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jefflins Oct 24, 2002 10:00 PM

how does auto bracketing work?
I'm looking at the canon s30, g2 and olympus c730...all do exposure bracketing, which sounds nice...howdoes it work? Does the camera actually just take one picture, then save 3 copies to memory with the different exposure, or does it take 3 pix in succession (doubt this, but want to be sure). Thanks!

Wildman Oct 24, 2002 10:33 PM

My Powershot Pro90 (similar to the G1 with a big zoom lens) shoots three separate exposures. Can't say how others work.

ajitkataria Oct 24, 2002 11:51 PM

Bracketing is a technique used to take a series of images of the same scene at a variety of different exposures that "bracket" the metered exposure (or manual exposure). "Auto" simply means the camera will automatically take these exposures as a burst of 2, 3 or 5 frames with exposure settings of anything between 0.3 and 2.0 EV difference. This can be useful if you're not sure exactly how the shot will turn out or are worried that the scene has a difficult dynamic range. On a digital camera this can also be used to combine under and over exposed images together to produce an image with more dynamic range than the camera can normally capture.

When setting up for bracketing you can usually select the number of frames to be taken (typically 3 or 5), the exposure setting and the order in which to take the shots (eg. 0,-,+ or -,0,+ etc.).

jefflins Oct 25, 2002 2:04 PM

Thanks for the info!

So my question then is this: if your subject isn't perfectly still...or perhaps it blinks, then you would possibly get 3 very different pix...not just exposure wise, but composition wise?

What if a flash is required? Can the flash regenerate quickly enough?

How long between exposures? Is it like one burst of 3 shots over 2 secs, or is there a pause between each pic.


Wildman Oct 25, 2002 4:43 PM

The camera takes three separate pictures... it will wait for the flash to recharge (in my Pro90). If the subject moves, your picture will be of the second (and third) position. Bracketing works best for sunsets and landscape pix. Other cameras might cache the photo and apply the different exposure settings to that single picture, but the Pro90 does NOT.

ajitkataria Oct 26, 2002 1:49 AM

I feel that Auto Bracketing feature is more useful with still/stationary subjects in difficult lighting situations.

you must be clear on the point as to which flash is being used, the buil-in or the accessory flash? most of the modern accessory flashes would charge quickly and put themselves in the instant-ON mode, whereas the buil-in flash might take some time to charge and you might lose the shot.

I also feel that when used with flash most of the situations of difficult lighting are handled by the auto exposure and you might not require the bracketing at that point of time.

jefflins Oct 28, 2002 9:48 PM

Thanks for the info! Now if I could only decide on which cam to get...

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