JVC RS500 / 600 Owners

[AVSCraig]

question

how many nits am I getting?

0.8 gain screen...~14' throw. 118" wide 2.35 screen with the rs400?

thanks in advance

How many foot lamberts are you getting, and how many lumens is your projector putting out ?

[bmoney]

How many foot lamberts are you getting, and how many lumens is your projector putting out ?

no clue...didnt know if there was a way to predict it (not necessarily be spot on accurate)

[AVSCraig]

no clue...didnt know if there was a way to predict it (not necessarily be spot on accurate)

You need a light meter and a 100 IRE test pattern !

[stanger89]

Good question. I found this via Google -

Nits vs Lumens
When comparing Nits to Lumens, in simple terms, 1 Nit represents more light than 1 ANSI lumen. The mathematical difference between Nits and Lumens is complex. However, for the consumer comparing a TV with a video projector, one way put it is 1 Nit is the approximate equivalent of 3.426 ANSI Lumens.

Using that reference point, in order to determine what a specific number of Nits is comparable to a specific number of ANSI lumens, you multiply the number of Nits by 3.426.

If you want to do the reverse (you know the lumens and want to find out its equivalent in Nits), then you would divide the number of Lumens by 3.426.

Here are some examples:

200 Nits is the equivalent of about 685 ANSI Lumens
500 Nits is comparable to about 1,713 ANSI Lumens
730 Nits is comparable to about 2,500 ANSI Lumens
1,000 Nits is comparable to about 3,426 ANSI Lumens
1,500 Nits is comparable to about 5,139 ANSI Lumens
2,000 Nits is comparable to about 6,582 ANSI Lumens

https://www.lifewire.com/understanding-nits-lumens-brightness-4125499

I'm getting around 452 nits ? That's what I come up with. Not sure how accurate this is.

Well that site is way wrong.  Nits are a measure of luminance (light emitted/reflected from a source), where as Lumens are a unit of illuminance (light incident to a source).  So a nit is a measure similar to a foot-Lambert or candella/meter^2, where as Lumens, well we all know what that is, measure of the amount of light produced by the light source.

So you can't convert Lumens directly to Nits, in the same way you can't convert Lumens directly to ftL, because you need to know the area those lumens are spread over, and the gain of the surface.

So to bmoney's question, if we assume 1600 Lumens, that would be:
1600 Lumens / (118" * 118" / 1.78 / 144) * 0.8 gain
1600 Lumens / 54 sqft * 0.8 gain
23 fL / 3.426 nits/fL ~= 81 nits

[Tom Bley]

Well that site is way wrong.  Nits are a measure of luminance (light emitted/reflected from a source), where as Lumens are a unit of illuminance (light incident to a source).  So a nit is a measure similar to a foot-Lambert or candella/meter^2, where as Lumens, well we all know what that is, measure of the amount of light produced by the light source.

So you can't convert Lumens directly to Nits, in the same way you can't convert Lumens directly to ftL, because you need to know the area those lumens are spread over, and the gain of the surface.

So to bmoney's question, if we assume 1600 Lumens, that would be:
1600 Lumens / (118" * 118" / 1.78 / 144) * 0.8 gain
1600 Lumens / 54 sqft * 0.8 gain
23 fL / 3.426 nits/fL ~= 81 nits

He has a 118" wide 2.35 screen.

Stanger, if I have a 115" wide 2.35 screen with 1.1 gain and 1,700 lumens what are the nits?  Do you just do the calculation with 2.35 instead of 1.78?

So, if you know the actual lumens is this a correct conversion tool?

http://www.unitconversion.org/luminance/foot-lamberts-to-nits-conversion.html

Oops!  Nevermind, that conversion is Foot lamberts to nits.

[AVSMike]

question

how many nits am I getting?

0.8 gain screen...~14' throw. 118" wide 2.35 screen with the rs400?

thanks in advance

With a new lamp, you would get around 90 nits. Since he is at short throw, I used 1,800 lumens.

[AVSMike]

He has a 118" wide 2.35 screen.

Stanger, if I have a 115" wide 2.35 screen with 1.1 gain and 1,700 lumens what are the nits?  Do you just do the calculation with 2.35 instead of 1.78?

So, if you know the actual lumens is this a correct conversion tool?

http://www.unitconversion.org/luminance/foot-lamberts-to-nits-conversion.html

You did not give throw distance. If at short end of throw, new lamp and P3 filter in place, then 99 nits. Same situation without P3 filter, 127 nits

[bmoney]

With a new lamp, you would get around 90 nits. Since he is at short throw, I used 1,800 lumens.

thanks!

