Pixiq

Getting great HDR or HDRI photographs may seem like a lot of hassle.  Breaking it down into 4 simple steps, however, may be the ticket to getting you to try the many great multi-shot techniques.

Although each multi-shot technique consists of specific work-flows, there are many similarities between the various techniques.  The typical work-flow for most multi-shot techniques consists of these four steps:

• Shooting the image sequence
• Image preprocessing
• Merging the photos together
• Post-processing (optimizing) the merged image

1. Shooting the Image Sequence

The first step in capturing almost any multi-shot photograph involves using a tripod.  Assume that all multi-shot techniques will benefit from the use of a tripod – even if it is possible to shoot Super-Resolution or HDR images without one.

It should also be noted that using a preset white balance setting is recommended although less important if you are shooting in RAW.  RAW does allow you to adjust the whit balance later when converting your images to other formats without sacrificing image quality.

You will want to ensure that the focal distance is constant within an image sequence except in the instance of Focus Stacking of course.  The proper way to ensure that this is done properly is to focus manually.  You’ll also want to retain a constant ISO as well.  Don’t use the Auto-ISO setting if you’re camera has that ability.

Manual exposure settings are quickly become ideal in ensuring you get the best possible results for your multi-shot photographs.  Exceptions are always around the corner and HDR photographers can easily use auto-bracketing in Av mode to get great results.

When taking shots that require abnormally slow shutter speeds it becomes necessary to use a tripod in conjunction with mirror lockup.

2. Image Preprocessing

The organizational and tactical methods presented below will save you hours later.  It’s the difference between an easier workflow and a frustrating afternoon.

First, download and rename your images to your hard drive.  You really don’t want to just use what the camera gives you because most cameras reset the numbering sequence after 9999 has been reached.  It’s certainly possible you’ll end up with naming issues in folders and such as that number rolls over.   Most image processing programs and photo management programs have renaming functionality built in to the download process.  Use it to rename your photos to something meaningful and consistent.  I actually just use the shooting date but you can also add a key word like the event or holiday or whatever you suits you.

Your next step here will be to visually inspect your images.  Many people like to tag unusable images before re-examining and deleting them.  I do recommend this method although I have been know to just delete really unusable images upon first inspection.  How you tag your images will vary depending on which image editing software your using and personal preference.

After your initial inspection you should add IPTC metadata to your photo files.  This will help you later locate specific images or groups of images according you your own user-defined criteria.  This is called key-wording and the more of it you do the better off you’ll be.

Next, you’ll want to group all of the images from the sequence together.  This can be done easily in Adobe Bridge and Lightroom as well as Apple’s Aperture and many more photo management programs.  They will allow you to arrange the image groups in virtual stacks.  It’s a good idea to put your best shot at the top of the stack.  For panoramic or focus stacking shots you will often find yourself working with a variable amount of images and a photograph of your hand can help to separate one sequence from another.

The last step in preprocessing is actually processing your images.  How you go about preparing your photographs depends largely on which format your camera uses to save images and which formats your application supports.  You may be able to use RAW directly and won’t have much initial processing to do.  This is ideal, but some applications do call for TIFF files or JPEGs so you may have to convert first.  To do this, convert all images in the batch using the same basic settings with white balance, aberrations correction, and vignetting being the most important to keep consistent.  If you need to fix the slanted horizon now is the time.  Just make sure that this is done consistently by keeping your pixels the same size.  Keep in mind that for most mutli-shot techniques it is desirable to straighten and crop images after they have been merged.

3. Merging Your Images into One

This step varies greatly depending on which multi-shot technique you are working with.  Here is a quick rundown of applications for the various techniques.  Each comes with detailed and varied processes and nuances that we’ll get into in future articles.

Photoshop has a “Merge to HDR” command built in and PhotoAcute, FDRTools, and Phtomatix all work well with HDR or HDRI photographs.  Helicon Focus and CombineZM work for focus stacking and the DOP Detail Extractor is for improving local contrast.

This is not all of the programs available but is a good place to start.

4. Optimizing Your Merged Image

Merged images need to be further optimized after the merge has taken place.  Often the image needs to be cropped which is done by hand in focus stacking and in panoramas.  It is usually a good idea to shoot your initial images for a larger area than you wish to appear in your final image to compensate for potential shifts and distortions.  Also, most optimization scenarios will require a local contrast improvement and/or final sharpening.  Lens distortion can be corrected before or after merging.

Now you’re ready to show off all of your hard work.  Have any multi-shot photographs you’d like to share?  Use the comments section below.