When you buy used, know that you're trading off the saving with peace of mind. Used equipment no longer carries warranty (most of the time). You don't know the condition it has been handled by previous owners. You might not even know its current flaws. You can ask the seller, but how do you know if he's telling you everything, if he knows at all? However, sometimes the saving can be significant that you might be willing to make the trade-off. For example, the Canon 5D Mark II, currently a hot item, is selling for $2500 new and $2100 used, a 19% saving for a current hot item, significantly high enough to make you consider the trade-off.
So, assume that you want to buy used. You have talked to the seller over the phone about its condition and what's included in the package.
*Do your homework beforehand*! Do research about the equipment before you see the seller. Pay attention to the most common errors or faults that can happen with the equipment. (For example, for cameras, do an online search for something like "Canon [model] error". It should turn up myriad of common error conditions. Study them.)
Now the inspection. Obviously you won't find out everything. Something might come up later, when you get home. But this list will get you through the most common faults. If you find them, you can use them to renegotiate on the price, that is, if you still want the equipment. And of course, spend the amount of time proportional to the asking price of the equipment, ie, you don't want to spend an hour inspecting a 10-year-old camera that is selling for $100!! *Inspect the equipment under strong lighting condition*! You can't find that scratch on the mirror unless you have good light!!
The Visual Inspection:
* Completeness: Make sure that the package includes what the seller claims it to be. It doesn't have to include everything that came in the original package, just what the seller is selling you (or what you think you get). Don't get home and find out that there's no battery charger (if indeed it's supposed to be there)!
Most important items:
- Battery
- Charger
Other items that might be included:
- Lens
- Box
- Manuals
- Warranty card
- CD
- Video cable
- USB cable
- Strap
- Body cap
- 2 lens caps for each lens
- Eyepiece cup
- Memory card
* Fit: Make sure that all the pieces fit together! The lens should fit into the camera. The battery should fit into the camera! The battery should fit into the charger! (You'd be amazed at how often sellers shove things into the package, intentionally or not, that don't belong there!!)
* Exterior Condition: This might or might not make any difference to you or the inner working of the camera, but the exterior condition oftentimes indicates what you can expect on the inside. Look for dings and scratches. (For "professional" cameras, expect heavy use and abuse.) Pay close attention lens front and back elements, LCD screens.
* Interior Condition: You can't dissemble the camera or the lens completely, but you can take off the lens and look at the mirror and surrounding area. Look for scratches on the mirror. If possible, lock up the mirror and see if there's any dirt on the sensor.
The Functional Inspection:
* The Lens: Make sure that the movements (focusing, zooming, aperture) go all the way from one end to the other and there's no blockage of any kind. Notice the smoothness of movement. Look into the viewfinder to make sure that the movements do what they are intended to do. Test the small aperture.
* The Shutter: Put the camera at continuous firing mode. Set the camera to the minimum megapixel setting. Turn the shutter speed to the fastest and test fire 10 shots in rapid succession. Look at the resulting photos to see if things look right. Now turn the shutter speed to 2s and test fire.
* Memory Writing: Set the camera to the maximum megapixel setting and test fire 10 shots in rapid succession to see how well the camera records the photos into the memory card.
* The Built-In Flash: If the camera has a built-in flash, turn the camera to Complete Program, take the camera into a dark area, and push the shutter-release button. The flash should pop up and fire.
* Re-creation of the Error Conditions: If you have done your research beforehand, you should know what conditions create which Error. Attempt to re-create at least one error. This should scare the heck out of the seller, especially one who is not knowledgeable and who has never encountered such error! (This is mean! :-D )
This battery of tests should be sufficient to uncover most of the common faults for now. Again, you don't have the time, the resources, or maybe even the need or the necessity, to test out everything. You *want* to take the equipment home so badly; you can't wait; you don't want to do all the tests; you just want to make believe that everything's alright; you just want to take it home and start shooting!!
Take your newly-bought equipment home, prepare your bed, kick your wife off, put the equipment in her place, caress it, whisper to it.
Have a good night!! :-D
