Scanning Problems Troubleshooting

Scanning is where many film photographers first encounter frustration. The negative looks perfect, but the scan has dust spots, colour casts, banding, or softness that wasn't there before.

This guide covers common scanning problems, their causes, and practical solutions.

Scanner Types: A Quick Overview

Before troubleshooting, it helps to understand the three main scanner types and their characteristics:

Flatbed scanners (e.g., Epson V600, V850) are the most accessible option. A flat glass surface with a transparency unit in the lid scans film by passing a sensor across it. Best for medium and large format film; adequate for 35mm. Affordable and versatile, but slower than other methods.

Dedicated film scanners (e.g., Plustek 8100, Nikon Coolscan) are purpose-built for film. They use higher-quality optics optimised for small negatives, delivering superior 35mm results compared to flatbeds. However, they're typically limited to one format and increasingly hard to find new.

DSLR/mirrorless scanning uses a digital camera with a macro lens to photograph negatives on a light table. The fastest method with excellent quality, but requires more initial setup and inversion software. Scales well to any film format.

Key Terms

DPI (dots per inch): Scanner resolution measurement. Higher DPI captures more detail, but actual resolving power often falls below manufacturer specs. For 35mm, 2400-3200 effective DPI is typically sufficient.

Bit depth: The amount of colour information captured per pixel. 8-bit provides 256 levels per channel (16.7 million colours total); 16-bit provides 65,536 levels per channel. Scan at 16-bit for maximum editing flexibility, especially when working with colour negatives.

Dust and Scratches

The most universal scanning problem. Every speck on your negative becomes a spot in your image.

Prevention: The Best Solution

Before scanning:

• Let negatives dry completely (4+ hours) in a dust-free environment
• Handle negatives only by edges or rebate
• Store in archival sleeves immediately after drying
• Clean your scanning area—dust settles constantly

Cleaning negatives:

Hardware Solutions: Infrared Dust Removal

Many scanners offer infrared-based dust detection and removal:

Digital ICE (Image Correction and Enhancement):

• Shines infrared light through the negative
• IR is blocked by dust and scratches but passes through the negative
• Scanner maps dust locations and removes them automatically
• Works excellently for colour negative and slide film

ICE for black and white:

• Traditional silver B&W negatives block infrared (silver reflects IR)
• Digital ICE cannot distinguish dust from image detail on B&W
• Some chromogenic B&W films (Ilford XP2, Kodak BW400CN) work with ICE because they use dyes, not silver

Other implementations:

• VueScan: "Infrared clean" option
• SilverFast: "iSRD" (Infrared Smart Removal of Defects)
• Nikon scanners: Built-in ICE
• Epson scanners: "Digital ICE" on film scanning models

Software Solutions

When hardware dust removal isn't available or isn't working:

Clone and heal tools:

• Photoshop: Spot Healing Brush, Clone Stamp, Content-Aware Fill
• Lightroom: Spot Removal tool
• GIMP: Clone tool, Heal tool
• Capture One: Spot Removal

Automated dust removal:

• Photoshop: Filter > Noise > Dust & Scratches (use with layer mask)
• Lightroom: Use Visualize Spots to find dust
• Some dedicated plugins: Imagenomic Realgrain, etc.

Best practice workflow:

1. Clean the negative before scanning
2. Use ICE if available
3. Clean remaining spots in software
4. Create a preset for consistent spot removal

Newton Rings

Newton rings appear as rainbow-coloured concentric circles or irregular patterns, usually when film contacts glass.

What Causes Newton Rings

When two smooth surfaces come into close contact but aren't perfectly touching, light waves interfere with each other. The result: visible interference patterns.

Common scenarios:

• Film contacting scanner glass
• Film holders with glass that presses against film
• Wet mounting with air bubbles
• Film curling and partially touching surfaces

Solutions

Anti-Newton Ring (ANR) glass:

• One surface is slightly textured (etched)
• Breaks up the interference pattern
• Available as scanner glass replacements or in film holders
• Slight cost to sharpness (negligible with quality ANR glass)

Film holders with no glass:

• Many dedicated film scanners use tensioned holders with no glass contact
• Film suspended in holder, only air on both sides
• Eliminates Newton rings entirely
• Examples: Epson holders, Nikon FH-series

Keep film flat without glass:

• Use proper film holders designed for your scanner
• Store film properly to minimise curl
• Let film acclimate to room temperature before scanning

Wet mounting:

