Picture Settings Pitfalls

Pitfall #1: Resolution

With older devices such as this Marantz projector (maximum resolution: 720p), you’ll need to try various types of input signal to see which gives the best results.

Only one resolution matters here: the highest resolution! That is: 1,920 x 1,080 pixels stored in the “progressive scan” format, each frame of which contains the full number of lines. Since more and more screens have this “1080p” format as their native resolution, more and more home cinemas can now match each pixel on the disc to a pixel on the screen, with no alteration in between.

Every Blu-ray player can output 1080p resolution via HDMI. The most important criterion for an ultra-sharp picture, therefore, is actually whether the display accepts signals at the highest resolution. Not only that, but the display must communicate this ability to the player. Normally, the device is set to do so automatically, but the process can fail — then, you have to go into the menu and try out the various options manually. If you pick a format that the projector or TV cannot handle, the player will usually jump back to the previous setting.

So, what if the other devices lack 1080p support? Before the time of Blu-rays, 1080p was rare even in HDTV-compatible, high-end devices. Owners of these older devices are left facing the question: 1080i or 720p? If the display’s electronics can reliably recognise film-based 1080i signals, it’ll be able to display the picture almost as well as if it arrived as 1080p. In other cases, where the player is interpolating between the picture’s lines, 720p signals will display better — especially if your display has 720 or 768 lines.

Avoid setting standard resolutions — 480 or 576 lines, for example — as these will produce low-quality images. Although Blu-ray players can also deliver signals in these formats, it really isn’t what they were built for!

Pitfall #2: Frame rate

The true film frame rate of 24 frames per second is only possible at 1080p.

Blu-ray films are almost always stored at 24 frames per second — that is, at the genuine cinema frame rate. Video with 24 images per second will only play back via HDMI. With YUV, S-Video, and cinch, the only way to transmit 24 images per second is to convert them to 60 hertz first. Make sure you set the HDMI resolution to 1080p — otherwise, this will also use 60 hertz.

Blu-ray discs made it possible, for the first time, to output 24 pictures per second. This bypasses the conversion to 60 hertz — but why is that so important? Since 60 is not a whole-number multiple of 24, 60-hertz signals exhibit irregular motion sequences. The process involves multiplying the original number of frames by 2.5, by displaying one frame twice, the next three times, and so on alternately (“3:2 pulldown”). To reproduce genuine cinema-style video, therefore, 24p is essential. (Depending on the type of display you use, the 24 images each second will actually display at 72, 96, or 120 hertz.)

To make the difference clear and simple: 24p judders regularly (both in the cinema and the home cinema); 60p judders irregularly (which looks less attractive).

Many newer screens can detect the irregular sequence of 60 hertz signals and convert the video back into the original 24 film frames — with their slight, regular judder. You’ll then barely see a difference between the player’s 1080/24p and 1080/60p output settings. You’ll have more trouble with discs recorded at 50 hertz, however. These will usually be European DVDs, but can also in rare cases be Blu-rays — containing, for example, home-made camcorder recordings. Such discs always output at 50-hertz — the player is powerless to adjust the frame rate.

Pitfall #3: Film mode

Virtually all players offer at least three modes for Blu-rays and DVDs: “Film”, “Video”, and “Automatic”. These determine how the player deals with the problem of interlaced and progressive scan. On both Blu-rays and DVDs, the video signals can originate from various different types of source material. The name of the game, as ever, is to make the video coming from the player’s output as similar as possible to what the studio originally recorded. To produce the best sharpness and the least errors, the player needs to combine interlaced images that stem from the same frame of film.

In “Video” mode, the player turns interlaced images into full frames by interpolating the missing lines. But these interpolated values (determined by averaging) contain no additional information, and the picture is therefore less sharp than in “Film” mode. What’s more, edges of round objects or diagonal lines can develop picture errors. In “Automatic” mode — option three — the player tries to decide whether the signal derives from film or video and processes it accordingly.

In general, we advise against using the “Video” setting, which quite simply makes films look worse. The “Automatic” mode, on the other hand, will process every type of material appropriately — if it works correctly. After all, differentiating between film and video sources is no easy task: If, for example, the de-interlacer needs to consider a few sequences of images before it can decide on the right mode, you’ll see artefacts during the process.

