where there’s smoke there’s forum fire
Ive been using and loving my D7000 for just over a month now, and have noticed an odd shadow at the top of the image when I use some of the higher shutter speeds, mainly at 1/8000th.
what it seems to me is that the mirror is not moving fast enough, and the sensor is catching the edge of the mirror as it flips up
also, i have had the mirror freeze on me in the up position, and I get an ERR warning in the viewfinder
anyone else had these issues?
Cheers!
Daniel
It's more likely that one of the shutter planes isn't moving fast enough, rather than a problem with the mirror.
Given the reversal of the image through a lens, what constitutes the "top of the image" is really the bottom edge of the sensor. Because the mirror clears the bottom of the sensor first, and the top of the sensor last, I am positive that it is not a mirror issue if your image has a shadow on top.
At speeds up to 1/250ths of a second, the whole sensor window is open simultaneously. Anything faster, and the shutter opening is only a fraction of the image. At 1/500 of a second, a slot, covering 50% of the height of the sensor, is moving from the top of the sensor to the bottom. Confusing as this may be, the slot starts at the top of the sensor, which is the bottom of the image. It ends at the bottom of the sensor, which is the top of the image. At 1/1000 s, the slot covers 25% of the height. At 1/8000s, this is reduced to a slot of just 3% that races through the sensor field in 1/250 of a second.
Now: if you have a shadow at the top of the image, something strange is happening in the last microseconds of the shutter actuation, when the slot arrives at the bottom of the sensor (= the top of the image). A shadow would indicate underexposure. This would suggest that the slot narrows on the last few millimeters of its travel. We can therefore be reasonably sure in saying that the leading curtain is slowing down prematurely, while the trailing curtain keeps its speed to the end.
I think this is a warranty issue. I know that the issue is complex, and I can't describe it in simpler terms. But Nikon's service department should not have trouble with this reasoning and should give you a free fix or a replacement. Good luck!
Can you post a picture?
oh noooo
looks like i'm having a problem somewhat similar. at fast shutter speeds, i'm getting a lock up. it's like the mirror flips up but it doesnt complete the cycle. it happens randomly but quite frequently especially above 1/800. when this happens, i get an Err at the top LCD and I have to press the shutter button again to bring it back to it's original position so that i can snap again.
is this a good time for me to send it for warranty asap?
fisher, to me unless you really need the camera right now i would send it in to be looked at if this is happening as often as it sounds in your message.
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