After using canon 5D mark II for some days, I can write some more detailed observations. I won’t copy specifications, because you can find them on many web pages. Here will rather be some observations from field.
1. Files are really big. Camera can “easily” create files near 40 MB in RAW. Yes you read right. So be aware if your computer isn’t up to date with hardware. And my 8 GB CF cards was BIG two years ago, but now...
If you want smaller files, you can use SRAW1 (10 MP instead of 21 MP) or SRAW2 (5.2 MP). Nice feature when you don’t need full resolution. But if you have full resolution photo, you can make big prints or you can crop a lot.
2. There were many talking about noise. Don’t talk too much. Take a picture in range where you can use it. The expanded ISO sensitivity range goes from 50 to 25600. And if you see bear on your backyard in the evening, use what do you want. Better noise photo, then no photo.
For real world, photographer can use ISO 6400 for normal prints without fear that client will noticed noise.
3. One of my biggest disappointments is the relatively slow shutter lag and mirror blackout time specs. It’s frame rate is 3.9 fps. Not fast enough for using 5D mark II as sports camera, but better then old version of 5D and not bad at all if we look at number of pixels per seconds.
4. On camera you won’t find pop-up flash. I’m a big fun of pop-up flash on DSLR. Look at examples in this article.
I did just some shots with 580EX so I can’t write about this at this moment. My first feeling is that it works like 30D – very good, but not excellently. You can read about some issues with flash on 5D mark II.
5. After first lens changes I didn’t noticed dust on sensor. If I say what other users have written - EOS Integrated Cleaning System works very good. But more about dust after some months :-)
6. Images from Canon 5D mark II are excellent. I noticed a little more saturated color and images also have more pop. But Auto White Balance still isn’t very good. White Balance is too cold on some photos taken in afternoon sun in shadow.
Maybe Canon can make a little change in exposure metering - in my opinion almost every photo taken in cloudy weather can be little more on the right side of histogram (evaluative metering).
7. Custom modes (C1, C2 and C3 on exposure mode dial) are great. You setup the camera, register the settings and the camera will use your registered settings when the particular C mode is selected.
8. Canon 5D mark II uses 9 AF points. For my opinion AF points are positioned too narrow (just in the center part of viewfinder). Center AF point is about twice as sensitive as the other focus points. Six not-selectable assist focus points are present around the center point. I found center focus point with AI Servo to be very good. AF is fast enough for my normal use and I can say that AF is accurate and I don’t have problems.
If your camera and/or lens aren’t “compatible”, you will found front/back focus. On this new camera you can use AF Microadjustment to adjust anomalies. I didn’t try this feature, because my lenses don’t show front or back focus issue.
9. And now one very annoying behavior on Canon's DSLRs. When photographer press shutter button and then look at picture review on LCD, he can’t use magnification button immediately. Well he can, but without benefit :-)
Photographer must first press PLAY button, then he can use magnification button. Hey Canon!!
10. Exposure metering is very conservative – exposure is very rarely overexposured. In some cases histogram is to the left. We know this from Canon flash systems. If you know your camera, you will use (flash) exposure compensation.
11. Live view is very nice feature. Many web pages have detailed description of how it works – with examples. For me is important when I want to check if object is in focus.
12. I tried video and we can say – hut down to Canon. I will try to extract a sequence (photo) from video and make a print. If it will be usable, we can say that Canon has 30 fps :-)
13. LCD is fantastic. Probably the best LCD in DSLR world. It has automatic brightness adjustment – a good idea.
14. Some users report creeky CF card door. I can compare this door with door on 30D and they are the same. Nothing special, but we must mentioned better sealing against dust and moisture.
15. The My Menu feature allows you to prepare a custom menu. Yes, you can now have Mirror lockup, Format, Quality by your hand.
16. Canon 5D mark II use LP-E6 battery. But at this time (after half a year of introduction) you can’t find this battery in the store. Not in Europe. Occasionally (and just for some hours) batteries are available over the ocean. Canon – be a shame.
Otherwise this battery has integrated chip and camera can show very good indication.
That's all folks - for now.