Maybe One of Our Resident Experts Can Explain..........

I note that some folks post-process 5, or more, photos to produce an HDR image.

What is the benefit of more than 3 images?

My D800 can shoot up to 9 frames to bracket. Four over and four under.

If I shoot +/- 1 for the 9 frames, I would get: +4, +3, +2, +1, 0, -1, -2, -3, -4

In post-processing all 9 frames, wouldn't the +4 and -4 cancel out the other exposures?

I always thought that the ability to shoot 5, 7, or 9 exposures was to pick and choose the one that best fine tunes your photo; Like +3, 0, -4, or +2, 0, -1.

Can anyone show that post-processing more than three exposures enhances the final result?

It's pretty simple, really...

Dynamic range of your camera + dynamic range of the scene = total # of bracketed shots needed.

I did a lot of HDR with my D300s. 5 frames was the sweet spot for that camera (in my opinion). The D800 has been touted as having the best dynamic range of any camera ever produced, and when I did some HDR with it, I have to agree. There wasn't much visible with 3 frames, and barely anything noticeable with 5. The sensor is so advanced, the "need" for HDR is negligible.

And no, the +4 and -4 don't cancel out the other exposures. I don't know that I could accurately put into Layman's terms how tone mapping works, but the wiki page on Dynamic Range does a pretty good job. Reading up on Ansel Adams' Zone System will explain it even better.

The answer is, as always, it depends. The more severe the differences in the lighting situation the more you'll benefit from having the little gaps filled in. A lot depends on the skills of the person doing the post processing as well, in particular because a well exposed '0' image from a D800 has 9 stops of dynamic range already present in the RAW file, giving you all the well-metered pieces of the -4 to +4 stop images. So, the -4 image really gives you -8EV to +1EV light information, while the +4 image gives you -1EV to +8EV light information, expanding your overall light information from -4 to +4 to -8 to +8. That said, you wouldn't necessarily need anything other than a 3 image bracket (-4, 0, +4) to give you the same light information.

So, why shoot more? The reason you do has less to do with how much light information you have access to, it's has to do with how well the program you're using plays with that light information when it's in 3 files vs. 5, 7 or 9 files. My experience is that giving the program more files to cull from will allow you to create a more natural looking image from the result, with less noise.

Given that you can fairly easily produce +/-3EV images using LR or ACR from a RAW file, I was able to turn a 3 exposure HDR series into 5, 7 & 9 exposure HDR series, and I used various combinations with the same set of presets in HDR Efex Pro 2 to see how the treatments would differ (http://nikonites.com/hdr/21994-playing-3-exposure-hdr-series.html). The differences are very subtle, but they are perceptible, mainly in the fine details of darker areas.

I've used upwards of 13 images to create a single HDR in a dimly lit chapel environment with bright sunlight beaming through the stained glass windows, and can say for sure that I would never have been able to capture these with 3 or even 5 images...

Wow, Jake! If I could click "like" more than once for those, I would!

When I did HDR with the 300s I would use 5+ shots. But, with the 610 the dynamic range is better and I can get away with even 2 shots to achieve the same. I have some time off. Maybe I will do a comparison.

BackdoorHippie said:

I've used upwards of 13 images to create a single HDR in a dimly lit chapel environment with bright sunlight beaming through the stained glass windows, and can say for sure that I would never have been able to capture these with 3 or even 5 images...

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Out of all of your photos, this one is my all-time favorite! Last week I tried to do something similar at my church using an ultra wide because I keep thinking about this photo. I didn't try HDR, but I'm sure it would enhance the image nicely--it's something I want to learn.

You don't HAVE to shoot with a full stop. My D7100 will do it in 1/3 stop increments. Sometime with more subtle differences you get better results.

I used to use 3 images with my D80 as that was all it would do in a bracketed set. My D7100 does 5, so now I use 5. I would say by comparison the ones using 5 images are usually better, but my post processing skills have also improved, so I can't say for sure that it is the reason for better photos.

I do a lot of outdoor HDR shots, so the light is ALWAYS changing, even if only slightly. In that situation I would think that more shots would be better. My only problem with more shots would be that the files end up HUGE and the post processing takes longer.

Not sure if that helps with the big picture everyone is contributing to.