Part 1: FUNimation Remastered Season Sets, AKA 'Orange Bricks'
These sets contain footage remastered by FUNimation with a filter process. The process sharpened the image and cleaned up much of the film-grain from the film masters that FUNimation was originally given to produce the English dub of the series. The video has been reformatted into a widescreen format; a controversial decision; which crops off the very top and bottom sections of the picture but has also increased the amount of picture seen on the sides (this is because of how 'TV cutoff' works differently with fullscreen and widescreen ratios). The filter process also causes 'breakage' in the pictures during shaky sequences; in scenes where the Earth is quaking, you'll often see the outlines on characters get broken up.
These sets contain 3 audio tracks; A Japanese language track with optional subtitles, an English language track with the Japanese OST; compatible with surround sound, and an English language track with the US broadcast soundtrack (composed by Bruce Faulconer). The English subtitles can be turned on with any track but they are solely a direct translation of the Japanese audio and do not often match up with the English dub.
As can be seen in the image above, this release of the series is split into 9 seasons of varying length. They range between 26 and 39 episodes.
The final disc of each set contains a 'Special Features' menu. Most of these are just trailers for other shows licensed by FUNimation. The first season, however, also contains a featurette about the remastering process.
The sets contain guidebooks with character bios, episode guides and some modern art of the characters.
These sets are often referred to as the 'Orange Bricks' by the fandom.
The Dragon Box sets contain footage remastered by Toei Animation in Japan, in a frame-by-frame restoration process. The picture is sharper than that of the Orange Bricks and there's no breakage in shaky scenes, however the film-grain is more apparent. The picture is also slightly darker than that of the Orange Bricks.
Originally intended as a Japan-only release, Toei had the series split into 2 Dragon Box sets; both quite pricey due to the amount of material each would contain. After some-odd years*, Toei finally agreed to allow FUNimation to do a western release of the Dragon Box.
FUNimation's Dragon Box release was instead split into seven boxes; all with similar styling to the two Japanese boxes (i.e. yellow blocks with modern art of individual characters). The Toei remasters were left entirely intact; FUNimation added an English language track as well as, again, some trailers for some of their other shows.
The sets contain small guidebooks called 'Dragonbooks' with character bios, episode guides, family trees, some modern art of the characters and some of Akira Toriyama's concept art.
These sets contain only 2 audio tracks; a Japanese language track with the Japanese OST and optional subtitles, and an English language track with the Japanese OST. Bruce Faulconer's musical score is not present in the Dragon Box release.
Dragon Box-styled releases were done in Japan for the Dragon Ball and Dragon Ball Z movies, the Dragon Ball series and the Dragon Ball GT series as well. FUNimation has not, as of yet, announced any plans to release these other sets in the western world.
*The first Dragon Box was released in Japan in 2003. The first Dragon Box set released in North America came in 2009. Thus it took 5-6 years before FUNimation was able to acquire the rights to release the Dragon Box and, in the meantime, did their own remastered release in the form of the Orange Bricks.
I have seen claims to the effect that Kai is just Dragon Ball Z being shown again with a new name, that Kai specifically refers to a new English dub of Dragon Ball Z, that Kai has the violence extremely edited, among others. These claims are all false; some more than others.
So first off, let us clarify what Dragon Ball Kai is. Dragon Ball Kai is, effectively, a director's cut of Dragon Ball Z, produced in Japan. The idea behind Kai was to edit out the 'filler' to make a more coherent and faster paced version of the show which would also be more true to the Dragon Ball Z manga. This means that much of the 'staring contest' and 'powering-up' scenes have been cut down or removed. The Garlic Jr. saga has also been entirely removed as it does not exist in the manga.
In addition to the cutting/trimming of scenes, Toei Animation also did a new remastering process for the sake of Kai which included colour-correction and reformatting into high definition.
An entirely new musical score was composed for Dragon Ball Kai. However, as I covered in a post several months ago, much of that score has been retroactively replaced after a lawsuit.
On the note of edited violence; yes, Dragon Ball Kai has been subject to stricter censorship than Dragon Ball Z. Broadcasting regulations in Japan have become stricter since Z first aired. For example, when Goku and Raditz die, it is no longer possible to see right through their torsos. The holes have been replaced with dark patches. Nudity such as Gohan's genitals has also been edited out or covered in some fashion.
This censorship is rather mild at best and the implications remain entirely intact. The claim made by some that the editing is extreme stems from editing that exists exclusively in the North American television broadcast version of the show.
Currently, Nicktoons and CW4Kids are broadcasting Kai in North America and, since both are meant as very kid-friendly names, the violence is far more edited. CW4Kids is particularly notorious for extreme edits to the show.
However, these edits do not appear on the home video releases nor have they ever appeared in Japan, either on TV or on DVD/Blu-Ray.
In Japan, Kai was broadcast on television in a widescreen ratio, however the fullscreen ratio of the original series was left intact and used for home video releases.
FUNimation is once again handling the English dub of the series. Rather than reusing recordings they had already made for Dragon Ball Z, they opted to dub Kai from scratch. Much of their original Z cast returned along with a handful of recasts. This time around, FUNimation has made a strong effort to keep the English dub very true to the original, Japanese dialogue. FUNimation also retitled the series Dragon Ball Z Kai in an attempt to lessen confusion...yeah, we can see how well that worked out.
In North America, you can find releases of Dragon Ball Z Kai on both DVD and Blu-Ray. Similar to the Dragon Box release, these contain the Toei remasters (the ones made for Kai) along with 2 audio tracks: Japanese with optional subtitles and the English dub, both using the same soundtrack.
These releases contain special features such as interviews with FUNimation voice actors and directors.
Something to watch out for when picking these sets up is whether you want the 'Part' releases or the 'Season' releases. As the series has been going, FUNimation's been releasing it in 'parts', each containing ~13 episodes. Recently, they've begun releasing seasons. Dragon Ball Z Kai Season One is now available and contains the first 26 episodes (making it a compiled version of parts 1 and 2).
Phew. Let's hope that can clear things up for some people.