We've blogged a number of great home ideas for your photos, including md-canvas, resources for framing your blow-ups, and amy (rustyletter)'s cool lamp idea for diploma display, which is also a great use for any photo that you want transformed into a useful household object. But we ourselves were a little in the dark about the capacity of our trusty digital camera for high-quality print output.
How do you ensure that the images you take are of a high enough resolution to be high impact on your walls?
The anwer is that it's not easy if you're uncompromising on image clarity and are using a consumer grade digital camera.
This chart explains the concept of megapixels and provides the number of them you need for the output size you're targeting. Asuming you want the image to be glossy-magazine clear, which generally requires a resolution of at least 300dpi (dots per inch), the chart reveals that most consumer grade digital cameras just can't deliver the megapixels you need for largescale wow. But if you'll settle for the artsiness of soft focus, you can still print your digital snaps quite large.
Here's some context: a phone camera typically provides no more than 2 or 3 megapixels. A consumer digital camera delivers up to about 10 these days. According to the chart, an 18" x 26" print (at 300dpi) requires a 44 megapixel capture!
Now we know why most pros are so loyal to film.
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Comments (7)
Um, unless I'm reading it wrong, I don't think that chart is accurate. I'm a professional photographer, I use a digital camera with 12.9 megapixels, and according to Photoshop, and one full frame (uncropped, 1:1.5 ratio) picture @ 72 dpi is 3872 x 2592 pixels, or 53.7" x 36". While I've never made an 18"x 26" print, I've made several 16"x 20" prints, and they all look fine. I would imagine I could go much larger, if I wanted, especially if I adjusted it to be 300dpi. As far as I'm concerned, that chart is fairly bogus. I'm just working off of experience.
And, as far as I know, a 44 megapixel camera doesn't even exist. Last I heard, the most a camera had was 16-something, and that was about 6 months ago. Obviously, the more megapixels, the better, but these cameras are expensive. Probably not worth buying for a few design projects. I don't know if there's a good camera retailer in the area (I moved here from DC in August, I bought all of my equipment out there), but if you have a project that needs some big prints, rent the camera.
The problem with taking it to 300 dpi is that you're getting resampling - so even though you'll get a bigger image size, you're going to have digital artifacts in the larger image. Just increasing the ppi/dpi doesn't increase the size. It will look bigger on your screen but you will not get more information just by scaling up your resolution. This is why it's important to shoot in a raw file when you have that option available, and convert to a lossless tiff.
Yeah adjusting 3872 x 2592 pixels to 300 dpi would only result in a print that measures approximately 13" x 8.75" if you do not change the overall pixel count. If you're getting 16" x 20" prints (at 300 dpi), there is a little resampling going on, but not a whole lot, which is probably why they look fine to you.
It was 3872 x 2592 @ 72 dpi, not 300.
I agree with Samantha--I'm not trusting this chart for accuracy either. Using a 10.2 megapixel camera, I got a crisp and clear 20x24 print--shot in raw and with only minimal changes. I have another print that size (different subject) from medium format film and the clarity and quality is the same.
Regarding pixels, inches and dpi: Dpi can get confusing because it's a ratio—dots (or pixels) per inch.
By definition, a 3872x2592-pixel image contains a fixed number of pixels (about 10 million). This is true regardless of whether it's at 72 dpi or 300 dpi. The image can display its 10 million pixels at 300 per inch (more dense, therefore sharper in a print), or it can display the 10 million pixels at only 72 per inch (larger area, but less dense). (It could be any other value too, but these are the common ones.)
Try this: open an image in Photoshop. Go to Image Size and uncheck Resample Image. Now change the resolution from 300 to 72 dpi (or any other number). You will see that the size changes in inches, but the number of pixels stays the same.
It's a different story if you have, for example, two 3x5-inch images at different dpi. If you have a 3x5-inch image at 72 dpi, it only contains 77,760 pixels. A 3x5-inch image at 300 dpi would contains 1.35 million pixels.
Oh, by the way—I think Hasselblad has a 39-megapixel camera, and Phase One might make something approaching that size.
Still, very large prints can be generated from smaller images. I think part of this is thanks to software and printing techniques (upscaling, interpolation, up-rezzing, whatever you want to call it), but it also has to do with the apparent sharpness of the image, since larger images are often viewed from a distance.