DSLRcontroller remote focusing
January 2018
DSLRcontroller has helped me address my focus issues and minimized the freezing of my fingers in the cold.
A complete walk through is available in a short video at the website. Because I found that LiveView 10x was not enough for me to be confident about my focus, I look at the image with a loupe. My first loupe was handheld which was quite a breath-holding balancing trick. Then I found one that I could simply lay on the viewfinder, look through while using one hand on the focusing ring:
Variants can be found at coin and stamp stores. Then a friend of mine, Steve Ricketts, told me about using a phone app or a tablet. I looked around and found that most simply replaced the shutter remote and intervalometer. Remote focus was the important part, so was very willing to pay the $10.99 for that feature alone.
While the newest camera models can be controlled wirelessly, anything older than a Canon 60D must be wired (as shown above). Works on Nikon, Sony, etc. Make sure your camera is awake when you plug it in or start the app. Your camera automatically goes into LiveView. From the app, you can now control everything from ISO, white balance exposure, f/ratio, movie trigger, and so on.
Here is what it looks like in use on a star with a Bahtinov mask in place.
While you can change focus manually and see the result on the screen, I prefer to do it remotely, so I first set the switch on the lens to AF. Then at upper left you see AF, which if you tap, will cycle to R-MF (remote manual focus). You then single tap the forward and reverse buttons (R-L arrows) to change the focus by microstep. Take a picture with the shutter icon at lower right, wait for the exposure to finish and the 3s download to the camera/app. Now you can super zoom in to check the diffraction spikes (for Bahtinov mask user).
I find I still use the loupe to give me maximum confidence right away. On a modestly bright star without the mask, I can see the red and blue rings when the star is slightly out of focus, which I adjust until the colour disappears.
The one slight habit to remember at the end of focusing (and pulling out the cord) before doing your image run is to put the lens back on manual focus.
I have requested the developers to add a 15x and 20x button so I can forget the loupe.