This is an interesting thing.
In theory the scanning works like this:
laser projects blue lines over the surface
depth cameras record the image of these lines - and from the way the lines deform on the surface calculates the distance (depth) of each pixel of a line
the depth camera analyzes ONLY the lines, nothing else - it doesn’t “see” anything on the surface besides the laser lines
to be well recognized the image recorded by the depth camera has to be good enough – the lines in the image have to be bright enough to analyze
different surfaces, materials reflect light in different amounts, so the same lines on different surfaces are sometimes very visible, sometimes barely visible - like on black glossy plastics.
In these cases Revoscan needs help - he needs to see the lines better.
There are two ways for that - either increase exposure in the depth camera, which brightens the depth image as a whole or make the laser lines brighter.
At first glance it seems the same - both options work so why have both?
On black surfaces - yeah, they basically work the same .
You can either increase depth exposure or laser brightness.
I did find one difference today though:
raising exposure of the depth camera - maybe there are different ISOs in the sensor, the image stream just gets a stronger gain to make the image brighter
there is also an option of setting exposure time to longer (the camera does this automatically - we don’t control it), so instead of 1/100th of a second per frame, it can go 1/50th or 1/20th - today I found out that MetroX also uses that method
the result of this was that with low exposure I got 30fps during scanning - when I increased exposure to the max - my scanning rate dropped to 17fps!
And this is todays revelation - if you have to help Revoscan, start with increasing the laser lines brightness, because increasing depth exposure will also reduce scanning rate.
There are also red materials, which are well visible but absorb blue light - in this case also start with making laser lines brighter because by increasing depth exposure you’ll be also making the surface brighter together with the laser lines, so even at max exposure they still won’t be well visible to Revoscan.
Hi!
From what I’ve found about laser 3d scanners, using the brightest laser line is not always the best setting because it can lead to overexposure or excessive reflection from certain surfaces. This can distort the data being captured in the following ways:
Saturation: If the laser line is too bright, highly reflective surfaces (like shiny metals or glass) may saturate the sensor, resulting in incomplete or incorrect data for those areas.
Loss of Detail: A very bright laser may create too wide or diffuse a line, leading to a reduction in the precision of the scan and a loss of finer details.
Surface Interaction: Some surfaces may scatter the laser too much when it’s overly bright, causing inaccuracies. Conversely, surfaces that are too dark may not reflect enough light for the scanner to detect the laser line at all.
For optimal results, it’s important to balance the laser intensity based on the material and reflectivity of the surface being scanned, allowing the scanner to capture the most accurate data possible without overexposure or underexposure.
My laser brightness is never at max , it is always around 90%
But I don’t like to scan with too bright laser settings since it also capture stuff that waste my time so I prefer to test out the brightness settings according to my object only , of course it will depends on the scanned object and it’s color surface .
My best results was when there was enough of brightness to capture the object surface only , it scanned smooth and much faster as well .
Of course with multi color surface scanning it is a different story and not my workflow.
I realise this is an old thread, but recently the choice of increasing laser power or camera exposure came up on a job. puty, you mentioned about having your laser at 90% or when just the surface is being scanned without noise, but where abouts is your depth exposure when doing the tests? Like 50%, play with the laser power and if still not enough when you reach 90%, increase the camera setting. Just interested as to where you start with the depth setting as a default.
