What’s Your Preference?

paktire · #1 (**permalink**) 09-10-2010, 09:13 AM

HI ALL,

what is the real benefit of using bracketing while using RAW format?

Isn't it that if we shoot in RAW we can simply make +/- exposure adjustments?

imran

JeffSmith · #2 (**permalink**) 09-10-2010, 11:01 AM

RAW images are not a catch-all for exposure errors, otherwise why bother with setting your exposure in the first place?

If your RAW image has an area burned out, bleached or just too dark, there's no way you can recover data from those areas. As the old saying goes, "you can't make a silk purse out of a sow's ear" or the one I prefer..."You can't polish a turd"

Skies are often subject to bleaching. You can use a GND filter, but if you have the time, bracketing RAW gives you far more control onver your final image in post processing because you can stack the images to get the results you want.

Bracketing allows you to capture data at all levels of the shot (provided you have the right exposure) and therefore allows you to obtain a greater tonal range in your final image.

Remember, you camera is not as clever as your eyes and brain at determining tonal range, it's something you have to create when faced with challenging lighting conditions

nickbedford · #3 (**permalink**) 09-10-2010, 03:18 PM

A bright daylight environment may contain a dynamic range of anywhere between 10 and 20 stops of light intensity (a stop being a doubling in light). The human eye is capable of around 18 stops of dynamic range.

Because of this dynamic range (the variance in light intensity our eyes and brain can distinguish), it allows us to see a huge range of intensities, from the bright sky to shadowed areas all at the same time.

Unfortunately most DSLR cameras can only manage around 6-9 stops of dynamic range. So bracketing is a method to "move the range bracket" up and down the intensity scale in a scene to capture each segment of light intensity then piece them all together.

If your camera maps 6 stops of intensity normally into a 0.0-1.0 reading, then HDR / bracketing is a way of compressing all 15-20 stops (from multiple exposures) into the same area, bringing out a vivid amount of detail not unlike what we see.