Live data from Hacker News

DIY True 4K Projector

youtu.be

11–20 of 45 posts

Re: DIY True 4K Projector

#11

Interesting. I’ve been thinking of trying to find a decent projector that operates off 12V for hurricane season. Something cheap because we’d not use it too often. DIY might be an option. I don’t have access to any way to make the metal panels like this one has though.

Does hurricane season mean your family is camping out in the basement?

Florida doesn’t do basements.

Re: DIY True 4K Projector

#12
Since the right people might be reading through the comments here -

I've been looking at making a hi-res ceiling projector for a living space. Perhaps not one, but a set of several projectors with an overlap, but the key point is that they need to be placed in a way so not to interfere with the normal flow of life. Nor to be easily shadowed by people walking around, etc. This (likely) mandates placing them around the room perimeter, possibly on the walls at some height. This in turn means that they will be projecting at an angle.

Do I understand correctly that it's not possible in principle to achieve proper focus on the target surface when projecting at an angle like this? That is if I am to project, say, a star field then it's not be possible to have stars close to the projector and far from it to be both in focus at the same time?

Re: DIY True 4K Projector

#13

Interesting. I’ve been thinking of trying to find a decent projector that operates off 12V for hurricane season. Something cheap because we’d not use it too often. DIY might be an option. I don’t have access to any way to make the metal panels like this one has though.

Get one of these 12->230VAC boost converters. Had a 1 kW one in my VW van a decade ago, that thing could run anything except flourescent tubes.

Re: DIY True 4K Projector

#14

Since the right people might be reading through the comments here - I've been looking at making a hi-res ceiling projector for a living space. Perhaps not one, but a set of several projectors with an overlap, but the key point is that they need to be placed in a way so not to interfere with the normal flow of life. Nor to be easily shadowed by people walking around, etc. This (likely) mandates placing them around the…

Look up "Short Throw Laser Projectors" it's somewhat possible with funky optics depending on how much distance you can afford.

Re: DIY True 4K Projector

#15

Since the right people might be reading through the comments here - I've been looking at making a hi-res ceiling projector for a living space. Perhaps not one, but a set of several projectors with an overlap, but the key point is that they need to be placed in a way so not to interfere with the normal flow of life. Nor to be easily shadowed by people walking around, etc. This (likely) mandates placing them around the…

Most projectors are throwing at some angle. For example, the bottom of the image is further away than the top is. Like my projector lens is in line with the top edge of my screen, and works just fine. Most projectors have some way of compensating for this skew.

I would think if you mounted it vertically on a wall, it would be fine. You would still want it centered horizontally though.

Re: DIY True 4K Projector

#16

Since the right people might be reading through the comments here - I've been looking at making a hi-res ceiling projector for a living space. Perhaps not one, but a set of several projectors with an overlap, but the key point is that they need to be placed in a way so not to interfere with the normal flow of life. Nor to be easily shadowed by people walking around, etc. This (likely) mandates placing them around the…

In principle, it is possible. A tilt-shift camera can bring any plane in focus, so running it in reverse will project the image sharply on your ceiling.

See https://en.wikipedia.org/wiki/Tilt–shift_photography for cameras. https://www.projectorcentral.com/Understanding-Lens-Offset-a... learnt me that you can buy projectors that use this method. I suspect that back-projecting televisions (https://en.wikipedia.org/wiki/Rear-projection_television) often use it, too.

Re: DIY True 4K Projector

#17
post #7

When you buy an expensive projector you are paying almost entirely for brightness, so this result isn't too surprising.

You pay for brightness (My 4K projector has a xenon arc light source) and for black level (LCOS, etc.)

Re: DIY True 4K Projector

#18

Since the right people might be reading through the comments here - I've been looking at making a hi-res ceiling projector for a living space. Perhaps not one, but a set of several projectors with an overlap, but the key point is that they need to be placed in a way so not to interfere with the normal flow of life. Nor to be easily shadowed by people walking around, etc. This (likely) mandates placing them around the…

[deleted]

Re: DIY True 4K Projector

#19
A bit disingenuous for the presenter to completely ignore the obvious vignetting of his dim projected image, the results seemed pretty mediocre from where I'm sitting.

Re: DIY True 4K Projector

#20
The audio seems to be a let down though: plug something into the (disassembled) phone's audio jack.

I wonder if phones can deal with USB audio cards (that have surround options), or if there are any Bluetooth audio solutions that offer surround sound.

Or I guess you can replace the phone with a PC/laptop, and have the display connected to an LVDS driver..

Post reply on HN