[wao]

Sakuga (作画)

Generally refers to the drawings in an anime.

More often than not it is talking about how the pictures are drawn - are they close to the model, do they show good expressions, are they anatomically/proportionally correct, are the shadows right, etc...
However, some people use it with reference to the animation as a whole (drawings + line quality + movement (and timing) + shading etc, but not colour). I think that isn't entirely accurate.

When you see people going about "nani kono sakuga" or "hidoi sakuga" they're usually complaining about the poor quality of drawings, but if it's smooth they'll usually say "yoku ugoiteru ne" (something to that extent), or maybe something like "sugee douga". If it's smooth and well-drawn and moves WELL (meaning with nuance, sense of weight, etc.) they'll say "kami sakuga". A common appreciation of cool animation seems to be 鳥肌が立った - I got goosebumps. Like shivers down your spine.

An important, related term is Sakuga kantoku (作画監督) also abbreviated as "sakkan". Literally translated as "animation director", which is misleading. The job of a sakkan is to correct the genga made by key animators (see below). Corrected drawings are done on yellow paper, apparently. This is one of the important roles, and is one of the 4 most important per episode (the other 3 being scriptwriter, storyboarder and episode director).

I am going to ((very) extensively) blather on about this so I have put it in a spoiler tag.

Spoiler for About sakkans/animation directors:

Very much more often than not, the correcting they do is with regards to the sakuga as described earlier - and less to do with the movement and nuances. For most TV shows the sakkan just refers to the designs and corrects the faces, not even so that they necessarily look as convincing as possible, but so that they fit as close as possible to the model sheets. In most productions of anime, it's more about making it look like the character than anything else. (Sticking to the designs is highly recommended to most ordinary animators so that the sakkan doesn't die. But this ends up restricting movement.)

Sakkans are usually more experienced key animators (unless you're a prodigy or summat), and get paid a higher salary. However, they can have a really, really stressful job because if the schedule is really screwed up they get pressed really hard to correct the rushed genga (sometimes having to entirely redo it themselves). And they get blamed if the product looks off-model... So sometimes if you see a whole load of sakkans or sakkan-assistants in a show it can be a sign that that episode either was rushed, or had really unacceptable genga, or both. Example: Ergo Proxy episode 8, where the schedule was really rushed and a lot of sakkan-assistants (in addition to 2 sakkans) had to be used, but the designs still looked kind of off.
But having lots of sakkans could also mean that they wanted real perfection so they got sakkans proficient in different things to get it done very nicely. You can get awesome results sometimes, too - see Eureka 7, Kamichu! and RahXephon, etc.

Sakkans don't actually direct the animation in that they don't tell the animators what actions to do - most of the time anyway. There have been some exceptions: for example, I remember for the anime segment in Kill Bill, it was the animation director who went to see Tarantino with the other staff, and carefully observed the type of actions Tarantino wanted (he got them roughly acted out). Another exception, I believe, is Ghibli movies (sometimes?).
For OVAs and movies sakkans usually do correct the movement and timing and nuances. The occasional charismatic ones do it for TV animation too.
This is as far as I have observed and heard, anyway. It seems like the people who decide what actions the people actually do in the show are determined by the storyboarder and episode director more than the animation director. The episode director has to make sure that the animation for that ep doesn't go overbudget and such, so if budget-saving tactics are to be used, it is likely to be the episode director's decision.

An interesting story about episode director vs. animator vs. director, is with regards to the famous Ichiro Itano, originator of the beautiful and eye-catching Itano Circus style of animating rockets [Started in Macross, see Macross, Plus, Zero. Very famous example in Daicon IV. See other people imitating it in Eureka 7, particularly OP2, as well as the Futakoi Alternative OP].

Originally Posted by AniPages Daily

It's full of interesting anecdotes about his early days, like the way he got in trouble for constantly drawing limbs flying on Gundam, or the way he got personally recognized once by Tomino when he drew every drawing in a shot at full 24 frames, and the director of that episode got mad at him and changed it back to regulation limited, and he went behind the back of the director and changed it back, and the director got pissed at him in the screening room in front of Tomino, but Tomino loved what Itano had done and told him to ignore the director, calling him a "nobody" in memorable Tomino fashion.

(from here)

Sakkans can be further categorised into Character Sakkans (キャラクター作画監督), Mechanic Sakkans (メカ作画監督), Layout Sakkans (レイアウト作画監督 or L/O 作画監督), sometimes an additional Effect Sakkan (エフェクト作画監督) though the last one is usually lumped in with Mecha sakkans, like with the great Takashi Hashimoto who is a master of FX animation. Most of these self-explanatory, though with Layout Sakkans it's a bit different from the plain old "Layout" credit (as far as I understand; there may be times where both overlap or a person credited to one actually did both.)

As far as I'm aware of, "layout" is a process before the animation where after the storyboards are done, someone decides where the characters should be placed in terms of the frame and so on so that the key animators have a guide to where to place the characters. Hayao Miyazaki did this for the masterpiece TV anime "3000 Leagues in Search of Mother". But it appears "layout sakkans" do it after the genga is done and modify it a bit. The idea of "sakkan" is, after all, usually about doing it after key animation is done. From some accounts I hear it's also got to do with correcting difficult poses and strange positionings but I'm not entirely sure, really.

Another thing is Sou-Sakuga kantoku (総作画監督) - "Overall Animation Director". This is, afaik, exclusively about correcting faces. The sou-sakkan is usually the (animation) character designer as well, and is the person sakkans turn to if the don't know how to correct the drawings so that it looks like the models, which teh sou-sakkans are the most familiar with. Sometimes the sou-sakkans will just consistently assist the sakkans, going uncredited most of the time.
Sou-sakkans seem to be a more recent "invention" (as compared to "sakkans" which started way back during the old Toei Doga days) and almost all anime have them now - one unsurprising exception being Noein, which takes a very different animation approach from most anime and the designs consequently vary wildly everywhere; yet the character designer does not have a sou-sakkan credit, in fact the only thing he's been a normal sakkan for is the OP!

With regards to otaku using "sakkan", it's sometimes like a verb - when they see stuff that looks off model or crudely drawn a common whine is "sakkan irete choudai" - please 'sakkan' (correct) this for us.

Genga (原画)

Usually translated as key animation. It literally means "original drawings". This is something I'm still not entirely clear about, but basically they draw the important frames in a show - and leave the in-between stuff to, well, the in-between animators. In-between animation work is called douga 動画 and also involves tracing the lines from the genga so that it looks neat and so on, called clean-up.

Spoiler for extra stuff:

From what it seems it's largely not like the Western system where the key animator works closely with his or her assistant animator(s) and refines it a lot before passing it to an in-betweener. Here the genga and douga people are quite separated (many times, douga is outsourced anyway) so the genga set would just come with instructions and arrows and hints on shading and such.
It's not always like this though, some key animators actually just draw most of the frames on their own - since many times, all the instructions you give are nowhere near as good as just doing it on your own, or showing others through pictures. The in-betweeners then just have to add trivial tweens and clean up the picture.
I'm not entirely clear on it though, but for one thing most TV anime is limited animation (they try not to draw a new picture for every single frame).

In more recent years the emergence of this thing called "2nd Key Animation" (第二原画) has appeared, I think it is something like preliminary clean-up so the key animators spend more time on the movement and placement, while the 2nd keys add the design details and possibly the shadows, and clean up the lines. I don't know for sure though.

edit: I can be wrong on some of this