Is it possible to increase scanner resolution with a closeup lens?

[ddsTech]

Last year I scratch-built a structured light scanner using the David-Laserscanner software, an LED projector, a Point Grey Chameleon 1.3 MP Mono USB 2.0 camera, and a nice Fujinon lens. After a few months of experimentation, with pretty decent results, I added a Proxar A28.5mm .2m Close Up Lens (Carl Zeiss Ikon Proxar Four A28 5 Close Up Lens Slip on Set in Case | eBay) to the front of the camera lens and was blown away by the incredible increase in resolution of the camera image and scans. I ultimately ditched the project because the process of manually positioning the model, and manually fusing the scans took too long.

Here's my question... for those of you scanner gurus who have a scanner opened up for experimentation..... wouldn't it be possible to just add one of these closeup lenses to the front of a scanners' camera lens, reposition the cameras a bit closer to the model so the image is in focus and have vastly improved scan resolution? There's the possibility of slight distortion, but for single units and short-span bridges, wouldn't this be a viable option?

Here's a sample scan I got using my scratch-built setup with the closeup lens on the front of the camera lens:




Nice detail, right! I have two of these closeup lenses and would be willing to loan them out to someone willing to test out this theory. What do you think..... viable or not?

 

[Affinity]

Beautiful detail! Wow.. But is it accurate as far as milling a design built on these scans?

 

[NicelyMKV]

Nice! I would be worried about distortion, accuracy of the image and decreasing the field of view by moving the cameras closer ,and/ or, adding the lens. I think the cameras mounted further away, and angled, allows access to hard to see areas? Just my opinions.

Awesome job with your project by the way.

 

[ddsTech]

... is it accurate as far as milling a design built on these scans?

Unfortunately, I didn't have time to follow through with the project enough to get something milled. Compared with scans I've seen from commercial scanners, I'd bet the accuracy is very adequate.

NicelyMKV: "I would be worried about distortion, accuracy of the image and decreasing the field of view by moving the cameras closer ,and/ or, adding the lens. I think the cameras mounted further away, and angled, allows access to hard to see areas?"

This particular closeup lens is professional-grade and very high quality. There may be distortion issues.... that's what I'd like to find out. It would be very easy to test it on a commercial machine because it is a 28.5mm lens which press-fits over the front of machine vision lenses (it fit perfectly on my 6mm C-mount Fujinon lens).

The focal distance using the .2m closeup lens (with the 6mm Fujinon camera lens) is about 7 7/8" inches, which is very similar to the distance used in commercial scanners. Camera placement would not need to be changed much at all. It would just be a matter if fine forward/back fixture placement to get perfect focus, then lock everything down permanently. The field of view is large enough for a complete full arch in a single scan, as is shown in the top picture. Even that picture is cropped from the actual scan window size.

It just seems like with very minor modifications (pop a closeup lens on, refocus and recalibrate) most 1.3MP camera scanners could be given better "vision".