[AVSMike]

Easy way to do this is calculate foot lamberts and use a foot lambert to nit calculator.
http://www.unitconversion.org/luminance/foot-lamberts-to-nits-conversion.html

You will notice that 30FL gives you about 103 nits.

[Tom Bley]

You did not give throw distance. If at short end of throw, new lamp and P3 filter in place, then 99 nits. Same situation without P3 filter, 127 nits

Thanks, Mike.  I'll be at about 19ft throw or just under unfortunately.  I have viewed with Manni's BT2020NF color space and I still thought it looked great, I couldn't really see a difference without the filter to be honest.  The light output went up but, only slightly as well.  I guess that's a good thing.  It shows with the filter in place it doesn't take away much light.

[AVSCraig]

Easy way to do this is calculate foot lamberts and use a foot lambert to nit calculator.
http://www.unitconversion.org/luminance/foot-lamberts-to-nits-conversion.html

You will notice that 30FL gives you about 103 nits.

That's better. That other site didn't seem right, but I've not actually calculated for nits.

[AVSCraig]

Looks like I have about 130 nits for 4K.

[stanger89]

He has a 118" wide 2.35 screen.

Stanger, if I have a 115" wide 2.35 screen with 1.1 gain and 1,700 lumens what are the nits?  Do you just do the calculation with 2.35 instead of 1.78?

If you're not using an anamorphic lens you have to use a 1.78:1 are since that's what's projected.  So you'd have:
115" * 115"/1.78 = 7429 / 144 = 51.6 sqft.
1700 Lumens / 51.6 sqft ~= 33fL * 1.1 gain = 36.3fL

Which would be about 124 nits.

So, if you know the actual lumens is this a correct conversion tool?

http://www.unitconversion.org/luminance/foot-lamberts-to-nits-conversion.html

Oops!  Nevermind, that conversion is Foot lamberts to nits.

Yup, but that's the correct thing to do, you can't convert Lumens to nits because Lumens is light output, not brightness on screen.  Brightness on screen depends on the Lumens hitting it, the area, and the gain.

[Paul Heroy]

I've had the RS500 for nearly 5 months now. While it throws a terrific image, there are some other issues that have me mulling switching back to a Sony esp with the recent 4K models just announced. (I'd be looking at the VW285ES.)

To wit: A good percentage of my viewing on the big screen is movies in 3D. I have an SI Black Diamond which retains polarization and thus doesn't work with any 3D glasses but the JVC / Xpand models with 180 degree rotation. So I shelled out for the one and only 3D glasses option from Xpand. My wife hates these glasses compared to the lighter and more comfortable glasses we had been using, and I'm getting tired of them too. It's hampering our enjoyment of an otherwise terrific 3D image. It's really grating that JVC decided to not use the industry standard alignment here, but obviously very few of the industry decision makers really care with the near demise of 3D.

There are other minor issues, mainly the delay in HDMI sync any time the signal changes. Wouldn't be something I'd get worked up about on its own but with the 3D glasses issue it adds another straw to the pile.

I've never been tempted to ditch a projector this soon but I'm considering it, which is really disappointing b/c it's overall a fantastic piece of gear.

[AVSMike]

I've had the RS500 for nearly 5 months now. While it throws a terrific image, there are some other issues that have me mulling switching back to a Sony esp with the recent 4K models just announced. (I'd be looking at the VW285ES.)

To wit: A good percentage of my viewing on the big screen is movies in 3D. I have an SI Black Diamond which retains polarization and thus doesn't work with any 3D glasses but the JVC / Xpand models with 180 degree rotation. So I shelled out for the one and only 3D glasses option from Xpand. My wife hates these glasses compared to the lighter and more comfortable glasses we had been using, and I'm getting tired of them too. It's hampering our enjoyment of an otherwise terrific 3D image. It's really grating that JVC decided to not use the industry standard alignment here, but obviously very few of the industry decision makers really care with the near demise of 3D.

There are other minor issues, mainly the delay in HDMI sync any time the signal changes. Wouldn't be something I'd get worked up about on its own but with the 3D glasses issue it adds another straw to the pile.

I've never been tempted to ditch a projector this soon but I'm considering it, which is really disappointing b/c it's overall a fantastic piece of gear.

Actually JVC did it the right way, when viewed from an engineering viewpoint. What JVC did means that you lose less light output for 3D and light output is critical for 3D. It just happens that no other manufacturer goes through the trouble to do this, so it leaves JVC all alone.