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Official Mitsubishi hc4000 ONLY Thread - Page 59

post #1741 of 2810
10/22/11 at 7:49pm
Quote:
Originally Posted by fleaman View Post

If 143" diagonal 16"9 is 125" wide, then yes.

When you say 'downshift', are you wanting to shift the 2.35 image down? 'cos most people here are trying to shift it up.

The furthest up you can shift your 2.35 is to the top of the 16:9 box (at the 143" diagonal size, if that's what you're doing, 125" wide). So the offset would be what the 16:9 143" diagonal size is, ASSUMING you shift the 2.35 image to the very top of the 16:9 box. If you don't, the offset increases from there.

You're right, I meant shift up. How do I figure out how much I can digitally shift up for my situation?
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post #1742 of 2810
10/22/11 at 7:58pm
Quote:
Originally Posted by WynsWrld98 View Post

You're right, I meant shift up. How do I figure out how much I can digitally shift up for my situation?

As mentioned, you can only shift up to the top of the 16:9 box, so your offset is what ever the 143" diagonal, 125" wide 16:9 offset is.

If you didn't do any shifting, the 2.35 image would normally be projected in the middle of the 16:9 box, which would mean the offset would be more than the offset for the 16:9 size. By shifting the 2.35 to the top, you're getting the offset of the 125" wide 16:9 image.

So to summarize with 2.35 CIH> The offset of the 2.35 image would normally be more than the offset of the same size (wide) 16:9 image, since the 2.35 image is normally projected in the middle of the 16:9 box (black bars top and bottom). By shifting the 2.35 image to the top, you get the offset of the 16:9 equivalent wide size (so less offset than if you just left the 2.35 in the middle), and no black bars above, but double thick black bars below.
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post #1743 of 2810
10/22/11 at 8:33pm
Quote:
Originally Posted by fleaman View Post

As mentioned, you can only shift up to the top of the 16:9 box, so your offset is what ever the 143" diagonal, 125" wide 16:9 offset is.

If you didn't do any shifting, the 2.35 image would normally be projected in the middle of the 16:9 box, which would mean the offset would be more than the offset for the 16:9 size. By shifting the 2.35 to the top, you're getting the offset of the 125" wide 16:9 image.

So to summarize with 2.35 CIH> The offset of the 2.35 image would normally be more than the offset of the same size (wide) 16:9 image, since the 2.35 image is normally projected in the middle of the 16:9 box (black bars top and bottom). By shifting the 2.35 image to the top, you get the offset of the 16:9 equivalent wide size (so less offset than if you just left the 2.35 in the middle), and no black bars above, but double thick black bars below.

I must be tired because I've read this a couple of times and still don't know my answer. My guess is you're saying plug in 143" diagonal 16:9 into the Mitsubishi calculator and that's as good as it gets? That offset figure is 23.7". I'm not sure how anyone does a CIH setup with this projector unless they have a VERY high ceiling, even if you lower the 16:9 diagonal to 120" the Mitsubishi calculator shows a 19.8" offset which is still huge. Am I understanding things correctly??
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post #1744 of 2810
10/22/11 at 8:53pm
Quote:
Originally Posted by WynsWrld98 View Post

I must be tired because I've read this a couple of times and still don't know my answer. My guess is you're saying plug in 143" diagonal 16:9 into the Mitsubishi calculator and that's as good as it gets? That offset figure is 23.7". I'm not sure how anyone does a CIH setup with this projector unless they have a VERY high ceiling, even if you lower the 16:9 diagonal to 120" the Mitsubishi calculator shows a 19.8" offset which is still huge. Am I understanding things correctly??

Yes.

At that size it's gonna be tough if you have low ceilings. But then again, at that size you're really pushing the extreme limits of the HC4000's lumens anyway.

