anamorphic lenses + aspect ratios

[vega2K]

Originally Posted by Trogdor2010

It is worth mentioning you can make an anamorphic lens by hand for as little as $100-$200 just by buying a couple of prisms, hardware and knowing how to build it. I have not built my anamorphic lens yet, but I'm currently using the prisms to watch cinemascope movies on a 12 foot wide screen, and while not perfect, I could never go back to black bars on cinemascope movie.

+1 I am building mine now and after my preliminary test, I agree whole heartedly.

[Erman_94]

ok again let me see if i have (somewhat) of a grip on this...

with a 2.35:1 screen, in order to fill the entire screen i would either need an AL or a projector capable of "artificial lens emulation" with the latter being deemed a "decrease in quality" so to speak (i.e. AL is for high-end, the artificial lens is the run-around way of doing things)

in order to watch 1:78:1 content on a 2.35:1 screen without black bars on the sides, i would need some sort of masking option where i either A) have a screen that can mask the screen itself down to size (expensive) or B) build/buy a black/dark masking system to place on the side of the screen to up the contrast

now, assuming that is correct, let me throw some more ideas out there:

1) can someone explain or kindly link me to a post or website that explains what "gain" and "throw" are? from my minimal understanding:

gain = brightness of the screen & the higher the gain, the brighter. what factor(s) would determine what gain to get?

throw = something to do with the distance or height of the projector to the screen? again, what factor(s) would determine what your throw would be?


thanks

[igotcabada]

Screen Gain: As it applies to projectors, gain is the measurement of a projection screen’s light reflectance with unity gain being one. A high gain screen will reflect more light along a narrower path than lower gain screen. Screen gains under one use a gray screen to absorb ambient light to help maintain contrast ratios.

Throw Distance: Throw distance is the measurement from the projector's lens to the screen. A projector with a zoom lens will have a range of throw distances for any given image size, while a projector without a zoom lens will only be able to project one image size at a given distance from the screen. In Projector Central's articles, throw distance is normally quoted for a 100" diagonal screen.

[Erman_94]

thanks for the response/definitions


so how would you know what kind of gain you need? (my room would be dedicated room, so pretty much all black and no light)

how can you determine what the throw distance should be?

[Fors*]

Originally Posted by Erman_94

thanks for the response/definitions


so how would you know what kind of gain you need? (my room would be dedicated room, so pretty much all black and no light)

how can you determine what the throw distance should be?

A low gain of 1:1 or 1:0 would easily work.

As far as throw distance, they make this calculator for this question.

[Erman_94]

so im assuming buying the projector before the screen is the smart thing to do?

EDIT: so in a dark, dedicated theater room, the screen gain should be close to the standard? or did i just make that up?

[Fors*]

Originally Posted by Erman_94

so im assuming buying the projector before the screen is the smart thing to do?

EDIT: so in a dark, dedicated theater room, the screen gain should be close to the standard? or did i just make that up?

I am relatively new to projectors, but I can tell you my screen has a gain of 1:1 and with a room with good light control, it can be anywhere I believe from 1:0 to 1:3. I really couldn't find anyting at 1:3, so I got 1:1 because I knew I had total control of the light in the room. The picture is amazing too!

I am pretty sure you need to make sure the projector throwing distance will cooperate with the distance from it to the placement of your screen. If it falls within range, you should be Ok with some lens adjustments, depending on what projector you are looking at. I had to precisely measure the width I had to determine what size screen I could get, and the biggest for me was 92" diagonally, or 80" in width. It fit just barely between my front speakers.

[Swede]

Originally Posted by Erman_94

ok again let me see if i have (somewhat) of a grip on this...

with a 2.35:1 screen, in order to fill the entire screen i would either need an AL or a projector capable of "artificial lens emulation" with the latter being deemed a "decrease in quality" so to speak (i.e. AL is for high-end, the artificial lens is the run-around way of doing things)

...or manually zoom the image to fit the screen. That's what I do currently, and it is a bit of a hassle adjusting the zoom / lens shift between 16:9 and 2.35:1 every time, which is why the AE4000 is high on my wishlist for my next pj

Originally Posted by Erman_94

so im assuming buying the projector before the screen is the smart thing to do?

EDIT: so in a dark, dedicated theater room, the screen gain should be close to the standard? or did i just make that up?

Yes, that is always a good idea, especially for first time buyers. If for nothing else so you can try it out on a white wall or sheet to see what size of screen you want to go for, and is suitable for the HT room you will be using it in...

