Table of Contents
1. Resolution: PPI vs DPI and What They Mean for Your Output
Resolution is the single most misunderstood export setting. For digital display, we measure in pixels per inch (PPI); for print, dots per inch (DPI). The two are not interchangeable, but they determine how sharp your image appears at a given size.
For web use, 72 PPI is the historic standard, but modern high-DPI displays (Retina, 4K) benefit from exporting at 150-200 PPI. A 1920×1080 pixel image at 72 PPI will look soft on a 5K iMac. Instead, export at 2x resolution: 3840×2160 pixels at 144 PPI. This ensures crispness across devices without bloating file size unnecessarily.
For print, the rule is 300 DPI for high-quality output. A 4×6-inch print requires 1200×1800 pixels (4×300 × 6×300). For large-format prints (posters, banners), you can drop to 150-200 DPI because viewing distance increases. A 24×36-inch poster at 150 DPI needs 3600×5400 pixels. Always check your printer's native resolution -- some inkjet printers prefer 360 or 720 DPI for optimal dot placement.
Key stat: A 300 DPI print at 8×10 inches requires 2400×3000 pixels -- roughly 7.2 megapixels. Most modern cameras exceed this, so downsizing is common.
Pro tip: When exporting for both web and print from the same master file, create two separate exports. Never resize a web export up to print size -- you'll introduce interpolation artifacts. Start from the full-resolution original each time.
2. Color Space: sRGB, Adobe RGB, and ProPhoto RGB Explained
Color space defines the range (gamut) of colors your image can display. sRGB is the smallest gamut but the most universally compatible -- every web browser, social media platform, and consumer monitor assumes sRGB. Adobe RGB offers a wider gamut, especially in greens and cyans, making it ideal for professional print workflows. ProPhoto RGB is the largest, used only in raw processing and high-end editing.
For web export, always convert to sRGB. Uploading an Adobe RGB image to Instagram or your portfolio site will result in dull, desaturated colors because the browser clips out-of-gamut colors. In Lightroom, check 'Convert to sRGB' in the export dialog. In Photoshop, use Edit > Convert to Profile > sRGB IEC61966-2.1. Do not use 'Assign Profile' -- that changes interpretation, not actual color values.
For print, the choice depends on your printer and paper. Most inkjet printers (Canon Pro, Epson SureColor) have gamuts larger than sRGB but smaller than Adobe RGB. Adobe RGB is a safe middle ground. If your lab specifies a custom profile (e.g., 'Fuji Crystal Archive' or 'Ilford Galerie'), soft-proof in Photoshop using that profile before exporting. For fine-art giclée prints on matte paper, ProPhoto RGB preserves subtle tonal transitions better, but only if your entire workflow (camera, monitor, software) supports it.
Color space mistakes are costly. A wedding photographer who exports proofs in Adobe RGB for a client's web gallery will receive complaints about 'washed out' images. Always match the color space to the final medium: sRGB for screens, Adobe RGB for commercial print, ProPhoto RGB only for archival raw processing.
3. File Format: JPEG, TIFF, PNG, and When to Use Each
JPEG is the default for web and most print labs. It uses lossy compression, meaning some data is discarded to reduce file size. At quality setting 80-90 (Lightroom scale 80-100), the compression is visually lossless for most images. Below 60, artifacts become visible, especially in skies and gradients. For print, use JPEG quality 100 or switch to TIFF.
TIFF is lossless and supports 16-bit depth, preserving maximum tonal information. Use TIFF for archival storage, client delivery for retouching, or when your print lab requires it. The downside: file sizes are 5-10x larger than JPEG. A 24-megapixel TIFF at 16-bit is roughly 140 MB. For web, TIFF is impractical -- no browser displays it natively.
PNG is lossless but uses a different compression algorithm optimized for graphics with sharp edges and transparency. Use PNG for web graphics, logos, or images with text overlays. For photographs, PNG files are typically larger than JPEG with no quality benefit -- stick to JPEG for photos.
HEIF (High Efficiency Image File Format) is gaining traction on Apple devices and modern web platforms. It offers better compression than JPEG (roughly 50% smaller at equivalent quality) and supports 10-bit color. However, compatibility is still limited -- Windows and Android support is inconsistent. Export HEIF only if your target audience uses Apple devices exclusively.
Pro tip: For print labs that accept JPEG, always request their specific compression guidelines. Some labs prefer JPEG quality 12 (Photoshop scale) while others recommend TIFF for large prints. When in doubt, ask for a test print before the full run.
4. Sharpening for Output: Capture, Creative, and Output Sharpening
Sharpening is not a one-size-fits-all step. Professional workflows separate sharpening into three stages: capture sharpening (to counteract the camera's anti-aliasing filter), creative sharpening (to enhance specific areas), and output sharpening (to compensate for the output medium's characteristics).
Output sharpening is the most critical for export. A web image displayed on a screen needs less sharpening than a print, because screens have higher contrast and no ink spread. Lightroom's export dialog includes presets for 'Screen', 'Matte Paper', and 'Glossy Paper'. These apply the correct amount of sharpening based on the output medium. For Photoshop, use Filter > Sharpen > Smart Sharpen with settings: Amount 50-100%, Radius 0.5-1.0 pixels, Remove Gaussian Blur.
For print, the paper type matters. Glossy paper holds sharpness well -- use low sharpening (Amount 50-70%). Matte paper scatters light, softening edges -- use higher sharpening (Amount 80-120%). Always view the print at normal viewing distance before adjusting. Over-sharpening creates halos that look unnatural, especially around high-contrast edges like tree branches against sky.
Web sharpening is trickier because of varying screen resolutions. A safe approach: export at 2x resolution (e.g., 2000px wide for a 1000px display container) and let the browser downsample. This effectively anti-aliases the image, reducing the need for heavy sharpening. Test your images on a Retina display and a standard 1080p monitor to ensure they look crisp on both.
5. Metadata, File Naming, and Batch Export Workflows
Metadata (EXIF, IPTC) can be a privacy risk or a useful tool. For client delivery, strip camera serial numbers, GPS coordinates, and software version info. Keep copyright, contact info, and caption fields. Lightroom's export dialog has a 'Minimize Embedded Metadata' option that removes everything except copyright and contact. For stock photography, include full metadata -- agencies require it for search indexing.
File naming conventions prevent chaos. Use a consistent pattern: YYYY-MM-DD_ProjectName_SequenceNumber.ext (e.g., 2026-06-01_SmithWedding_001.jpg). Avoid spaces and special characters -- use hyphens or underscores. For batch exports, Lightroom's 'Rename To' option can apply this automatically. For print labs that require specific naming (e.g., 'Print_4x6_001.tif'), create a preset.
Batch export is essential for efficiency. In Lightroom, create export presets for each common scenario: 'Web - sRGB - 2000px', 'Print - Adobe RGB - 300 DPI - TIFF', 'Client Gallery - sRGB - 1600px - Watermark'. Use the 'Export with Preset' shortcut to apply them in one click. For Photoshop, use Image Processor (File > Scripts > Image Processor) to batch-convert folders of images to JPEG or TIFF with consistent settings.
Pro tip: Always export to a dedicated folder named by date and project. Never overwrite originals. Use a versioning system: v01, v02, etc. If a client requests changes, you can trace back to the correct export without re-editing.