According to Wikipedia, Caterpillar eyes form “well focussed but poorly resolved images.” I don’t know what that means exactly. Anyone know of a way to provide or point to an example of a well focussed but poorly resolved image?
Off hand that doesnt make any sense.
Now, you CAN have something that is capable of high resolution, like the hubble telescope before it was fixed the first time, but it is just out of focus say. You can then take that image, and with a bunch of fancy math,software, and heavy computing power, figure out what the image would look like had it been in focus.
How THAT might apply to the bug world I can’t see (heh) offhand.
Could they mean something analogous to low-resolution, but sharp pixels?
In that section, an image is shown in a variety of resolutions, ranging from 100x100 pixels down to a single pixel. Assuming they started in each case with the same image and just lowered the resolution, then in all cases the image is well-focused; but when you try to represent the entire image with a single pixel, that’s the poorest possible resolution. That would be well-focused, but poorly resolved.
I assume the caterpillar article is suggesting that the insect has optics that deliver a good image to the retina, but that t retina has relatively few receptor cells (where each receptor cell may be regarded as an image pixel).
I took the 20x20 image above and made a version that is blurred (from the high rez source) then made into the low 20x20 resolution. You can see the difference here:
Its clear that the non-blurred image is the superior image. So these insects probably dont have a lot of elements catching light but the lenses in their eyes are probably high-quality.
I was just visiting the Wikipedia page on Charon. Note the second and third images. Both are well focused and yet one clearly has better resolution than the other. (The first one is not an actual image but a computer reconstruction.)
This is extremely common in astronomical photos.