I have 100" ceilings (8'4"), if I mounted my PJ as close to the ceiling as possible (with a mount), that would probably get the lens center 7" from my ceiling. With a 125" wide x 53" tall 2.35 shifted to the top, the bottom of the 2.35 image would be about 16" from my floor is my guess.

Now, if you don't use a ceiling mount, it you mounted it upside down on a shelf up to the ceiling, you could get the lens center as close as 4" from the ceiling, so that will gain you another 3".

But again, that is a HUGE screen, and the larger you go in size, the larger the offset gets...
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post #1745 of 2810
10/22/11 at 8:57pm
The 16:9 image size for what we're talking about is 108" diagonal (when watching 16:9 programming) which I don't consider huge. If I made the 2.35:1 size any smaller the 16:9 image size would be tiny.

Even if you lower the 16:9 diagonal to 120" the Mitsubishi calculator shows a 19.8" offset which is still huge.
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post #1746 of 2810
10/22/11 at 9:02pm
Well, compared to PJ's that have no offset, this PJ does have a large offset.

Of course 6-8 years ago, the offset of this PJ would be considered about average.

If you run a smaller screen and want your PJ out of the way (not hanging 3-4ft down from the ceiling), or you have high ceilings and run a larger screen, PJ's with offsets like the HC4000 are a godsend.

OTOH, if you have low ceilings (basement) and want to run a large screen, your screwed.

Ironically one of the reasons I have this PJ (HC3800 actually) is due to the large offset!
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post #1747 of 2810
10/22/11 at 9:10pm
For the size screen and offset you want, I would think the Benq W6000 would be the better choice. Problem is, I don't think it has the CIH feature that the Mits does. Maybe, I'm just not that familiar with that PJ.
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post #1748 of 2810
10/22/11 at 9:55pm
i have 8' ceilings
how big a screen can i get?
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post #1749 of 2810
10/23/11 at 12:03am
Since there are lots of questions on mounting and CIH calculations, I'm posting more instructions on how to use the Mitsubishi HC4000 Online calculator to decide the mounting options:

1) Decide on the size of the 2.35 screen width first. For example, I planned a 110.5 x 47 screen so for the calculation purpose the 110.5 width is what you plug into the "Screen Details" width and press enter. It will automatically calculate the corresponding 16x9 height and diagonal which is what will be projected ultimately. For me, this worked out to 110.5 x 62.5 = 127" diagonal 16x9 image. Make a note of the difference between the height of the 2.35 image and the height of the 16x9 image. This would work out to 62.5 - 47 = 15.5 inches.

2) Then, enter the ceiling height. If you have a 100" ceiling, input this figure and press enter. The calculator will give you the distance between the floor and bottom of the 16x9 image. It will also give you the distance between the floor and projector bottom. Your aim should be to maximize the distance between the floor and bottom of the image by changing the pole and image diagonal setting. Forget about the offset figure - practically it isn't very relevant because you have other figures to guide you.

3). If you are doing CIH, remember to add the 15.5 inches to the distance between the bottom of the image and floor. For a 100" ceiling, 5" pole and 110.5" image width, the maximum distance between the floor and image bottom would be 8.4" (as per the calculator) plus the 15.5" (due to shifting up the 2.35 image digitally) resulting in 24" almost.

4) Make sure that your projector throw distance falls between the Longest and Shortest. To my understanding, irrespective of whether you physically move the projector or you change the zoom, the offset will be the same for a particular image size.

5) Verify these figures with the projector central's calculator. Use the 16:9 option only. I'm not sure how accurate the 2.35 calculator would be (I never tried it).

In my opinion, I found that for a throw of 13.6 feet, the image size of 110.5 x 47 was optimal in terms of brightness, clarity, lack of pixel visibility and size. I could increase the height by another 1-2" maximum without changing the brightness significantly but that was the limit. Going beyond that resulted in a significant drop in brightness on Low lamp mode. Anywhere from 45-49 would be ideal I guess. I know that there is a great deal of subjectivity involved here but this can be taken as a starting point. Others who are running a CIH can probably confirm this. Also, as you can see in my previous post, I've painted the screen wall black so the black bars that are projected above the 2.35 screen are completely invisible.

