When to delete bracketed exposures?

When photographing what seems to be a high contrast scene, I often bracket my exposures, just in case I want to use HDR later. Then, when I load them in Lightroom, sometimes the base exposure looks OK. The histogram might have a peak towards the blacks, be a little flat in the midtones, and another peak in the highlights, but the whites aren't clipped and there is decent detail in the shadows. In this case I don't see an advantage in processing with HDR. Is there something I'm missing? Is there any reason to keep the extra bracketed exposures?

It is likely, even if the histogram is not clipped, that you will get more available detail in the shadows and highlights with an HDR image. In Lightroom, the DNG file that is created by three bracketed shots will look exactly like the base exposure (if you don't check the Auto Tone box), but once you start adjusting the settings in the Develop module, you will find that you can recover a lot more highlights and open the shadows much more with the HDR image than you could with the base image.

Thanks for the explanation. Once I played around with the what I thought was a well-exposed base exposure vs the Lightroom CC HDR DNG, I could see a lot less noise in the shadows in the DNG. (Wow, lots of acronyms in that sentence, sorry).

Due to the way the RGB color space works, the closer any color is to being pure white or black, the less values exist to describe that color.

For instance, in 8-bit RGB (0-255), how can you accurately pinpoint the shade of red near pure white? Red would have to be:
R - 255; B - 250; G - 250
Which means you only have a handful of numbers to describe the shade of red before it loses saturation and becomes white. This is in opposition to the real world, where an object can simultaneously be extremely bright, but also be of a very intense and saturated color.

While the 14-bit register of Raw files has a heck of a ton more numbers to work with, in practice colors will always lose saturation and be less accurate if you recover them vs. getting the actual tone recorded with an appropriate exposure.

I want to point out that this has absolutely nothing to do with ETTR as long as you don't go too far and end up having to recover highlights, carry on ETTR'ing as usual. Cameras use logarithmic tone scaling, while processed images are linear, only the former benefits from a brighter exposure.

I sometimes just use the best ETTR exposure that hasn't clipped the highlights, sometimes use the same but merge in a longer expossure for the shadows - just to reduce noise and sometimes put the whole lot into an HDR program anyway.

As to what to keep, it depends on how good the image is and how unique. I'm used to deleting a lot of raw files, but if it is from a vacation, I usually wait 6 months before doing my final cull (before that I will delete anything I can't be bothered to process). So if I took a 5 shot bracket and liked the image I'd keep all raws around for at least 6 months. If I thought I might ever print it, I'd keep all raws and archive them just in case.

I keep everything forever.

Higgs Boson wrote in post #17586226
I keep everything forever.

Me too.