Projecting an SLS system: Scanning precision

Write here about construction, ideas, equipment, tips n tricks etc. related to structured light scanning
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Micr0
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Joined: 15 Nov 2016, 15:20
Location: New York City

Re: Projecting an SLS system: Scanning precision

Post by Micr0 »

mading wrote: 30 Apr 2017, 18:48 I did it!
I open it and loose the lens. It works!
I made in the spare time. Still don't know how to use fusion properly.
Exciting!
Excellent start. Very good alignment. Please post a picture of the fusion result when you get it.
µ
mading
Posts: 307
Joined: 31 Jan 2017, 13:09

Re: Projecting an SLS system: Scanning precision

Post by mading »

Thanks Micro! As soon as I finish to align the rotation I'll post some pictures.
I'll give a look at the manual of the fusion tab, before continuing.. :D
F
LG PF50, LG PF1500, RangeVision DIY: 2x DahengMer630, 2X12 and 2X16 mm 5Mp ZK lenses, RV turntable
Curiousjeff
Posts: 121
Joined: 16 Nov 2016, 22:31

Re: Projecting an SLS system: Scanning precision

Post by Curiousjeff »

There could be some confusion about "Clean HDMI". It is usually means that the image is transferred without overlapping information like shutter speed, exposure, etc. I does not refere to the type of signal.

Even though its seems obvious that a clean output should be able available, it's often not the case. Canon for example would record internally to the SD card without the overlapping information (of course) but any live output using HDMI would have all this overlapping information (like on the LCD screen) and make it worthless for David without the use of MagicLantern

Back to compression. I don't remember what kind of settings were available with the Nikon. The Gh4 has all kinds of output (50 Mbps, 100 Mbps, 200 Mbps, MOV, AVCHD, MP4, FullHD, 4K). Also, like all DSLR, the video image comes from a chip with much more pixels.

I do try to use the best quality signal 1080p with the GH4, but I don't recall the difference with the other settings. I guess it's just common sense that the purest signal is what is best for David.

Regarding global shutter, I DON'T see any advantage. My PointGrey is a mono - global shutter camera and it does not get rid of the surface/frequency problem which we often encounter. It's not much better then the GH4, but it's faster and easier to move around.

Jeff
Dasq3d
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Joined: 28 Mar 2017, 13:26

Re: Projecting an SLS system: Scanning precision

Post by Dasq3d »

Hi Jeff.

I haven't tried an SLR setup but i imagine the lenses are generally better than the donkeys old Cosmicars that i use.

I'm guessing that the SLR will still try to do some enhancements on the feed before it gets to the screen.
This is why some people prefer one brand over another. Nikon have richer greens and sharper edges is a made up example that you will find in any review.

With a rolling shutter your sensor is constantly receiving new pixels in a kind of waterfall and it tries to grab images from a constantly changing source with a global shutter every frame gets a sensor wipe in between and the next frame is taken with a fresh unique set of pixels. So a global does much better with avoiding motion blur from the previous frame. Obviously the things we scan a motionless but the patterns are constantly changing very so its possible with a rolling shutter you will receive some of the previous pattern in the next but with a correctly synced global you should only get the current pattern.

Don't forget to go outside every once in a while and use your built in scanners.
mading
Posts: 307
Joined: 31 Jan 2017, 13:09

Re: Projecting an SLS system: Scanning precision

Post by mading »

Hi to all.
Well, I'm surprised about the quality of the surface, even with a simple webcam.
It's also to say that my panel scale is 154 mm, so a little bit large for this scroll.

Looking forward to post more work, before going "serious" with IS camera!

Cheers

--edit
the "bump" on the right is a missing part, created in fusion.
volume is the result of 19 scans merged in fusion.

--re-edit
K132 is original, not modded yet. Good! I wonder what "laser" projector would perform.
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Capture_2.jpg
LG PF50, LG PF1500, RangeVision DIY: 2x DahengMer630, 2X12 and 2X16 mm 5Mp ZK lenses, RV turntable
mading
Posts: 307
Joined: 31 Jan 2017, 13:09

Re: Projecting an SLS system: Scanning precision

Post by mading »

Old post.
New camera! DMK 23UX236 (7AEFA94E).

I'm experiencing vertical waves:
2017-11-13_17-16-43.png
David4.2.0 64 bit
Acer K132 non-mod, 60 Hz (nvidia quadro fx770M, dell precision M4400)

Waves are independent from camera aperture, focus and projector focus.
I'm sure many already posted this issue in the old forum..
I hope somebody from this forum will help me in finding a possible solution.
LG PF50, LG PF1500, RangeVision DIY: 2x DahengMer630, 2X12 and 2X16 mm 5Mp ZK lenses, RV turntable
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Micr0
Posts: 586
Joined: 15 Nov 2016, 15:20
Location: New York City

Re: Projecting an SLS system: Scanning precision

Post by Micr0 »

mading wrote: 13 Nov 2017, 16:24 Old post.
New camera! DMK 23UX236 (7AEFA94E).

I'm experiencing vertical waves:
2017-11-13_17-16-43.png
David4.2.0 64 bit
Acer K132 non-mod, 60 Hz (nvidia quadro fx770M, dell precision M4400)

Waves are independent from camera aperture, focus and projector focus.
I'm sure many already posted this issue in the old forum..
I hope somebody from this forum will help me in finding a possible solution.
This topic has been well covered. Search here and the old forum. Start by adjusting the projector or camera frame rate till you get the best surface quality.
µ
mading
Posts: 307
Joined: 31 Jan 2017, 13:09

Re: Projecting an SLS system: Scanning precision

Post by mading »

Although I already saw many posts in the past, I still did not find how to change projector refresh rate in decimals.
My card does not allow my to change this number in decimals: as soon as I save a 58.540 Hz, it save it as 59.
Images ar quite stable, with no bands moving up and down.
I can only see some flickering at the top of the sinewaves.
I tried with david 5, problem is less evident (I have a lot of dust coming from the used lens, that finished over the new sensor....)
2017-11-14_15-43-34.png
Although flat surfaces tends to have an irregular surface texture:
2017-11-14_15-47-35.png
I have to admit that I'm impressed by the texture from monochrome:
2017-11-14_15-48-13.png
LG PF50, LG PF1500, RangeVision DIY: 2x DahengMer630, 2X12 and 2X16 mm 5Mp ZK lenses, RV turntable
mading
Posts: 307
Joined: 31 Jan 2017, 13:09

Re: Projecting an SLS system: Scanning precision

Post by mading »

I double-checked my NVidia Control Panel: it does not allow me to use a "non-native" resolution. That sounds a little bit unusual. I'm using an HDMI cable with a displayport adaptor.
I can choose a different resolution (i.e. 1920x1080 at 60Hz) but I did not succeed in creating an effective custom resolution.
running Win 10 (updated at yesterday).
LG PF50, LG PF1500, RangeVision DIY: 2x DahengMer630, 2X12 and 2X16 mm 5Mp ZK lenses, RV turntable
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Micr0
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Location: New York City

Re: Projecting an SLS system: Scanning precision

Post by Micr0 »

Before you get ahead of yourself, do a series of scans at say 30º, align, and fuse them at a res of 1500 and a sharpness of 2 and see what you get. Don't go by a single scan. The surface finish you are getting is very good and a lot of those imperfections will smooth out during the fusing process. Post results if you can.
µ
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