Swapping the stock lens in a Escam QD900 with a 16 mm lens can add an almost 4 X optical zoom to your camera. A view from a stock Escam QD900 looks like this
You can zoom in about 4x before things start to get too blurry
with 16 mm lens the unzoomed view becomes
Again you can zoom in about 4x before things start to get too blurry but now that means you can read a license plate up to about 200 feet away.
If you have a bit of dexterity you can probably swap out the lenses easily. I did it and my fingers are on the stiff side. It does mean disassembling the camera though and focusing the lens while the camera is still apart and turned on so you will have to decide if you are comfortable with that. I suggest sliding business cards between the case and the boards to minimize the risk of shorting out the boards on the case. Also be careful to not disconnect any of the wires while you are in there.