Is there a way to turn this off so I don't have to go through and delete one copy of everything all the time.
The raw images are exactly that: the raw data that came from the sensor.
They need more workIf you only want either one, butyou have greater potential fro editingto decide which one.
Nikon has this article on their website that will give you a basic understanding of what this is all about:
What are the differences between: RAW, NEF, Compressed-NEF, TIFF, and JPG file formats?
JPEG: These images are a standard for web and email images as well as images from compact digital cameras.
JPEG is a standardized image-compression format. JPEG compression
reduces the file size but has no effect on the number of pixels in the
image (i.e., the resolution). JPEG was designed to compress the file
size of photos and can handle as many colors as are in the picture. It
is also lossy, meaning that some information is lost during
compression, and the decompressed image is not a total match with the
original. This means that a little bit of image detail quality is lost
when saved as JPEG.
Most cameras have several different quality settings (Fine, Normal and
Basic, for instance) which make the file size smaller at the expense
of image quality. At the highest quality setting of "Fine" there is
very little actual quality loss. Nikon digital cameras represent JPEG
capture as Fine (1:4 JPG), Normal (1:8 JPG), and Basic (1:16 JPG).
Be aware that JPEG compression quality loss is cumulative, meaning
that if you open a JPEG image and edit it (crop, change color, resize,
etc.) and resave it as a JPEG image quality will be lost. It is a good
idea not to repeatedly save as a JPEG.
In most cases, even for high-quality printing, JPEG compression is
more than adequate. It is important to remember not to compress a file
that is already in JPEG format, especially if you are looking for the
best quality print possible.
TIFF A TIF image is an uncompressed image showing the full detail of the image with no quality loss. TIFF images are very large and can
take large amounts of storage space and can take a long time to save
to the memory card.
When a TIF image is created in the camera, the camera takes the RAW
image from the camera's sensor and converts it into the TIFF format
using the settings in the camera's menus. There is little reason to
shoot TIFF images in the camera.
RAW A RAW image is the pure data directly saved from the camera's image sensor onto the card. With other image formats the camera
processes the raw data and converts it to TIFF or JPEG, but with RAW
mode the pure data is saved and can be edited later. Since no
corrections have been made there is more opportunity to edit the file
later. RAW images must be converted to a printable format (like TIFF)
using proprietary software.
RAW images are larger than JPEG but not as large as TIFF.
NEF Nikon calls images saved in the RAW format "NEF" files. Nikon RAW NEF files can be edited in Nikon View Editor, PictureProject,
Nikon Capture Editor and Nikon Adobe Photoshop plug-in.
This unique format consists of the RAW data of an image, along with an
instruction set that provides extensive image editing capability not
available with other file formats. With a NEF file, the original RAW
data of an image is never changed. All corrections and adjustments
that you make are preserved in the file's instruction set. You can
change the instruction set as many times as you like without ever
disturbing the original image's RAW data. Using the software listed
above you can change the shooting White Balance, adjust Exposure
Compensation as well as basic color, sharpening and levels controls.
Current Nikon DSLR cameras, including the D3-series, D2-series, D700,
D300(S), D200, D100, D7000, D5000, D3100, D3000, D90, D80, D70s, D70,
D60, D50, D40X, D40, all support the NEF RAW file format. All future
Nikon Digital SLR cameras will support the NEF RAW file, and some
Coolpix cameras will as well.
Many users think of their NEF files as their original digital
"negative" which they then make changes to and save the changed files
as TIFF (or JPEG) for printing.
Compressed NEF Visually lossless compression method used for NEF in D70 and other Nikon products that support NEF compression.