Sensor noise and noise patterns exist in all sensors, but they will generally be visible only at the highest ISO settings. Even new sensors sometimes have dead or stuck pixels, but they don't generally cause problems unless there are a ton of them. Stuck pixels will register as a wrong-colour dot. Dead pixels are pixels that don't respond to light they show up as black dots. A camera's sensor must be in good condition, free of electronic issues like stuck pixels and unusual noise patterns. Unlike a film camera, a digital camera's image capture device is an integral part of the camera body. This is not necessarily fatal- we can replace light seals- but material and labour costs for this work will affect our offer. In many older cameras, the foam material has broken down into a sticky goo or a crumbly mess. In film cameras, there are usually strips of foam or other material laid into the gaps where the film door meets the body: these help to ensure that the gap is sealed against light and dust. Others respond correctly at some light levels but not at others- like the jumpy shutter speed scenario, these are the most troublesome.Īnd like shutter speed, metering can easily be off by a stop before it realistically starts to affect imaging- but we try to keep error to within a half stop, for the very same reasons as the shutter speed scenario. Some light meters do not respond at all some are offset by a fixed amount. Light meters should respond correctly at all three intensities. We check film camera light meter function with a calibrated light source at three intensities. That's why we don't generally make offers on cameras where the shutter speeds are outside of that +/-0.5 stop tolerance. We can't do anything about the human error, but we can try to minimize the machine error. Realistically, shutter speeds can be off by a stop or more without a great deal of effect on day to day shooting: most modern film has excellent latitude, and human error in metering is more likely to cause a noticeably bad exposure than a slightly-off shutter.īut inaccuracies in shutter speeds can compound with inaccuracies in metering and human error to produce exposures that are not ideal. Not only are the exposures less predictable with a jumpy shutter, but it's also a sign that the shutter may be on its way out. For example, a shutter that is consistently a half stop slow is better than a shutter that's perfect 90% of the time but occasionally jumps out of spec. Shutter speeds should be within a half stop of nominal speed, and they should be consistent. We check film camera shutter speeds by machine. The information below should give you some insight into how we try to live up to that promise. We do our best to ensure that we buy and sell only the kind of equipment that we believe can provide that kind of experience. We want anyone who buys equipment from us to have fun taking pictures- not to spend their days fighting with a half-working camera. We focus on buying and selling good quality, reliable equipment. And if you're buying a camera somewhere else, perhaps this page will give you some insight into what to look out for. If you are buying or selling a camera through us, we feel that it's only fair to let you know how we test and price equipment.
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