The target stickers on the height stick are ideal for calibrating and efficient since the routines were built for them. However, often times vegetation or real world objects prevent us from being able to see the target squares and accurately calibrating at those heights. Though the targets are helpful, any known heights can be used to calibrate midspan or pole height photos.
It's helpful to know that the red and white sections on the SECO rod (the height stick most commonly used with Katapult Pro) are exactly 12" long and correspond to the whole foot. By counting the sections, you can then use where the red and white sections meet to place a manual calibration height.
There are two ways to place manual calibration markers. The first option is use the shortcut 'a' or the "Anchor Point" input. You can then click in the photo at the desired height and enter the height value. The other option, if you are in the middle of either the pole height or midspan height routines, is to simply delete out the height detail in the top left, enter the new known height, then click in the photo.
When placing manual heights, there are a few guidelines to remember:
Katapult Pro will accurately measure the heights up to 3 times the known heights. It is helpful to use heights as far up the stick as possible.
The software requires a minimum of 4 known heights although 5 is often more useful.
The software uses the spacing between the calibration markers to accurately measure heights of attachments. It's helpful to divide up the space between all your markers somewhat evenly, avoiding scenarios where markers are too close or too far apart from one another.
You'll notice after placing 4 markers accurately the calibration inputs change colors from purple to green. The green indicates the calibration markers pass the linear regression model but not necessarily that heights are perfectly placed. If the markers turn yellow or red, that indicates that at least one of the calibration heights is incorrect and should be deleted out and replaced (avoid dragging markers until they turn green).