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Re: 3D scanning - high resolution for small objects

Posted: 10 Jan 2021, 16:39
by OBNRacerMan
Micr0 wrote: 10 Jan 2021, 16:11 I guess we will all have to upgrade to 4K projectors. :)
I do not know yet "real" 4k projectors (mostly there is pixel shift technology). While this is about the same as in cheap models from the DMD 0.23/0.33" 1366 * 768 matrix they make FullHD, but here they get 4k from the FullHD DMD 0.47" matrix. And pixel shift systems don't perform well in scanning.

P.S. Still, it is more correct not to chase the megapixel, but using an honest FullHD projector to reduce (in any way possible) its illumination field - the result will be good, and the price is acceptable.

Re: 3D scanning - high resolution for small objects

Posted: 16 Jan 2021, 06:26
by kth307000
OBNRacerMan wrote: 10 Jan 2021, 16:39
Micr0 wrote: 10 Jan 2021, 16:11 I guess we will all have to upgrade to 4K projectors. :)
I do not know yet "real" 4k projectors (mostly there is pixel shift technology). While this is about the same as in cheap models from the DMD 0.23/0.33" 1366 * 768 matrix they make FullHD, but here they get 4k from the FullHD DMD 0.47" matrix. And pixel shift systems don't perform well in scanning.

P.S. Still, it is more correct not to chase the megapixel, but using an honest FullHD projector to reduce (in any way possible) its illumination field - the result will be good, and the price is acceptable.
Hello OBNRacerMan
Thank you for always good information.

I recently purchased the product below to replace the projector.
https://ko.aliexpress.com/item/32842506 ... 46db9bt_bt searchweb0_0,searchweb201602_,searchweb201603_

However, when tested, the screen is too large to be projected properly at the distance required for scanning.
I want to make the screen smaller, but it doesn't get smaller.
There are not many options that can be set, so I tried various things, but I think it is not suitable for scanning.

It would be helpful if you recommend a projector that is inexpensive.

Thank you.

Re: 3D scanning - high resolution for small objects

Posted: 16 Jan 2021, 08:17
by OBNRacerMan
Among the newer projector models, there are almost no options with suitable specifications. All manufacturers try to make the picture bigger by reducing the projection ratio.
One of the best for use in a scanner is the LG PF1500, but the model is old and difficult to find even used on sale.

Re: 3D scanning - high resolution for small objects

Posted: 16 Jan 2021, 10:18
by kth307000
OBNRacerMan wrote: 16 Jan 2021, 08:17 Among the newer projector models, there are almost no options with suitable specifications. All manufacturers try to make the picture bigger by reducing the projection ratio.
One of the best for use in a scanner is the LG PF1500, but the model is old and difficult to find even used on sale.
Thank you for good information.
When you search for LG PF1500 in Korea, it is sold as the latest model.
Isn't the model number different?

Re: 3D scanning - high resolution for small objects

Posted: 16 Jan 2021, 13:17
by OBNRacerMan
I know that in Russia it is almost impossible to buy PF1500 (or its next generation - HF60). If such an advertisement comes across, then the projector instantly "leaves". We have an average price for such a used one in good condition around USD550-750
P.S. I am not aware of the exact differences in the versions of this model for different regions.

Re: 3D scanning - high resolution for small objects

Posted: 19 Jan 2021, 19:06
by barryvanbakel
What is the throw ration of the LG?

"My HD projector (1280 * 720) has a throw ratio of 1: 1.47 with a focusing of 100mm, AAXA projectors have a TR 1: 1.2 "

Re: 3D scanning - high resolution for small objects

Posted: 19 Jan 2021, 21:42
by OBNRacerMan
barryvanbakel wrote: 19 Jan 2021, 19:06 What is the throw ration of the LG?
LG PF1500 TR 1.40:1 - 1.54:1 (this model has a working optical zoom (not to be confused with digital zoom, which spoils the picture))