EDIT: While discussing the slight drop in brightness due to the size of the CIH image, one of the forum members suggested that I switch on Brilliant Color, which gave me a boost in lumens without necessitating changing the lamp to high. This is what I recommend to those who are planning a similar setup to mine and who don't want to sacrifice lamp life or change gamma.
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post #1750 of 2810
10/23/11 at 5:34am
Quote:
Originally Posted by contentedbloke View Post

In my opinion, I found that for a throw of 13.6 feet, the image size of 110.5 x 47 was optimal in terms of brightness, clarity, lack of pixel visibility and size.

Thanks for this, if I may trouble you with one more clarification : I believe your seating distance is around 13 to 14 feet. If you walk to towards your screen, at what point can you see the pixel structure?

I am in a similar situation to yours, except my seating will be closer than yours, mine is at 10', do to having a room that is wider than it is long. I already have a 46" tall scope screen in place, but can lower the screen on the wall. (Actually it would probably be a good idea to do this part anyway, to place the viewers eyes at 1/3 of the screen height. I tend to have to look up a wee bit now.) So I can compensate for the offset.

What I can't do is move the seating. If you could check this out for me I would really appreciate it. It would help me determine if I need to stick an anamorphic lens in front of the HC4000, or if I can get a way with zooming.

Thanks,
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post #1751 of 2810
10/23/11 at 9:09am
Hey coderguy, do you think we could get you to edit your first post in the thread with some FAQs? Offset and CIH in particular.
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post #1752 of 2810
10/23/11 at 10:28am
Quote:
Originally Posted by curttard View Post

Hey coderguy, do you think we could get you to edit your first post in the thread with some FAQs? Offset and CIH in particular.

I think I have the second post with all of the specs etc, I can add to that one for sure....what all do we want to put in it?
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post #1753 of 2810
10/23/11 at 11:59am
Finally hooked up the projector and watching football on it right now. Liking the picture quality so far. One quick question, is it bad for the bulb if I keep switching channel back and forth? I have Directv and when I change channel, due to the native resolution, the screen would go blank, blue screen, projector said no signal, blank screen, then picture. I want to preserve the bulb life but it might be hard to not watching football on the big screen. Thanks.
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post #1754 of 2810
10/23/11 at 2:31pm
Thread Starter 
New Elite Projector Calculator has been released.

(accessible from below link)

...and Supports Mitsubishi hc3800 / hc4000 / hc7800

Make sure to select a projector before changing any settings, as there is an issue if you move stuff
around before changing projectors (working on it later). Seems to work fine in Firefox and IE.

LINK TO CALCULATOR IS IN THIS POST:
http://www.avsforum.com/avs-vb/showt...7#post21116957

...
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post #1755 of 2810
10/23/11 at 3:24pm
Quote:
Originally Posted by MOS67T View Post

Finally hooked up the projector and watching football on it right now. Liking the picture quality so far. One quick question, is it bad for the bulb if I keep switching channel back and forth? I have Directv and when I change channel, due to the native resolution, the screen would go blank, blue screen, projector said no signal, blank screen, then picture. I want to preserve the bulb life but it might be hard to not watching football on the big screen. Thanks.

You're just losing signal and the display is blanking, but the lamp is still lit and running as normal. Shouldn't harm your lamp in the least.
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post #1756 of 2810
10/23/11 at 6:32pm
Quote:
Originally Posted by curttard View Post


Nope, just an EyeOneLT.

Brightness difference is fairly significant in my case because I went from 106" 16:9 to equivalent of 140" 16:9 (iirc) for my CIH.

