RAW vs JPEG: Demystifying image size and quality on your Nikon DSLR

    By | Tutorials | 31/03/2013 11:00am

    When it comes to RAW, JPEG, and image quality settings, it can all seem a little confusing… But help is at hand! By the end of this tutorial, you’ll know just what the difference between JPEG and RAW is, which to choose and how to choose it.

    Your Nikon DSLR allows you to record your images as two different file types – RAW or JPEG. But if you switch between the two using your camera’s Image quality menu you will see a range of options. JPEG is the world’s most popular digital image format. These files can be opened by many different computer programs, and the file size is scalable. Images can be compressed so that the file size is smaller – a property that is particularly useful with email.

    Nikon image size and quality

    Compression comes at a price: the more compressed a file is, the more the image quality deteriorates. On Nikon DSLRs, you get three levels of compression to choose from – the highest quality is ‘Fine’, the next-best is ‘Normal’, and ‘Basic’ is the lowest quality, and best reserved for emergencies.

    Your camera also gives you a choice as to how many pixels you want your picture to have. To choose the maximum number your sensor allows, select Large (L). Medium (M) produces images 75 per cent of the width or height, while Small (S) produces images half the width or height of the full-size version.

    To get the smallest file sizes and to fit the most shots on your memory card, you could choose the Small size and Basic quality settings, but in almost all situations, you should record Large images at Fine quality or choose the superior RAW format.

    The RAW option stores the data in a semi-processed state (like a digital negative). It captures more tonal information than a JPEG, which makes RAW images invaluable for editing purposes.

    RAW files are larger in size than JPEGs, so fill up your card quicker, and take longer to process in the camera. For high-speed continuous shooting, therefore, you can shoot longer sequences without the buffer filling up if you switch to JPEG.

    RAW files need specialist software to be processed – and need to be converted to a file format such as JPEG if they are to be viewed on the web and other PC programs. However, the disadvantages are worth putting up with in order to have the increased editing flexibility.

    On most Nikons, RAW files are a fixed format, but on the advanced models even these can be adjusted. The size always corresponds to the sensor’s maximum resolution, but you can alter the bit-depth, which affects the tonal range and subtlety, and the compression setting too. These enable you to trade off ultimate image quality against file size in the same way you can with JPEG quality settings.

    The reason for all these file size and quality adjustments is to enable you to make the most of your memory card space. But memory is a lot cheaper than it used to be, so while it’s worth picking the most efficient size and quality settings for your needs, it’s not worth compromising on quality to get more images on the card – instead, get a bigger card!

    Card capacity isn’t the only consideration, because today’s DSLRs combine higher resolutions with higher continuous shooting speeds, which means large amounts of data must be saved quickly. This means memory card speed could be just as important. While you’re working out the best settings for your photos, you should also consider whether your current memory cards are up to the job.


    Nikon image size and quality

    Info Screen

    On a smaller Nikon D-SLR like the D3100, you need to press the ‘i’ button to display the Info screen, then use the multi-selector to highlight the quality (‘QUAL’) settings, top right.

    Nikon image size and quality

    RAW or JPEG?

    If you choose RAW from the Image quality menu, you’ll see that the Image size menu below is greyed out (RAW files are always shot at full size). To shoot JPEGs, choose Fine, Norm or Basic.

    Nikon image size and quality

    Image Size

    If you choose one of these JPEG options, you can then use the Image size menu to choose the Large (L), Medium (M) or Small (S) image size, but see the box at the top of this page before deciding.

    Nikon image size and quality

    Using the QUAL button

    On more advanced Nikons like this D600, you press the QUAL button then turn the rear command dial – the Image Size and Quality settings are displayed on the top LCD panel or the info display on the back.


    Raw compression

    D3100 Just one setting

    On a basic D-SLR like the D3100, there are no RAW (NEF) options. This camera shoots ‘12-bit’, ‘compressed’ RAW files, which are still better than JPEGS.

    Raw compression

    D600 12-bit

    More advanced cameras like the D600, have a NEF (RAW) recording option on the Shooting menu. This provides two options – ‘Type’, and NEF (RAW) bit depth…

    Raw compression

    D600 14-bit

    The ‘bit depth’ is the number of bits of data used, and the 14-bit option will potentially produce smoother images, though the differences may not be obvious.

    Raw compression

    D600 Compressed

    The ‘Type’ option offers different compression options. On smaller Nikons, RAW files are compressed by default. ‘Compressed’ reduces the file size.

    Raw compression

    D600 Lossless compressed

    This option produces larger files which are compressed, but in a way that doesn’t affect the image quality at all (rather like compressed TIFF files versus compressed JPEGs).

    Raw compression

    D4 Uncompressed

    The Nikon D4 goes one step further, offering a third option where there’s no compression at all. This produces the largest files, so high-capacity cards will be essential.

    Posted on Sunday, March 31st, 2013 at 11:00 am under Tutorials. You can subscribe to comments.

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