3D scanning of small and complicated parts

I am trying to get a proper understanding of the things involved when scanning small parts with features bad for scanning, like circuit boards or things that simply are not as smooth as the test objects seen in tutorials.
Due to the limitations I gave up on laser scanning for this although I still prefer it for bigger parts with less features.
Photogrammetry works, well sort of...
Most programs require the cam to move around the object, which is pretty much useless for parts smaller than 3cm³ in size.
But even if the software claims to be able to use turntables I still struggle massively getting any usable results.
I had testversions of 3D flow's Zephire and Agisoft Photoscan, both are able to use masks which helps a lot but they struggle with the camera positions.
No matter what I do and how I try to cheat the cams are always located at a max of 180° but never the full 360°
Agisoft would allow to enter cam positions but the algorthm behind it is beyond my understanding.

So far my approach was to mask the background out and if the cam alignment failed (which it always did) to manually add reference points into the single pics.
But still no 360° scans but a lot of cams in the exact same location.
I know a 8MP DSLR is not perfect but the image quailty is decent enough for all the details.
Is there a software out there that is dedicated for turntable use but is no laser scanning software?
Or maybe a program / plugin to calculate cam positions for a turntable if the cam location is actually fixed?
I mean with a turntable and fixed cam I would expect that all cam positions in the model are at least at the level and distance but in some cases it looked more like a wave pattern.
My ultimate goal is to go down in size to about 5mm³ in size, like insects and tiny machine parts.
Zephyr Pro seems to be right tool for the job but it out of my reach price wise as I only do 3D as a hobby.
123D and other cloud services fail totally for this task for the obvious reasons of size and fixed cam.

Qcks2 years ago

Well... since you're looking for very small objects...
Have you ever looked at the USB microscopes?
http://en.wikipedia.org/wiki/USB_microscope
They can take pictures and all that jazz at the small sizes you're describing, though I've not really heard or thought about using them with 3d modelling stuff.

USB microscopes are 8-10 megapixel cameras with giant magnifying lens on them. So... I'd think that'd help with what you're asking. The only problem with this would be the amplification of movement, so you might need to build a miniature turn table.

The Image quality is moderate. It's not a DSLR camera, but it's a bit better then the cellphone camera's from the early 2000's. The microscopes have built in LED's for lighting, but you'd probably want more light to enhance the image quality.

The USB microscope runs around $20 (US) on Ebay, Sometimes a little more sometimes a little less.

Downunder35m (author)  Qcks2 years ago

I had a look into them last year and decided against them as their focus is only in the centre of the image.
They are basically just a webcam with better magnification.
Some
simple structures still can be scanned but if it bigger than about 1/3
of the viewing field you get too much lens distrotion.
Without knowing the exact properties of lens and CCD it is next to impossible to get accurate results.

But
since the same limitations in terms of shape, thickness and reflection
apply I just do more tests with my DSLR for now and limit my size to
about 20mm³ for now.
With a turntable (no matter of the object size) the main problem is to properly align the cameras.
The free products like 123D catch simply can't do this at all, so proper software is the first key.
Masking and refining the procedure the next.

If
you ever tried to scan a small curcuit board with pins and SMD parts
you might know what type of problem I mean and doing insects with tiny
legs only works once I got the bigger things working 100%.

Since I can not afford a box of cameras a single one has to do ;)