HDR Tip #9 – In HDR Photography Do The HDR Processing First

HDR Tip #9 – In HDR Photography Do The HDR Processing First

The term Workflow can have different meanings depending on the photographer. Photographers have their own tried and true techniques to realize their desired results. Generally though, most professionals believe an optimal workflow must focus on the big things first and then move on to the details.

There is no sense in starting off correcting minor blemishes when the cropping, exposure or color balance is off because you won't know what the actual blemish will look like until the bigger items have been corrected. You could even end up spending hours correcting an imperfection like removing branches or wires from a scene only to later decide that you would have been better off just cropping them out in the first place.

Processing images for HDR adds a whole new tool set as well as new technical reasons to rethink your workflow. In regular single image low dynamic range photography you may typically take an image in to Lightroom or similar program, apply lens corrections, rotate & crop, adjust white balance, exposure, and clarity and then maybe some selective saturation enhancement, this is not the workflow you want for HDR images.

While it may seem counter intuitive HDR Is the biggest step in the workflow and should always come first. For HDR images you will be merging multiple individual files with varying exposure settings. Ideally you will want to merge the RAW files which have as few differences between images as possible, other than exposure. The resulting merged image should look as flat and boring as possible so that you can adjust the contrast in the tone mapping process to taste. Just like making a soup, you can always add salt, but if you go too far it is hard to take it back out, the same goes for contrast.

The other thing is that many of the adjustments you may want to make to images in Lightroom may have different effects at different exposure levels, so the amount of change you apply will vary for each of your exposure frames. If you do make changes prior to the HDR Process you will send TIFF files to be merged and not the original RAW files which, can clip the highlights or shadow ends of the histogram and not allow you to pull back precious detail in those areas.

When using applications like HDR Expose 2, HDR Express or 32Float v2 you also have the added benefit of being able to do most of your corrections on the full 32-bit color image data, in our Beyond RGB color space. This means that you have significantly finer granularity to make adjustments without running the risk of inducing color shifts or posterization.

Here is an example:

This is a straight JPEG rendition from the original RAW file my 0EV exposure.

Here are the over and under exposed frames.

Now when I look at these images I can see some changes I want to make to them. I will want to crop and rotate the image to level the horizon. I want to bring out detail in the foreground with local contrast or "clarity". I may also want to add a little selective saturation or warm up the white balance. So what is the best workflow or series of steps to get to my desired result?

When I made these changes on an individual image in Lightroom first, then sync those changes to the other two frames and then exported to the HDR Expose 2 Lightroom Plug-in with the Lightroom changes, this is my result:

It's not bad, but there is too much contrast in the foreground from the clarity step in LR and I've lost most of the detail in the clouds that I wanted to preserve thanks to the RAW to TIFF conversion prior to the HDR Merge.

Here is the same image merged from the original RAW images in HDR Expose 2:

The result is more natural looking and most importantly, I was able to retain the cloud detail that attracted me to the scene in the first place. Here I took the image in to HDR Expose 2 and was able to make the exposure and highlight and shadow adjustments along with the local contrast and selective saturation corrections all on my full 32-bit color image. So all my color and tonal processing was done on the maximum amount of data my files had to offer.

In the end I saved it as a TIFF file and returned to Lightroom to do the crop and rotate steps. When I saw the final result, I decided I didn't like the warmer white balance I'd committed to in the previous example, so I just skipped that change. It is much easier to make those subjective decisions when you can view the full HDR image at the end of the workflow rather than the individual exposure frames at the beginning.

The key to a good workflow is cracking the biggest nut first and slowly working your way down to the smaller ones. In the case of HDR processing the HDR step is the largest nut to crack and should always come first.