Blend exposures using 32-bit files

Peter Fenech

Create a low-noise, high quality HDR image in RAW software using this lesser-known technique

Today’s dSLRs have ever increasing dynamic ranges – the ability to capture detail in highlights and shadows. However their sensors cannot match the human eye for detail and colour retention at the exposure extremes. HDR software offers a solution, but at the cost of noise. Other options are manual layer merging, using masks, or the highly sophisticated luminosity mask technique. Here we discuss a lesser-known blending technique, which makes use of Photoshop’s Merge to HDR feature, 32-bit Tiff files and Adobe Camera Raw.

Tool kit

1. Bracketing mode

2. Adobe Camera Raw or Lightroom

3. Photoshop Cs5 or later

Synchronise RAW edits

Blend exposures using 32-bit files












Perform lens corrections and basic edits in Camera Raw, clicking Synchronise so each file in your bracketed series is identically processed. This can be done later, but it is best to maintain a non-destructive approach where possible. Leave most sliders set to zero for now.

Create your ‘super-tiff’ file

Blend exposures using 32-bit files












Open your files in Photoshop, go File > Automate > Merge to HDR Pro and Add Open Files. In the HDR Pro window, select 32 Bit as the Mode and check Remove ghosts if images were shot handheld. Leave all other settings at their defaults

Perform tonal adjustments

Blend exposures using 32-bit files












Click OK and save your merged file. Re-open this Tiff in Camera Raw or Lightroom and use the Shadows and Highlights sliders to increase the dynamic range of your photo. Since more image data is present in the file, processing can be pushed further with less degradation.  

Blend exposures using 32-bit files
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