LONG EXPOSURES

derekG

derekG

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derek
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Not sure what i am doing wrong here, but playing around with long exposures today, but all pics just show a white screen, eg f8, bulb setting, iso 100, set to manual on D7000, also tried 20 and 30 second exposures same thing?
 
derekG said:
Not sure what i am doing wrong here, but playing around with long exposures today, but all pics just show a white screen, eg f8, bulb setting, iso 100, set to manual on D7000, also tried 20 and 30 second exposures same thing?
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It's totally burnt out (completely over exposed) , if you want to do a long exposure in daylight your going to need a ND filter of some type to reduce the amount of light reaching the sensor :thumbs:
 
I did think it was too much light but thank you very much for confirming, tried to change the exposure manually, but soon realised you cant in manual mode.
 
derekG said:
I did think it was too much light but thank you very much for confirming, tried to change the exposure manually, but soon realised you cant in manual mode.
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Of course you can change the exposure manually In manual mode, that's what its there for!

You'll still massively overexpose an image trying to do long exposures in daytime though, without an nd filter, or using a very shaded area and a very high aperture. You might just manage to get 1-2 seconds, but if you want 10 seconds + it Will have to be dark already or you will need a filter.
 
When in bulb setting i cant change exposure settings.
 
On an average autumn day, f8 at ISO 100 will need about 1/125 second shutter speed. Any slower and you will over expose.

Thirty seconds is 3,750 times as much time as you need - Or it's 12 stops over exposed!


Steve.
 
derekG said:
When in bulb setting i cant change exposure settings.
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I think your referring to Exposure Value e.g. +/-2 stops and no you cannot change this is M/Bulb...but you do have full control over your exposure by changing a combination of shutter speed/aperture/ISO in addition to adding filtration, I do rather like the bucket of water analogy :thumbs:
 
Okay i will try later when dark using wireless remote ,and tomorrow using my nd grads , thanks for the help.
 
markmullen said:
Think of your exposure as water filling a bucket from a hose.

Leave the tap open too long and you'll soon overfill the bucket. This is your shutter speed.

Use too big a hosepipe and you'll soon overfill the bucket. This is your aperture.
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Squeeze the hose and it takes longer to fill the bucket - this is your ND filter ;)
 
That water analogy is from Bryan Peterson isn't it? Or at least he has something very similar in his books. Certainly a good way of visualising it.
 
@Pookeyhead . David ,,having had a quick mooch through the link ,the part where he has taken a picture of a battery on a white background and then a black background to show how the meter can be fooled into giving a wrong exposure , i would have to disagree about one point ,,,,,,,,,


"You'll notice that the paper has been rendered exactly the same shade of grey as the previous pic, yet in reality, one was white, and the other black. Because of this, it's the battery that's been wrongly exposed, not the paper."

if you manage to get a black piece of paper to look grey then its wrongly exposed ,( along with the battery thats sitting on it )
 
I do understand the basics, but perhaps not fully explained what i was trying to do, which was trying to set up my wireless remote with the camera on bulb setting in a darkened room, and thinking in a senior moment i could dial in exposure values to compensate for the available light but that wasnt happening, and if i had thought it out further without posting my predicament i would eventually fathomed it out, thanks for all the replies., and i should have said n d filter in previous post.

Rob,thanks for the offer will take you up on it.
 
donut said:
@Pookeyhead . David ,,having had a quick mooch through the link ,the part where he has taken a picture of a battery on a white background and then a black background to show how the meter can be fooled into giving a wrong exposure , i would have to disagree about one point ,,,,,,,,,


"You'll notice that the paper has been rendered exactly the same shade of grey as the previous pic, yet in reality, one was white, and the other black. Because of this, it's the battery that's been wrongly exposed, not the paper."

if you manage to get a black piece of paper to look grey then its wrongly exposed ,( along with the battery thats sitting on it )
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The intention was to photograph the battery, not the background, so the battery is incorrectly exposed because the meter has been influenced by the large area occupied by the background. Just as in the shot with the window... the intention was to photograph the hand not the window.. so the meter has incorrectly exposed the hand due to being influenced by the majority bright background....

10/10 for trying though :)
 
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i realise the intention was to expose the battery ,but if the paper was exposed properly ,then the battery would have been as well .i also understand the point he was trying to make about fooling meters ,
 
donut said:
i realise the intention was to expose the battery...
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No no no no no!

The intention was to show what happens if you rely on the camera's meter to determine the exposure for you.
 
completely agree with what he's saying with regards to black ,, white ,,, grey cards all coming out grey ,,,,

why did the original article have a battery on the paper ?
the part i disagreed with was where he stated that

" it's the battery that's been wrongly exposed, not the paper."

i said that the paper was wrongly exposed ,and with it the battery ,( that just happened to be there )
 
StewartR said:
No no no no no!

The intention was to show what happens if you rely on the camera's meter to determine the exposure for you.
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i refer the right honourable gentleman to #22
 
jerry12953 said:
Erm.....so please explain the ISO setting.......:naughty:
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If the bucket is smaller it will fill up quicker as you do not need so much water. If the ISO is higher you do not need so much light. :)
 
BBR said:
Surely the ISO setting would be the size of the bucket?
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Yes.

Amount of light = water pressure.
Aperture = amount the tap is open.
Shutter speed = time the tap is open
ISO = bucket size.


Steve.
 
On behalf of difficult people everywhere, may I just remind you that there's only one bucket. :nono:

I think it refers to the correct exposure. Whatever that might be.

This is a good way of using all those "difficult" smileys. The "puke" one has to be the best, but I really can't imagine ever using it............
 
Lol. I think of this as buckets plural.
Each bucket is a pixel at iso100. The more sensitive iso is more shallow buckets but they are wider.
So high iso buckets, they fill up more quickly but are less accurate so more noise.
Not perfect but it helps me out chatting to people

Sent from my Nexus 7 using Talk Photography Forums mobile app
 
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