Lux meter - Sony 295 ES - 800 Lux?

[RedCharles]

Been super busy with work, family stuff. Anyway, I finally caught Covid, which has given me enough time screw around with my Sony 295 ES (1500 lumens) that I temporarily set up in my office while I remodel my living room.

I saw a video on YouTube about using a lux meter to measure projector brightness. He was using a JVC and he was getting 340 Lux on high. I forget the size of his screen.

The Lux meter, I got off Amazon was cheap. Like 30 bucks.

So after four hours of researching, tweaking and testing, I'm very confused.

Baseline, stock settings, D65, 50 every setting, 8bit computer, high lamp give me around 350ish Lux on a 77 inch image from about 8 feet.

Boosting RGB gain in the secret menu, high lamp, 60 contrast, my normal settings, gives me 550ish Lux.

Turning off Enhanced HDMI, limiting the bandwidth, and setting dynamic range to limited rather than full, gave me almost 800 Lux. It was quite bright. And it looked pretty good. My only theory on why this brightens the image is that running the projector in 1080 opens up the lcos color filters more, allowing more light through, but I'm just guessing.

Am I ruining the bulb by juicing the settings? Or is high bulb, just high bulb?

In some forum post somewhere there was a conversion formula for Lux to lumens. And I came up with 3700ish lumens, which makes no sense to me. I'm probably misapplying these measurements.

I'm more confused than when I started.

 

[RedCharles]

No one knows why limiting the bandwidth would significantly increase the brightness?

 

[BMXTRIX]

A 77" diagonal image is 1.6425257 square meters in size. Lux is measured in square meters and lumens are measured in square feet, so you have to do some size conversions.

So, going here:

Lux to lumens (lm) conversion calculator

Lux (lx) to lumens (lm) conversion calculator and how to calculate.

www.rapidtables.com

Put your brightness in (in lux), use the drop down to select that your measurement is square meters (as is standard for lux measurements) and put your screen size in (1.6425257) the surface area box, then hit calculate.

Just over 1,300 lumens.

Yes, the HDR color filter takes away some brightness. This is pretty well established. It is because projectors generally suck at HDR content and don't process HDR properly and never will until 10,000 or 20,000+ lumens is normal in the home on a 120" diagonal. Granted a miniscule 77" size is far smaller than what anyone uses in home theater, so I hope that was just for testing.

At the end of the day, Sony projectors are well known to be dim. I find this to be problematic with their products and one of the reasons I think that JVC is almost always the way to go. The Sony models still look really good, but they do tend to try to aim for a 100" diagonal maybe 120", but not a 133"+ sized image.

Anyway, I don't know about what all tweaks you have been playing with, and I am next to positive that you aren't doing any damage to the lamp. Running a lamp in high brightness does shorten lamp life, but that's consistent with all projectors. Likewise, I'm not sure how many hours are on the lamp, so, more life used will mean a dimmer lamp.

At the end of the day, LUX is meaningless on projectors because it is FULLY dependent on screen size. Any projector review that talks about LUX is providing just crap information. Useless. You have to work through all this math to get back to the actual brightness in foot lumens, and it sucks to do. But, if you are measuring things yourself, LUX is the common way for many devices to take measurements, so you measure in LUX, then convert to lumens. Just know your screen size and ensure you are putting in the proper numbers.

 

[AcuDefTechGuy]

It is because projectors generally suck at HDR content and don't process HDR properly and never will until 10,000 or 20,000+ lumens is normal in the home on a 120" diagonal.

Yep. I have a 6,000-lumen PJ and I'm already dreaming about a 10,000-lumen PJ.