DPI and Vector Cutting

[Tim Bateson]

This discussion evolved from the thread: http://www.sawmillcreek.org/showthread.php?t=146903 - I thought it deserved it's own thread.

I had always been under the impression that DPI had nothing to do with Vector Cutting. Due to the discussion above and my own tests, I now believe otherwise.

The following pictures where all done with the same image and same vector settings. However the oval on the left of each picture was set at 75 DPI the one on the right of each picture was set at 1200 DPI. There is some distortion due to the enlarging of the photos, but the difference is obvious.

[Harper Abbot]

wow... was the cutting speed affected by the DPI adjustment?

[Tim Bateson]

wow... was the cutting speed affected by the DPI adjustment?


No - there was no difference in run-time.

[Mike Null]

Well, my machine was open for minute so I thought I'd give it a try.

The results are virtually indistinguishable. My camera battery is dead as usual but I put them under a magnifying glass and can detect the slightest difference (rougher cut) between the 125 dpi and the 500 but none between the 500 dpi and the 1000 dpi.

There was .01 second cycle time difference with each dpi setting.

FWIW, I raster at 500 dpi and vector without changing the settings.

[Larry Bratton]

Well, my machine was open for minute so I thought I'd give it a try.

The results are virtually indistinguishable. My camera battery is dead as usual but I put them under a magnifying glass and can detect the slightest difference (rougher cut) between the 125 dpi and the 500 but none between the 500 dpi and the 1000 dpi.

There was .01 second cycle time difference with each dpi setting.

FWIW, I raster at 500 dpi and vector without changing the settings.
Would there be any advantage to setting a lower dpi, if the results are similar to Mikes? I just leave mine at 600dpi on vector cutting, as I believed it didn't matter. Doesn't seem to affect the speed any significant amount.

[Peck Sidara]

Tim,

I'm not surprised to see the results you're getting. Mostly because you're comparing the far ends of resolution. Compare 300 to 600, 600 to 1200 or even 300 to 1200 and you likely wont see a difference in quality nor times.

Your original impression is still right in my view. You'd just stumbled upon something 99% of users wouldn't have. Congrats;)

[Tim Bateson]

All I did was show proof that DPI mattered... However yes the average vector cut will have a default DPI of 400 - 600 and this would never be noticeable as Mike had demonstrated.
I had noticed this issue last year when sending massive jobs to the laser, it would take forever to load. Lowering the DPI, which I thought didn't matter, sped up the load considerably, however the finished vector cuts where less than desirable, but acceptable for that job.