In order to choose an appropriate lens (focal length/FOV) for my application I am trying to use a lens calculator like this one Lens Calculator | Focal Length | Working Distance | Field of View.
-Working distance is adjustable between 35 -43 mm
-h x v of flat object to be observed 32 x 20.4mm
I need to acquire images in QQQVGA Format.
Using the calculator to calculate the appropriate focal length for my application if I choose the MT9V034 1/3" sensor I cannot use 32x20.4 as FOV in input to the calculator because that would restore a focal length valid for VGA mode of the sensor.
The calculator restores Horizontal 4.5mm and Vertical 2.9mm when choosing the global shutter sensor.
QUESTION → Is it correct to divide by 8 to determine the equivalent sensor H and V in QQQVGA mode? If not how to obtain those values?
In the calculator if I insert the working distance above and the h x v of my object in the field of view I get a focal length of 0.6 to 0.7.
QUESTION → Does this approach seem reasonable?
Finally , when S-mount lens have for example focal length of Xmm is that length valid if the Lens is screwed all the way into the lens holder only?