IMAX vs My Home Theater

[mtrycrafts]

I guess I should keep dreaming, huh?

Sure. Life is one long dream

 

[mtrycrafts]

ROFL...

I tell you, I can't watch movies like those Imax ones... the screen is just way too big, and it makes me sick... Don't get me wrong, I like big screens, but those things are just rediculus. A friend made a HT in his house, with a screen that stretches from one side of a wall to the other, and it was just too big for the room... no-one likes to watch movies there, the room is too short for how wide the screen is..

One reason why standard were created

http://s3.carltonbale.com/distance_chart.html

But, an IMAX is like being out doors.

 

[Seth=L]

One reason why standard were created

http://s3.carltonbale.com/distance_chart.html

But, an IMAX is like being out doors.

Graph confused me, just like all graphs.

 

[furrycute]

In order to watch an IMAX movie properly, you should ideally sit in the center (both up down center and left right center) of the theater. This position offers you the best possible view. Otherwise if you sit on the side, the field of view is way too big, and will make you dizzy.

I don't remember the details, but IMAX film's resolution is way higher than standard film's resolution. Have you seen those IMAX film reels? Those things are gigantic. I don't think you will ever have that kind of video resolution in your home theater. Even if technology progresses to the point where we will be able to fit IMAX resolution films onto some super duper DVD, all that extra resolution will be wasted on our home theater screens. The walls in our homes are just to small to take full advantage of all that resolution.

 

[Lightning Steve]

I swear I would rather set in front of a 19'' TV and wear headphones then to go to a movie!

Every single time I go to the theater I fall asleep, slept through the whole new Aliens/Predator movie (I really wanted to see it too!). The Drive-in 2-3 movies no problem. Have only been to one I-Max movie, was great and it kept me awake!

 

[Sheep]

IMAX has great picture, the sound is another story. I saw 300 in IMAX and I wasn't that impressed, especially in the bass response. Even the demo before hand was lacking. My local cinema's are pretty good with better bass, but the picture isn't as good.

With Blu-Ray, and a good THX ultra system or A WmAx creation (though most of his creations are 2 channel only) would be the best out there. IMAX needs to fill more seats, is all.

SheepStar

 

[WmAx]

The thing is, mtrycrafts, I find that talk of analog film resolution is usually all in theory(without considering sufficient real world variables), in both still photography and motion picture photography.

A huge (and costly) end to end research project [1] was performed not that long ago with the joint efforts of CBS, CST and the Fondazione Ugo Bordoni Organization in order to determine the actual achieved resolution (measured in lines/per picture height) from negative to release print used in screening. Several different films were used, and several theaters across the world were used for the test. In the best case example(end to end), under 900 lines/per picture height were feasibly achieved(MTF>50), and typically substantially less, usually in the 700 lines/per picture height range. Based on this work, a 720 HDTV display can resolve the typical 35mm release print as shown in typical theatres, and a 1080P HDTV display can exceed the best case 35mm release print practical resolution.

-Chris

Footnotes
[1] Image Resolution of 35mm Film In Theatrical Presentation ( they recently updated their site, and it's not in top notch working order yet, there for you may have to search through Google to find the access link )
Baroncini, Vittorio; Mahler, Hank; Sintas, Mattheiu; Delpit, Thierry
http://www.cst.fr

I have an article from 2001 by David Carlstroma member/pres of an audio club and this is what he has to say:

Straight forward film production involves a film negative with a resolution of around 7000 line pairs per inch. 35mm lenses do compromise this resolution, and the contact printing process for release prints will reduce the resolution a bit more, but we can expect at least 2000 line pairs delivered to the screen in a normal movie without optical effects. HDTV offers 1080x1792 pixels. But we must compare apples to apples. TV resolution is quoted in lines not line pairs and we have to discount the TV lines by the Kell factor to estimate the ability of the raster media to resolve real world objects.
(1792/2)*0.7= 672 by (1080/2)*0.7=378 is roughly the same resolution of HDTV in film terms. The 35mm image is about 1" wide, so 672/2000=0.31 is a fair comparison of HDTV to movie film resolution. Roughly speaking this says a movie is three times as sharp as HDTV.