So wow that is a big screen I have a130" 2:35 screen and still trying to get the settings where I want them for brightness and pop. What do you use with a screen that size to maintain brightness.
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post #1757 of 2810
10/23/11 at 6:47pm
Quote:
Originally Posted by contentedbloke View Post

4) Make sure that your projector throw distance falls between the Longest and Shortest. To my understanding, irrespective of whether you physically move the projector or you change the zoom, the offset will be the same for a particular image size.

I'd say "not necessarily". I would think most would, since their 2.35 image is actually a 16:9 image of significantly greater than usual size, would want maximum light output, thus shortest throw distance.
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post #1758 of 2810
10/23/11 at 6:58pm
Quote:
Originally Posted by bishopt View Post

I think I have the second post with all of the specs etc, I can add to that one for sure....what all do we want to put in it?


Let's see, contentedbloke covered a lot of it in his post a couple back.

I'd include:

Mits HC4000 projector calculator: http://www.mitsubishielectric.com/bu...s/prjcalc.html

(make sure to change model to HC4000)

- HC4000 CIH options: if using a 2.35 screen, one can set that option in the Install menu (iirc); then, to switch between 2.35 and 16:9 content, simply press the Aspect button on the remote

- With this option, you are actually projecting a 16:9 letterboxed image as usual, this just makes it easy to switch between 2.35 and 16:9 without needing an anamorphic lens.

- To figure out offset etc, plug in the width of your 2.35 screen as the width in the calculator. This will calculate throw, offset etc for what is actually being projected, which is a large 16:9 frame with a letterboxed 16:9 image. In other words, a 120" wide 2.35 screen means an actual projected image of 120" x 67.5", or a 137" 16:9 image. The offset for this size image would be 22.7" from the center of the lens.

- Drawbacks: The 16:9 content is being digitally scaled down to fit in the 2.35 screen. This means that instead of using 1920x1080 pixels, you are only using something like 1446 x 817. So you are not getting the full resolution of the projector OR the content, making 1:1 pixel-mapping impossible and giving up some sharpness. In addition, as compared to 16:9 content on a 16:9 screen, the pixels will be bigger and the image dimmer, since this 16:9 content is being projected as a smaller image inside the much larger ACTUAL projected image.
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post #1759 of 2810
10/23/11 at 7:12pm
Thread Starter 
My calculator is fairly accurate for throw distance brightness, as it does the 2.35 to 16:9 throw brightness conversion automatically when you change the aspect in the program, but it doesn't convert the offset correctly (it will in Beta 03).

You can figure the offset for 2.35 in my program by changing the aspect ratio screen size from 2.35 back to 16:9 for a 120" image and raising the inches up +6". That will give you the offset with max UPSHIFT enabled I believe.
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post #1760 of 2810
10/24/11 at 6:11am
Quote:
Originally Posted by curttard View Post

Let's see, contentedbloke covered a lot of it in his post a couple back.

I'd include:

Mits HC4000 projector calculator: http://www.mitsubishielectric.com/bu...s/prjcalc.html

(make sure to change model to HC4000)

- HC4000 CIH options: if using a 2.35 screen, one can set that option in the Install menu (iirc); then, to switch between 2.35 and 16:9 content, simply press the Aspect button on the remote

- With this option, you are actually projecting a 16:9 letterboxed image as usual, this just makes it easy to switch between 2.35 and 16:9 without needing an anamorphic lens.

- To figure out offset etc, plug in the width of your 2.35 screen as the width in the calculator. This will calculate throw, offset etc for what is actually being projected, which is a large 16:9 frame with a letterboxed 16:9 image. In other words, a 120" wide 2.35 screen means an actual projected image of 120" x 67.5", or a 137" 16:9 image. The offset for this size image would be 22.7" from the center of the lens.

