To sharpen before or after?

[Neilmac50]

Hello to everyone from South Africa,this is my first post on the forum although I have been a frequent user of Lightroom since the third itteration. A basic question to do with making HDR images within Lightroom Classic. At the moment my workflow has me sharpening the individual DNG files before putting them through the HDR process.Should I instead wait until I have the completed  conversion to  HDR DNG and then do the sharpening?Is there any advantages or disadvantages to either way?The only one I can think of is sharpening before hand may introduce some noise in the darker DNG files

Thank you in advance for any replies.

Neil

[richardplondon]

From your mention of DNG. it seems these are Raw files you are starting with. And a Lightroom internal HDR merge produces something which is effectively still "like" a Raw in many ways. So IMO it is best to think of not only sharpening, but all the other aspects of Develop adjustment too, as still to happen.

In any case if you are using the internal HDR merge which is part of Lightroom, I don't think there's a lot of point in pre-applying processing since that will just be ignored - according to this link: https://protogtech.com/adobe-lightroom/adobe-dng-hdr-format-part-2/

On the other hand if you are using an external program to do the merge (Photomatix for example) then things may be different.

There are two options: either this other program refers back to the original Raw files involved and makes its own Raw conversion of them using some sort of default processing including sharpening - that is unusual. More commonly, this other program requires non-Raw data (a converted bitmap) in which case some slight level of basic so-called "capture" pre-sharpening seems like a good idea. Also some attention to White Balance and such.

But all this quite conservatively done, and without a lot of e.g. Clarity, Shadows, Highlights, Contrast either since those adjustments distort / rearrange tone contrasts locally .

For HDR input purposes you really want to proceed from true brightness values derived from the scene, at each pixel. Pictorial considerations only come in later, when controlling the output of the overall HDR procedure. An external HDR merge program has its own options for that: you might choose between tone-mapping and fusion methods and set various visual enhancement parameters.

Lightroom's internal HDR produces only a bland unprocessed image and the "controlling the output" as well as the visual enhancement consists of your subsequent Develop adjustments, applied to that new merged DNG.

[ edit: oh, and welcome to the forum! ]

[Neilmac50]

Thanks for all that useful info Richard,one point I find slightly different to your description is after I have the merged HDR PANO DNG I find that the lens correction is already ticked for 'remove chromatic aberration' and the option 'enable profile corrections' also ticked as I normally have them set for single images.However once again thank you and thanks for that useful link.Cheers, Neil.

[richardplondon]

I believe LR may copy over some settings metadata from one of the source images. But since these settings were not used during the HDR merging process, and will not have affected that, before or after makes no difference.

For tonal edits etc, if you have judged those visually by looking at one of the source shots, those same settings if copied to the output image would be unlikely to be suitable.

IMO it is simpler and easier to just treat the HDR merge as a brand new image - which is what it is - and not spend a lot of time on processing the source shots first. Of course, these do still remain available afterwards and one can compare what processing is achievable with one of those, vs what you can get from the Merge. It is not always a clear-cut decision which one to use.

[Todd Shaner · Accepted solution]

Neilmac50  wrote

I find slightly different to your description is after I have the merged HDR PANO DNG I find that the lens correction is already ticked for 'remove chromatic aberration' and the option 'enable profile corrections' also ticked as I normally have them set for single images.

Both Photo Merge to HDR and Panorama copy over the Develop settings from the "most selected" image file to the output DNG file. The settings in the other image files are ignored.

[Neilmac50]

I also remembered late last night that I have a preset on initially importing the images to 'enable profile corrections' and 'remove chromatic aberration', perhaps this explains the subtle difference? Thank you all for your most informative replies, a most welcome introduction to this forum.Cheers.

[Todd Shaner]

The actual settings copied-over from the "most selected" image file to the HDR DNG file may have changed over time (LR 4>5>6>7). So I ran a test with ALL of the Develop controls applied using LR 7.2 Photo Merge to HDR.

1) During HDR processing the selected image files are converted to linear DNG files with NO settings applied. These linear DNG files are then merged and output to a single 16bit Floating Point HDR DNG file.

2) Next all of the Develop settings from the "most selected" image file are applied to the output HDR DNG file except Tone, Vibrance, Saturation, Tone Curve, Dehaze, and the Local Controls.

The bottom-line is as richardplondon stated, "IMO it is simpler and easier to just treat the HDR merge as a brand new image - which is what it is - and not spend a lot of time on processing the source shots first."

Hope this helpful.

[Just Shoot Me]

Neilmac50  wrote

I also remembered late last night that I have a preset on initially importing the images to 'enable profile corrections' and 'remove chromatic aberration', perhaps this explains the subtle difference? Thank you all for your most informative replies, a most welcome introduction to this forum.Cheers.

Depending on the make and model of camera you are using most of the time those 2 options, Profile correction and chromatic, are Auto applied without having to check those 2 option in the Lens Correction section of the Develop module.

You will get a notice of this at the bottom of the lens correction panel that looks like this.