How do I photograph moving subjects to allow good HDR processing?

Question

I've started to experiment with HDR photography and would love to have a few shots of my family rendered via HDR. There's one problem - my family is human and they move, sometimes a LOT. How would be the best way to go about photographing them in order to produce the best possible HDR result? I am using a tripod with my Nikon D90 and the typical RAW shots with +2, 0, -2 EV bracketing.

The results I've had so far often end up with ghosting and other minor details either removed or blurred - what am I doing wrong?

Answer 1

Doing an automatic conversion with Photomatix, Photoshop etc. is not the only way to blend multiple exposures in order to extend the dynamic range as as you've found it can be very difficult if you have moving subjects.

A simple way of achiveing HDR effects is to simply layer the images in photoshop and mask the relevant parts of each image. e.g. take the shadow area from one image, take the people from another and take the sky from a third image. This works very well if there's a clear boundary between areas of different brightness. Feathering the edges of each mask makes hides the transitions. If the areas where there is movement don't cross any transitions then it's not a problem.

Another advantage of this method is that it doesn't create and HDR artifacts, such as halos, so produces a more natural looking image. Also it doesn't require any speicial software as layer masking can be done with any competant photo editing program.

Here's an example from a few years ago when I climbed Mount Snowdon with some friends. Coming down there wasn't a lot of time to hang about as we had to get down before sunset. Looking down the valley there was no exposure that was even close to capturing the whole dynamic range:

There was a lot of motion in the people climbing down (especially the dog) so I couldn't do a straight HDR without getting motion halos. I stacked the images in photoshop and took the sky from the darkest exposure, the middle ground from the middle exposure and the foreground (and importantly all the people) from the lightest exposure. I'm not 100% happy with the result, it still looks a little too fake but for a quick snap shot and momento of the day it does the job:

Answer 2

If you're taking bracketed shots, ghosting of moving people / objects is always going to be an issue when combining to create an HDR image (of course, bracketing without a tripod will bring in the extra issue of ghosting due to camera movement).

The 2 solutions are:

1. Shoot a single RAW and generate an HDR from this (my personal preference for shots focusing on people)
2. Fix the HDR ghosting in Photoshop - put the tonemapped image onto the top layer, then pick the bracketed shot with the best exposure for the people, place this under the tonemapped layer and mask through to fix the people. Naturally, it takes a bit of work to maintain the HDR effect on the people that are masked through, you may well need to use some pseudo-HDR filters (such as Topaz Labs Adjust, or onOne's HDR filter).

As a side point, you mention that you bracket 3 RAW shots. Technically this isn't really necessary as the benefit of RAW files is negated in the process (since the HDR / tonemapped results is usually a JPEG). RAW is a must when shooting single shots, as point 1 above.

Side point number 2, the HDR process can make skin tones appear quite bizarre - overly textured and withered / worn. I usually remove the HDR effect from people in shots (if they are the main subject).

Answer 3

When I started experimenting with HDR initially I had the same problem but I managed to work out the best workflow for this kind of situation.

Like it has been already mentioned you have two solutions and both of them will give you great results.

Solution 1

Shoot 3 brackets in RAW (typically -/+ 2EV). Remember, if you put your D90 in high burst mode the brackets will be taken really fast in order to minimalise movement.

Use Photoshop CS5 to stack the pictures in Merge to HDR Pro. Now, I realise that Photomatix is the most popular HDR stacking software but I have to say that the guys from Adobe really made a great job with the HDR engine in CS5. You will be surprised by its performance and ability to reduce ghosting completely. Simply select one frame which you want to appear as a main frame and then the ghosting will disappear.

There is a number of video tutorials on the web on how to use the Merge to HDR Pro engine so you won't have any difficulties with it. Go to www.photoshopsupport.com for more.

Solution 2

If you do not have Photoshop CS5 and want to use Photomatix then follow a different workflow.

Shoot one exposure in RAW and then create so called 'fake HDR' by creating the brackets. Open your file in either Photoshop CS4 or CS5, Adobe Lightroom 2 or 3 or Aperture (these are the market leading) and RAW converter should appear automatically. Then adjust the exposure bar and create one -2 EV (exposure value) and one +2EV shot. Remember, when saving your files you won't be able to save it as your native RAW so to minimalise data loss save your files as 16bit TIFF. Then stack the pictures in Photomatix as usual.

Here is one of my first fake HDR

http://www.flickr.com/photos/grzegorz_rogala/4937391125/

Good luck with your photography

Greg

Answer 4

Another option (though more labor intensive) is to shoot your subjects first, then the HDR. There are some tricks to this though...

1. The 1st shot, the one of your subjects, has to be on a tripod.

2. The tripod and therefore camera CANNOT move, ever! (at least until you're done:))

3. You have to have some PS skills.

When you come across the scene, and you think to yourself, "self, this would make a rockin' HDR!" set up your pod and compose. Then, photograph your subjects, exposing correctly for them. Forget about overall exposure, just get them right. Shoot in RAW so that you have max info available to you in the digi-darkroom.

After you shoot your subjects, direct them out of frame (if you know them or are feeling brave) or exercise that all-to-critical photog skill called patience and wait for the zone to clear. Then shoot your brackets.

Take it all back home and load up your fav software. Here's where it gets intense. Create your HDR of scene from your brackets. Do this first as you will have to match your subjects later. After you are happy with scene, bring in your subject frame. New layer...mask...clean. Your goal is to wipe out background but leave your subjects. Use a soft brush. Make transitions and blends look natural. Once your mask is good, it's time to breath life into this layer. Curves, channels and sat is the best way to go on this as well. (A work around is to open your subject file, create "brackets" within RAW, save as, then make an "HDR" from those new files. Try to match it to the true HDR of the scene, then proceed with the mask.)

This takes time, but will yield the results you're looking for.

You can also invest in a battery pack and a pro-level strobe with lightning fast recycle times, bracket burst fire on your loved ones, shell out the cash for burnt retina repair, and HDR blend those pics. Just saying...

Answer 5

Ian,

You have quite a few responses that can probably very helpful to you. I don't know what camera you have - might be useful to know :)

You could use masks to overlay images and then show parts of the image that you wanted to use. Aside from bracketing you could also stack the images. I have an example below from a program I've used in the past called hdrinstant. You need Lightroom to use if though. It let's you do HDR with moving subjects but you don't bracket - again, what camera do you have??? :)

This example is not great - my main interest in photography is not hdr.

I went to see some animals at a lake last year. I used the burst mode on my casio to get 60 images at 60fps.

Then I opened them in Lightroom and ran the plug-in I mentioned above to stack them and gain detail in the darker areas -

Like all HDR images, you must tonemap them!

The flamingos were moving around a fair bit because we were making quite a lot of noise.. The images themselves are zoomed and have been re-framed.

Re the software, I don't know about all the odds and ends, but you expose to the highlights and let the software do the recuperating of the dark areas.

Hope this helps.