Gear Talk > Processing & Publication

Batch processing HDR images

<< < (2/2)

pluton:

--- Quote from: armando_m on December 26, 2018, 16:20:36 ---
The difference you show seems very well within the range of what is possible to do with just shadow/highlight sliders in LR, specially with a D800 NEF file at 100 ISO



--- End quote ---
This was may thought also.  It has been my observation (with my own old transparencies) that the range of EVs in a Kodachrome transparency that is transilluminated with diffuse light is less than the EV range of the typical original scene. Ektachrome--especially now that the D-max has faded---is less contrasty than the Kodachrome.
However, I will try the HDR technique next time I copy slides to see if the files so processed have a better, more pleasing look.

charlie:
It has been my experience that the D800 (or a scanner like the epson V700) can have a hard time extracting all of the detail from a slide in one exposure. So I can see why you'd want to do the HDR thing.

There is not a batch function for HDR in Lightroom but there is a keyboard shortcut that will run the HDR function in the background, sort of a manual batch option. You can apply this to several sets of images at a time so essentially you'll be able to walk away from your computer for longer periods before coming back start more HDR process'. The shortcut is Ctrl-Shift-H, it skips the preview dialog box and will apply the last settings you used for HDR.   

Select 5 images you want to merge for HDR & press Ctrl-Shift-H, select the next 5 images to merge for HDR & press Ctrl-Shift-H, and so on. My slow old computer can handle 4 or 5 sets of HDR process' at a time before LR stops responding, a newer/stronger computer should be able to handle more at a time.

Seapy:
Thank you Charlie, for confirming my approach and the tip for Lightroom, I will try it with the next batch. I have been using control-H but wasn't aware of the additional 'shift' function.  I am sure there will be something in Photoshop/Bridge which would allow an unlimited batch to be run but this is good enough, I don't expect to be doing thousands of exposures, my time is free!

I am running a 6 core 3.06Ghz Intel MacPro 5.1 with 24Gb Ram. I did freeze it with 12 D800 NEF's in one batch but on the second run it swallowed them and returned a nice image.  I do have another strip to take me to 32Gb RAM but tests have shown the computer runs faster with 24Gb because there are only 3 RAM channels, so if you fit 4 strips, 2 strips have to share 1 channel, which slows things down (a tad).

Another benefit of this exposure stacking method, I seem to see better detail in the final image than any of the individual images.  Some of the plants have name labels which in each individual image the lettering is indistinct, bitty. In the stacked HDR image the lettering is solid and clearly distinct, presumably this also extends to the rest of the image so it appears that I am also  extracting more detail from the slide by using multiple exposures.  This isn't immediately obvious because generally these images aren't the sharpest I have seen... My father didn't own a tripod.

Off to get a bigger SSD, more elbow room...  ;D    ...500Gb or 1Tb, Samsung 860EVO or Crutial MX500, decisions!  :-\  All my SSD's are 250Gb Crutial, I feel it's time to step up a gear with the D800.

Seapy:
OK, I'm processing a batch of D800 photographs in bracketed sets of 5 with Lightroom using ctrl+shift+H combo. Lr reports number of operations in progress, in this case 3, I will try for more, but don't want to push things...

Seems faster than previous method of one at a time...

Processing 15 images of the Meikleour Beech Hedge which holds the record for the largest hedge in the World.

Seapy:
This is the result from one of the D800 files I copied this evening, HDR from five bracketed images of a slide my father made in 1965 using a contaflex with Kodachrome.
 .

Navigation

[0] Message Index

[*] Previous page