank fine art photographer John Freeman of Abba’s Creations Photography for his valuable input and testing during the development of the Advanced Focus Stacking technique.