Screen gain would depend on the projector you get. If you go for a projector with high lumens and bad black levels (which would NOT be a good idea for a dedicated room) you could use a low-gain grayscreen to help increase the blacks. If you go for a more suitable low-lumen, high contrast projector you could use a slightly higher gain screen to help with the brightness output, but that wouldn't really be necessary since you would have a dedicated room with total light control, so a natural gain of around 1.0 would be fine.

[Erman_94]

thanks for the responses guys

im assuming black levels are determined by the contrast ratio of the projector, correct?

if so, what is a very good contrast ratio to be looking at? How come the new panny is 80,000:1...but the Sim2 C3X 1080 Lumis is only 35,000:1?

is panny listing the dynamic ratio and not the true ratio or something?


also, what would be the general differences between those two projectors? at $30K the Sim2 is definitely out of my range, but im just interested in where the difference in price comes from with projectors

thanks

[munniximp]

I have to admit I was not grasping the screen size differences very well, until now. Thanks!

[phansson]

Originally Posted by Erman_94

thanks for the responses guys

im assuming black levels are determined by the contrast ratio of the projector, correct?

if so, what is a very good contrast ratio to be looking at? How come the new panny is 80,000:1...but the Sim2 C3X 1080 Lumis is only 35,000:1?

is panny listing the dynamic ratio and not the true ratio or something?


also, what would be the general differences between those two projectors? at $30K the Sim2 is definitely out of my range, but im just interested in where the difference in price comes from with projectors

thanks

Contrast ratio is not really uniform between companies. IE you cannot compare the numbers of Sony Vs Sim2 Vs Panasonic because the companies use different formulas and criteria for determining those numbers. Generally, the more you spend on a projector, the better the contrast ratio. I know that isn't 100% entirely true, but probably pretty close.

Even thought the Sim2 says that its contrast ratio is 35,000 to 1, it is probably (ask Brainsturgeon) better than the panasonic that touts higher contrast ratio numbers.

Bottom line, touted numbers by companies do not mean squat. Look at reviews after PJ's are calibrated for real world numbers.

[Trogdor2010]

Originally Posted by phansson

Contrast ratio is not really uniform between companies. IE you cannot compare the numbers of Sony Vs Sim2 Vs Panasonic because the companies use different formulas and criteria for determining those numbers. Generally, the more you spend on a projector, the better the contrast ratio. I know that isn't 100% entirely true, but probably pretty close.

Even thought the Sim2 says that its contrast ratio is 35,000 to 1, it is probably (ask Brainsturgeon) better than the panasonic that touts higher contrast ratio numbers.

Bottom line, touted numbers by companies do not mean squat. Look at reviews after PJ's are calibrated for real world numbers.

Another facotr that isn't talked about frequently when it comes to contrast, the light output of black, lower levels of fLs (footlamberts) for the color of black achieve better black levels, higher levels of fLs for whites determine brightness. This is scaled from black to white we know as contrast ratio, since contrast ratios are often determined publicly by it's blacks rather than black and white, it's frequently misleading, and thus if a projector can produce less fLs for blacks and more fLs for whites, the projector has a better contrast ratio, meaning a brighter projector with dimmer blacks will have a better contrast ratio, but it is very difficult to achieve and why dimmer home theater projectors have higher contrast ratings than non CRT based movie theater projectors, they are alot more expensive to achieve a bigger and dimmer image.

[GeologyNut]

Originally Posted by Swede

...or manually zoom the image to fit the screen. That's what I do currently, and it is a bit of a hassle adjusting the zoom / lens shift between 16:9 and 2.35:1 every time, which is why the AE4000 is high on my wishlist for my next pj



Yes, that is always a good idea, especially for first time buyers. If for nothing else so you can try it out on a white wall or sheet to see what size of screen you want to go for, and is suitable for the HT room you will be using it in...

Screen gain would depend on the projector you get. If you go for a projector with high lumens and bad black levels (which would NOT be a good idea for a dedicated room) you could use a low-gain grayscreen to help increase the blacks. If you go for a more suitable low-lumen, high contrast projector you could use a slightly higher gain screen to help with the brightness output, but that wouldn't really be necessary since you would have a dedicated room with total light control, so a natural gain of around 1.0 would be fine.

The AE4000U is amazing, nuff said!! Now compared to a Sims2, I dunno, but still I love the AE4000U!