- Drawbacks: The 16:9 content is being digitally scaled down to fit in the 2.35 screen. This means that instead of using 1920x1080 pixels, you are only using something like 1446 x 817. So you are not getting the full resolution of the projector OR the content, making 1:1 pixel-mapping impossible and giving up some sharpness. In addition, as compared to 16:9 content on a 16:9 screen, the pixels will be bigger and the image dimmer, since this 16:9 content is being projected as a smaller image inside the much larger ACTUAL projected image.



Thanks Curttard - Done...everyone take a look at the first page of the thread, post 2 contains information regarding the HC4000...I am willing to add more just need to know what we would like to add...good candidates are any common questions that get asked multiple times...
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post #1761 of 2810
10/24/11 at 11:24am
Thread Starter 
One of you could create a separate thread called Mits hc4000/hc3800 Tricks and Quick Start Advice, or Bishop could add this information.

---------------------------------------------------
Common questions that need to be addressed:
---------------------------------------------------

How to calibrate the projector (Test Disc only method vs. Calibration Method)?
How to determine Offsets when in 2.35 mode?
What is a realistic lumens I can get out of this projector and still maintain close enough to a best mode?
(answer should be about 800, but it's a subjective answer since everyone has different color accuracy sensitivity)

How the Mits displays 2.35 mode and what options are available?
Does keystone ruin the image?
What are some sample throw distances for 2.35 and 16:9?
For 2.35 screens, how to hide one black bar and mask the other black bar with the Mits, (masking vs. motorized screen vs. overspill onto black wall ----- etc...)

-------------------------------------------------------------

I'd create the thread, but I'd probably get accused by someone as always needing to create my own threads...
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post #1762 of 2810
10/24/11 at 2:21pm
Quote:
Originally Posted by MOS67T View Post

. One quick question, is it bad for the bulb if I keep switching channel back and forth? I have Directv and when I change channel, due to the native resolution, the screen would go blank, blue screen, projector said no signal, blank screen, then picture. I want to preserve the bulb life but it might be hard to not watching football on the big screen. Thanks.

Quote:
Originally Posted by BMaugans View Post

You're just losing signal and the display is blanking, but the lamp is still lit and running as normal. Shouldn't harm your lamp in the least.

Correct. To add; the lamp/bulb is either on or off, it does not change brightness or turn off when the PJ is powered up. The exception is when you manually change from low lamp to high lamp mode (brightness changes, but lamp still does not turn 'off').

The DLP display chip is the part that controls the display/brightness, etc. The microscopic mirrors either reflect the light away from the color wheel (projecting black---or the best black it can), or reflect light to the CW.

Lamp always on, DLP chip reflecting lamp light away from or to the CW.
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post #1763 of 2810
10/24/11 at 11:17pm
OK, thanks guys for the quick reply. I figured that was the case but wanted to make sure. I am enjoying this projector but I must say that the picture quality on my plasma is better, sharper, and clearer. But you can't beat the picture quality on such a big screen. Still a good buy to me. Thanks everyone.
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post #1764 of 2810
10/25/11 at 12:55am
Quote:
Originally Posted by MOS67T View Post

I am enjoying this projector but I must say that the picture quality on my plasma is better, sharper, and clearer..

Make sure you compare apples to apples.

Take the screen width of your HC4000 screen, do you sit 1.5x screen widths back? 2x? Well, what ever that multiplier is, do the same with your plasma, i.e. sit the same 1.5x screen width of the plasma size back when comparing to your HC4000.

If you sit the same distance from your plasma and your HC4000 screen, of course the HC4000 won't be able to compete at the larger screen size.

And don't forget that most PJ's need 100-200hrs to settle in (lamp brightness and red push wise), and that you should spend some time calibrating it, especially gamma. Front projection isn't exactly an 'easy button'. You might find that you will fine tune your set up over time (calibration, screens, adjusting room against ambient light, reflections, etc.). Simple things like white walls/ceilings, especially near the screen, can really take the 'pop' out of the image. There's a reason no commercial theaters have white or light colored walls, etc.
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post #1765 of 2810
10/25/11 at 4:37am
So far my initial impressions are "Wow". This thing really looks good out of the box. Haven't calibrated yet, going to break in a touch before doing so. Just switched to cinema mode and medium color temp as stated in the projectorcentral.com review.

