If your HDTV has a fixed frame, such as an LCD/plasma panel or a rear-projection TV, and you want to see the CinemaScope™ image at its intended aspect ratio, there is not much that can be done about the bars at the top and bottom of the screen. As a result, the bars use part of the valuable vertical resolution of the 16:9 TV or the projector's chip. To make things worse some technologies, such as LCD projection, show the black bars as dark gray, distracting the viewing of the actual image.
The HD chip of a front projector is fixed to the resolution of its design (720px1280 or 1080px1920 pixels). Many projectors today are chip-based DLP, LCD, and LCoS technologies at 720p resolution. More recently, several affordable 1080p projectors were introduced to the market.
It is a very cool idea to get fixed height no matter what aspect ratio you are using. Since you are forced to live with content which is in 1920x1080 format in order to get a 2.35 aspect ratio you need to use a scaler to scale only the portion you want and to produce non-square pixels. Although the 1920 stays the same, you have to take the portion of the image that is not in black bars and scale it up to 1080 lines. This warps the image and thus requires an anamorphic lens to display it correctly.
However, if I am displaying a 16x9 image there is no warping of the image and therefore I do not want the anamorphic lens.
For a 4x3 image, I could put black bars in, but it would be better to warp in reverse and have a inverse-anamorphic lens. I don't know if one of those exists or if it is worth it.
What you have not described in your system is how you go about adjusting your system for the different aspect ratios. How do you change the lens? How do you change the warping of the scaler? What do you do when the aspect ration is only 1.85 or something else?
It would be nice to get details about how your system eventually was set up.
You have also not pointed out that it is extremely important to have a great scaler. Remember, regardless of using the full potential of the projector you are still only getting a portion of the 1920x1080 signal to work with. This is very similiar to taking 480p content and displaying it on an HDTV.
Your first two paragraphs describe what the articles already say; I do not take them as questions.
The answer to your third paragraph: the sled supporting the lens removes the anamorphic lens in front of the path of the projector to view any non-2.35:1 content, showing that content with side pillars obviously. The anamorphic lens is a separate piece; it is not to replace the projector lens.
Your 4:3 question is responded above, there no need for inverse lens. There is no need for any lens on non 2.35:1 content.
1.85:1 aspect ratio content will show with very thin top/bottom black bars on 16:9 AR viewing, or you can apply a very small overscan to make those bars go away.
There are lens that perform the switching of formats within the same lens structure, they do not use a sled to transport those lens in/out, but they are always in the path of the projected image, even in 16:9 and 4:3 content.
I personally do not want ANY lens in front unless I need them, so a sled is money well spent when it comes from my pocket. Some people use no transport and move the lens manually in/out, some people save on the sled and have the lens always in front.
Regarding the details of the system I implemented, two articles before this one provide the names of the manufacturers of the HW. The next articles on this series will go a bit deeper about the pieces, although I am not planning to make this series a technical review of components, when reviews are available I will provide some links.
Regarding my choices, there are many products in the market that can be used for an equivalent purpose, from projectors, scalers, lenses, screens, etc.
Regarding the importance of the scaler, I mentioned several times in the articles how important is the overall quality of the scaler and the lens for a quality result. Many projectors already include a scaler but a $3k to $5K quality scaler could not possibly be within the enclosure of a $3K projector.
Regarding your comparison of 480p displayed on a HDTV, which you said is similar to the scaling of CinemaScope
Thanks for the reply. You are correct, the first two paragraphs were not questions. I was trying to sum up what you said as a precursor to my question. Sorry for the confusion.
You are also correct that it is a huge difference between scaling 480i to 1080p then the 2:35 aspect ratio. I was only pointing out that a good scaler makes a difference. Besides, only a good scaler will allow you to have the type of control necessary for the scaling required in the first place.
I reread your articles and I now see from your picture in Article 1 and some other statements that you indicated that you were using a sled to move the lens. Sorry, I missed it the first go around.
While I understand the desire and theory to display constant height material, it seems all this effort could be avoided and a much better image obtained if they would just make front projectors with the 2.35 native aspect ratio imaging chips.
Scaling any fixed pixel display is going to soften the image somewhat. I understand gaining image brightness and vertical resolution with the current solutions, but a native imager chip would seem to be a much "cleaner" and overall cheaper solution.
Rodolfo, you work around these manufacturers all the time... do you know of any plans to offer projectors with a 2.35 native aspect ratio? I realize that for narrower images some of the pixels would be "wasted", but this would be IMO a much better solution. For DLP we would be at the mercy of TI to offer that imager, but for others, it seems they have control of their display chips and could tool up for this, if they wanted to.
