Can someone explain to me or point me to a web page that explains the correlation between exposure value (ev) and f-stops? My digital camera's manual is less than erudite on this matter. I have been using the auto bracket function to expose the same scene - usually high contrast - at different ev values and then blending them to obtain an increase in dynamic range, but so far it's been guesswork as to how much to set the compensation value to. If I was using my trusty old Nikon FM I could just set different f-stop values and know what I was doing. Help - anyone? Stefan

There's no correlation as such, ev is relative to the cameras metered exposure, whereas f-stops are absolute values. Setting ev +1 is one stop more exposure - equivalent to going to a one stop wider f-stop or going for one stop slower shutter. ev -1 is one stop less exposure and so on. Depending on which digital camera you have, you may be able to change from auto/program mode where the camera is deciding shutter/aperture for you to an aperture priority mode (av) where you can set the f-stop yourself. -- Mark

Ah ha! At least now I can make an informed decision when I shoot those pesky high contrast scenes. Thanks Mark.

It takes more than just setting a switch to +/-1 ;) Actually it's only meant to give you the ability to bracket your shots (which means creating a series of increased and decreased exposure, so you get at least one shot with the perfect exposure). But you can set it in smaller steps than +/-1 I assume ? +1 is a pretty big step. But anyway, if you are looking for high contrast photos, you shouldn't be doing it with that setting. The idea is to have your camera meter only your subject and not make an average reading for the whole photo - afterall high contrast is the same as underexposure ;) With the standard/matrix (or whatever it's called) setting, the camera will try to get everything correctly exposed. But that's not possible, it's just one of those 'brand X washes your white clothes even whiter!" kind of things :) By calculating the overall best setting, it will have to make an average between so many things (dark shadows, mid tones, sunlit areas, sunlit reflective areas, etc) that nothing eventually is done right. It'll make your pictures overall dull and grey-ish. So by being able to set it to center/spot metering, the camera only picks the center of the picture (like a face/person) and it will not care about the rest. Now if your subject is brightly lit and the background is less well lit, the brightly lit subject will be correctly exposed and appear normal, and thus the background will be.....yes.....darker, because the camera uses what it metered from the subject. (just imagine shooting someone's face lit by sunlight indoors). That's what gives you the foundation for a high contrast picture. You can also take this outdoors, but you need some assistance (I'm always alone, so I haven't been able to do this much). Fashion photographers use very bright lights to simulate extra sunlight (the color/tone of the light is very natural) or use a gold or silver reflector to reflect the sunlight onto the subject. (works less good, but is cheaper, easy to carry along and doesn't require power). As long as the background of the shot is far away (so that it doesn't get lit by the lights), the camera will make the subject look normally lit and the background darker, with more contrast. One of my heros is Mario Testino, who almost always uses this technique in his photos. It's really, really easy, but the equipment is expensive and together with the powersource, cables, etc, you'd need a few extra people to help you out :D But believe me, like this even the biggest idiot can make fantastic high contast photos! ;) Perhaps I should write a little guide about that for r'osity....

Rork - After seeing his shots of Naomi Campbell, Testino is all right with me. :) Did I get any drool on you? -=>Donald

Don't worry, the floor is already soaked from my drooling ;)

Rork, after many years of shooting landscapes and dealing with various lighting conditions, I'm very familiar with setting exposures for particular parts of a scene etc. That's not my issue. I was just trying to figure out what the exposure value meant in terms of digital equipment, as it didn't seem to correlate to anything in particular. I can set the auto bracket function in increments ranging from -0.3 to +2.0, so there's a wide latitude there. At least now I can make a more informed judgement of how much to set the bracketing function to, after I've taken some exposure readings. You may have misunderstood my post. I am not looking for high contrast photos, but trying to pack as much detail as possible into what can be high contrast scenes at times. I've been doing digital photography only since the beginning of the year and am still working out the finer points of processing the images to get better and better results. It sure is a lot of fun though.

(I'm still interested in that high contrast feature article, Bart...) ;-) (*