There’s an interesting new feature in Lightroom 4.1 Release Candidate 2 – the ability to adjust 32 bit HDR images in Lightroom.

I confess I’m not that big a fan of HDR and I don’t play with it often, but this picture is a good example of when I might use it. The component frames were taken last month in the Lake District near “our” village, Rosthwaite. These have been my favourite trees since I came across them early on a misty Christmas morning 5 years ago and on my recent visit, as you can see, there was a huge contrast range and the clouds were extraordinarily bright. It was an obvious HDR scene.

So I shot 5 frames at 1 stop intervals, beginning at – 3 1/3 stops. The camera is a Nikon D700 and I was shooting raw files. Back at the house, I did minimal preparation work in Lightroom – just dust spotting – and a couple of Library tasks:

  • set the colour label to green
  • stack them

I do these because there’s always a risk that during the culling phase of my workflow I’ll mistakenly decide that a frame is badly-exposed or badly-composed, so the green reminds me that it is intended to be part of an HDR or panorama.

But until today I didn’t do anything else with the pictures – I don’t want to have folk thinking I’m getting into HDR!

So, what’s the new Lightroom workflow?

  1. Select all the frames in Library
  2. Choose the menu command Edit In > Merge to HDR Pro in Photoshop.
  3. In Photoshop’s HDR Pro dialog, I then set it to 32 bit output
  4. I placed the white point on the very brightest part of the clouds, and clicked OK
  5. I didn’t do anything else in Photoshop except saving the file as a 32 bit TIF
  6. Back in Lightroom, the 32 bit TIF was catalogued automatically
  7. Adjust it in Develop.

As well as overall and local white balance, I changed some Basic panel values  and produced the final picture below.

It does make me wonder. I did so little to this picture in Photoshop other than run the HDR Pro dialog, so how far are we away from doing the HDR process entirely within Lightroom….


Another curious detail is that once the 32 bit HDR file is back in Lightroom, you can use Library > Convert Photo to DNG to change the TIF to a DNG 1.4 which supports 32 bit floating data. \

Why you would do this is less clear to me, because you would lose the flexibility to process it as a 32-bit image in Photoshop (DNG means it would be sent to Photoshop as 16 bit).

But for a long time I’ve done something similar with JPEGs from a point and shoot camera and from my iPad. Converting these files to DNG distinguishes the original photos from derivative JPEGs which I might have generated for email, web etc. So packaging these HDR-merged TIF files as DNGs would also mark them out as pseudo-originals, and would also permit Lightroom to update their embedded previews.