Why not the darkness captured when the shutter closes?

k.udhay

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Hi. This question is definitely going to be silly. I just wanted to give a try though!

Well, when the shutter release button is pressed, the shutter moves out leaving light to the sensor. Once the set shutter duration is complete, it comes back to its original position. This leaves a dark space in front of the sensor. Why is this not captured? If the sensor stops recording just before the shutter closes, what happens in film cameras? Thanks in advance!

P.s. - I got this question, when I got a pitch black photo because I had forgotten to remove my lens cover. Thought the same should happen with shutter, as well.
 

peter27

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Film is photo sensitive: it reacts to light. Where there is no light, there is no reaction. If you release the shutter of a film camera whilst the lens cap is on (and the cap is light proof), the film remains blank at this point. If you realise in time that you've done this, you can rewind and expose the film again, properly this time, with no harm done.
 

manaheim

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Something tells me that's not what OP meant...
 

chris

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Your digital sensor, or film, is sensitive to light. Darkness is the absence of light so you there is nothing for the sensor to react to - you cannot capture what is not there.
 

manaheim

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I still don't think that's what he meant, but you could argue that you can capture the absence of light...
 

cgipson1

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Hi. This question is definitely going to be silly. I just wanted to give a try though!

Well, when the shutter release button is pressed, the shutter moves out leaving light to the sensor. Once the set shutter duration is complete, it comes back to its original position. This leaves a dark space in front of the sensor. Why is this not captured? If the sensor stops recording just before the shutter closes, what happens in film cameras? Thanks in advance!

P.s. - I got this question, when I got a pitch black photo because I had forgotten to remove my lens cover. Thought the same should happen with shutter, as well.

With the lens cap on... no light hits the film... so all you get is black. When the shutter opens to record on an image, light hits the film and the film records it. When the shutter closes, it shuts off the light. So at that time, no further changes are made to the film... it will not record / overwrite the absence of light over the top of the light exposed image.

In other words, the film is only changed by exposure to light, it does not change when exposed to the absence of light... which is why it is safe to work in a "darkroom"!

Is that what you were asking?
 

cgipson1

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I still don't think that's what he meant, but you could argue that you can capture the absence of light...

Only because of the lack of light... which would be like having a lens cap on. One there is light applied to the film, that exposure will not "go away" if the film is then exposed to dark, or the absence of light.. correct? (playing devil's advocate today, are we?) ;) lol!
 

Josh66

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I think what the OP wants to know is why can you not see the shutter in the photo, since it moves across the frame. Or, why does it not darken the frame near the edges as it is closing.

The answer is that there are actually two shutters. They move together, as a slit. So the whole frame is not exposed simultaneously, but it is all exposed for the same length of time.

If you watch an animation of a shutter working, I think it will all make sense to you. I'm on my phone right now, so it will kind of be a pain in the ass to find and then post one...
 

cgipson1

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I think what the OP wants to know is why can you not see the shutter in the photo, since it moves across the frame. Or, why does it not darken the frame near the edges as it is closing.

The answer is that there are actually two shutters. They move together, as a slit. So the whole frame is not exposed simultaneously, but it is all exposed for the same length of time.

If you watch an animation of a shutter working, I think it will all make sense to you. I'm on my phone right now, so it will kind of be a pain in the ass to find and then post one...

Really? OP states" Once the set shutter duration is complete, it comes back to its original position. This leaves a dark space in front of the sensor. Why is this not captured?" I think COMPLETE is the keyword here....
 

cgipson1

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There are no photons in darkness.

EXACTLY! And I started to use the P word... but thought maybe I shouldn't get too "technical" on this one, lol!
 

manaheim

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I think what the OP wants to know is why can you not see the shutter in the photo, since it moves across the frame. Or, why does it not darken the frame near the edges as it is closing.

The answer is that there are actually two shutters. They move together, as a slit. So the whole frame is not exposed simultaneously, but it is all exposed for the same length of time.

If you watch an animation of a shutter working, I think it will all make sense to you. I'm on my phone right now, so it will kind of be a pain in the ass to find and then post one...

Yeah I bet that's it.


To all you "no photos in darkness" people... you sure about that? True darkness (absolutely zero light) is pretty hard to come by.
 

ronlane

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I think what the OP wants to know is why can you not see the shutter in the photo, since it moves across the frame. Or, why does it not darken the frame near the edges as it is closing.

The answer is that there are actually two shutters. They move together, as a slit. So the whole frame is not exposed simultaneously, but it is all exposed for the same length of time.

If you watch an animation of a shutter working, I think it will all make sense to you. I'm on my phone right now, so it will kind of be a pain in the ass to find and then post one...

Yeah I bet that's it.


To all you "no photos in darkness" people... you sure about that? True darkness (absolutely zero light) is pretty hard to come by.

Interest point Manaheim. Wouldn't that be by definition a black hole?
 

cgipson1

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I think what the OP wants to know is why can you not see the shutter in the photo, since it moves across the frame. Or, why does it not darken the frame near the edges as it is closing.

The answer is that there are actually two shutters. They move together, as a slit. So the whole frame is not exposed simultaneously, but it is all exposed for the same length of time.

If you watch an animation of a shutter working, I think it will all make sense to you. I'm on my phone right now, so it will kind of be a pain in the ass to find and then post one...

Yeah I bet that's it.


To all you "no photos in darkness" people... you sure about that? True darkness (absolutely zero light) is pretty hard to come by.

UH.. lens cap on... shutter closed... that is pretty much zero light! ;)
 

cgipson1

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I think what the OP wants to know is why can you not see the shutter in the photo, since it moves across the frame. Or, why does it not darken the frame near the edges as it is closing.

The answer is that there are actually two shutters. They move together, as a slit. So the whole frame is not exposed simultaneously, but it is all exposed for the same length of time.

If you watch an animation of a shutter working, I think it will all make sense to you. I'm on my phone right now, so it will kind of be a pain in the ass to find and then post one...

Yeah I bet that's it.


To all you "no photos in darkness" people... you sure about that? True darkness (absolutely zero light) is pretty hard to come by.

Interest point Manaheim. Wouldn't that be by definition a black hole?

Don't get me started...
 

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