Lightroom won't merge HDRs

[jaylaphotography]

After updating to Lightroom 2015.8 and using it for a while, Lightroom won't fully process HDR images using the 'Photo > Photo Merge > HDR' function (it did for a little bit though)

After selecting the files (7 RAW files) and attempting to merge them the progress bar stops about a third in and does not continue moving.

I have tried merging normally through the use of the menu, by bypassing the preview (using the Shift key), and I have unchecked & checked Graphics processing in preferences with no luck.

I have also tried merging a smaller amount of files - this worked only once, but after trying it again it did not want to merge the files again.

Can someone tell me what I could be missing?

[Akash Sharma]

Hi jaylaphotography,

Please backup your Lightroom preferences and reset preferences following the steps below:-

1. Close Lightroom

2. Hold down [CTRL/CMD]+[Alt/Optn]+[Shift] and launch Lightroom

3. Overwrite the preferences when prompted in the dialog.

Let us know if that helps,

Regards,

Akash

[Rob_Cullen]

Using seven (7) raw files seems excessive to me, and not necessary. Hard to imagine a scene that would need that extreme range of exposure.

I reproduce these notes below as were provided in a forum post by-

~Rikk Flohr
Community Manager - Adobe Systems

HDR Exposures

According to the engineering team - if your two exposures are three or less stops apart, (ie 0, -1.5, +1.5), a third exposure is not needed. In this case, merging the -1.5 and the +1.5 and ignoring the 0 should give you as good or better results than using all three exposures. For example, a -2/0/+2, spread is 4 stops and requires a third exposure. See the guide below.
Under to Over optimum number of exposures:
Up to:
-1.5 to 1.5 = 2 exposure
-3.0 to 3.0 = 3 exposure
-4.5 to 4.5 = 4 exposure
-6.0 to 6.0 = 5 exposure

HDR/Pano Settings

Please note that the settings that are copied over will differ between the HDR and Panorama cases.

For a Panorama, the merge tool is changing geometric attributes, and will therefore not copy over existing geometric settings such as Lens Corrections/Upright (with the exception of Defringe settings).

For HDR, the merge tool is expanding tonal range, so existing primary tone settings (such as Exposure, Contrast, Highlights, Shadows, Whites, and Blacks) are not copied over.

Settings cleared for both the HDR & Pano cases:
- Local Corrections
- Red Eye
- Upright
- Crop

Settings that are copied over (with some exceptions):
- Basic Panel (except primary tone adjustments for HDR)
- Tone Curves (HDR no, Pano yes)
- HSL/Color/B&W
- Split Toning
- Detail Panel
- Lens Correction (HDR yes, Pano only Defringe)
- Effects Panel
- Camera Calibration (except Process Version, which must always be current for HDR)
- Spot Healing (retained for Panos only)

[jaylaphotography]

Thanks - this is good to know.

Could you provide a link to these details you have provided from Rikk Flohr?

When doing multiple exposures (for landscapes) I typically shoot with 1 exposure difference, e.g. -3/-2/-1/0/+1/+2/+3, hence the 7 exposures.

I suspect this is over-kill?

[Rob_Cullen]

a link to these details you have provided from Rikk Flohr?

Gladly-

Lightroom 6/CC2015 – Photo Merge Tidbits (Part 1) | Rikk Flohr's Fleeting Glimpse Images

Lightroom 6/CC2015 – Photo Merge Tidbits (Part 2) | Rikk Flohr's Fleeting Glimpse Images

And there was some good discussion here in this forum thread-

HDR in Lightroom, Part 2