That is impressive to have a THX theater there; enjoy.

ps. no idea where his 1792 came from or that a 35mm is about 1"wide as I just measured an old 35mm slide that is 1 3/8" wide so don't shoot the messenger

Here is a link to Kell Factor:
http://en.wikipedia.org/wiki/Kell_factor

 

[mtrycrafts]

The thing is, mtrycrafts, I find that talk of analog film resolution is usually all in theory(without considering sufficient real world variables), in both still photography and motion picture photography.

A huge (and costly) end to end research project [1] was performed not that long ago with the joint efforts of CBS, CST and the Fondazione Ugo Bordoni Organization in order to determine the actual achieved resolution (measured in lines/per picture height) from negative to release print used in screening. Several different films were used, and several theaters across the world were used for the test. In the best case example(end to end), under 900 lines/per picture height were feasibly achieved(MTF>50), and typically substantially less, usually in the 700 lines/per picture height range. Based on this work, a 720 HDTV display can resolve the typical 35mm release print as shown in typical theatres, and a 1080P HDTV display can exceed the best case 35mm release print practical resolution.

-Chris

Footnotes
[1] Image Resolution of 35mm Film In Theatrical Presentation ( they recently updated their site, and it's not in top notch working order yet, there for you may have to search through Google to find the access link )
Baroncini, Vittorio; Mahler, Hank; Sintas, Mattheiu; Delpit, Thierry
http://www.cst.fr

Interesting. Searching and reading of that study, found it on Google and NYU is also mentioning this study.

 

[mtrycrafts]

Further searching reveals more

interesting links of other experiments and comparisons

http://www.crystalcanyons.net/pages/TechNotes/FilmVsCP5000.shtm

University of Colorado has interesting target filmed and digitized with interesting outcomes different from the film research. This also talks of line pairs and lpm, line pairs/mm.

http://www.clarkvision.com/imagedetail/film.vs.digital.1.html

shows different film sizes and megapixel equivalents.
Not sure if any of his film types are equivalents to the film industry uses but is a much different results.

So, I am at a loss who and what is the real story.

 

[WmAx]

interesting links of other experiments and comparisons

http://www.crystalcanyons.net/pages/TechNotes/FilmVsCP5000.shtm

University of Colorado has interesting target filmed and digitized with interesting outcomes different from the film research. This also talks of line pairs and lpm, line pairs/mm.

http://www.clarkvision.com/imagedetail/film.vs.digital.1.html

shows different film sizes and megapixel equivalents.
Not sure if any of his film types are equivalents to the film industry uses but is a much different results.

So, I am at a loss who and what is the real story.

Please note that you have linked to comparisons of still image color photography film - which typically has nearly 2x the lines/per picture height, in best of conditions, as compared to the motion picture film industry film that is typically used. Why the disparity from still to motion? I am not sure. It could be, that most still image film seems to be tested at low ISO(low light sensitivity) that would not work well in normal motion picture settings, due to having to capture a minimum of 24 frames per second in any condition(various apertures, etc.). Or, there could be a complication in the fast rate of movement(relatively) of the motion picture film causing a reduction in optimal resolution. Or some other reason. I am limited to looking at the actual end test results, I have no way to know all of the variables that may be at play.

It should be noted that the link you gave to a 5MP digital vs. film, the person insists upon quoting lines resolution at the MTF=10 rating. Under MTF=50, the resolved detail rapidly becomes essentially worthless, as with real images/photography, it is not often that pure black on pure white is the only detail in a scene, in fact, this circumstance is usually almost always in the extreme minority. Commonly, the actual contrast between items is far less, and as a result, low MTF is not useful. One could take the raw plotted data from the motion picture film research I referenced and say the typical negative resolved 2000 lines. But this would be at a low MTF that is not practically resolved by the human eye.

