Hello @SBrown check out my detailed exploration of the 16MP Arducam:
Oddly, I was seeing we could NOT get a score with the honeycomb covered. It had to be UNCOVERED.
With a standard 8.5"x11" printer sized card, I got good scores (<0.3), but the lens cal is only accurate at the 4 alignment points. It is notably off across much of the bed, indicating the lens calibration was not so good.
If you want a larger card, use the laser to cut the circle pattern out of white posterboard and glue on top of black foamboard. The foamboard may not be all that flat though, maybe you want to glue onto black posterboard glued onto like masonite or MDF. I did not do this in the end, I used the printer paper sized one. Like I say, good scores, but poor lens cal.
In my case running it off-machine did NOT improve the lens cal, in fact I got very poor scores. I do not know why. It should have worked.
Also note the 16MP was sold with a WAY too wide lens for this, and a lot of the resolution is wasted off-bed, AND it’s creating a ton of fisheye distortion to try to correct. However, getting an M12 lens that fits the field of view, AND fits the unusual 1/2.8" imager, AND physically fits in the mount, AND has an IR filter is still ongoing. I ordered many parts to try and will let you know. Notably, Amazon’s “Arducam” M12 lens set does NOT fit, as it was actually for an Arducam with a much smaller imager.
The most promising lens I think is going to work is this varifocal in the 2.8mm-12mm version (this “mm” measure actually sets field of view)
https://es.aliexpress.com/item/1005001349942062.html?gatewayAdapt=glo2esp&spm=a2g0o.9042311.0.0.45d463c0NFUByL
Why? Well, an M12 mount, it’s for a 1/3" imager, so 1/2.8" will fit just unused margins, and since we’re using the center of the lens this might mean less fisheye. It has an IR filter (16MP Arducam doesn’t seem to have a filter with the lens removed but not certain). The 2.8-12mm zoom encompasses my target FOV estimate. The adjustable zoom is going to drastically increase the effective resolution because we can adjust it to perfectly encompass the bed and no extra. Even a small amount of extra FOV consumes quite a lot of the pixels! I mean, if your bed occupies 2/3 of the FOV, with only 1/6th the width on either side unused, that’s STILL only able to use roughly 45% of the pixels. It could be nearly 2x the total resolution!