Friday, August 30, 2002
Member since:
July 2002
July 2002
I was just curious as to how you guys can judge the quality of the video on DVD. You mention how 'crisp' something is or the 'graniness'. what is that, how can I spot it? I always thought all DVDs were perfect [:)]
Friday, August 30, 2002
Member since:
March 2002
March 2002
Good question, DrunkenMonkey2k2, and assuredly the evaluation of picture quality is not a science but more of an impression, no matter what so-called experts say. It's rather like evaluating sound quality, which can and does differ on different systems. But, to answer your question, first, it helps to see a really lot of DVDs over the years in order to have a basis for comparison and then have a pretty good TV set to notice any differences. I was interested to find out that DVDTown's own Per Kristensen uses virtually the same set I use, a Sony flat-screen Vega XBR, to do his viewing.
Anyway, the most common problems I see in video quality are (1) black areas that are not consistent and thus don't produce as three-dimensional an image as possible, or black areas that extend into other areas of the screen; (2) grain, those pesky little dots or snowy sections of the screen, often produced in nighttime shooting, in older film stock, in large, solid-color areas, or in poor transfers; (3) moiré effects, jittery lines, most noticeable in closely spaced horizontal lines like Venetian blinds, bricks in walls, and automobile grilles; (4) color bleed-through, fairly self evident; (5) general blurriness or haziness of the picture; (6) roughness in edges or delineation; (7) brightness of color or washed-out texture of color; (8) naturalness of color, especially evident in flesh tones; (9) pixilation or leftover pixels; (10) halo effects; and many others that vary from disc to disc.
The minor problem when evaluating some of these qualities is trying to determine if the director intended them or not. Is the color dull or washed out on purpose or because the film stock has faded or because the disc transfer was mishandled? The problem of judging is further complicated by whether one is playing back the film in enhanced anamorphic widescreen or ordinary letterboxing. If your equipment can accomplish the former, the picture quality will be bettered to a good degree.
And lastly, no, not all DVDs are perfect in video quality because not all film stock is perfect and not all films are transferred to disc perfectly.
One last example: It has been my experience that in general DVDs from Fox have a clearer, crisper picture quality than those from MGM. I can only attribute these differences to the authoring shops that do the transfers for the two studios, which in some cases use more or less compression, more or less expertise, or just better or inferior electronics. Have you compared one of Columbia TriStar's (Sony's) Superbit editions to one of their regular editions of the same film? It's instructive.
John P.
[Post edited by John J. Puccio on Sep 1, 2002]
Anyway, the most common problems I see in video quality are (1) black areas that are not consistent and thus don't produce as three-dimensional an image as possible, or black areas that extend into other areas of the screen; (2) grain, those pesky little dots or snowy sections of the screen, often produced in nighttime shooting, in older film stock, in large, solid-color areas, or in poor transfers; (3) moiré effects, jittery lines, most noticeable in closely spaced horizontal lines like Venetian blinds, bricks in walls, and automobile grilles; (4) color bleed-through, fairly self evident; (5) general blurriness or haziness of the picture; (6) roughness in edges or delineation; (7) brightness of color or washed-out texture of color; (8) naturalness of color, especially evident in flesh tones; (9) pixilation or leftover pixels; (10) halo effects; and many others that vary from disc to disc.
The minor problem when evaluating some of these qualities is trying to determine if the director intended them or not. Is the color dull or washed out on purpose or because the film stock has faded or because the disc transfer was mishandled? The problem of judging is further complicated by whether one is playing back the film in enhanced anamorphic widescreen or ordinary letterboxing. If your equipment can accomplish the former, the picture quality will be bettered to a good degree.
And lastly, no, not all DVDs are perfect in video quality because not all film stock is perfect and not all films are transferred to disc perfectly.
One last example: It has been my experience that in general DVDs from Fox have a clearer, crisper picture quality than those from MGM. I can only attribute these differences to the authoring shops that do the transfers for the two studios, which in some cases use more or less compression, more or less expertise, or just better or inferior electronics. Have you compared one of Columbia TriStar's (Sony's) Superbit editions to one of their regular editions of the same film? It's instructive.
John P.
[Post edited by John J. Puccio on Sep 1, 2002]
Friday, August 30, 2002
Member since:
March 2002
March 2002
Grain is something inherent in film negatives. Think of the paper in books--some paper stock is smooth, but others are rougher, where you can see the actual threads of the wood used to make the paper. The same goes for film prints. Some negatives, when blown up to viewable size for movie theatres and DVDs, appear to be coarse, and the grainier a type of negative, the less it is able to capture background detail due to the nature of lighting foreground objects. That's why sometimes we complain about grain that gets out of control--it looks as if everything was roughed up physically.