-Chris

 

[WmAx]

Mtrycrafts, here is a comparison of still image photography, comparing a 6MP digital system(Canon 10D), an 11MP digital system(Canon 1DS) and a 35mm color film(FujiFilm Provia ISO100), all using the same FOV(field of view) and extremely high grade lenses. The film was scanned using a verified [1] extremely high grade scanner that is able to extract all relevant data from the film, as compared to an industry standard reference drum scanner.

The 35mm film here, is as sharp, or very slightly sharper, as compared to a standard 6MP digtal system using a Bayer Mosiac image sensor(far from ideal - a Bayer Mosiac does not capture the limit of the 'MP' rating it is given - so this comparison is giving the film the advantage here, in comparing to a specific 'MP' rated camera). It should also be noted that this level of sharpness from 35mm color film is only obtainable in the best of conditions(professional quality lens, pro level post-process scanning or pro level image transfer to photograph paper, etc.).

http://www.sphoto.com/techinfo/ocesideharbor.htm

[1]
http://www.sphoto.com/techinfo/nikon4000vsTango.htm

 

[furrycute]

Interesting comparison.

I recommend dpreview.com for anyone who is interested in digital cameras. Tons of useful info there.

So 35mm film can out resolve a 6mp digital image. But nowadays most DSLR's have 10mp or 12mp sensors. This doubling in resolution should enable today's digital images to achieve parity with 35mm film in terms of resolution. But there are still some areas where 35mm film is still superior to digital film. I don't know the technical stuff, but I do seem to recall analog film has much higher bit depth than digital images.

With all things being said, you just can't argue against the convenience of digital cameras. You can take hundreds if not thousands of images on one memory card. Do the post processing on your computer. And just keep the ones you like. Zero post processing cost. This is just impossible to achieve with 35mm film.

 

[WmAx]

Interesting comparison.

I recommend dpreview.com for anyone who is interested in digital cameras. Tons of useful info there.

So 35mm film can out resolve a 6mp digital image. But nowadays most DSLR's have 10mp or 12mp sensors. This doubling in resolution should enable today's digital images to achieve parity with 35mm film in terms of resolution.

Well, 35mm(assuming professional level processing of the film in post process) is about even(slightly above) a standard Bayer sensor equipped 6MP camera system. The 11MP 1DS image example in the test is substantially superior in relevant sharpness, compared to the film. And remember, these all assume low ISO. Film rapidly becomes grain filled and lower resolution at higher ISOs, where as a modern DSLR can remain grain free up into high ISO ranges. The 6MP DSLR at ISO 800 compared to an ISO800 color film would make film look bad in relative comparison of sharpness/grain.

But there are still some areas where 35mm film is still superior to digital film. I don't know the technical stuff, but I do seem to recall analog film has much higher bit depth than digital images.

Negative film has a slightly higher dynamic range compared to a standard digital sensor. This tends to matter most in situations where you have large contrasting subjects -- for example a white item in an otherwise dark scene where you need to have good exposure of the darker detail. However, there are specialty digital camera systems that are as capable, if not more so, than negative film in this regard. Refer to FujiFilm S3 and S5 DSLR bodies. They have two sensor banks recording in parallel. One sensor set is 2 stops underexposed at all times. In post process of the raw file data, you can merge these data sets so that in brighter ranges, the underexposed data set is used, and in mid to darker ranges, the normal data set is used. Digital cameras do not actually have as big a problem with dynamic range as is commonly perceived. The camera's internal processor applies a rather high gamma curve to the linear data collection from the sensor before processing to a JPEG file, there by increasing contrast and blowing out high lights that otherwise are actually captured by the sensor before processing. Many auto process RAW converters may do the same thing by default. Using proper RAW post processing techniques, you can salvage this otherwise lost data.

