Form1 needs an iris in front of the laser, it’s as simple as that.
It’s not exactly rocket science, internal reflections are a very common thing; most applications that require a regular, nice and clean gaussian spot have an iris to cut down on extraneous reflections and halos.
The road to getting them to do that is showing them not doing it is causing problems.
Or as @Ante_Vukorepa says, it’s not rocket-science - @JoshK already implemented his own - albeit for the form1 not the form1+ I don’t see why we can’t do it ourselves.
as an aside I just had a closer look at my Form1+ laser and noticed it has no collimating lens, while the original Form1 laser did…
@Monger_Designs you’r totally right.
However in my case, i print pretty large item but small too. I attached an image to show you one of them. The head is only 4mm but you can clearly see the eye, hair, mouth, … ( maybe not on the image )
My point is that maybe for some users the laser is defective but i believe the rabbit ear is a “normal behavior”.
It could still be the laser with a too bright dot, a square shape or anything else, but i have the feeling this is not the cause of your problem ( i’m only talking from my experience )
To be fair, maybe we should make and share a really detailed ( tiny ? ) model that everyone could print to see if all the details pop up. I don’t have any comparaison for my little girl, maybe i can have better result … 
( the rook don’t have a high level of details in my point )
I have a Form1+.
@Gillesalexandre It’s not a matter of details. I chose the rook as I have seen this before and it always seems to effect the rook. The rook is round and the large diameter means that the flare will run over the area outside the rook over and over again. On small objects with fine details and thin walls I don’t see as many artifacts. Please try the rook, at 0.025 and see if all of your bricks come out smooth and clean, it will only cost you a little resin and about 7.5 hours. I would really like to know how it comes out for you.
oops - sry for some reason I thought you were waiting on the upgrade …
@RocusHalbasch.
Yes i can try to print the rook ( so without supports ? ) but that won’t be before at least 3 weeks. I’m on a big project and i’m printing days&nights for that
Awesome. Thank you. I’m curious if you will get a perfect one. I never have. I’ve only gotten “good enough”. Oh yeah do it at 0.025.
I’ve been talking to support and they just told me that they don’t print the sample rooks at 0.025. They always print them at 0.1 because “for some reason” they don’t come out well or they fail at 0.025. So now I wonder how can they say their prints come out just fine on their in house printers with flares/bunny ears when they can’t dependably print a rook at 0.025 on them. I suppose they haven’t considered that the flares may be causing the poor quality on the rook at 0.025, or have somehow eliminated it as a possibility.
Anyway I would really appreciate it if some other user who has a printer with flares/bunny ears would print the rook at 0.025 to see if you get the same results as I do.
Wouldn’t it make more sense (from a debugging standpoint) for someone who HASN’T got an imperfect laser beam profile to try printing it at 0.025?
If they can’t print it at that resolution as well, then you’ve pretty effectively excluded the laser as the culprit. Otherwise you’ve just confirmed that laser might be the culprit.
@RocusHalbasch & @Ante_Vukorepa I suspect that most (or perhaps even all?) Form1+'s have laser flare. Most spot photos aren’t helpful since the F1 case is such an good filter, and if spot photo’s are taken with the case open and a magnet then it’s hard to get the contrast right.
If someone does have a provably well defined spot and can’t print the rook at 25µ - I’m not sure that tells us anything since it could be any of a number of non-systemic issues causing their failure - including “dirty mirrors”.
So - I think - we’re just looking to collate results from anyone printing tallish (>5cm) vertically (or nearly vertical) oriented objects at 25µ or 10cm+ tall objects at 50µ - along with the best images of their spot they can manage.
I haven’t been able to print anything at 25µ yet (all failed), so I’m focusing on 50µ for now - and have results that definitively show some of the effects of flare, I’m still putting it all together, but will be making a new thread with lots of pics and a video.
@Ante_Vukorepa how long have you been waiting on your Form1+ now? I look forward to your investigations on this with machine in hand.
@KevinHolmes I’m considering creating a simplified model that will demonstrate the problem clearly and take less time and resin to print. I was going to just make a hollow cylinder as I’m pretty sure that will do the trick. Are there any other shapes or forms you have noticed that dependably show the problem? I like the cylinder because no matter which direction your flare is it should still show just as clearly.
@RocusHalbasch I tried cylinders - large ones that took most of the build platform - and they printed quite well, it was very hard to pick out flare issues. Conversely vertical objects with flat thin walls (one 3mm thick piece showed no effect) show the effect very well.
I’m still within the expected lead time, i ordered a few weeks before Christmas etc. so lead times were stretching all the way into February. Since the EU store still says “Estimated delivery 02/2015” and i purchased just as it switched from 01/2015 to 02/2015, i’m guessing i’m somewhere at the beginning of the Feb queue.
There’s another often overlooked cause of failed prints at 25 microns - print duration. Especially with really tall objects. The longer the print, the more likely for it to fail, for numerous reasons, including but not limited to: pigment settling, PDMS oxygen starvation, PDMS wear…
Here is the first of my simpler test prints this is a replacement for the Rook. It is smaller, has way less volume and is simpler so you know more clearly what the problem is. Still print it at 0.025 with no supports. I haven’t tried this version yet I printed one with a different rotation and thicker walls and it worked so this one should work even better. Anyway this should probably be used instead of the rook from this point forward,
I have taken down my variant of the rook as it is no longer needed and is not my work. If you need my version which was modified for the Form1 let me know and I cand give it to you.