Thursday, June 23, 2011

HDR vs Topaz Adjust

There are times when it is impossible to shoot for HDR processing.  Maybe because only one image can be captured before the scene changes.  Or maybe some other technique is being employed, and it's not practical to repeat the technique multiple times at different exposures. 

Shooting panorama is one instance when I find it just too complex and time consuming to consider making exposures for HDR processing.  For panoramas, I take several partially overlapping exposures and then stitch them using a dedicated software for the purpose (such as PTGui). The outcome is usually flawless.  To bring out the details buried in the shadows, I'll then subject the stitched panorama to a dose of Topaz Adjust. 

Note: To enlarge any image in this posting, simply click on it.

Here's an example from a recent job photographing a kitchen:
Topaz Adjust 4 processed, Canon 5D, 17mm tilt shift lens, 3 images stitched, 0.8 sec., f/11
It's a stitched panorama shot.  The Topaz Adjust processing makes it look just like a moderately processed HDR image.

Below another picture of the same kitchen.  This is a real HDR image, processed from 6 exposures using Nik HDR Efex Pro.

Original image, processes for tonal optimization in Lightroom
Above is one of the original images from the sequence, tonally adjusted in Lightroom.  I selected this one because it had the best overall exposure.

Image above, after additional processing in Topaz Adjust 4

After passing the single image through Topaz Adjust, this is what resulted, above.  Notice the shadow tones are nicely expanded without blowing out the lighter areas.

Conclusion:  In some situations, Topaz Adjust offers a solution that rivals HDR processing, without the need for multiple exposures. 

However, one has to be realistic about what Topaz can do.  It won't create details that don't exist in the original.  Shadows that recede into blackness can't release more information than they possess.  That's why we use HDR processing.  We expose a frame for the darkest areas and intentionally blow out the highlights, knowing that it will give forth information that we will combine with other exposures that intentionally underexpose the shadowed areas.

Topaz Adjust is a power tool for extending the tonal range of an image.  But HDR processing is an absolute necessity when the shadows are so deep that no amount of Topaz magic will coax out any detail.

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