I agree with akirby, the domain format is were the investment goes to, 16:9.
aaron,
I have not heard of any effort toward 2.35:1 chips on any technology, DLP, LCoS, LCD, etc for the purpose you describe, I must admit that I never went deeper to get more information about the subject, but I will certainly do.
The premium of having a chip with more pixels on both sides to maintain 1080 vertically and match the 2.35:1 aspect ratio would only be put to work on 2.35:1 content for a market of people that is reduced, for now.
There is another purist way to implement 2.35 without a lens and scaler, using the zoom of your front projector. This can't really be covered here due to the length required to explain all this and I have an article in our publishing corral waiting...
I can tell you this, the zoom 2.35 method is not for everybody and not all projectors have the features to do it. Rodolfo is concentrating on the automated plug and play version for 2.35 since most of our readers fall into that category. The zoom method is for the hands on videophile only who knows how to drive his system.
I personally am using the zoom lens method to achieve constant height projection. I am using a Panasonic 900 projector firing on a 96" 16x9 screen that I have masked down to a 2.4:1 aspect ratio.
I then use the zoom lens (along with the vertical lens adjustment) to keep the image the same height, whether it is 1.33:1, 1.78:1, 1,85:1, 2.35:1, or 2.4.1.
I would not like the readers to interpret by the way the comment is made that the zoom method is for videophiles and the CinemaScope with anamorphic lens is not, which is not true.
In fact, I could present it as that the zoom method is actually not for videophiles regarding quality when is not making use of the full resolution and light of the projector chip, as the CinemaScope system does "when using top quality scaler/lens/projector", but that is not the purpose of my article, and I intentionally stayed away from comparisons.
I mentioned that there is a place for both methods and the decision is in the hands of consumers, and the choice is mainly driven by money and the quality of the CinemaScope system, but also based on operational complexity of manual adjustments, and the projector's functionality, done in a repetitive manner.
There are people that will definitely not spend what they spent on their 1080p projector on adding a CinemaScope system, and prefer to go for the less costly zoom method, temporarily or permanently.
There are also people that cannot implement the zoom method practically, even though they might want to save the money of a CinemaScope system, because their ceiling-mounted projectors are accessible only by bringing the ladder from the garage and adjusting the non-motorized zoom and focus manually every time they switch the aspect ratio of the movie they watch, a task that many times needs two people to be done correctly. Not to mention doing this in front of the HT guests.
Again, this article is to cover 2.35:1 CinemaScope using the anamorphic lens implementation that is starting to be used widely in the projector industry, and I intentionally stayed away from analyzing and comparing the pros and cons of each method precisely to avoid confusing consumers within a series of articles that is complex enough already.
Well, right after I posted my reply, it dawned on me that 2.40 material is still only going to be encoded on the HD disc as 1920 horizontal pixels regardless and the vertical resolution likewise will be less than 1080, so scaling would have to be done in both directions anyway.
Although I think it might be a "cleaner" way to do it, you would still have scaling issues to deal with. Oh well, for the foreseeable future I will just watch the wider aspect ratio films with a smaller vertical height.
I understand the zoom method as well, but both seem somewhat awkward to implement. I suppose if everything is automated in the Cinemascope arrangement, it would greatly reduce the "hassle" of going between formats. Unfortunately this drives up the cost of such solutions quite a bit.
I do think it's terrific that the cost of all these components is going down however, so hopefully soon a fully automated "package" with projector, scaling processor, lens and masking screen will become more affordable for mainstream consumers...
2.40:1 will have 1920 horizomtally, as yoiu said, but there is nothing to scale in that direction, the full chip is used on that axis.
Only the vertical would be scaled (as 2.35:1), plus the optical stretch by the anamorphic lens to make the image wider, but that is not part of the scaling function.
The 2.40 would still show with two very small bars (like the 1.85 would on 16:9), but a minor overscan adjustment could take care of that. I personally leave it as is because the 2.35:1 image is so poweful that two small bars do not affect me.
As you said prices are coming down for high quality products.
I guess I wasn't being clear when I talked about horizontal scaling. I meant in the hypothetical case of a native imager that had 1080 X 2592 or similar "native" pixels, the HD content from an HD DVD or Blu-ray source would still have to be electronically scaled horizontally (to eliminate the anamorphic lens) as well as scaled vertically (since the image on disc would not have a full 1080 pixels of vertical resolution) to fill the entire imaging chip.
I realize also that some of the imager pixels would be "wasted" on other image ratios, but nothing is really "lost" in that scenario. We always have the highest resolution the image is capable of displaying with minimal distortion of the image. Of course it might be that optically stretching the image would cause far fewer artifacts than electronically doing so. Unfortunately I don't have the exposure to the good "toys" to know personally, so I'll trust your reviews and experience in this regard. There is no substitute for firsthand experience!
