HDR, How Many Shots are Needed?

The other day I was reading a Forum on Nikon D90. Someone asked how many bracketed shots were needed to make a good image. The Nikon D90 supports three bracketed shots although you can change the number of F/Stops between each shot. The camera also support bracketing by white balance and shutter speed, but for HDR, you want to keep the same aperture and vary the shutter speed.

I decided that I would do an experiment because I normally go with the three shots. I should state that when I use HDR I am trying to make a landscape picture that captures a fuller range of the values that the human eye sees, not what could be considered an image with unreal colors.

So I went up into Big Cottonwood Canyon here in Salt Lake and stopped at Storm Mountain. That is a beautiful rugged area, although it is prettier in the summer than it is in the winter. It was about 6pm at night. I took the following exposures.

-4 EC 1/3000s F/11
-3 EC 1/1500s F/11
-2 EC 1/750s F/11
-1 EC 1/350s F/11
0 EC 1/180s F/11
+1 EC 1/90s F/11
+2 EC 1/45s F/11
+3 EC 1/20s F/11
+4 EC 1/10s F/11

These were taken by setting my bracketing to three frames, 1 f/stop apart. I then set my exposure compensation to -3 and took the -4, -3, and -2 shots. I then set exposure compensation to 0 and took the -1, 0, and +1 shots. Exposure compensation was then set to +3 and shots +2, +3, and +4 were taken.

I then produced three images using the software package Essential HDR Standard Edition.

The first image contains all nine shots.


The second image has three shots with each of them being 1 f/stop apart. The middle shot has an exposure compensation of +0.


The third image has three shots with each of them being 2 f/stops apart. The middle shot has an exposure compensation of +0.


The fourth image has three shots with each of them being 3 f/stops apart. The middle shot has an exposure compensation of +0.


Although I think that the thee shot with one f/stop difference is acceptable, the nine shot appears to have more detail to it. So if you have the time and can make sure you don't change the position of your camera, the nine shots will most likely give you a better image.

I think that this image is not a real good image to have done the test with. I'll have to try a different subject sometime.

ViewNX Picture Control

When you shoot Nikon RAW, the picture control that you have specified is not applied to the raw image. It is only applied to jpeg images. The picture control can still be applied using ViewNX. I downloaded Fuji Velvia, Kodak Ektachrome, and Kodak Kodachrome 2 pictures controls and installed them on my D90 and ViewNX.

You can create your own Picture Controls using ViewNX and you can find some on the web. I use the ones created by Jake Khuon. A website that goes more into the theory of it and has links to Jake's picture controls is: http://esfotoclix.com/tech/picctrl/. The url to the picture controls is: http://www.neebu.net/~khuon/photography/NIKON/CUSTOMPC/.

I have taken a RAW picture that I took using a D40 and applied each picture control. A lot of the time I couldn't see much difference, but occasionally the difference was dramatic. Looking at the following images, it is difficult to see the differences between the different Picture Controls. To see them better, you can open a couple of browsers on this blog and then select the various pictures to view them side by side. Here are the images.

Standard

Neutral

Vivid

Monochrome

D2XMODE1

D2XMODE2

D2XMODE3

Portrait

Landscape

Fuji Velvia

Kodak Extachrome

Kodak Kodachrome 2

D40 Recorded Value


Picture Controls can be used to produce a certain look automatically or allow you to wait until you start processing RAW files to see which Picture Control looks best.

With ViewNX there is the ability to create you own Picture Controls. There are a number of sites on the web that describe how to do this.

Panoramic Pictures

Panoramic pictures are something that have fascinated me for some time. I live in the west where most of the time, the vistas I see cannot be captured on one frame, even if I am using a wide angle lens. Programs such as Photoshop Elements from Adobe make it very easy. The version I use is version 7.

My family was recently on a trip to California and a storm was forecast to move in one the morning we were leaving. Having to chain up going over the Sierras is not fun. If we left too late, I might have had to chain up multiple times going through Nevada on I-80. Needless to say, we left early in the morning. After crossing the summit on the eastern side of the Sierras there is a lake called Donner Lake. We were making good time so we stopped and drove along the shore of the lake until we found an access point. It was a dark heavily clouded morning. I took a number of pictures, and made sure that on seven of them I overlapped each side by at least 20%. I then used Photoshop Elements to stitch them together. Here are the seven individual pictures.












You will notice, especially on the left side of the panoramic picture that the top of the mountain is cut off. This is because as Photoshop Elements fits things together the center is narrower in height than the sides images are. When you crop the image, you tend to lose the tops and the bottoms of the beginning and ending pictures. So when you take images for combining in a panoramic remember to leave plenty of space for cropping.

The pictures were taken with a Nikon D90 at F/13 at 1/45s.