Quote:
A wide angle lens would be nice, for ~ $30.
Man, the Axis 206 has the narrowest FoV I've ever seen, save a pinhole in a wall.
-Nick
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The URL I posted contains wide angle and narrow/tele ones too. The second tab gives a table of specifications for the various lenses. Note that the 4mm lens has a viewing angle of ~70 deg. I never tried to make an accurate measure of the Axis, and instead relied on tables like this along with field of view calculators such as
http://www.123securityproducts.com/calculator.html.
Anyway, note that the wider the viewing angle the higher the Distortion. Even with the Axis 4mm lens, the vertical lines are curving out or becoming barrels. The wider you go, the stronger this effect. Processing an image looking at size and shapes gets trickier unless you correct for the distortion -- taking more processing and introducing new artifacts due to resampling.
This isn't the same thing as this poll, but I'd be curious if/when teams buy alternative lenses to see comparative photos compared to the stock lens. This will in the long run save lots of team money and lead to better naive choices. It'd be a great little white paper, but may be better done as a collaborative wiki or collective forum post.
A strong cautionary note.
The axis sensor doesn't contain an IR blocking filter. Instead, the filter is expected to be built into the lens. This is cool in case you want to change the lens and do some rudimentary IR imaging. Not so cool if you neglect to use a lens with an IR filter somewhere around 650nm or so, and then notice that your contrast and color saturation are lousy -- I speak from experience. And in the end it is pretty much a waste of money. I have heard of teams that were able to transfer the IR filter from one lens to another, but I question whether this is a good use of time over ordering what you need in the first place. Note that on the page I posted, only two lenses contain the filter. So in fact, while this table is useful for comparison, I no longer recommend purchasing the lenses here unless someone comes up with an easy process for the IR cutoff.
Greg McKaskle