Camera image file sizes and quality loss after importing

Discussion in 'Digital Photography' started by mfuser1, Aug 21, 2009.

  1. mfuser1 macrumors newbie

    Aug 21, 2009
    I've slowly been accumulating 7000+ images in to my iPhoto library over the last five years. The library size has grown to 50GB. (including videos)

    These photos have come from various makes and models of cameras over the years: Sony, Sanyo, Casio, HP as well as different megapixel levels: 3MP, 4MP, 7MP, 10MP, 12MP.

    I've noticed that after importing a photo, if I view it in iPhoto or Preview, that simply saving it REDUCES the file size significantly. An example is a 4MB photo sometimes goes down to 1.3MB. I have compared the two images in Preview after saving and cannot see any difference. I know about JPG compression etc. but am not sure that this is what's happening. Do some cameras have larger file sizes than are needed?

    Try opening an image in Preview, rotate it right 90 degrees, then left 90 degrees. Save it and look at the file size shrink. Am I losing quality?

    I'd like to shrink my iPhoto library, is this a way to do it or will I be losing quality? If I cant see a difference, should I care? I know nothing about images, quality etc.

  2. MKSinSA macrumors regular


    Aug 1, 2009
    Alamo City, Lone Star State
    You would be losing quality, but if you don't notice the difference, it's no big deal unless you plan to publish them professionally. For the number of photos you have, it doesn't sound very efficient, but it is a way to go. A batch photo compression program would streamline the process.

    HTH :cool:

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