Got photo-quality image on leather! This image is small- it’s really stunning in person.
I’m coming to understand this. Fundamentally, DC-excited tubes are limited to about 500Hz, RF can go 20KHz-50KHz and actually turn on-off the beam energy that fast, but you won’t see it unless the raster speed is high enough for that spatial period to be larger than the spot size. Horizontal resolution is limited by spot size at that point. If we give it a higher freq, then the spots merge together and it’s not doing this micro-dithering hacked grayscale mode anymore.
At this point, I don’t have any control over the beam power other than speed. And I have a lot of power I can’t so easily control- I have my X axis set at 1500mm/s and it’s usually burning harder than I like but I can’t turn it down any further by going faster. The PWM is running 5KHz and 30%-40% max (again totally different use of the PWM). Which translates to a spatial period of 0.3mm, so that makes total sense to be the limit unless I can slow the axis acceleration and increase the speed some more to reduce its net power. That is, it can switch faster but the axis isn’t moving fast enough to separate higher KHz dashes.
I can see that there’s trouble getting consistent beam if the pulse on-time is <10nS. This might be the driver, or could even by the way numerical quanta work in the Ruida PWM. This shading would benefit if very light shades that end up with short pulses instead use a fixed on-time and increasing period with lighter shades (more off-time). Makes sense. Ruida grayscale can’t do that, though, and I’m not sure if the transport format could give it data from LB’s end to do anything in this area.
