David SLS Failed Calibration

[drndadoo]

You don´t need to coat all objects, just the dark, shiny  or transparent objects should be coated.

I did not understand this part with calibration and rotation, but yeah you need to find the right angle between cam and calibration panels. if you are testing the "positive" => and "negative" =<  angle it should work with both.

[cadman777]

By 'rotation' I mean the angle of the cal panels to the cam.

It seems that the rotation of the panels is not the same every time I calibrate it.

Why is that?

Also, how do you coat only some parts of an object and not others?
For example: That bottle of glue has a shiny label, a matte plastic bottle, a shiny cap and a semi-translucent dispensor nozzle. When I scanned it w/no coating, it barely registered the matte platic bottle, and didn't register any of the other parts. But when I coated and re-scanned, the bottle had all kinds of thick lines in it, while the other parts barely registered.

What's causing that?

Note: The cam is auto-focus, and the projector is 3k lumens and 3k:1 contrast.

[drndadoo]

I will try to answer what I know first 🙂

It is easier to coat object as whole. Then there is no difference btw. coated and non coated parts.

auto-focus on cam should be off!!

Angle btw. cam and calibration panels doesn´t have to be the same each time. What is important that angle is not too wide or too narrow.

[cadman777]

Thanx for the info on cal panel orientation.

There is no way to turn-off auto-focus on this cam unless and until I change the lens, b/c the autofocus in part of the glass lens. I just hate to discard this Zeiss lens! But probably will do it b/c it's getting in the way. Also, there is auto aperature. I haven't found any advice on how to disable auto-aperature. If you can send me a link on how to do this, I'd be grateful. 

Can you tell me which projector has square-shapeed 'pixels' (in contrast to the usual diamond-shaped 'pixels')?

[I believe the 'pixels' are the shape of the MICRO MIRRORS in the dmd chiip!]

Yes, I realize that coating the entire part is better than trying to coat only one area on the part.

That's why I asked the question.

However, I find that coating makes a scan have heavy grains and lines compared to uncoated.

Why is that?

Also, I find that my black paper background has the greatest amount of scan data, albeit with 'orange peel' texture.

Can you send me a link which explains the cause of this?
I'm trying to figure out all the things that cause bad scans, so I can get good scans 95% of the time under any and all circumstances.

Does HP have a link to a GUIDE showing all the different problems that occur with scans, and their possible causes, along with their potential solutions? Here's an example of what I'm talking about, as-presented by the 3d printer software developers: https://www.simplify3d.com/support/print-quality-troubleshooting/

Thanx ... Chris

[drndadoo]

https://support.hp.com/us-en/product/hp-3d-structured-light-scanner/14169438

Here you can find how to´s, user guides, FAQs and so on...some of your questions are covered in this documents.

Autofocus is a big problem. If focus is changed after the calibration then you need to recalibrate.

That equipment what you are using is not meant to be used for scanning, that is probably why you have all this problems.

That is why sometimes calibration is successfull and sometimes is not. Google if you can turn autofocus off.

[cadman777]

Thanx for the info.

Guess I'll have to break-down and buy a lens, dissemble this cam, and make a housing for it all.

At least I know it works.

The FAQ page has a lot to work with, so I'll probably be a while before I have any more questions, b/c I'll be figuring out the controls.

Appreciate it ....

[drndadoo]

Check with manufacturer support if you can switch all "auto" functions of your cam off.