Friday, February 18, 2011

Photos in the raw

For those of you who have a camera that can shoot "raw" and you are not using it are totally missing out!   Capturing an image in raw mode is like getting dressed for the day.  When you take a shower, I am guessing that none of you shower with clothes on, so that is where we will make the analogy.  This is not kinky in any way, just a way to explain.

What is raw?
A raw image file can be compared to the not yet visible image in an exposed but undeveloped negative--you've taken the picture, advanced the film, but not developed the roll.  The file contains exactly what the imaging chip in the camera recorded. (The imaging chip is the film for a digital camera.) This means that you are now able to get the most quality from your image.  Raw files take up LOTS of space on your card, but require processing in a dedicated photo editing software (the software that came with the camera).  Another cool thing about raw files is that you can process them over and over and over.

What is jpeg?
A jpeg image file is like a processed and developed negative.  All the sharpening, contrast, white balance, color saturation, etc. has been completed in the camera and then compressed.   Jpeg images take up less space on your card so many photographers choose to shoot in this mode.  They may not have time to do the post-processing required by raw files, and for most jpeg images, the quality may be sufficient to get a decent printed image.


So below I have compared 5 images.  Image #1 shows the picture as it was captured in raw.  (In order to post it with this blog I saved it as a jpeg).  So this is the "naked" image.   It is an ok picture, but the exposure is not perfect.  I snapped this of my daughter while I was waiting for a client to arrive and didn't fine tune the exposure reading from my light meter before I took the picture.  I know, I know.  But since the camera was in raw mode, I can make it better. I uploaded the image to a photo editing software and processed or "dressed" the image. Now don't get the idea that the purpose of raw is to "fix" everything.  It's purpose is to "enhance", "develop", "process", "retain quality". 

Next, let's put some "clothes" on it.  The first thing I did to the image was to lighten it.  It was too dark for my taste, and looked a little muddy.  Image #2 shows the lightened image.  Then, I "accessorised" the image--#3 has increased contrast,  #4 is sharpened, and #5 is warmed up a bit.

Processing your images in the raw mode will preserve the quality before you play with it in your photo editing software. 

Friday, February 4, 2011

F-stop is not a swear word

Think about what happens to your eyes when you have been sitting in a dark movie theatre in the middle of the day and exit the theatre through the side door that goes directly outside.  You immediately squint your eyes because it is so bright, right?  The aperture of the camera works in the same way your eyes work.  (Well, I am hoping your eyes work because you might have a bit of a problem with photography if your eyes are not up to par). 

The number one job of a camera is to gather light.  This is accomplished by the aperture.  It opens and closes to increase or decrease the amount of light that is allowed in the camera to create an image.  The size of the aperture opening is represented by f/stops, i.e., f/2.8, f/8, f/16, etc.  Okay, now pay attention here because this is where lots of people get confused:  the larger the f/number, the smaller the aperture opening.  It works in the same way as an iris of an eye (that's the colored part of the eye), except we don't manually adjust the iris of our eyes to let in less or more light.  I will put in a plug here for READ YOUR MANUAL because a photographer should be in control of the camera, not the camera in control of the photographer.  Your manual might refer to f/stop as 'aperture value'.  Don't lose heart, it means the same.




If you look at the yellow image to the right, you will see 8 standard f/numbers next to an aperture size.  This is a good representation of the way light is allowed in the camera.  FYI, the aperture is located in the lens, not the camera.

With this information, now would be a good time to go practice using the different aperture sizes.  Take a notebook with you and write down the frame number, and the corresponding information about each image taken.  It would be very beneficial to see the differences in aperture size if you were to take all your test shots of the same setting.  For instance, you decide to practice on your flowers in your yard.  Your notes might look like this:
Frame #
1--f/16 at 60 (shutter speed).
2--f/16 at 125
3--f/11 at 60
4--f/11 at 125
etc.

When you upload the images to your computer, you will see the difference of the f/stops in the outcome of the image.