I'm trying to use the new feature of lightroom 4.1 that allows us to edit 32bits floating point tif directly within Lightroom. The workflow seems easy enough when you have Photoshop but I do not.

I tried creating a 32bits floating point image using Luminance HDR but to no success Lightroom 4.1 does not recognize the file: "Preview not available for this file".

Is there any OpenSource software that can generate a 32bits tif file that would be compatible with Lightroom 4.1?

(Btw, I went into Luminance preferences and changed output type to 32bits floating point, it's also possible that Luminance works but I need to set some other option, if it's the case, I would appreciate if you can point me to the important settings).

  • \$\begingroup\$ I saw a post on high bitdepth support in GIMP recently, but I am not sure if it is for the current or next version. I'll check for the article and report back. UPDATE: libregraphicsworld.org/blog/entry/… suggest it is next release, 3.0. And even with support it is not safe to assume that the .tiff exporter will have functionality for it. \$\endgroup\$
    – Alendri
    Commented Aug 15, 2012 at 12:00
  • 2
    \$\begingroup\$ I am currently working on this feature! :) Davide -- Principal Maintainer of Luminance HDR \$\endgroup\$
    – user11148
    Commented Aug 15, 2012 at 14:07
  • \$\begingroup\$ Good to hear! If you don't have access to lightroom and/or need any help testing it out, let me know. \$\endgroup\$
    – Benoittr
    Commented Aug 15, 2012 at 15:31

1 Answer 1


As a short term solution (until Davide adds native support to Luminance HDR), you should be able to save the file as Radiance HDR format in Luminance HDR, then open it in Picturenaut, then save it from Picturenaut as 32-bit tiff without any compression. You can then open this file in Lightroom.


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