Dooku wrote in post #4825009
I would like to ask what the real practical advantages are of a full frame camera?
If I should get a full frame then would it be best to wait for the successor of the 5D?
The main full frame advantages are:
- Larger, better seperated pixels for any given Mp amount, this gives better image quality, lower noise etc.
- Better depth of field control. Larger sensors have inherently shallower DOF, so are ideal for separating subject from distracting backgrounds, picking one point of the image out to be the focus of attention etc.
- Wide angles are truly wide, so a 10-20mm is a real ultrawide, not the equivalent of 16-32mm. If you are starting with a 24-105L, this will be very noticeable as 24mm is much wider than 38.5mm equivalent.
- Larger brighter viewfinder, making composition, manual focusing, DOF preview, etc., easier.
This all makes the 5D a pleasure to use and it is a fantastic camera for most situations and easily superior to a crop camera for portraits, landscapes etc.
On the other hand, the 40D will be a better fast action camera, with it's much higher frames per second capability. It also has the advantage in bird photography etc., where the higher pixel density becomes an advantage as more pixels cover the subject, thus giving more 'reach' when the subject only fills a part of the frame, effectively giving you a longer lens.
I can't recommend one over the other, as you haven't said what you actually intend to shoot with your new camera and that is critical. You should decide what features are important to you and see which fills those needs most closely. Many photographers on here have both a full frame and a crop body, using whichever is best for the job in hand. I am one of these, having a 20D and a 5D. I aim to replace the 20D with a 40D, when it eventually dies (it's got about 80,000 on the clock so will probably fall off it's perch sometime this year).
As for waiting for a new 5D, you need to decide if (a) you really want full frame, but the current 5D just doesn't meet your needs (b) you think the new 5D will meet them (higher fps rate for example) and (c) you are prepared to wait the best part of a year before you actually buy the camera (and it will cost a lot more than the current one). The next new camera announcement is due in september and they will then take a little while to get into the stores and there will be a very long waiting list for one, so if you don't have it pre-ordered well in advance .....
If you want to get back into it for this summer, you will need to buy a current 5D if you want full frame, or a crop camera if that is what you choose. I don't know how your budget is, but if you decide you want to wait for the new 5D, but shoot now, you could buy a 40D to use until then, either selling it or keeping it as a second body when the 5DII is released (which would give the best of both worlds). Alternatively, you could get up and running cheaply with a used 20D / 30D body for this year, which would then get most of it's money back if you sell it at the end of the year, or be a cheap second body.
There isn't a lot of difference between a 20D and a 30D, but the 40D is a definite step up in terms of specification. My old 20D is still capable of turning in excellent quality results however.
I hope some of this rambling helps your decision making process in some way.
Oh, and welcome to POTN 