HY450 LED projector review

Browsing AliExpress I stumbled across this incredibly cheap LED projector. It is advertised to have an extreme short throw and wide angle optics so I thought this would be ideal for space constraint applications like simulators. You know, ads always exaggerate but the price was so low I couldn't resist and bought one to try it out. I've payed 142€ with free shipping and now there's a deal even cheaper.

My biggest concern was that I had to fight with a chinese manual or decipher chinese symbols to find the language setting menu. But I was surprised, the language was pre-set to english and there even was a small printed manual included explaining the most important steps for commissioning.

Of course, you can't trust the ads. It's not 4k or 8k. The actual resolution is 1920 x 1080. It's also said that it has an automatical focus and trapezoid correction but this doen't work at all. There's a built in camera so it could check it's own image. But as the camera has the same viewing angle as the projector there's physically no way to detect or correct trapezoidal distortion. When turning the automatical correction on and off the settings jump between two differently distorted images. So you have to do that manually.

As often with Chinese devices the UI is somewhat unconvenient, IMHO. For example almost all settings can be adjusted in the "projection settings" menu except for the focus which can only be tuned with the remote control. The remote control even has a gyroscope so it can be used as a "space mouse" to control the pointer. But due to a software bug the pointer freezes in some situations so you have to go back to the cursor keys.

But those are only minor issues. The most important thing is the image quality. Here, there's really not much to critizise. The colors are bright and strong. There is no grey veil in dark regions like known from LED backlit LCD screens. Dark areas are really pitch black which should be good for simulation night conditions.

What's also amazing is that the projector is a complete Android device. Theoretically, you could download games and play them directly or stream Netflix or Disney movies. And all that for a price lower than I payed for my mobile phone or TV. My son noticed that there might be an issue with the security level of the video decoder and maybe you can't watch Netflix in full HD. I'm no expert here and I don't care much. My main interest is flight simulation so let's get back to that topic.

The projector has an HDMI and a USB connector. Connecting a PC works flawlessly. It idetifies as 4k display but of course anything above 1920x1080 doesn't make much sense. One thing that really annoys me is that the signal source selection is not stored permanently. The projector also doesn't switch to HDMI automatically if you plug it in or turn on the PC. Instead, it always boots into the main menu and you have to select the HDMI input manually with the remote control. This is cumbersome especially if you have multiple projectors. But we already have an idea how to fix this: A keyboard can be conected to the USB port. This could also be an arduino that emulates a keyboard and feeds a "3 x cursor left + 1 x enter" sequence to the projector automatically selecting the HDMI source.

to be continued...

The wide angle optics enables a 1m wide image to be thrown to a canvas only 0.6m away from the projectors lens. This equals a FOV of around 80° and enables installation in very limited space. However, this advantage comes with a big disadvantage: The depth of field is quite bad. If the projector is not exactly on the centerline perpendicular to the canvas you can correct the trapezoidal distortion. But you cannot correct the focus across the whole area. If the focus is perfect in the center the image gets blurred in the corners.

Unfortunatelly, this also means that the projector is not very well suited for curved screens. If a 1m wide screen is bent more than a few cm the image starts to become blurry. And I haven't found an optical zoom to change the FOV angle. You can reduce the image size with digital zoom but then you loose resolution.

I have to do some more experiments to see if I find a solution. I also haven't tested the speakers, yet.

..are you using screen wall software for matching curves? Can't remember the name right now.

(Answer moved to the other thread because it belongs more to my personal design than to the HY450 prejector in general)