@SachaGloor I’ve been printing it in black, but anything should work fine I think. All sides should be straight. If there is wavyness or roughness on any of the sides that may be the result of flare.
Thanks Christopher.
With that I was able to measure with pixels. So the printer specs say it has a 300 micron effective laser cure. Let’s see what that looks like…
Hmm…
I’m not at home but someone needs to take a really underexposed picture of the laser spot to see if our 300 micron buddy is hiding in there. The shape of the spots under those conditions might be much more telling.
That would be interesting to try.
But what we see there got me wondering if maybe the Form1 laser was 300 micron, but the Form1+ laser may have a larger dot. But what I did learn is the yellow ring beyond the white dot is probably in the evil category too. If a lens were used to shrink/focus everything just a bit, the surface quality might improve dramatically. Imagine if your parts had a harder surface when they came out of the printer.
1 Like
Yeah I was thinking pretty much the same thing. If the iris had about a 300-500 micron opening, and was placed closer to the Y galvo than the laser you could probably get much better results.
I rigged up my Canon 5D Mark II to a fixed height above the Form1+ and took a photo at 1/8000 and 1.4f (the fastest my camera runs) and then took a longer exposure so you that the laser dot is in the exact same position.
https://dl.dropboxusercontent.com/u/7696226/IMG_6991.JPG
1 Like
Thank you. I’m glad someone with a dslr and the knowledge to use it saw that post. So judging from your shots a dslr coupled with a fast lens will get down to being able to see the core laser spot, or at least close to it. So a series of different exposures could be used to get a feel for the shape of the laser at different intensities. Also shots done on different dslrs but using the same fstop, ISO, and shutter speeds should be comparable. That gives us a viable mechanism to compare laser point shape and intensity. It just requires a dslr and knowledge of how to use it in manual mode.
@JoshK don’t quite understand what you mean by this.
Single lense would do more harm than good, because it would decollimate the beam - the beam would get wider as you’d move away from the center during printing (in tandem with the change in laser beam’s length).
Hah, not quite. Different makes have different calibrations and can be off by as much as a whole stop (i.e. one camera make & model’s ISO 100 is another make & model’s ISO 200).
1 Like
I vote more good than harm, but you are right, two lenses would be best to keep the beam straight. None of this is feasible on the already released Form1+ though.
I’m aware, but when the range is so broad one stop isn’t a huge difference. I didn’t mean they would be exact, just close enough and much much better than what we have.
True that.
Whatever the difference, it will still be miles ahead from cellphone photos.
I am more curious about what is causing that apparent blue rectangle above the laser dot. Look it is full page width.
Likely a reflection from the cover or bounce-back from the bottom of the paper.
1 Like
@Ante_Vukorepa Thanks for the insight.
Not so sure about the reflection from the cover it seems like it must be an internal reflection as it is shaped by the hole in the tray mount underneath it so anything involving the cover seems incorrect. As for bounce back from the bottom of the paper I’m not sure how that would work.
1 Like
Well, white paper fluoresces pretty strongly (blue) when hit by a laser of this wavelength. It’s especially strong on the underside, where the laser hits with full intensity.
When i test stuff on my DIY thing with a piece of paper, i often get half the desk around it lit blue from the light bounced back off the bottom of the paper.
My guess is something similar might be happening here.
I don’t know if that is right or not, but I know how to find out. Do the picture again, but this time cut a hole in the paper where the laser would hit. That will eliminate bounce-back from the paper.
@JoshK Sneaky sneaky.
@JoshK Doing the test with a whole in the paper would mean having a beam shooting out of the printer. It seems very unsafe even with the laser running at reduced power.