Questions about bracketing

Photography knowledge exchange.

Moderator: Scott Waters

Post Reply
User avatar
R.Lynch
Posts: 33
Joined: June 8th, 2010, 7:43 am
Contact:

Questions about bracketing

Post by R.Lynch » July 11th, 2010, 5:32 pm

I was wondering if someone with a bit more detailed knowledge of photography could help me (and maybe others) out by explaining bracketing. Is this something that is done commonly by professional photographers or is it something that helps but you can get by without? Also is bracketing done manually or is it a setting that can be set? Any general comments/ explanations would be much appreciated.
Cheers,

bgorum
Posts: 617
Joined: June 7th, 2010, 5:46 am
Location: Albuquerque, NM
Contact:

Re: Questions about bracketing

Post by bgorum » July 12th, 2010, 5:44 am

Back in the days of film I think bracketing was something that many photographers did almost religiously. It made sense to do so since you could not see the results of a shot until the slides came back from the lab and by then it was too late to change the exposure if it was wrong. It was quite common to shoot one shot at whatever you thought the correct exposure was and then shoot a couple of shots at greater and less exposure on either side of that for insurance. I always bracketed in 1/2 stops and the later film cameras I used would do the bracketed series for me automatically if I set them to. Now with digital I never bracket anymore, per se and see little need to. Instead I'll check the histogram after taking a shot and if it looks all bunched up to one side I'll shoot a second shot where I increase or decrease exposure as appropriate to get the histogram nicely centered (assuming a mid toned subject of course) and avoid clipping any highlights or shadows. (It's important to know how to interpret the histogram. For example if I am at White Sands and I photograph a bleached earless lizard on the gypsum dunes I would expect my histogram to be mostly to the left side, but I don't want to see it piled up against the left edge, which would indicate I'm blowing my highlights. In the same way if I photograph a melanistic diamondback on a dark basalt flow I would expect the histogram to be mostly on the right, but not piled up against the right edge, which would mean I will have blocked up detailess shadows). After the second shot I'll then check the histogram again. I almost never need to shoot a third exposure, though sometimes I'll over compensate in the second shot and need to shoot a third that splits the difference between the first and second shots. I think most digital SLRs still have an auto bracketing feature, but I couldn't even tell you how or where to set it on mine!

User avatar
R.Lynch
Posts: 33
Joined: June 8th, 2010, 7:43 am
Contact:

Re: Questions about bracketing

Post by R.Lynch » July 12th, 2010, 7:23 am

Great explanation! Thanks so much bgorum!
I had a feeling that bracketing was something done more commonly by film users, but wasn't really sure why DSLR's continued to offer the setting. I guess when I'm slightly altering my exposure by hand I'm essentially doing what the bracketing setting would do, just with DSLR's I don't have to worry about eating up film.
I think I'll be paying a little closer attention to the histogram I get now too. I always took a glance at it after taking a shot, but I never really paid too much attention to how stacked it was to either side - I just tried to keep it center most of the time.
Thanks for the help!
Ryan

User avatar
Lizardman1988
Posts: 235
Joined: June 7th, 2010, 5:38 am
Location: Hays, KS
Contact:

Re: Questions about bracketing

Post by Lizardman1988 » July 12th, 2010, 4:55 pm

There's another reason for bracketing to remain on DSLRs that is becoming ever more popular (by the day, it seems), and this would be HDR (High Dynamic Range) photography. In essence, HDR gives you the ability to produce images that have detail in both the lightest and darkest parts of the photo by combining multiple photographs taken at different exposures, which is why auto bracketing comes in handy. Look it up if you haven't already, there are some neat HDR images, although they are not for everyone.

milmoejoe
Posts: 27
Joined: June 9th, 2010, 4:01 am
Location: DC Area
Contact:

Re: Questions about bracketing

Post by milmoejoe » July 13th, 2010, 7:20 am

Simple answer - yes, bracketing can be a critical tool and easy to do. In Aperture Priority mode, simply turn the exposure wheel left or right to compensate.

User avatar
R.Lynch
Posts: 33
Joined: June 8th, 2010, 7:43 am
Contact:

Re: Questions about bracketing

Post by R.Lynch » July 14th, 2010, 1:23 pm

Thanks guys!

Now on a related question to what Lizardman brought up, is HDR something that can only be done on the computer using software and the RAW files? Or are HDR images produced using the auto bracketing function on the camera?

milmoejoe
Posts: 27
Joined: June 9th, 2010, 4:01 am
Location: DC Area
Contact:

Re: Questions about bracketing

Post by milmoejoe » July 16th, 2010, 3:19 am

Most times HDR is done by taking the bracketed exposures in camera and merging the HDR on computer. The "Photomatix" program is a popular choice for HDR merges.

Some new cameras have an "in camera" HDR feature, I haven't used one, but have heard it's still mostly a gimmick feature.

User avatar
brick911
Posts: 3488
Joined: June 7th, 2010, 8:52 am
Location: Morrisville, PA

Re: Questions about bracketing

Post by brick911 » July 19th, 2010, 9:20 am

Is there any reason HDR can't be achieved, using RAW files? I've never shot in RAW, so excuse my ignorance.

User avatar
chrish
Posts: 3298
Joined: June 7th, 2010, 10:14 pm
Location: San Antonio, TX
Contact:

Re: Questions about bracketing

Post by chrish » July 24th, 2010, 8:59 am

Absolutely you can do some HDR using a single raw file. Most raw files will give you at least 1 stop on either side of the exposure of recoverable data so you can create an adjusment that is +1 stop and an adjustment that is -1 stop and use those to get your dynamic range details.

The trick is to "expose to the right" (i.e. overexpose) in the initial photo. There is more recoverable data in a slightly overexposed area than a slightly underexposed area. Therefore if you darken an overexposed area 2 stops, you can generally recover good detail. However if you lighten an underexposed area 2 stops, you are more likely to get noise in the detail.

Post Reply