In “Film” mode, this cannot happen, but the device often has to rely on information stored on the disc. That’s no problem with Blu-rays, since these store the film as a progressive-scan (24p) signal in the first place (see box below). With DVDs, however, the markers that are meant to show the player what type of signal it’s receiving are not very reliable — if they even exist. Bad de-interlacing results in comb effects on moving edges and during scene-transitions.

Pitfall #4: Deep Color and xvYCC

Some camcorders use the extended xvYCC colour space, which Blu-ray does not support.

Version 1.3 of HDMI introduced two new possibilities for transmitting colours: “Deep Color” and “xvYCC”. The latter is also known as “xv-Color” or “Extended Color” and refers to a colour space that extends beyond that of the common EBU/ITU 601 and 709 standards. But Blu-ray films aren’t stored using this extended standard, so we recommend switching it off — otherwise, you might be seeing the wrong colours. There’s one exception to this: Some HD camcorders record in xv-Color, and the additional colours remain in the signal when transferred to disc.

Deep Color promises finer gradation of brightness levels within a given colour space. The brightness information transmits at either 12 or 16 bits, instead of the usual eight bits. But since Blu-ray discs can’t carry more than eight bits, the extension brings no benefits in a standard setup. If, however, the player is altering the video signal, Deep Color minimises the risk of this process introducing picture errors (see Point 6). NB: Both Deep Color and xvYCC require a compatible screen.

Pitfall #5: RGB — normal and extended

YUV is the correct colour space for HDMI transmissions from a Blu-ray player to a TV or projector. But you can also select “RGB”, of which HDMI offers two varieties: “Normal” and “Extended”. Every screen understands the RGB colour standard, since HDMI includes backward compatibility with DVI, which only uses RGB.

Because clipping can occur in analogue signals and in conversion from YCbCr to RGB, “Normal” RGB leaves the top 20 and bottom 16 of the 256 greyscale steps (in eight-bit encoding) empty — this is also because levels 0 and 255 carry synchronisation pulses.

These high and low regions also contain so-called blacker-than-black and whiter-than-white content; these signals should remain intact but should not appear on the screen — if they appear at all, they should be barely visible. “Normal” RGB ensures that this is the case — so long as the display device is also set up correctly.

Both Blu-ray and DVD content is stored in YUV, so this is best standard to choose — YUV defines the correct brightness range. The exception is if you select xvYCC, which uses the non-Blu-ray range of 0 to 255.

Pitfall #6: Picture mode and user settings

Denon’s high-end Denon DVD-A1 DU can even adjust the video signal’s gamma curve.

Many Blu-ray players now provide picture controls for manipulating the video signal — especially its brightness and colours. But you should be extremely careful with these controls, which, if used incorrectly, can do a lot more harm than good.

Bear the following in mind as a general principle while adjusting the player’s settings: When a setting adds quality in one place, it will also take quality away somewhere else. If, for example, you add extra brightness to improve differentiation of dark scenes, you’ll make areas of light colours look worse. An otherwise soft, blue sky can suddenly break up into several distinct zones because the few remaining brightness levels no longer allow a smooth blend. It’s less dangerous if the HDMI connection is transmitting in Deep Color (see Point 4). This type of connection provides not only 256, but actually four times that number of brightness values per colour channel.

In general, however, the rule is as follows: First set the screen up to display signals as correctly as possible. Real sticklers can adjust their TV with the help of a test disc, and Blu-ray players are excellent sources for test signals — almost as good as professional test-pattern generators. If you choose to use a test disc, make sure that the player doesn’t alter the original signal, since this would produce incorrect results. It’s hard to say how neutral a Blu-ray player’s video output is, but magazines and online reviews will provide insight into individual models. The PlayStation 3, for example, produces very neutral results.

In any case, players almost always ship with a standard setting that provides neutral playback. In Pioneer players, bear in mind that you’ll need to switch to the “Professional” setting if the player asks what type of display is attached. If, instead, you select LCD or plasma, the player will attempt to tailor its output to the properties of the chosen screen type — making is essentially impossible to use a test disc to adjust basic settings.

To put it simply, once again: First, calibrate the screen correctly. Only if this fails to give you perfect results should you turn to the player’s video controls. But proceed with caution, or you might do more harm than good. This applies both to critical settings and to seemingly simple adjustments such as sharpness enhancement and noise suppression.

On the positive side, these picture controls are a valuable addition for expert users, who can use them to achieve optimum results from the player by tailoring the signal to suit the display. They can even correct mastering errors, such as excessive noise or bad colour adjustment.