Form1+ laser flare issues illustrated - pics and video

@Steve_Johnstone hmmmm - it seems to me that you got such great shots because you are using a pro-sumer camera that you obviously know how to to use. I’m not sure if that qualifies as a standard procedure… we need a procedure that people with Phone camera’s can use

I’m gonna start a separate thread asking for ideas on a process for spot shots with a phone camera

Hi Kevin,

If you watch the video you will see that I actually took the photos with 3 different devices - the cannon, an old iPhone 2, and a new Samson Galaxy S5 phone. The S5 actual produced the best results.

You know what another name for a “spatial filter” is?
An iris. Or a hole. Yes, it is that simple.


@Ante_Vukorepa Like I said I am not an optics guy.

Here’s something else that is best shown with a picture:


I have yet to perform the spot test myself, but I have been actively reading all of these threads regarding laser issues. One of the most interesting methods I’ve seen, and I’m not sure who invented it (they can chime in here) is the spot cure of resin on acrylic.

One thing that may be interesting regarding that test would be to develop and circulate a model of printable ring, say 3cm in diameter with a 2mm wall and a 5mm height as a containment dam for resin. The idea would be to take a thin sheet of plex, locate the spot first without resin, center the ring on that location, drip into the ring enough resin to touch all edges of the ring, and then perform some decided upon number of consecutive spot tests (say 2 or 3), then immediately irrigate the uncured resin away with IPA. This could provide the standard spot we could compare. For those with a height gauge, knowing the height of the cured resin at various points may also be useful to understand laser power output as well.

The most important thing, as @KevinHolmes noted, is a standard methodology.


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If that’s your laser-spot-test Ante, you should get your Form1+ an exorcism :slight_smile:


@ChristopherBarr - I agree, and am also wondering if this is the best way forward for comparing our laser spot profiles; then folks don’t have to be nervous about taking pictures with the case open.

It was my idea btw:)

I think perhaps we should start with 2 runs of the spot test against the liquid resin drop before the rinse off with IPA . In my experience 1 spot test gives a relatively clear profile - but 2 is better.

Ideally it should be done with black resin - but perhaps other resins could be used if the cured blob could be coloured somehow?

here’s my result again…

I’m not sure we need a damn to contain a mini pool of resin - a simple liquid blob held with clear rounded surface tension edges should suffice.

Here is my result with two runs of the spot test using black resin.

And the laser picture.

that’s quite interesting to see a good photo of the spot, in combination with the cured blob. I take it the cured blob is on printed transparency?

How are your prints at 50 microns? have you tried any tall pieces with vertical or near vertical front oriented faces?

Hey Kevin,

I just used my resin tray for the spot test and then scraped it off the bottom. Let me look around to see if I have anything transparent that would slide into the tray holder.

Best Regards,

I’ve done the test too. I do not have any print quality problems with my printer.

With cover:


Without the cover:

The blue flare is not realy visible be my eyes. But on the foto.



Many thanks @SachaGloor - that’s very helpful.

That clearly shows that the flare you have is oriented in the Y axis - so if it was causing you any issues, you would have seem them on the tall calibration pieces - which actually looked perfect in your shots.

What that tells me - is that there is a large range in laser quality in the Form1+ - i.e. your laser spot is very very much better than mine, @Monger_Designs and @RocusHalbasch and presumably many others…

I think the core of the issue here is the print quality tests that FormLabs or their refurbishing factory runs before they ship their printers. I’m guessing whatever they print doesn’t completely cover the spectrum of what users will be printing (for example jewelry with fine details, or tall parts, etc). That may be the reason why they ship them with this type of laser spot profiles, because they think it makes no difference in their test prints.


Can someone measure this distance on their printer please? (Between the top metal pieces).

@SachaGloor could you please also print the rook from my post in the thread about my Y axis galvo at 25um with no supports and see if it comes out cleanly. I think it is a much more sensitive test Of flare problems.

175mm between the top metal pieces.

@RocusHalbasch Yes i will print the rock. Please give me a link to it. What material should i use ?


@SachaGloor thanks I really look forward to seeing your results. Please make sure to print it with no supports at 25 micron layer height. You will need to use the preform tool to orient it so the base points down.

Rook Sample by whack23 on Sketchfab