First, does the 20D have a aspect ratio choice like the F828.<--I found this answer, and yes it does. Howeer, does it also have a "standar" aspect ratio?
I haven't seen any aspect ratio choice in the menu for my 20D, but it does auto-detect whether you're in "portrait" or "landscape" mode. That is, it senses whether you're holding the camera vertically or horizontally.
For other aspect ratios, I find it far easier to just crop the image later on, either in Adobe Camera RAW or in Photoshop.
Second, here are some DoF pictures I took. Composition is off, but I wanted to maximize background to show DoF. Could you any of you give a rough estimate of how much better the 20D will do with Shallow DoF than the pictrures I've posted. I don't want to invest 3500 in a camera only to have the shallow DoF not be acceptable to me.
I can only point to the f/2.8 image taken at 24mm (38.4mm equivalent) in the previous thread on this topic, to show how shallow DoF is when doing portraiture on a wide lens.
For shallower DoF, you'd need to look at fixed focal length lenses, such as the superb EF 135mm f/2L, the (also superb) EF 85mm f/1.2L, and the very good EF 50mm f/1.4.
Given your budget hints, trying to get a used EF 200mm f/2L seems out of the question, although that one's about as good as it gets.
Third, I've narrowed down what I would want for at least one lens. I will give you my reaswons, and then you can answer and correct any preconceived errors in my thinking.
I'd like to have the Cannon 200MM IS, the one that costs 1700.00 US. I think this is a good all around lens that will give me an efffective 320MM zoom compared to the Sony F828's 200mm equivalent. Plus it has IS and F2.8.
I assume you mean the EF 70-200mm f/2.8L IS? Canon doesn't have a fixed focal length lens at 200mm with IS.
There is, however, the EF 300mm f/2.8L IS, another really good (and really expensive) lens.
What lens would best compliment the 200MM above? Should it also be IS?
That depends on the kind of photography you want to do.
IS is typically most useful when you do handheld shots, shots on a tripod in wind, and particularly useful in lowlight situations.
Given that you later write that you intend to do your wide angle shots with your F828, my guess is that the 50mm f/1.4 would complement the 70-200mm f/2.8L IS nicely. But you can always get that second lens later!
How much trouble is keeping the sensor clean and cleaning it when necessary going to be and what is involved in doing it correctly?
Search this site for "sensor cleaning", there are two good articles on it.
Finally, is the battery grip worth having, more so for ergonomics than battery life?
It's a matter of taste, I think. Battery life is pretty much a non-issue with the 20D -- for me! -- and the second battery available in the grip would only nearly double your capacity, for a rather larger increase in weight. I keep my second battery in the camera bag or in my pocket.
Also, the battery grip for the 20D has exhibited problems that Canon just recently acknowledged. I don't know whether this acknowledgment has resulted in new grips working better or not.
Ergonomics-wise, I'd probably love having a vertical grip, and since you seem to do a bit of hand-held portraiture, so would you.
Last, the new Sony DSC R1 that replaces the F828 is out. It has a sensor size equal to the 20D, although it is still limited by a fixed lens, F16, and other factors. Just for comparison sake, do you think that almost the same size CMOS sensor is equal or nearly equal to the 20D's?
We 20D owners would like to think that it isn't. ::
But seriously, I await proper test results.
I have one other thing I wanted to add. Tonight I talked with the owner of the local photo store and was explaning my understanding of the 1.6 crop factor of the 20D. As I understand what people have said, you get LESS image than you see in the LCD and viewfinder. So if you have a person's ears and chin just in the image you see while shooting the picture, you will lose some of their ears and chin when you view it on screen. Is this correct? He said he thought I had that wrong. He said you should see whatever the viewfinder/LCD are stated as in the manual, which I think is 97% for the 20D.
He is correct.
In the 20D viewfinder, you see
less than what you photograph.
This is slightly annoying, because I try to frame my photograph to avoid cropping, if possible, and not having 100% coverage ruins this slightly.
But it's far better to have leeway than to lose parts of the image because the viewfinder coverage was, say, 105% ...