The sharpness, color, "pop", and resolution of this pj is quite the upgrade from my previous one, granted that one was 8 years old. The image has a really nice 3D quality to it. I was watching planet earth on blu ray yesterday and it was stunning.

So far, I'm loving it

btw, I have this in my man cave basement with 7' ceilings, mounted down about 8" or so... plus 2 more to get to the center of the lens, so about 10 total inches and the offset is a complete non issue for me, just a couple clicks of keystone aren't a big deal, but to each his own. Running a 100" screen.
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post #1766 of 2810
10/25/11 at 4:39am
Btw, I will add some additional impressions after a few weeks worth of use.
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post #1767 of 2810
10/25/11 at 4:56am
Thread Starter 
I completely agree about a few clicks of keystone not being an issue with this projector. It is still FAR FAR sharper than an LCD or MOST LCOS projectors. Compared to the older Epson's or older LCOS projectors (can't speak to the newer ones), the Mits would need enormous amounts of keystone enabled to become that un-sharp.

People have confused old-style keystone on older projectors that have inferior lens's and sharpness to start with and issues in Chromatic Aberration. These issues stack up, but the Mits starts so clean that enabling a little keystone is a non-issue for movie watchers. Keystone did not work as well on 720p projectors because they have fewer pixels to play around with in the sense of a noticeable resolution loss, but with 1080p this isn't as big of an issue. The resolution loss in the scaling algorithm is very minor at the lower-end of the keystone.

When adjusting keystone, walk up to the screen and make sure to find the sweet spot in sharpness, also re-adjust the sharpness control to match. Sometimes even though you really only need 1-2 clicks of keystone, 3 clicks may make the projector sharper as the distortion from the keystone may become smoother, but it depends on any CA you may have caused by positioning the projector near closest throw or not. What I mean is, there is a sweet spot in the keystone usually, and it is not always exactly matching of how much you need to correct the trapezoidal effect, sometimes adding one more notch or reducing one notch may actually make things more even on a pixel or text basis even though the other amount was the exact centering of the anti-trapezoidal angle.
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post #1768 of 2810
10/25/11 at 5:21am
Quote:
Originally Posted by Mr. Snifter View Post

So far my initial impressions are "Wow". This thing really looks good out of the box. Haven't calibrated yet, going to break in a touch before doing so. Just switched to cinema mode and medium color temp as stated in the projectorcentral.com review.

The sharpness, color, "pop", and resolution of this pj is quite the upgrade from my previous one, granted that one was 8 years old. The image has a really nice 3D quality to it. I was watching planet earth on blu ray yesterday and it was stunning.

So far, I'm loving it

btw, I have this in my man cave basement with 7' ceilings, mounted down about 8" or so... plus 2 more to get to the center of the lens, so about 10 total inches and the offset is a complete non issue for me, just a couple clicks of keystone aren't a big deal, but to each his own. Running a 100" screen.

Congrats...and for some reason I'm not shocked, another happy camper...Enjoy and come back and let us know what you think after watching it for awhile...I watched X-men First class last night...looked awesome
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post #1769 of 2810
10/25/11 at 5:31am
Thread Starter 
Determining the true effect of Keystone on the image mathematically

I have figured out how to calculate actual pixel resolution loss with keystone (or very very close).

Simplest Layman Explanation:
As you tilt the projector, the edges become more trapezoidal, but the re-scale algorithm when adding keystone takes the distortion on the edges and balances this distortion back into the entire image. So what you are doing is trading a more intense distortion on the edge for a distributed distortion across the whole screen. This is much like if you have spilled milk on a table, then if you spread the milk across the entire table, it becomes harder to see, and you can now only see the spilled particles if you look up close at the table.

