When addressing image resolution, there are a few things you need to know…
Born Digital are images created with a digital camera. We recommend that your ﬁles be kept or converted to 16-bit mode (16-bit grayscale or 48-bit RGB). If you are using a color-managed system or have a professional retoucher, you may send us the retouched ﬁle without interpolating the ﬁle to a speciﬁc ppi. We will scale the ﬁle as necessary when printing.
Scaling Your Image
Scaling your image file up is not required for our modern printers that do this internally with algorithms best matched to the printer. Some software purports to improve image quality through scaling. We do not recommend that this be used to enhance details that, in reality, were not captured in the image. There is no software that can create detail where it does not exist. The only solution is to return to the scene or event and re-photograph it in a higher resolution.
You may want to scale your images to a consistent size if you are applying special effect, grain or other filters so you achieve a consistent affect across images. Two images both printed at 20×24 inches, but one image is at 180 ppi and the other is at 240 ppi, with the same grain filter will have a different grain effect when printed. To achieve a consistent effect the ppi of the smaller file should be adjusted to the same as the larger file.
Large prints may print beautifully when they are scaled up from 72 ppi by our printers, depending on the subject matter. When the subject matter is soft with broad tones and no ﬁne details, it is more likely to meet the best visual standards, even when printed with signiﬁcant scaling. Conversely, an image with ﬁne details may not print with acceptable quality if the original resolution falls below 200 ppi for a given print size regardless of how you scale the image to 300 ppi (printing level).
Photographic Film Scans
Need higher resolution, shoot large format film. Large format film (4×5 inch or 8×10 inch) used with the proper technique and lenses can provide more detail and color quality than most digital cameras and usually at a lower initial cost. If you are planning on shooting hundreds of super-high resolution images, then the economics switches back to a super high resolution digital camera. Large format film will not be available in the not to distant future, so do this while you can.
For scanning film we recommend that ﬁlm scans be made in 16-bit grayscale or 48-bit RGB mode with enough resolution to capture the ﬁnest details in the subject matter – or down to the grain level, depending on your preference.
Mega Pixels vs. Print Size
A ﬁnely detailed subject photographed with a 12 mega pixel (MP) camera, can be expected to produce a maximum print size of 15 x 20 inches (not including a border). If the subject matter is, for example, in a Pictorialistic style with soft tones and no ﬁne details, the same 12 MP camera might produce a perfect 42 x 56 inch image (or a 4 x 5 foot print with 2-3 inch border).
Resolution to Print Size Guide
Click image to enlarge.
For more information, read our detailed white paper on resolution and digital files.
Ultra High Resolution with DSLR’s
You can capture a scene in high resolution with a 12 MP camera by taking several photographs to cover the scene and then using software (e.g., Kolor’s AutopanPro) to stitch the images together, creating a single image with a much higher resolution.
The image above illustrates eleven 12 MP images combined to create a 90 MP ﬁle, a much higher resolution ﬁle than can be produced with the largest pro digital back currently available. While we do not suggest using this technique for portraiture, landscape scenes can be quite dynamic with dramatic results. This technique is used by many artists to create large format, realistic-looking collages.
Artwork Reproduction Scans
Fine artwork can be reproduced in several different ways: ﬂatbed scanning, digital camera copying, scanning ﬁlm copies, or drum scanning. Whichever of these methods you decide on, we recommend the following best-practice to anyone making digital reproductions:
– Calibrate the system you are using.
– Scan at the highest color quality (48-bit RGB) with a spatial resolution sufﬁcient to capture as much of the detail of the original as possible.
– Do not adjust the tone, white point, or black point in the scanning or camera software. Use a “linear curve.” The scan may appear ﬂat, but it is the most accurate.
– For best results, the contrast should be adjusted when the print is made. If there are particular colors that are problematic and you want to edit the ﬁle before sending it to us to print, edit the color proﬁle or, if you edit the ﬁle directly, leave the edits as layers so they are reversible.
– If you are ordering scans request 48-bit ﬁles, unedited, at the highest resolution.