Files, raw processing and workflow

Pressing the shutter is the middle of the photographic process, not the end. The data the sensor records must be turned into an image, adjusted, selected, named, stored safely and delivered in the right form for a screen or a print. Decisions here, starting with whether the camera saves JPEG or raw files, determine how much you can correct and improve later, and whether your pictures will still exist in ten years. This lesson explains image files and bit depth, the difference between JPEG and raw, the steps of raw processing in a sensible order, non-destructive editing and catalogs, culling and rating, metadata and keywords, backup, and exporting for screens and print. PHOT-202 develops editing and retouching in depth; this lesson builds a sound workflow.

Pixels and bit depth

A digital image is a grid of pixels, each storing numbers for red, green and blue. The number of bits per channel, the bit depth, sets how many distinct levels each channel can hold:

• 8 bits: 2⁸ = 256 levels per channel, about 16.7 million colors in total. JPEG files are 8-bit.
• 12 bits: 4,096 levels; 14 bits: 16,384 levels. Most camera sensors record raw data at 12 or 14 bits.
• 16 bits: 65,536 levels, used by editing software and TIFF files to avoid rounding errors during heavy adjustments.

More levels do not make an image look different straight out of the camera. They matter when you edit: brightening shadows or stretching contrast spreads the existing levels apart, and with too few levels, smooth gradients such as skies break into visible bands (posterization).

JPEG and raw

A camera can save each picture as a JPEG, a raw file, or both:

• A JPEG is a finished image: the camera has demosaiced the sensor data (Lesson 1), applied white balance, picture style, contrast, sharpening, noise reduction and lens corrections, converted it to 8 bits and a color space (usually sRGB), and compressed it. JPEGs are small, universally readable and ready to share, but most of the original data has been discarded, so large corrections afterward degrade quality.
• A raw file stores the sensor's data almost as recorded, with the camera's settings attached as notes. Nothing is baked in: white balance, exposure, color and noise reduction are decided later, losslessly, with the full bit depth and dynamic range. Raw files are larger, need processing software, and each manufacturer uses its own format (such as .CR3, .NEF, .ARW, .RAF), though the open DNG format is widely supported.

HEIF/HEIC, used by many phones and some cameras, is a modern alternative to JPEG with better compression and 10-bit support.

For learning and for any important work, shoot raw (or raw plus JPEG): it forgives exposure and white balance errors and gives the most quality. JPEG suits situations that need immediate delivery and high volume, such as news and some events, where the camera's processing is set up carefully in advance.

Raw processing in order

Raw processing software (such as Lightroom, Capture One, darktable, RawTherapee or the manufacturers' own programs) presents adjustments in roughly the order in which it makes sense to apply them:

• Lens corrections: apply the lens profile to correct distortion, vignetting and chromatic aberration (Lesson 2).
• Crop and straighten: level horizons and verticals, and refine the composition. Keep enough pixels for the intended use.
• White balance: set temperature and tint, by eye or with the eyedropper on a neutral area (Lesson 8).
• Exposure: set the overall brightness, checking the histogram.
• Tone: adjust highlights and shadows to recover detail at the ends, set white and black points, and shape contrast with a tone curve.
• Presence and color: clarity and texture for midtone contrast, vibrance and saturation, and adjustments to individual hues.
• Local adjustments: brighten, darken, warm or cool specific areas with brushes, gradients and AI-generated masks of the sky, subject or background, the digital equivalent of the darkroom's dodging and burning.
• Detail: noise reduction and sharpening, judged at 100 % magnification (Lesson 5).

Work from the general to the specific, make big decisions before small ones, and step away before final judgments: tired eyes over-saturate and over-sharpen. Compare with the original from time to time to make sure the edit has improved the picture rather than just changed it.

Non-destructive editing and catalogs

Modern raw processors are non-destructive: they never change the original file. Instead they store a list of instructions, the edits, in a database (catalog) or in a small sidecar file next to the image (such as an .xmp file), and apply them when displaying or exporting. You can return to any image years later and change or undo every adjustment, create several versions of the same picture, and copy settings from one image to many. A catalog also lets you search a whole collection by date, rating, keywords, camera settings or location in seconds.

Destructive editing, changing the pixels of a file directly, as in pixel-level retouching and compositing (PHOT-202), should always be done on a copy, ideally in layers, never on the original.

Culling, rating and metadata

Most shoots produce many more frames than will ever be used. Culling, choosing the best and rejecting the rest, is a skill. Do a first fast pass, flagging obvious rejects (blurred, closed eyes, missed moments) and possible keepers, then compare similar frames side by side and keep the strongest. Use star ratings and color labels consistently, for example: 1 star = possible, 3 stars = good, 5 stars = portfolio. Deleting rejects keeps the collection manageable, but some photographers keep everything because a rejected frame sometimes becomes useful later.

Every image carries metadata: EXIF data recorded by the camera (date, time, camera, lens, settings, and often GPS location) and IPTC data that you add (title, caption, keywords, creator, copyright notice and contact details). Adding your name and copyright notice on import, keywords for subjects and places, and captions for important images makes pictures findable and protects their attribution when shared. Be aware that GPS location in shared images can reveal where you live or where vulnerable people or species are; remove it when sharing such pictures.

File naming and folders

A consistent system saves endless searching. A common approach is folders by year and date or event (2026/2026-10-18_Harvest-Festival) and file names that include the date and a sequence number (20261018_0142.CR3), which stay unique and sort in order. Rename on import, not later. Decide on a system, write it down and apply it to every shoot.

Backup

Memory cards fail, hard drives fail, laptops are stolen and houses burn. The standard rule is 3-2-1: keep at least three copies of every important file, on at least two different kinds of storage, with at least one copy off site (another building or a cloud service). Cameras with two card slots can record to both cards at once for an immediate second copy, a common practice at weddings and other unrepeatable events. Back up before formatting cards (Lesson 1), test that backups can actually be restored, and replace drives before they get old.

Exporting for screens and print

Export settings depend on where the picture will go:

• For the web and social media: sRGB color space (Lesson 8), JPEG at good quality, and a size suited to the platform, often 2,000 to 4,000 pixels on the long edge. Apply output sharpening for screens. Remove sensitive metadata if needed.
• For print: the needed pixel count depends on print size and resolution. A typical standard for quality prints viewed close up is 300 pixels per inch (about 118 pixels per centimeter), though large prints viewed from a distance look excellent at 150 to 200 ppi. Export as high-quality JPEG or TIFF in the color space and profile the printer requires (PHOT-301).

Editing honestly

VIS-101 discussed the ethics of editing. In practice, the standard depends on context: news and documentary photography allows only adjustments that do not change the content (exposure, color, contrast, modest cropping), whereas commercial and artistic work may use any technique, ideally disclosed when it changes what the picture appears to show. Keep originals, so you can always show what the camera recorded, and be honest about composites and generated elements.