Slightly more Technical Explanation:
Digital keystone uses a scaling algorithm which is adjusted based on an equation of equal distribution or re-balancing the distortion from the bent edges back into the entire image. In effect, the compression algorithm squeezes the entire image down to the thinnest edge of the projected trapezoidal image. Below I will explain how to figure the actual distortion percentages on a pixel mapping basis mathematically.

How to figure the final resolution loss:
With a ruler or tape measure, physically measure the Horizontal Distance between widest and thinnest part of the trapezoid on one side BEFORE applying the keystone adjustment on the projector (but after tilting the projector), and then divide it by the screen width, and then multiply it times 2 (to account for both sides lost). Refer to the final formula below.

Now I imagine in order to prevent an aspect ratio distort from this effect, the same percentage of the Y-coordinate pixels will also need to be dropped. Although here is where there is some leeway in the algorithm, a small enough to be unnoticeable aspect distort could be applied on the edges to preserve an arbitrary amount of the lost pixels, but I'm not sure if they do that or not, let's assume no for now (worst-case resolution scenario therefore assumed below).

So the TOTAL and FINAL formula becomes:

PercentLoss = (Trap Wide to Thin Dist Measured / Screen Width) * 2
PercentLoss = 1 - PercentLoss
(changes it to percent of whole number for simpler calculation below)

New Keystone Pre-Scaled Resolution = (PercentLoss * 1920) x (PercentLoss * 1080)

Final Pre-Scaled Resolution for a 6" Trapezoid Angle of Keystone based on a 60" wide screen:

= 1536 x 864

Re-Mapping Equation (Final re-scale)
Here is where the distortion is occuring, they have to fit the resulting pixels by adding EXTRA pixels back into the grid in order to ensure the entire image size is retained. So I'm not going to write out this last part since there are various ways to do it, but it's why you lose the 1:1 pixel mapping, and it is how it is lost. So you may still have a fairly high resolution, but the "filler pixels" added back to get the full 1920x1080 grid in non-1:1 mapped format are what is causing the bold effect on text or slight visible distortion when you get close enough to the screen to see it. It is sort of like a mini-aspect distort on the basis of a 2x2 pixel grid for each section of the image which grows as you increase the keystone, this is necessary so that as a whole the overall aspect look of the entire image is still retained by distorting the finer details and spreading the distortion across the screen.

As you increase the keystone more and more, the minature re-mapped grids or distribution areas continue to expand from 2x2 to 4x4 to 8x8, etc. That is what boldens the text more and more as more filler pixels need to be added to prevent an overall aspect distortion effect of the whole image. Increasing keystone a large amount seems to move the bolded effect in one direction a little and this is due to the way the re-scale is pushing things over with filler pixels. The mini-grid areas that are getting extra pixels would actually be a different ratio and not all a perfect square, but for simplicity sakes I showed them as square.

We can see that the worst part of Keystone is not the resolution loss itself (although this plays a part), but it is the filler pixels distorting the appearance of fine detail (loss in 1:1 pixel mapping), but that said, it takes quite a bit of keystone to lose enough detail to be seen in movies or video from normal seating distances.

Hope that makes sense...

I reverse engineered this formula, I have never seen it, but I'm pretty darn confident this is how it works, or a close approximation.
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post #1770 of 2810
10/25/11 at 2:08pm
Digital Keystone absolutely does effect image quality, the real question is are your eyes trained well enough to notice it. For most the answer is no (thankfully) but do not be mislead into thinking it does not degrade your image. This is another one of those 'ignorance is bliss' situations because, much like RBE, if you are unaware do not go looking for it because once you see it you cannot un-train your eyes/brain. It can actually create several image degrading artifacts but then so can many other 'functions' of home theater gear. If you use it and are happy with your results then don't listen to a/v purists like me, many of us suffer from being mildly obsessive regarding this hobby.

Jason
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