scud said:
1. What are the things need to be checked when buying an used dslr?
2. How to check any fungus accumulation? WHere to focus on and how to tell?
3. How can we know if the cam has been dropped (even after changing the cam casing)?
4. What other things need to take note during testing of the cam?
1. External wear and tear. This only really matters if you're planning to sell - stuff like scratches really don't affect anything. Look for loose parts - dials, missing caps, damaged buttons, scratched LCD, etc.
2. Fungus only applies to lenses. The mirror or prism might get fungus, but since they flip out of the way during shooting, it doesn't matter. Anyway, fungus on the body itself is quite rare.
3. Other than physical damage externally, you can't. Just like you can't tell a car has been in an accident except for external signs. (Ok, you can after driving a while, but not on casual inspection.)
4. A lot...
- The mirror flips.
- The shutter moves (not stuck).
- The LCD panels all work.
- The picture can be taken.
- No hot pixels.
- Sensor not scratched.
- Metering is correct (ie not way off).
- Lotsa menus and options, though probably no need to check them. Unlikely software will have bug for that particular unit only.
- Can mount to lens and focus, stop down, etc.
- blah blah blah. (Sorry, tired. Someone else carry on.)
Three suggestions:
1. If buying from private owner, can consider asking him to make the transaction through a second hand shop that gives a warranty, eg TCW. They take 10% of the transaction price, but you can take it as an option to 'buy' a warranty. This, of course, may defeat the purpose of sourcing for a 2H in the first place - you want it as cheap as possible.
2. Go with someone who has used that model of camera. i think the wisdom of this move is obvious.
3. When asking for comments, don't ask for 'expert advise'. Makes people (myself included) feel very paiseh to answer.
HTH.