DLP Projector lenses - is hacking throw ratio possible?

[Micr0]

So one of these just fell into my lap:

https://www.projectorcentral.com/BenQ-MP730.htm

It's free so I'm not too worried about breaking it. It already has a throw ratio of 2.3 but I'm going to use it to try to experiment with lenses. Stock it can only focus as near as 39in which gives an image size of roughly 22in. I'll post what I find when I get it.

[contactpolyga]

A few years back, TI made the light commander which supported interchangeable Camera lenses as well as projector / camera triggers - at under 1K, it was a good deal except for ultra low lumen count and poor image quality. We used a few for projects and got rid of our last one earlier in the year due to having to clean out our storage. For a good deal maybe some are still available on EBay

https://cdn.slashgear.com/wp-content/up ... der-sg.jpg

Not DIY but the CEL5500 supports swappable lenses - price is super high but it does what people want.
https://dlinnovations.com/products/cel5 ... ht-engine/

Lastly if you want to create a macro image scenario, for most projector lenses, if you extend the amount of play you have with the zoom element you can focus much closer.

You can do this but detaching the lens and cutting the adjustment hole using a rotary tool to let you pull the lens out a bit longer. It won't help your throw ratio, but you can focus to a very small image.

[OBNRacerMan]

Decreasing the minimum focusing distance is good, but, nevertheless, I would prefer to have a high throw rate in order to be able to scan small objects without moving the projector close to them.
P.S. My projector without alterations can focus from a distance of 100mm (if slightly modified, then from 25mm, while giving out a projection of about 15 * 25mm)). But I cannot calibrate the system with such a projection, and the projector blocks the view for cameras ...

[contactpolyga]

I think the options there would be to put the cameras below or above the projector, - rotate the projector 90 degrees, and to risk destroying the projector and detach the projector light engine from the rest of the electronics.

[OBNRacerMan]

I think the options there would be to put the cameras below or above the projector, - rotate the projector 90 degrees, and to risk destroying the projector and detach the projector light engine from the rest of the electronics.

In my case, the cameras are already above the projector, with an offset to its back.
I also want to increase the distance from the projector to the model for the reason that at close range I get a very small depth of field from the projector.

Shallow depth of field at close range

[Fly]

https://youtu.be/YGlsrVm9AcU?si=_aA_eln8Yhe0bIOS This is my record of modifying a home projector to achieve interchangeable lenses and a high projection ratio.

[Fly]

https://youtu.be/Gzr7WLu_V8I The previous video link was broken, but this is the new link.This is my record of modifying a home projector to achieve interchangeable lenses and a high projection ratio.

[Fly]

https://youtu.be/Gzr7WLu_V8I The previous video link was broken, but this is the new link.。This is my record of modifying a home projector to achieve interchangeable lenses and a high projection ratio.