Every once in awhile someone sends me a favourite, special image from Facebook or some other web site or blog and they ask me to make an enlargement print. They are often surprised or disappointed when I have to inform them that this is unlikely to work, despite how amazingly good the image might appear on their laptop or cell phone.
If you have read part 1 of this series, you’ll know that I can produce amazingly good enlargement prints from a 12 MP, 10 MP or even an 8 MP camera file. So why won’t the Facebook image work?
Images that you find on Facebook, or for that matter, on most web sites and blogs, actually contain very few pixels, which are the key ingredients needed to produce sharp enlargements. Facebook restricts uploaded images to fit within only 720 pixels x 720 pixels (it used to be only 604). To verify this, click on any thumbnail in the Photo tab of any Facebook page. When the image opens up, right click on it and select Properties. The largest dimension you’ll see is typically 604 pixels, or 720 pixels in the case of more recent images. That’s only 0.5 MP, much less than any digital camera produces! When I receive an image in which one of the pixel dimensions is 604 (or 720), the image invariably was grabbed from Facebook.
Remarkably, these images can look exceptionally good when you see them on Facebook on an iPhone, iPad or laptop. That’s because the screen resolution (pixel density) of these devices is fairly high. The amazing iPhone 4 has a screen resolution of 326 ppi, which is awesome. Even some laptops have a screen resolution 145 ppi, which is also pretty skookum. Of course, on these displays, the images also occupy only a few square inches, which further contributes to apparent sharpness.
However, 604 pixels when printed over a space of 20″ will only be about 30 ppi effective print resolution. I know I can perform miracles, but really! At 30 ppi, the loss of definition will be quite extreme and I’m certain that most clients would be disappointed to see their favourite Facebook image, that looked so amazing on their iPhone, reduced to mush on paper or canvas. So in most cases, I end up rejecting those images.
So what’s to do then? If a client sends me a Facebook image (or other image evidently captured from a web site or blog), I explain to them the quality problem (604 pixels, mush, etc.). Then I ask them if they know the original photographer and if they can possibly get the original camera file. In most cases, they do and they can! So then they send me a full-resolution camera file from which I can produce a print we’re both proud of.
The moral of the story: don’t expect much from a Facebook image; but odds are you know the original photographer (hey, it’s your son, daughter, friend, etc., right?). So why settle for a web download when you can probably get the original, full-resolution camera file for printing.
Next time: The dirty truth about JPEG