Tarkin’s 16MP alignment camera got much better results on the most recent lens calibration pass. This flattens the fisheye lens distortion so the image is a good representation of linear distance in X and Y.
It’s looking pretty darn accurate now, and a great image! Feel free to try it out!
We do need a better fixing on the mount. It’s moved before by itself, which does of course change the alignment, but that’s a simpler step than the lens calibration. It’s a bit tricky- this does need to mount the camera at a particular angle, and I don’t know that angle specifically, I just rotated it to point where it needs to point. But it needs to hold that position even if bumped or being cleaned. At the same time it needs to be something reasonably easy to remove when needed.
I do have a new lens config coming for that which, if it fits as I hope, will be able to adjust the zoom to fit just the bed in the FOV and make the most of the available pixels- net effect, major improvement in image quality.
I was wondering about that, since the camera had been knocked out of alignment when I arrived on Monday afternoon. I made a brief attempt to re-align it, but I didn’t know the workflow or status so I gave up at that point.
I do wonder if we can possibly design a rigid little “exoskeleton” casing to go around the camera housing so that it is more locked in place? Once we know the geometry around the position it needs to be relative to Tarkin’s door frame, that sounds viable, yes? Any reason it couldn’t be made of simple baltic birch?
I’d like to VHB tape it to the door. That’s quite solid. VHB probably doesn’t have a great adhesion to a wood surface unless it’s painted or somehow resurfaced. Actually just wiping it with wood glue and letting it dry would probably make a good surface.
I had it VHB taped, I needed to take it off to try the recommended off-machine calibration and boy was it hard to remove even though it was only stuck on with like a 30mm circle. But that was VHB taping the pivot mount. That pivot mount only has 2 tiny screws and it can’t tighten down enough to keep it from being bumped.
When I put it back after cal, I used one of the ferrite cup magnets (not the powerful neodymium ones) and it’s too easy to move the mount now. Maybe simple answer is to just stick something in there to freeze the pivot in place and VHB tape the mount.
The alignment in LB (not lens calibration) you do after mounting is more difficult than it needs to be, IMHO. It burns an unnecessarily complicated pattern and the process is hard to get the burn right.
The quick test I did last night after calibrating the lens showed accuracy of about 1mm at the time. But, if the camera gets bonked, we’ll need to realign.
Yup, that was the impression I got from my brief tinkering with the process — seemed likely overly complicated.
I had intended to raise the topic here right afterwards, but you beat me to it.
Anyway, hopefully it becomes a non-issue soon through the miracle of Very High Bond tape… (I hadn’t encountered that acronym before, and now I can’t shake images of Daniel Craig going undercover in a head shop and discovering that “Delta 8” is in fact not his contact from the GRU)
VHB is indeed a miracle. It’s a pretty permanent bond in general, but if you wick in just regular isopropyl rubbing alcohol, it fully releases the pressure sensitive adhesive with no residue or damage to either surface- temporarily. The adhesive will actually stick again once the alcohol dries.
Same adhesive on foam tape. Once I needed to mount a fragile glass tube about 3/4" inside a PVC pipe, and anticipated breaking and needing to replace the glass at some point. How to secure it? Foam tape was high on the list, but that won’t press into a pipe without catching at first contact and rolling off.
Some experimentation found that fantastic property. I peeled off the paper from one side and wrapped the exposed adhesive side around the glass stem, then took off the other side’s paper on the outside and wetted with isopropyl alcohol which actually made the adhesive slippery. It slid into the PVC pipe easily and the foam even compressed radially on the way in. A short time later the glass is secured, shock-mounted in preloaded foam, and could be released later with isopropyl.
Anyhow, VHB will securely hold the pivot mount to the lid, and it’s not a soft foam type so it won’t shift around. However, the camera does pivot on that mount, and I’m not sure how to freeze it in one place. Perhaps I can wedge in a slice of VHB between the camera body and pivot mount and use that exact aforementioned isopropyl alcohol slickening method to adjust its orientation before it freezes in place.