Quote:
Originally Posted by Sharp11
The sensor issue: Are these the "spots" you're referring to? I don't know what they are - they're on every zoom shot, some regular shots, but not others and they're not on any of the non-polarizer shots. If it's a sensor issue, wouldn't the spots be there all the time? I'm asking because I really don't know 
I'm sure the sensor does need a good cleaning though, I've had this camera since May of 06 and have used it a lot - in many dirty places.
Ed |
They're dust spots and they're on the sensor. They may not show up in every photo for a number of reasons such as image content and/or exposure mask its existence and until/unless it gets welded, it can move.
The best way that I've found to check for dust is to set the aperture pretty small (ƒ16 or smaller), infinity focus and shoot at a solid, featureless subject that is reasonably light in color (cloudless sky, wall, etc) at a shutter speed long enough to ensure a mid tone exposure. Open in Photoshop (or similar) and apply Auto Levels. All of the "bits" you see are pieces of dust on your sensor. Reset the level and start playing with manually setting levels, or contrast, or curves, etc to get an idea of how much/how bad. If you have to go to extremes to get anything to show up, it's probably not worth cleaning. If you can see it before making any adjustments...or if you can see it in your photos (like the ones above), it's not worth spending the time adjusting in PS since you know you have to clean.
To clean, first step should always be using a bulb blower. Hold the camera body so the lens/lens opening is facing straight down, remove the lens, do whatever it takes to open up or lock the shutter and mirror, use your bulb blower a bunch (making sure that you don't touch the sensor with the blower tip). Release the shutter, install lens, take pic as described above, and check in Photoshop. Repeat until all dust is gone...if possible.
You'll find that you move dust around with each pass. Sometimes a subsequent image will be dirtier than the one before it. You just keep going until it seems like you can't get it any better.
You may also find that there are some stubborn spots that just won't go away. Those may be welded dust. They are particles that have attached themselves to your sensor either while wet or became wet once there and have now essentially bonded themselves to your sensor. You need to do a wet cleaning to get rid of these...and they won't always necessarily work (unfortunately). There's a bunch of ways to do it (pec pads, eclipse, etc) and I'm not sure that there is a "right" way.
Another option is sending the camera into Nikon and having them do a thorough check, clean, and service. It's not too expensive, their turn around is pretty quick (and they're not far from you, so shipping won't add much time for you either) and their cleanings get you as close back to "like new" as possible. If you haven't cleaned it in 3 years and you've done any lens swapping (which I know you have), I can almost guarantee that you have a bunch of welded dust. If you insist on continuing to use the D70s as your primary, I'd strongly suggest sending it to Nikon (but I really think you ought to consider moving up to a D90, D300 or D700 fora variety of reasons).