That is what I was referring to. I do understand the principles of CIH, but sometimes I think people mis-state things when they say that you lose "vertical resolution" watching the movie with the black bars at the top and bottom. The resolution is not in the image to begin with. You do lose image size and brightness, since much of the imager is not reflecting or passing light (depending on technology). I think it is largely the size difference that is most dramatic, but again with a larger image, the lost brightness is only compounded, so both are important factors.
In any case, I hope you don't get the wrong idea about my posts, I was just brain storming a bit and thought it might make for a good exchange. Presonally at some point in time, I would venture to guess we might see larger pixel count imagers in consumer front projectors. I think I have even read of a Cinemascope width ratio rear projection set for consumer use. I don't remember who was making the prototype, but I'm thinking it was probably JVC. I don't know how they were achieving that though. It may not have been with a larger pixel count imager.
I agree with the statements regarding original resolution that was never on the image, but I believe you misread my statements regarding which resolution we loose.
We loose the "projector's chip" resolution capability when we put that projector to display 30% of black bars. One clever way the CinemaScope system found to gain back those lines of resolution of the chip (and with them the brightness we agree we need, anticipating we will make the image larger at the end) is by having "a quality scaler" mapping 1080 from the 800+ lines of the image (the part that is not black bars).
Do that scaling job cheaply and one can destroy the image.
We never would have 2592 (horizontal pixels) of resolved image because the telecine transfer is done for a target of 1920 of consumer level media, so that is another problem I see when people start thinking how good would be if manufacturers of consumer products would do 2.35:1 chips with a larger width and more horizontal resolution while maintaining the vertical 1080 (because at times one would need to display a 16x9 fully resolved image). To use the full potential of that imaginary dream chip, the content has to be also with that resolution.
Would that be the Super Blue-laser wide format? Who knows, but as you see we need all the pieces in the image chain to make it work clean, the content, the disc format, the transfer technique, and the chip, AND MAINLY USEFUL FOR 2.35:1 content, systems, people, market, manufacturers; quite an uphill.
This brainstorming is good because it allow us to explore the constraints of having a true 2.35:1 system from the content to your screen; and we could appreciate the benefits a CinemaScope system when playing with all those constraints and still offer a theatrical image.
Regarding "the toys" you referred to, it depends how often you view 2.35:1 movies those toys might become a "must have and cannot live without them".
You have to see the faces of people when I click one button and the system opens the image to a wall to wall 2.35:1 shape while they still sit at the same chair, it fills all the peripheral vision and produces the theatrical impact. Add to it 16 speakers with clean and powerful amplification, and a shaking room, and they never want to leave.
Put a cheap scaler, a cut-corner anamorphic lens, a low light projector, and the image might be big but pitiful, and it might have been better a smaller image with black bars.
So as with any component claiming to reach the level of theater for large screen purposes, each piece is not a toy, it has to be a quality piece, and that usually does not come cheap.
However, the good news is that while this type of theatrical environment used to cost on the several tens of thousands, you have now a way to get some decent 1080p quality of the video pieces under $20K, that is exactly the purpose of this project and the articles.
One good part of this kind of system is that one could experiment with components and eventually upgrade them to better quality all and each individually, a projector, a scaler, the lens, a screen; a situation not possible with large RPTVs for example, where everything is in the same box.
If I had bags of money I'd definitely go for a sled-based anamorphic 1080p fp system today, but Joe six-pack doesn't have any clue.
IMO, before most folks care about constant-height or anamorphic 2:35:1 we will have direct-scan laser projectors (projectors which generate the
image by directly scanning one or more lasers onto the screen, rather than using a microdisplay device with fixed resolution).
Such a projector will have no need to scale a 2:35:1 image vertically to 16:9 and then to shrink the image back to 2:35:1 using an anamorphic lens. . .
And whlie I'm throwing around predictions, I expect that such projectors will pretty quickly be used with motion-adaptive scalers to show scaled 2k or 4k images from 1080p sources.
a 2.35 chip would obviously the best - but due to manufacturing expense & limited market, probably not any time soon.
however, my projector ALREADY has a decent scaler AND a lens - the 2 required ingredients, so it should be a lot simpler (compared to custom chip) to do the following:
1- ADD an option to the projector's built-in scaler to fill the chip with a (distorted) 2.35 image using all pixels
2- ADD a built-in lens element inside the projector that can slide in & out of the light path to stretch the 2.35 image. since this element will work with only 1 dedicated specific lens, it can be quite small & compact - maybe featuring a simple lever sticking out of the projector that can be manually used. (or make it motorized & auto-sensing for more $$$)
