I believe there use to be a few links to ancillary calculators at the bottom of the page.
One said something like:
How far can this camera see?
And would let you solve for focal length. I don't see them anymore though on the page.
Regarding what changes what in the 8 values in the calculator:
Of the three drop downs:
Resolution changes only PPF
Imager Size changes everything except for Distance
Unit changes Distance, Width and PPM/F (really just the UOM is changing)
Changing any of the 5 entry fields, (Focal Length, AOV, Distance, Width, and PPM/F) will affect all others with two big exceptions:
- Entry fields on right never affect ones on left.
- Entry fields on left never affect Distance.
One thing discussed a long time ago when this was brought up was possibly being able to "lock" down whatever values one wanted and then the data would pivot around those constants.
IPVMU Certified | 11/16/15 09:32am
Thank you Undisclosed 1 for your insight. What you've said matches my observations. What I'd really like is to be able to enter the distance, width and camera resolution and have the remaining fields update accordingly.
Luke, 1, thanks.
You probably notice that when you update the width or length, the AoV / focal length stays the same but the other one changes (i.e. change width, length changes, change length, width changes).
I think it makes more sense to do what you ask, i.e., if you change width, length stays constant, but AoV / focal length changes.
I want to check with our lead developer first in case I am missing any other elements that might be negatively impacted but I see what you asking for as being more natural. I'll update this later today.
Confirmed: we will switch operation to allow width and length to be changed without impacting the other (as discussed above).
There is one condition we then need to address. When selecting specific camera models, cameras with integrated lenses (whether fixed or varifocal) cannot support any combination of length and width. For example, a camera with a fixed 80° AoV at any specific distance, will only support one width. As such, entering in 10 for distance and 100 for width cannot work. Right now, if someone enters 100' width for a fixed 80° AoV, we just change the distance to match.
So how do we handle changing width and length for cameras with integrated lenses for combinations of width and length the camera cannot support?