what does it means to be 1 stop underexposed or 2 stops over exposed?

what does it means to be 1 stop underexposed or 2 stops over exposed? I've heard this several times but im not sure what it means. I was thinking it had to do with the exposure dial but im not sure..

If you are 1 stop underexposed, then you need to increase the amount of light that hits your sensor by 1 stop or twice the amount of light. That can be controlled by aperture, shutter speed or ISO settings.

Do you mean deliberately over and underexposing, if so there should be a function on your DSLR, for example if you are out and its a snowy day, lots of white stuff, you might dial in a 1 stop or even maybe a 2 stop over exposure to compensate for all that white, conversly if its dark you would under expose to compensate, you sometimes need to do this as your camera can be fooled by very bright or very dark scenes.

A "stop" is a doubling or halving of the amount of light or exposure. It's the unit of measurement photographers and cameras use when measuring light and exposure.

Your meter display in the viewfinder is probably graduated in either 1/2 or 1/3 stops.

The exposure settings (aperture, shutter, and ISO) are also usually graduated in the same 1/2 or 1/3 stops.

Aperture in 1 stop increments: f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/64, and so on...

Shutter in 1 stop increments: 1 sec, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, and so on...

ISO in 1 stop increments: 25, 50, 100, 200, 400, 800, 1600, 3200, 6400, 12800, 25600, and so on...

Henry Peach wrote: A "stop" is a doubling or halving of the amount of light or exposure. It's the unit of measurement photographers and cameras use when measuring light and exposure.

Your meter display in the viewfinder is probably graduated in either 1/2 or 1/3 stops.

The exposure settings (aperture, shutter, and ISO) are also usually graduated in the same 1/2 or 1/3 stops.

Aperture in 1 stop increments: f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/64, and so on...

Shutter in 1 stop increments: 1 sec, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, and so on...

ISO in 1 stop increments: 25, 50, 100, 200, 400, 800, 1600, 3200, 6400, 12800, 25600, and so on...

Absolutely

photobod wrote: Do you mean deliberately over and underexposing, if so there should be a function on your DSLR, for example if you are out and its a snowy day, lots of white stuff, you might dial in a 1 stop or even maybe a 2 stop over exposure to compensate for all that white, conversly if its dark you would under expose to compensate, you sometimes need to do this as your camera can be fooled by very bright or very dark scenes.

Yes I meant deliberately. Thanks. Now I also know how to make snow white. lol

Henry Peach wrote: A "stop" is a doubling or halving of the amount of light or exposure. It's the unit of measurement photographers and cameras use when measuring light and exposure.

Your meter display in the viewfinder is probably graduated in either 1/2 or 1/3 stops.

The exposure settings (aperture, shutter, and ISO) are also usually graduated in the same 1/2 or 1/3 stops.

Aperture in 1 stop increments: f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/64, and so on...

Shutter in 1 stop increments: 1 sec, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, and so on...

ISO in 1 stop increments: 25, 50, 100, 200, 400, 800, 1600, 3200, 6400, 12800, 25600, and so on...

Thank you.

Luis 1956 wrote:

photobod wrote: Do you mean deliberately over and underexposing, if so there should be a function on your DSLR, for example if you are out and its a snowy day, lots of white stuff, you might dial in a 1 stop or even maybe a 2 stop over exposure to compensate for all that white, conversly if its dark you would under expose to compensate, you sometimes need to do this as your camera can be fooled by very bright or very dark scenes.

Yes I meant deliberately. Thanks. Now I also know how to make snow white. lol

twas my pleasure

Great thread...

I was just searching on Google for "what does it mean to underexpose by one stop" and turns out the answer is on this site!  Cool stuff, I just signed up here last week.  

The histogram — the best friend you'll ever have — is the one
that helps you best with that: if you DR is properly recorded,
what ever the light meter says, your file will be ok.

You're going to need to understand the exposure triangle, stops and exposure. It's kinda hard to explain the technical parts without that.

However: underexposed means "didn't capture enough light". Overexposed, therefore and conversely, means "captured too much light."  How much of each is where the technical stuff comes into play, because we can measure how much light is needed (that's the job of the light meter) for a "proper" exposure. Changes to parameters (aperture, shutter speed, sensitivity) affect the "correctness" of the exposure.