Struggling with HDR: Edit highlights and shadows in RAW image before merging in DPP4?

[stevet1]

I'm struggling with high dynamic range situations.

I'm working with auto exposure bracketing of Raw photos and doing an HDR merge in DPP4.

Should I post process the individual Raw files to bring down the highlights and raise the shadows before I do the merge, or should I just let the software handle it?

Steve Thomas

[ebiggs1]

I don't. I do the HDR merge and edit the result if needed.

[Waddizzle]

What type of shooting scenario? Is it backlit?

Which shooting mode settings? Which exposure setting is being bracketed?

What are the AEB settings?

I shoot RAW and generate the image without any preprocessing. I use LR and PS. 

[stevet1]

Waddizzle,

Generally, it's landscape photos with blown out skies. I've been shooting in Av, so it's the shutter speed that varies, and maybe the ISO. I've also started using a + or - 2 stops.

I shoot in C-Raw, but the merge is rendered as a jpg, and DPP4 is kind of limited in what you can do with jpgs.

I also have Irvanview, and you can do a little more with jpgs there with colors and such.

Steve Thomas

[Waddizzle]

@stevet1 

I asked the web search engine if GIMP can process HDR images.  It reported that there’s a plug-in available.  I expect it’s easier to use than doing it manually.

https://youtu.be/_GvOXEriYLk?is=8JStDF8-bv0ElfNZ 

When I capture an HDR image stack, I typically set the camera to M mode with ISO Auto.  The ISO is what the camera controls to vary the exposure.

Food for thought! You are not limited to centering AEB at 0 Ev. You’re not limited to (3) exposures. You can also capture the exposures manually and not use AEB. I have captured exposures at +1, -1, and -2 before.  

When I do use AEB, I don’t always use every exposure. I typically capture (5) exposures separated by a full stop. Again, you don’t have to center it at 0 Ev. 

[stevet1]

Waddizzle,

I'll have to give that a try. I can start with a -1/3 stop of negative compensation or so, and start my bracketing from there. I'll have to see how that works out.

Mostly, I was trying to avoid processing each individual frame before the merge.

Steve Thomas

[Waddizzle]

@stevet1 

” Mostly, I was trying to avoid processing each individual frame before the merge. “

If you must convert RAW files into JPG files, then it’s best to apply the same DPP recipe to each file.

[johnrmoyer]

I hope some of this might be helpful. It is what works for me and may or may not work for you.

I suggest that if merging the photos in DPP it would be better not to use CRAW but regular RAW. The noise seems to me more like what I expect in regular RAW. DPP can merge the raw files.

The processing that seems to me advantageous before HDR merge includes "digital lens optimizer" and white balance, and if using DPP extending the dynamic range to plus 2: 

https://cam.start.canon/en/S002/manual/html/UG-04_EditImage_0040.html#EditImage_0050_11 

If using hugin to do the merge, then at this point save 16 bit TIFF files from DPP.

Things that should not be done before the merge include, unsharp mask, auto lighting optimizer peripheral illumination correction, distortion correction, gamma curve adjustment. DPP will apply these settings if they were enabled in the camera unless one disables each of them in DPP. DPP might do the right thing with unsharp mask. I suggest setting the camera to use the "standard" picture style when bracketing.

Hugin free software will permit saving a 16 bit TIFF which can then be edited in other software.

[stevet1]

John,

You wrote, "The processing that seems to me advantageous before HDR merge includes "digital lens optimizer" and white balance, and if using DPP extending the dynamic range to plus 2"

This is my first foray into 2 stop merging. I've always been leery about going that high, but DPP seems to be handling it pretty well. I'm also learning to use the histogram and ETTR in Live View with exposure compensation, so that my highlights don't climb that right hand wall. It's a leap of faith not to depend on that light meter exclusively.

Steve