×
Menu

EOS Lens Control and Auto-Focus

 
The Lens Control is accessible from Tools tab.
 
APT can control Canon compatible lens when they are attached to Digic III or latter camera. Lens "Auto Focus" (AF) must be set to ON and you have to be in LiveView mode. Don't forget to set your lens in manual focus (MF) mode before plan execution!
 
APT has its own automatic lens focusing that uses the Focusing Aid and FWHM (Full Width Half Maximum) or HFD (Half Flux Diameter) metrics to achieve better focus than the camera built-in automatic focusing which is not optimized for astro photography. The selection between FWHM and HFD is made from the Auto Focusing Aid panel. In the next few versions the Lens Auto-Focus will be fully integrated with Auto Focusing Aid.
 
To use Lens Auto-Focus, Turn ON the Lens control, turn ON Focusing Aid panel, make a rough focusing using the lens drive buttons and frame a star in the Focusing Aid panel. After that click on the “Start Auto Focus” button. The precision of the focusing depends on the precision of your lens drive. If you are not satisfied by the focus precision you can run auto focusing for second time or to try with manual control of the lens. It is recommended to use the LiveView Zoom x5 option.
 
Here is the usual scenario:
 
1.     Set the lens in AF mode
2.     Start LiveView, Focus Aid and Lens Control
3.     Frame a bright star with saturation 1 or 2
4.     Make rough focus
5.     Start Auto focus
6.     Set the lens in MF mode
 
EOS Lens Control and Auto-Focus
 
1

In

1. In
 
Drives the lens in "In" direction with three different step sizes. "<" is the smallest supported by the lens, "<<<" is the biggest supported.
 
2

Out

2. Out
 
Drives the lens in "Out" direction with three different step sizes. ">" is the smallest supported by the lens, ">>>" is the biggest supported.
 
3

Start Auto Focus

3. Start Auto Focus
 
Starts the APT lens focusing using FWHM (Full Width Half Maximum) or HFD (Half Flux Diameter) metrics.