Memory card light??
- Thread starter run4fun
- Start date
Horoscope Fish
Senior Member
Totally normal. That's the camera writing the photo data to the card. Since the card is being "accessed" the light blinks.
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Thanks...never noticed it!
Good to know! Thanks
Actually, it is computer controlled, and the camera will not turn off until the buffer is written to the card. However, one could remove the card, or remove the battery or AC power, and make writing fail.
I'll defer to the manual under Memory Card cautions.
Sounds good. Mine says:
"Do not remove the memory card or remove or disconnect the power source
until the access lamp has gone out. If the camera is switched off while
data remain in the buffer, the power will not turn off until all images in
the buffer have been recorded. If the battery is exhausted while images
remain in the buffer, the shutter release will be disabled and the images
transferred to the memory card."
run4fun did not specify, but I assumed he was referring to his D7100. I must admit though, that I've learned not to believe everything I read.
I see your point... D7100 manual does say (page 31)
Turn the power off before inserting or removing memory cards. Do
not remove memory cards from the camera, turn the camera off, or
remove or disconnect the power source during formatting or while
data are being recorded, deleted, or copied to a computer. Failure to
observe these precautions could result in loss of data or in damage to
the camera or card.
I doubt it is only speaking of a computer interface, since they discourage that.
Also says (page 32)
Do not remove the memory card or remove or disconnect the power
source during formatting.
but does not mention turning camera off while formatting.
Then D7100 (and all models I think) additionally says (page 58):
Do not remove the memory card or remove or disconnect the power source
until the access lamp has gone out. If the camera is switched off while
data remain in the buffer, the power will not turn off until all images in
the buffer have been recorded. If the battery is exhausted while images
remain in the buffer, the shutter release will be disabled and the images
transferred to the memory card.
The programmers would have done a pretty poor job if they allowed the camera to be turned off while writing the card (or while actively doing anything actually).
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Turning the switch off does not turn the camera off if there's still data in the buffer. The camera will stay on, even when the switch is turned off, until the data is written to the card. When that is done, then the camera will power down.
Likewise, I see your point.
Da da dut dut dah... Where's my banjo? Dueling thoughts that seem to both be correct and both initially incomplete.
Now I know not only to not turn the camera off if the light is lit, but it's okay to turn it off if the light is lit while the camera is writing to the card from the buffer. I'll think I'll just let the light go out before I turn the camera off.
Side note is I learned what the r17 means. Noticed it the other day and hadn't had a chance to look it out.
@WayneF , I have learned more than one thing and do appreciate the exchange.
You seem to perceive a difference where I don't. The card is only written from the buffer.
Manuals are hard, and in my experience, a separate effort. I have jaded notions, but designers implement the product, and then the tech pubs dept tries to describe using it. Some writers there are really good, but some are summer hires.
Designers do know what it does, but are more impressed with subtle features, without much idea how users will perceive it. And generally too busy to be much involved with the manual, that product is already finished. But when I was working, a few times it was me that had to do a first draft manual to send to tech pubs, since otherwise, they had no clue about the product. They tended to think my version was unacceptable, since they really didn't want to know how it works inside, but just wanted a few words about each button or menu (stuff they could see). Both points of view are poor from aspect of user with an overall job to do. But I always thought the user needed to know what it was going to do. Anyway, the finished manual often has surprises and disappointments to the designers.
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You seem to perceive a difference where I don't. The card is only written from the buffer.
Is the writing of files from the buffer the only time files on the card are accessed?
Writing, yes, that is my opinion. The camera creates the file, buffers it, and the buffer is written to the card. The buffer may only have one image in it most times. But there would not be two procedures created to write an image to the card.
Reading is something else, no damage done if reading is interrupted. But reading is one image, and fast, and I'd guess it waits for all operations to complete before turning off the camera. Why not?
What about when reading a movie file?
OK, maybe an exception, but reading is not destructive (does not change anything), so I imagine it just quits then.
What about writing a movie file?
It buffers frames (and writes blocks or sectors), so I imagine it just chooses a good stopping point, and does any necessary tidying up. File is terminated, but not destroyed.But I doubt the Off switch is an interrupt, it just quits when it loops back around to check it. And surely tidies up first.
OK, maybe an exception, but reading is not destructive (does not change anything), so I imagine it just quits then.
What about writing a movie file?
But I doubt the Off switch is an interrupt, it just quits when it loops back around to check it. And surely tidies up first.
So, any other question would have the same answer, which I suppose in summary is that we can disregard the Memory Card cautions, but if I understand your comments there is some imagination and doubt mixed into the general idea.
I imagine the green light has a purpose and doubt I'll put it to a test.
So, any other question would have the same answer, which I suppose in summary is that we can disregard the Memory Card cautions, but if I understand your comments there is some imagination and doubt mixed into the general idea.
I imagine the green light has a purpose and doubt I'll put it to a test.
I use the LED to time the write speed to the memory card.
I doubt it is ever necessary to tempt fate, but the manuals do clearly say "If the camera is switched off while data remain in the buffer, the power will not turn off until all images in the buffer have been recorded." And this would of course be good practice in design.
Removing the card or removing the battery would NOT be the same result.
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