What does EV mean in regards to HDR?

[jdong217]

I know it stands for exposure value, but I shoot with a Nikon D3100 and am confused as to what exactly I should be changing from shot to shot. Is it shutter speed or the exposure compensation +/- that goes from -5.0 to +5.0?

I just took a few different pictures and ran them through CS5. It just arbitrarily chooses which one is 0 EV for me then assigns approximate values to the other images. Sometimes even varying the shutter speed by a few seconds for long exposure gives me multiple images with the same EV value. If I want exact intervals like, say, -4, -3, -2,...+4 etc, how do I control that? My camera doesn't have auto-exposure bracketing some I'm not sure how this process works

 

[tevo]

^^^^ Really? You're going to spam on a photography forum? Gtfo. Really.

 

[tevo]

When shooting HDR, EV denotes which photo has the heightened exposure, the lowered exposure, and the central exposure. For instance, if you have 3 shots (+2), EV would say that the -2 is the underexposed photo, 0 is the normal exposure, and +2 is the overexposed photo.

 

[jdong217]

Is there a way to directly set EV on the D3100? It doesn't have aeb. If not, is there some general rule relating shutter speed to EV? Because I generally just go in intervals of one shutter speed but sometimes that seems to have little effect. Basically, I'm not sure what the increments should be with shutter speed

 

[ann]

EV = stop

You can shoot in manual mode. with Hdr, you set the aperture and change the shutter speed. What those numbers will be are determined by the lighting conditions.

 

[radiorickm]

EV is just that. EXPOSURE VALUE.

It takes a certain amount of light to make a properly exposed photo. Lets call it "x" amount.

How do you get "x" amount of light into your camera? You adjust the three sides of your exposure triangle. When setting the camera manually, there are many camera settings that will produce the same exposure value.

To create the HDR, you create exposures based on the dynamic range of the photo. If, in the normally exposed photo, you can see midrange ok, but shadows are black and highlight are blown, then you make exposures to fill in those detail. The shadows need more light, so an EV of + 3 stops maybe, and the highlights need less light, so an EV of -3 (these are examples)

So HOW do you change the EV. Once again, there are many things that you could do, by adjusting the "legs" of your exposure triangle. You could change the aperature above and below your current setting; but most lenses probably don't have 7 full stops of range. Same thing for the shutter; in the end you would have to combine shutter change and aperature change to drop the necessary steps above and below your "correct" exposure amount of "x" amount of light.

The simplest way of doing that is using the exposure compensation function. Take your correct exposure, set it to -3 for the second, and then to +3 for the third.

Of course, you can purposely under expose and over expose the photos in manual mode on the camera too.

BTW
There actually is an EV scale, where shooting in bright sunlight = EV15. If I remember, the sun was EV20 and a Nuclear blast was EV22.