New Mitsu P73 quad build

[logsquared]

Am I mistaken or is this a 2 lens setup? (1): The "standard" 2mm collimating lens and (2): A single corrective optic?

Yes, exactly right.

[steve-o]

Those pix look great! Is the single lens correction a new concept or something nobody uses because of the length required?
I thought it always needed to be telescopic; one to expand the slow axis to match the fast then re-collimate .. ? (.. or something like that )..

[planters]

[QUOTENot sure if i will spatial filter yet or not. Its just a beam machine.][/QUOTE]

Just a beam machine. Just a beam machine. Right.

[logsquared]

Those pix look great! Is the single lens correction a new concept or something nobody uses because of the length required?
I thought it always needed to be telescopic; one to expand the slow axis to match the fast then re-collimate .. ? (.. or something like that )..

Thanks!

I don't think the concept is new. I think most really want the smallest possible module.

Basically the wide stripe diodes are so astigmatic that the slow axis is really far from being collimated (parallel rays). This is especially true with the short (2mm FL) lenses. So, the slow axis is already expanding fast. You just have to wait till the size is where you want it then put a cylinder at that point with the focal length being the distance back to the collimating lens.

The down side is..... the weaker the collimating lens the less the expansion of the SA. Therefore the longer the distance to the correction optic.

The plus side is.... the distance from the diode is less critical for good focus. This makes alignment much easier. Also, only one correction optic needs to be rotated.

[logsquared]

[QUOTENot sure if i will spatial filter yet or not. Its just a beam machine.]

Just a beam machine. Just a beam machine. Right.

I don't follow.

[planters]

Firstly, I have done this single lens collimation as well and everything you said is spot on including the need for a little space. What I meant was; you sell the projector short. Those are impressive divergence numbers that most RGB projectors don't achieve. And, I too would nudge you to add the spatial filter as you may have the room and the beams do get crisper. I can't video this as the camera doesn't do justice to these high contrast beams and the change is too subtle for them, but not for my eye.

[polishedball]

Very nice beam shots. Awesome work.

Off topic but curious if our ever consider making the trip to GR for a LEM if something gets setup. Just noticed your location.

[logsquared]

And, I too would nudge you to add the spatial filter as you may have the room and the beams do get crisper.

Ok ok ok You guys are right. I do have the room. Its just lazy not to do it. Especially with the "planters technique". My attempt at making pinholes with foil years back was a terrible failure.

Very nice beam shots. Awesome work.

Off topic but curious if our ever consider making the trip to GR for a LEM if something gets setup. Just noticed your location.

Thanks.

I would love to hit up a LEM. Problem is I usually work weekends.

[jeejeedr]

I like your setup. Really nice like that, even if you need longer distances.
May I ask which optics you use and which distances we speak of here?

[logsquared]

I like your setup. Really nice like that, even if you need longer distances.
May I ask which optics you use and which distances we speak of here?

The collimation lens is a 2mm asphere. The correction optic is a 300mm FL lens set 300mm from the diodes.