Bracketing with stops???

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leeharrison2

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Lee Harrison
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I have been reading a book that it basically a photography course in a book to get you taking different picture and it's actually quite good, it talks a lot about bracketing(under and over exposing it to see what effect it has on you photos) but it always say drop by 2-3 stops and raise by 2-3 stops...

Stops, is this the aperture, shutter speed or just light in general reading off you metre, I took a still life picture and had my camera on f/11, 1/125... how would I change this to drop it my 2 stops???

Thank Lee
 
A Stop is changed / adjusted by any one, or combination, of the Shutter Speed (SS), Aperture (A), or ISO.

So, in the example you've given f/11, SS 1/125 ... a 2 stop decrease could be done by: -

- moving Aperture from f/11 to f/22 (f/11 => f/16 is one stop; f/16 => f/22 is another one stop)

- moving the Shutter Speed from 1/125 to 1/500 (1/125 => 1/250 is one stop; 1/250 => 1/500 is another one stop)

- moving both Aperture AND Shutter Speed; here you'd do one stop on the Aperture and another one stop on the Shutter Speed. Hence, f/11 => f/16 and Shutter Speed 1/125 => 1/250 {of course you could do this combination is other fractions; e.g. 1 1/2 stop Aperture + 1/2 stop in Shutter Speed}

All these presume you're keeping your ISO constant throughout.
 
is a stop a set number, like it f/11 -> f/16 1 stop on every camera, or does it vary, because my D40 goes f/11 -> f/13 -> f/14 -> f/16 -> f/18 -> f/20 -> f/22.

Thanks Lee
 
leeharrison2 said:
is a stop a set number, like it f/11 -> f/16 1 stop on every camera, or does it vary, because my D40 goes f/11 -> f/13 -> f/14 -> f/16 -> f/18 -> f/20 -> f/22.

Thanks Lee
Click to expand...

Those are 1/3rd stops. A full stop is the halving or doubling of either Aperture (3 clicks per stop as your camera is currently set up), Shutter Speed or ISO.

To change down a full stop from f13 would mean you changing to f18.
 
Last edited:
EdBray said:
Those are 1/3rd stops. A full stop is the halving or doubling of either Aperture (3 clicks per stop as your camera is currently set up), Shutter Speed or ISO.

To change down a full stop from f13 would mean you changing to f18.
Click to expand...

I agree with the fact that one stop difference is either a halving or doubling of the amount of light that reaches the film/sensor, but think that it needs to be pointed out that if you halve or double the aperture number (f11 to f22 for example) that is actually two stops difference.

Not trying to confuse the issue, honest :)
 
leeharrison2 said:
I have been reading a book that it basically a photography course in a book to get you taking different picture and it's actually quite good, it talks a lot about bracketing(under and over exposing it to see what effect it has on you photos) but it always say drop by 2-3 stops and raise by 2-3 stops...

Stops, is this the aperture, shutter speed or just light in general reading off you metre, I took a still life picture and had my camera on f/11, 1/125... how would I change this to drop it my 2 stops???

Thank Lee
Click to expand...

For bracketing shots it's the shutter speed that should be changed as this gives the same image at different exposures. Adjusting the aperture will also change the focus (depth of field) in the shot giving a different image between shots.
Be carefull of the shutter speed of the overexposed image, If shooting at 1/100th sec. two/three stops longer may need a tripod.
HTH :)
 
Wail said:
A Stop is changed / adjusted by any one, or combination, of the Shutter Speed (SS), Aperture (A), or ISO.

So, in the example you've given f/11, SS 1/125 ... a 2 stop decrease could be done by: -

- moving Aperture from f/11 to f/22 (f/11 => f/16 is one stop; f/16 => f/22 is another one stop)

- moving the Shutter Speed from 1/125 to 1/500 (1/125 => 1/250 is one stop; 1/250 => 1/500 is another one stop)

- moving both Aperture AND Shutter Speed; here you'd do one stop on the Aperture and another one stop on the Shutter Speed. Hence, f/11 => f/16 and Shutter Speed 1/125 => 1/250 {of course you could do this combination is other fractions; e.g. 1 1/2 stop Aperture + 1/2 stop in Shutter Speed}

All these presume you're keeping your ISO constant throughout.
Click to expand...

Thats a nice simple explanation - thanks :thumbs:
 
Anorak mode on. :thinking:
Our phrase "Stop", comes about because the first lenses had continuously variable apertures. It was only later, (Around 1873 rings a bell but could be wrong there), that click "Stops" where built into lenses. As has been said, each stop halves or doubles the light let through. Cant be arsed to get my Ilford manual down but the numbers are something to do with the square route of "Pie" and which way the wind is blowing.
Anorak mode off. :thumbs:
 
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