In computer animation, you can make mistakes and easily correct them.You can also instantly play back a scene to check everything looks OK - but the main problem lies in input. Unless you have a lot of money to spend on a very sexy graphics tablet, then drawing directly into the computer can be a royal pain. I have a tablet, its a only the size of a postage stamp - but it suffices. I have been wanting to upgrade for ages - but I'm too lazy to get a job and like an excuse to use the word paradox as often as possible inside the hours of a single day. The problem is, they cost a whole bunch of money. I was lucky enough to get mine nice and cheap, when Amazon made a pricing cock-up. Hurrah for cock-ups. But even my extremely small postage stamp sized Wacom tablet should have cost near enough a £100. The next step is around £300. So the problem is: input.
On top of the cost, a tablet isn't the most accurate thing to use. You are watching a screen and drawing with your hand in your peripheral vision. This is quite weird to get used to - but you adjust. It's just frustrating when you get a the correct line and run out of tablet to draw that line on. There are many other niggly bits too - Flash isn't strictly for animation: in fact its pretty damn naff really if you don't abuse the power of actionscript, but coding really was never my strong point. Also, there is a tendency to tween a lot in computer animation - this is where the computer does all the work. This don't look natural if you tween everything - but sadly because everything is tweened these days, it has become quite normal and people think things that are fully animated look 'weird' because everything isn't robotic.
So traditional animation then? Well the problem is, if you are a beginner - seeing the continuity of images can be quite difficult and the process of going from drawing to shooting your scene to check it works is a lot longer than if you use a computer. Then you have to go back and do entire drawings again instead of been able to delete the incorrect frame and touch it up. Again, input is the problem. Transferring your drawings from paper to digital ink can be quite a challenge if you don't own the right machinary. There are many ways to do it - I have tried nearly all of them and you just end up with nasty looking stuff, rather than the sleek, smooth looking stuff you get from drawing directly into a computer - albeit simplified sleek, smooth looking stuff.
The other problem is timing. Developing a sense of timing is a long process and I can plainly openly say: I don't have one yet. Im getting there. It's something I thought you could figure out as you went along, but it turns out its something you have to practise daily and pace around your room taking out beats in your head and learning to divide up a second a thousand different ways planning each movement on the beat on the dot so that your character doesn't look like he is skating along, or in one place : then another. Timing and weight are the essence of animation - ive got weight pretty much down. I understand physics, mass and how gravity effects both - objective weight, physiology, biology and all the other things people don't think even come into animation. I have a decent grip on them - but timing is my next port of call and I will get it - but doing that on paper is sooooooooooooooooooooooooooooooo hard. So im learning by doing - on the computer.
There are many other problems that come with both Computer and Traditional animation. Computer takes a lot more effort and time to really bring things to life, but paper takes a lot more time to make into a film. I'm getting there though, slowly but surely. It is just such a huge curve when you are teaching yourself.
Here is an exercise I did last night. I'm doing one a day to keep myself in practise. It's just a run cycle, but these are the kind of things you need to practise doing if you wana make believeable animation. All the inbetweens aren't there - because I don't have an inbetweener and again, I am just one man.
"A walk is the FIRST thing to learn. Learn walks of all kinds, 'cause walks are about the toughest thing to do right" - Ken Harris