John Jay
July 31st, 2010, 08:42 AM
I am running Canon EOS Utility from a 10 inch netbook as a monitor using the live view function. Using this system to pull focus is not recommended because of the lag, however as a monitor for framing it does the job well.
As you know SLR lenses do not have long throw - you are lucky if you get 90 degrees with some AF lenses! The width of a focus marker can sometimes be a deciding factor of whether you are in or out of focus.
I thought it would be nice to have a focus scale superimposed across the entire width of the screen with a pointer showing the current focus position of the lens. The basic idea is to measure the amount of movement of the focus ring and display it against the scale on screen.
I thought a neat way to do this is to take apart a wireless USB optical mouse and mount the optical sensor close to the focus ring. When the focus ring is turned the x coordinate of the mouse changes, so in effect the mouse pointer can be made to move up and down the on screen focus scale. This is the simple route, however it would be best to write a small app to do this, which I would probably do when I get to finesse the concept.
My <$10 mini USB 2.4G wireless optical mouse arrived today and this is where I have hit my first hurdle!. Before taking the mouse apart I have been doing some tests and although the mouse has switchable resolution between 800 and 1600 and is very smooth, I find that when I repeatedly move it say an inch to the left and back again, the mouse pointer does not always return to the same position, in other words there is drift. This is obviously not good and before I continue with this project I need to understand and resolve this drift problem.
Any help or suggestions are welcome!
As you know SLR lenses do not have long throw - you are lucky if you get 90 degrees with some AF lenses! The width of a focus marker can sometimes be a deciding factor of whether you are in or out of focus.
I thought it would be nice to have a focus scale superimposed across the entire width of the screen with a pointer showing the current focus position of the lens. The basic idea is to measure the amount of movement of the focus ring and display it against the scale on screen.
I thought a neat way to do this is to take apart a wireless USB optical mouse and mount the optical sensor close to the focus ring. When the focus ring is turned the x coordinate of the mouse changes, so in effect the mouse pointer can be made to move up and down the on screen focus scale. This is the simple route, however it would be best to write a small app to do this, which I would probably do when I get to finesse the concept.
My <$10 mini USB 2.4G wireless optical mouse arrived today and this is where I have hit my first hurdle!. Before taking the mouse apart I have been doing some tests and although the mouse has switchable resolution between 800 and 1600 and is very smooth, I find that when I repeatedly move it say an inch to the left and back again, the mouse pointer does not always return to the same position, in other words there is drift. This is obviously not good and before I continue with this project I need to understand and resolve this drift problem.
Any help or suggestions are welcome!