Slow shutter speeds - water

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This morning I went to dovedale and tried to shoot slow shutter speeds on water to get that misty effect

Only problem was I couldn't get my camera to take anything that wasn't massively overexposed unless it was 1second shutter speed or quicker.

Anything else no matter what speed or aperture (between f5.6 and f45!) and no matter how low the ISO, exposure was off the scale sat at plus 2 and just giving a blank white shot.

Please help?
 
Yes, it will be over-exposed!

The long shutter speeds you need for this effect must be compensated by a large reduction in brightness to maintain correct exposure. That is often way beyond the scope of normal camera controls so you need a neutral density filter (like dark glasses) to cut it down.

Most people go for a ten-stops ND filter, that looks almost black to the naked eye, but it will allow you to use much longer shutter speeds. There are lots of threads on using these very dark ND filters if you search.
 
For any given situation where you need to use a long exposure, the way to find the longest you can go before introducing filters is to set the ISO to it's lowest setting and to put the aperture of the lens at it's smallest setting. If the resulting shutter speed is still too fast to give you the result you are looking for, then you will need to introduce a filter to allow you to go slower without over exposing.
 
Scarecrow said:
For any given situation where you need to use a long exposure, the way to find the longest you can go before introducing filters is to set the ISO to it's lowest setting and to put the aperture of the lens at it's smallest setting. If the resulting shutter speed is still too fast to give you the result you are looking for, then you will need to introduce a filter to allow you to go slower without over exposing.
Click to expand...

True, but setting the highest f/number guarantees poor sharpness due to diffraction.

On a crop format camera, anything higher than f/11 will begin to impact noticeably, f/16 is getting poor. F/22 gets really bad and sharpness at f/45 (as the OP says) will be truly horrific.
 
Ah what a school boy error!

Doesn't a 10 stop filter completely flatten the water though?

Better get some filters ordered!
 
DTS said:
Ah what a school boy error!

Doesn't a 10 stop filter completely flatten the water though?

Better get some filters ordered!
Click to expand...

It's the shutter speed that flattens the water, or freezes it, and the filter is just a means to an end.

Personally I think tens stops is often too dark (it will reduce say 1/250sec normal exposure down to 4secs) but that's what most people use. On the other hand, once the blurring has got to a certain point, a bit more time makes very little difference.

A ten-stops and six-stops ND is probably the perfect combo, or eight-ish stops like the Hoya X400 or LightCraftWorkshop ND500 (ignore the numbers, they're rarely accurate with these things, and can vary batch to batch).

But the important thing is to use a filter that gets you in the zone. You can then use aperture and ISO to moderate the shutter speed.

Edit: beware a vari-ND filters. They're rubbish if you like to use wide-angles.
 
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Is this hi-tech's 10 stop filter?

Each filter seems to go up in .3 steps - 0.3 being nd2 or x2 etc only this one goes from 0.9 being x8 to the above saying x16

Cheers
 
A 10 stop is really handy, a polariser will give you 2/3 stops too. With the 10 stop, depending on how much noise your sensor generates, you can up the ISO to allow you to alter the shutter speed and therefore get exactly the "look" you want, from slight blur to full "mist"

Simon
 
DTS said:
Is this hi-tech's 10 stop filter?

Each filter seems to go up in .3 steps - 0.3 being nd2 or x2 etc only this one goes from 0.9 being x8 to the above saying x16

Cheers
Click to expand...

No, it says four stops ;)

Density is expressed in various ways: 0.3, 0.6, 0.3 etc is 1, 2 and 3 stops, or x2, x4, x8. Ten stops is 3.0 or x1024.

You also need a square filter holder for Hitech, and also for Lee. If you don't want to spend much, get a Haida 3.0 from CameraGearUK on ebay. There's a long thread on that one on here somewhere.
 
Or do it late in the day when there is barely enough light.
 
Ah gotcha - although I've got the 10mm holder for my polarizer :D
 
To be fair I just nipped up while the Mrs was at work and my little boy was at grandads!
 
You can also achieve the effect by combining several exposures.
 
HoppyUK said:
True, but setting the highest f/number guarantees poor sharpness due to diffraction.

On a crop format camera, anything higher than f/11 will begin to impact noticeably, f/16 is getting poor. F/22 gets really bad and sharpness at f/45 (as the OP says) will be truly horrific.
Click to expand...

Possibly. It depends on what the emphasis within the image is as to whether this would be a problem. If the majority of the emphasis is on the moving water, which is going to be blurred anyway, any loss of sharpness due to diffraction isn't going to matter.
 
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