For the most part, unless a movie is created entirely in the digital realm (like those computer animated movies), a transfer to DVD has more to do with the print itself rather than with the DVD technology. Ideally, studios should clean up film prints before encoding them onto DVD, but we all know that a couple of specks, hairs, and dust appear every so often.
Strictly speaking, you're right about DVDs being perfect because if you just stick a couple of megs' worth of video onto DVD, it'll look exactly the way the source print looks. That's where stuff like crispness and clarity come into play. When compressing an image for digital storage, an engineer has to decide how little information is needed to present a still-good-looking frame. Too few bits, and the frame looks blocky and pixelated. When something is crisp and smooth, it looks like a new face job--3-D and without any slack or softness to the picture.
Eddie Feng, Associate Review Editor, - EXTERNAL LINK -
[Post edited by posters5 on Aug 31, 2002]
For the most part, unless a movie is created entirely in the digital realm (like those computer animated movies), a transfer to DVD has more to do with the print itself rather than with the DVD technology. Ideally, studios should clean up film prints before encoding them onto DVD, but we all know that a couple of specks, hairs, and dust appear every so often.
Strictly speaking, you're right about DVDs being perfect because if you just stick a couple of megs' worth of video onto DVD, it'll look exactly the way the source print looks. That's where stuff like crispness and clarity come into play. When compressing an image for digital storage, an engineer has to decide how little information is needed to present a still-good-looking frame. Too few bits, and the frame looks blocky and pixelated. When something is crisp and smooth, it looks like a new face job--3-D and without any slack or softness to the picture.
Eddie Feng, Associate Review Editor, - EXTERNAL LINK -
[Post edited by posters5 on Aug 31, 2002]
Saturday, August 31, 2002
Member since:
July 2002
July 2002
Wow, thanks a lot, that really clears things up [:)] Although, I guess I won't be able to fully understand until I get a high definition tv, something I will eventually get :P And I have seen the superbit DVDs in stores and thought 'oh great another version of that film'. Is it worth getting over the original?
Saturday, August 31, 2002
Member since:
March 2002
March 2002
Sony's Superbit DVDs claim to use every available amount of space for maxed-out video and audio bit-rates. However, the trick to compression work is that, sometimes, extra digital storage is simply just extra. Since the DVD format's video resolution is limited to 'X' amount of lines anyway, you reach a certain point where using more data for a movie's video/audio does not significantly improve the presentation. In the end, most people have observed that only expensive monitors have been able to take advantage of the improved video of Superbit DVDs.
There are other problems associated with the Superbit line, of course. For example, most of the Superbit DVDs are re-visits of early Sony titles. Since studios have gotten better and better at mastering films for DVD, newer transfers look better than transfers made just last year anyway, so of course Air Force One Superbit looks and sounds better than Air Force One the original release! LOL. Also, the Crouching Tiger, Hidden Dragon Superbit seems to have used the same source print as the special edition DVD. Thus, the white specks and light dust in certain places still appear in the Superbit version. Yikes!
The Superbit philosophy actually has a lot to do with the Dolby Digital versus DTS issue. DD uses 10:1 compression while DTS uses 4:1 compression for audio. DTS is LESS compressed, so theoretically speaking, it has the capacity to sound richer and fuller. However, some quiet movies don't take full advantage of DTS's range, so those extra bits of info are wasted. Also, some people say that DTS mixes are louder, but don't be fooled by that remark. You see, DD utilizes dialogue equalization standards that are different from that of DTS's, so a true test of the formats means that you have to re-calibrate your system for each audio format's needs before punching the audio selection button on your remote control. When you do a fair comparison of the two audio tracks, you'll find that DTS usually sounds only a tad better than DD, not the whopping difference that some reviewers think exist, lol. :-)
There are other problems associated with the Superbit line, of course. For example, most of the Superbit DVDs are re-visits of early Sony titles. Since studios have gotten better and better at mastering films for DVD, newer transfers look better than transfers made just last year anyway, so of course Air Force One Superbit looks and sounds better than Air Force One the original release! LOL. Also, the Crouching Tiger, Hidden Dragon Superbit seems to have used the same source print as the special edition DVD. Thus, the white specks and light dust in certain places still appear in the Superbit version. Yikes!
The Superbit philosophy actually has a lot to do with the Dolby Digital versus DTS issue. DD uses 10:1 compression while DTS uses 4:1 compression for audio. DTS is LESS compressed, so theoretically speaking, it has the capacity to sound richer and fuller. However, some quiet movies don't take full advantage of DTS's range, so those extra bits of info are wasted. Also, some people say that DTS mixes are louder, but don't be fooled by that remark. You see, DD utilizes dialogue equalization standards that are different from that of DTS's, so a true test of the formats means that you have to re-calibrate your system for each audio format's needs before punching the audio selection button on your remote control. When you do a fair comparison of the two audio tracks, you'll find that DTS usually sounds only a tad better than DD, not the whopping difference that some reviewers think exist, lol. :-)
