Monday, January 15, 2007

Camera RAW

Warning: Boring camera stuff ahead!

This is what I did instead of coming up with blog ideas, so here's today's subject:

I've gotten into the habit of leaving my Nikon D70s in the RAW + JPEG mode. Every time I take a photograph, the camera actually puts TWO photos onto the memory disk; one is a JPEG image and the other is a RAW image. Both are of the exact same thing.

A JPEG image has already been processed by the camera, and is ready to look at on a computer or whatever. JPEG compresses the image file, and this image has lost some data in the compression.

The RAW image that the camera also creates, is the actual, complete, data dump of what the imaging sensor saw when I took the picture.

If the JPEG looks great, or almost great, I can tweak it in Photoshop Elements and save that image as the one I want to use.

But I learned really fast with this new camera, that Florida's incredible contrast in many sunlit scenes can "blow out" the highlights, or the whitest portions of a photograph. The image sensor was overloaded in these areas, and the detail of, say, the feathers on the back of a white bird, could be lost forever.

RAW images, being ALL of the original data from the imaging sensor, has the potential to give me a way to get back much of those lost details.

So, that's what I do. I shoot in the RAW + JPEG mode, and if the JPEG is good, cool, if it's over or underexposed too badly, I can use the RAW image to create a better image.

Each camera manufacturer handles the data in the RAW image files in their own, proprietary way. The Nikon software that came with my camera cannot open a RAW image from a Canon camera, and vice versa.

But the RAW files can be almost magical. I've been playing with some RAW files lately to see what I could do.

With a JPEG image from the camera, Photoshop, or Elements, or whatever, can only change the image a certain amount, but the image starts to look fake and weird really quick if you try to lighten or darken a photo very much.

Enter RAW.

Opening a RAW file will allow me to change the exposure several stops in either direction, of the image AFTER the image was taken, on the computer! You have no idea how marvelous this is to me, after 30+ years of dealing with slides and negatives that had an incorrect exposure. With filmIt's just pretty much too stinkin' bad pal. With film, you can burn lots of film with various exposures, hoping that one is really good. (That's called bracketing.)

For example, I'm always playing with the settings of my camera and trying new things, and on Christmas day, I inadvertently left my camera set at -2 stops of exposure compensation. All of my Christmas photos received 1/4 of the light they should have to create a properly exposed image.

Each and every Christmas photo I took was really dark.

But, I did still have the camera set on RAW + JPEG, and went in using Photoshop Elements and completely corrected each and every underexposed Christmas photo. You would never know that I did this if you saw the photos! Amazing.

AND, digital cameras have very good automatic white balance firmware/circuitry, but they aren't foolproof. You can still end up with a yellow image indoors, or an overly blue one outdoors.

Processing the RAW files in Photoshop Elements, I can change the white balance AFTER the photo is taken, and on the computer!

Anyway, I know this is a big yawn to most everyone (both of you) who read this blog, but I'm still reeling from the possibilities this opens up.

Last night, I played with an image I took from the fourth floor of a building, overlooking Melbourne, Florida, and the western sky.

The sky is kinda dark, which is what I was trying to capture, the sky, but the city below ended up too dark.

Using Photoshop Elements and multiple versions of the same photo, with different after-the-fact exposures thanks to RAW, I sandwiched two images, a darker and a lighter one, that lets me end up with one image wherein the sky is like I want it, but the city below is also lightened, so that you can see details of the city.

This first one is the image, exactly as it appears straight from the camera. I wanted to keep the sky dark and moody, but increase detail in the city below.

This next image is the "light" one I created so that I could use the better details in view of the city in my final image. I didn't care how the sky got too light in this one.

This next one is exposed only for the sky, to get it pretty much like I wanted it.

Using the layers on Photoshop Elements, I put the images on top of one another. Essentially, I put the light one on the top, and the dark one on the bottom, and "erased" the sky on the lighter one to let the darker one below come through. Only in the sky part though.

Now, OK, I know the photo isn't perfect. The city is too light, it doesn't look natural, but this was my very first shot at trying this. You can also see a line where the two different images meet, so it's not great.

But the potential for creating photos exposed in ways that would be truly impossible with just the camera itself makes my head spin.

That is all, carry on.

3 comments:

Hammer said...

Thanks for the advice, I have a fancy camera and no idea how to use it other than point,click and pray.

JAM said...

The only problem with using the RAW files, is that you have to be willing to learn to manipulate photos with Photoshop, or whatever imaging program you want.

It's perfectly ok to point and click. I've loved photography for years now, but I'm not so snobbish about it that I don't turn my camera to the "idiot" settings and fire away on occasion. Setting the camera on one of the auto settings with a flash attached at an indoor event will result in more good pictures than "fiddling" with the settings will.

If you point and shoot and don't want to fool with the photos later on the computer, don't bother with RAW.

I was just excited because, had I not had those RAW files from Christmas, I would have had to try to make the JPEGs look bright enough to see, and they would have looked obviously bad, but serviceable.

I guess the geek in me was jazzed because, for the first time, I can correct a missed exposure, after the fact. That's like inventing fire or the wheel, where photography is concerned. Big stuff.

Leanne said...

That's some excellent info, thanks for sharing! I'm going to shoot a few in RAW mode next time and see what happens when I get into editing mode. :D