Hi,
On 2022-01-04 9:05 a.m., Joel Penner wrote:
Hello,
I am doing microscopic focus stacking with mirrorless cameras. I have
a Cognisys Stackshot rail that I am doing this with, but I also have a
bunch of Canon 9000F & 8800F scanners, so I am wondering whether I
could use the precision these devices have to move a camera forward by
small increments.
I have already been experimenting with attaching a stepper motor to a
microscope, controlled by a Big Easy Driver and a Raspberry Pi. This
person used a scanner for focus stacking by connecting a scanner motor
to an external driver:
https://petapixel.com/2013/01/24/focus-stacking-macro-photographs-with-a-hacked-flatbed-scanner/
<https://petapixel.com/2013/01/24/focus-stacking-macro-photographs-with-a-hacked-flatbed-scanner/>
This would work for me, but would it be possible to manually move the
scanner imaging head with SANE and the scanner's firmware and
circuitry? Basically, I would need SANE to move the scanner imaging
head forward by a tiny increment, pause for a few seconds for the
camera to take a photo, move forward again and so on. I just need
total control of where the scanner imaging head is moved to and how
small the increments are. My goal is to use this rig to do timelapse
microscopic focus stacked images of plant growth.
Ideally, the scanner imaging head light would be turned off too but I
could also use tape or disconnect the LED array. I have other scanner
models as well if the firmware or drivers of these Canon scanners
isn't suitable.
Any ideas would be appreciated, thanks!
Joel
This *might* be possible if the usual movements that the scan head would
make are sufficient for your need.
What you can definitely do is to arrange for the scan head to move from
home quickly to a start position and have the head move more slowly to
an end position (speed depending on the requested resolution) after
which the head would usually return to the home position. By controlling
the rate at which the scan data is received from the machine, you might
also be able to get the scan head to pause when the scan data buffer is
full. Within the SANE API, those are really your options.
Some scanners have a more high-level control, such is the case with the
protocols that are handled by the pixma backend. I see that Povilas has
answered regarding the genesys backend and the scanners that are
supported there. The genesys controllers provide much more control over
the hardware. Even then, using the SANE API is going to be quite
limiting, but you could use the genesys code to directly control a
genesys scanner.
Honestly, you might be better off harvesting the components from the
scanner and using an arduino or something. ;D
Cheers,
Ralph