-Chris

 

[mtrycrafts]

Interesting comparison.

I recommend dpreview.com for anyone who is interested in digital cameras. Tons of useful info there.

So 35mm film can out resolve a 6mp digital image. But nowadays most DSLR's have 10mp or 12mp sensors. This doubling in resolution should enable today's digital images to achieve parity with 35mm film in terms of resolution. But there are still some areas where 35mm film is still superior to digital film. I don't know the technical stuff, but I do seem to recall analog film has much higher bit depth than digital images.

With all things being said, you just can't argue against the convenience of digital cameras. You can take hundreds if not thousands of images on one memory card. Do the post processing on your computer. And just keep the ones you like. Zero post processing cost. This is just impossible to achieve with 35mm film.

We were trying to get a credible source both for comparing the resolution of HD and 35mm motion picture film.
Scratching head still

 

[furrycute]

We were trying to get a credible source both for comparing the resolution of HD and 35mm motion picture film.
Scratching head still

Sorry about the digression

But look at it this way. A motion picture is just a bunch of static films stitched together in sequence. If you compare the resolution of a static 35mm film to that of a static digital image, I think you can get a rough idea of where analog vs. digital motion picture stands.

 

[WmAx]

Sorry about the digression

But look at it this way. A motion picture is just a bunch of static films stitched together in sequence. If you compare the resolution of a static 35mm film to that of a static digital image, I think you can get a rough idea of where analog vs. digital motion picture stands.

How is that? When measured(by three highly credible professional organizations involved with the film industry), various motion picture films did not equal what seems to be the ability of still film of the same size. Something in the mix is reducing the resolution, and I don't think it's the film itself. I read that IMAX film requires special mechanical process for film to be steady and expose and play back properly. I wonder if this effect is still present enough in 35mm small format to cause loss of overall resolution with the motion picture process?

-Chris

 

[furrycute]

Well, camcorders have to continuously record images. I guess in that nonstop sequence, it's just not possible achieve optimal exposure for each and every single frame.

Whereas in a still camera, it's just one shot. The conditions are there to achieve optimal exposure.

Otherwise, if a camcorder's continuous sequence images were just as good as a still camera's still image, no one would bother to purchase still cameras anymore. People would just grab a frame out of a camcorder recorded continuous sequence and frame it as a still picture.


With these new digital sensors, you now have the additional problem of limited memory capacity and limited hardware bandwidth. For a digital camcorder, if every single frame were a full sized 12mp image, imagine how much memory it would take to record a 2 hour length movie. Let's suppose a 12mp image takes up about 10 mb of space. 10mb x 30 frames/sec x 60 x 2, or about 36,000 mb, or about 36GB of data for a 2 hour movie.

And that 36GB of data assumes that some sort of compression is used on each still image to achieve small file size. That compression needs to be done in real time.

And the sensor has to move all this data from the chip to the camcorder's hardware in real time.

And the camcorder hardware has to calculate the optimal exposure settings for each still image.

All this gets really complicated real fast. So some compromise in image quality/size is inevitable.

 

[sparky77]

I did finally find the right terms to search for and found a couple of articles on hd versus film.

http://www.filmschoolonline.com/sample_lessons/sample_lesson_HD_vs_35mm.htm
http://www.eruditecommunications.net/film_vs_hd.html

It seems to me to be a pretty close tie so far. My only real remaining question is how many movies are actually recorded directly into digital format?

I don't think the movie industry will make the change to pure digital until the technology for projection has been refined enough to make it possible to project onto a "big screen."

For the most part I've been impressed with the pq at our theater here, and its not even using a new projector, still one of the old ones thats nearly 50 years old, all they did was change the light source, and add on a huge film spooling mechanism which takes up a lot of space in the projection room. Some movies on the other hand don't look so great mostly because of the abuse the reels have already been through from the dozens of other theaters that have handled them before we finally get them here.