Exposure Bracketing With Your Pentax SLR

A guide to how to use your Pentax SLR's exposure bracketing feature

23/12/2011 - 00:00

Your Pentax SLR may have a feature you've been ignoring to date... maybe because you didn't understand it or even know it was there. This guide explains where to find the feature and how you use it.


What is Exposure Bracketing?

Exposure bracketing is a mode on the camera that takes several photos around the automatic exposure above and below the suggested settings. It can be used when you're not sure what the best exposure is, or when you want to shoot a set of pictures to use in creating a high dynamic range (HDR) photo.

Pentax K20D scale for auto-bracketing

Where is the Exposure Bracketing mode?

Its location varies from camera to camera. On Pentax digital SLRs such as the Pentax K20D it's a button on the back left of the top plate that you depress while turning the front input dial to set on or off. On the K20D there's off, 3 or 5 frames. The back dial sets the bracket range, from 0.5 to 2 EV steps on the K20D. The settings you've made are displayed on the metering bar as three or five small markers above the scale. You can use bracketing with exposure compensation on the K20D and shift the markers left or right on the scale to under or over expose the bracket sequence.

Pentax K20D button for auto-bracketing

Using the exposure bracketing mode

Now you know what it is and where it is we're going to put the mode into practice. The first thing to do is set up the range you want. In our example we will chose a three frame bracket and 2 EV steps apart.

Bracket photo 0 Bracket photo -1 Bracket photo +1

The subject - a black ornament on a black background - is one that will fool the meter and a bracketed exposure can help.

The metered reading (above left) suggests 1.5sec at f/4 and a bracket gives two further readings of 0.7sec at f/4 (above middle) and 3sec at f/4 (above right). The middle shot is actually the fairest representation of the subject.

The same ornament on a brown background shows 1/6sec f/4 as the suggested exposure (below left) and a bracket of 1/8sec at f/4 (below middle) and 1/4sec at f/4 (below right. Here the over exposed shot to the right may be the preferred choice, although any one of these is usable.

Bracket photo 0 Bracket photo -1 Bracket photo +1

Next a look at shooting for HDR. This antique diver's helmet has a highly shiny copper surface with equally reflective brass window frame. A normal exposure would result in the highlights being washed out (bright with no detail). If you were to expose for the bright parts the rest would appear too dark. So three shots can be taken at different exposures and then blended using an HDR merging program such as Photomatix.

The first bracket was a two stop range from -2 to +2. This gave an unnecessary overexposed +2 stops shot (right), and the underexposed one (middle) still had some highlight detail missing, so exposure compensation was set to -1 shifting the bracket accordingly to give a -3, -1 and +1 exposure bracket which will be more useful for this HDR merge.
 
Bracket photo 0 Bracket photo -2 Bracket photo +2
     
Bracket photo -1 Bracket photo -3 Bracket photo +1

the merged hdr photo

With three exposures you can merge in a HDR program that automatically takes the best bits of each exposure in a blend that gives you a wider dynamic range photo.

Pentax SLR cameras with autobracketing

Film SLRs
Camera Model Auto-bracketed frames Maximum EV step increment Maximum fps
Pentax *ist 3 1 2.5
Pentax MZ-S 2, 3 or 5 1 2.5
Pentax MZ-3 3 1 2
Pentax Z-1 3 4 3
Pentax Z-1 P 3 4 4
Pentax MZ-6 3 1 2
Pentax MZ-60 3 1 1
       
Digital SLRs
Pentax *ist D 3 or 5   2.6
Pentax *ist DL 3 2 2.8
Pentax *ist DS2 3 2 2.8
Pentax K5 2, 3 or 5 2 7
Pentax K7 3 or 5 2 5.2
Pentax K10D 3 or 5 2 3
Pentax K20D 3 or 5 2 3
Pentax K100D 3 2 2.8
Pentax K200D 3 2 2.8
Pentax K-m / K2000 3 1.5 3.5
Pentax K-r  3 1.5 6
Pentax K-x 3 1.5 4.7

Please feel free to add cameras that we missed to this list by posting a comment below with the details and we'll amend the article.


Related Photos

john111

Link Posted 11/08/2018 - 06:35
You can ask anything related what are the primary verifications and some more formalities which is needed in this whole process online payday loans no credit check and after complete it it will always give the direct benefits. So for more and instant service you have to apply online which is most easiest idea for it.

zexin

Link Posted 24/09/2018 - 14:50
After open the article I got a picture that was amazing it has lenses on it that was amazing to watch it was about DSLR camera. I want to buy this this was available online only so I contact with custom essay writing so they can give me suggestion is this site trustable or not.
Add a Comment
You must be registered or logged-in to comment.