• Eliminates air gap entirely by using a liquid
• Film placed in scanning fluid on glass
• Excellent results but messy and time-consuming
• Requires special fluids (Kami Fluid, Lumina, etc.)
• Not practical for batch scanning

Oil mounting:

• Similar to wet mounting but with mineral oil or special scanning oil
• Outstanding results for critical work
• Very messy, requires cleaning negatives afterwards
• Reserved for exhibition prints or problematic negatives

Newton Rings with DSLR Scanning

DSLR scanning can have its own Newton ring issues:

• Film holders with glass (Essential Film Holder, etc.) may show rings
• ANR glass options available for most holders
• Keeping film flat with tension (MK1 negative holders) avoids the issue
• Some find slight film curl actually helps prevent contact

Colour Cast Issues

Colour problems are common with both negative and slide film scanning.

Orange Mask Removal (Colour Negative)

Colour negative film has an orange mask—a built-in filter that improves colour accuracy in printing. Scanners must remove this mask to produce correct colours.

Common problems:

Muddy or brown images:

• Scanner software not removing mask properly
• Wrong film profile selected
• Manual colour correction needed

Colour varies frame to frame:

• Inconsistent exposure causing different mask densities
• Scanner adjusting each frame differently

Solutions:

Use proper negative conversion:

• Negative Lab Pro (Lightroom plugin): Excellent automated conversion
• SilverFast NegaFix: Scanner software with film profiles
• VueScan: Film profiles for many stocks
• Capture One: Film profiles included

DSLR scanning:

• Never white balance on the orange mask
• Use conversion software designed for negatives
• Raw files give most flexibility for conversion

Manual correction workflow:

1. Set white point from film rebate (unexposed area)
2. Invert the image
3. Adjust per-channel curves to balance colours
4. Fine-tune with HSL adjustments

Scanner Calibration

Scanners drift over time. Regular calibration helps maintain colour accuracy.

IT8 calibration targets:

• Standard colour reference targets
• Scan the target, software creates a colour profile
• VueScan and SilverFast support IT8 calibration
• Targets available for slides (positive) and prints

When to calibrate:

• When you first get a scanner
• Annually for consistent use
• If colours suddenly seem off
• After lamp replacement

Manual Colour Correction

For scans with colour casts:

Find a neutral reference:

• Look for something that should be neutral grey or white
• Use that as your white balance point
• Eyedropper tools in most software

Per-channel curves:

• If shadows are magenta, reduce magenta in shadows (add green)
• If highlights are yellow, reduce yellow in highlights (add blue)
• Each channel can be adjusted independently

Colour problems by film type:

Banding

Banding appears as regular stripes or lines across the image. The pattern is usually consistent and mechanical in origin.

LED Light Source Banding

Some scanners with LED light sources can produce banding due to:

• PWM (pulse-width modulation) of the LED
• Interaction between scan speed and light pulsing

Solutions:

• Update scanner firmware if available
• Try different scan speeds (DPI settings)
• Some software has anti-banding options
• Consider different scanner if persistent

CCD Sensor Banding

Symptoms:

• Very fine, regular horizontal lines
• Varies with scan settings
• May be more visible in shadows

Causes:

• CCD readout noise
• Electrical interference
• Sensor defect

Solutions:

• Multi-pass scanning (averages out noise)
• Scan at higher bit depth (16-bit)
• Check for electrical interference (move scanner away from other devices)
• If persistent, sensor may need service

Film Holder Banding

Symptoms:

• Bands correspond to holder position
• Visible where film isn't fully flat

Causes:

• Film not flat in holder
• Holder not seating properly

Solutions:

• Ensure film is fully seated in holder
• Check holder for warping or damage
• Use holders designed for your scanner

Focus Problems

Soft scans often come from focus issues rather than the negative itself.

Film Not Flat

The most common focus problem. Even slight film curl puts parts of the frame out of the scanner's depth of field.

Symptoms:

• Part of frame sharp, part soft
• Sharpness varies across frame
• Focus seems to shift near edges

Solutions:

Better film holders:

• Holders that tension the film flat
• Glass carriers (watch for Newton rings)
• ANR glass sandwich

Film flattening:

• Store negatives under weight for a few hours before scanning
• Use anti-curl solution in final rinse when developing
• Scan film soon after drying (before it curls excessively)

DSLR scanning specific:

• Essential Film Holder, Negative Supply, or similar quality holders
• Glass holder with ANR glass
• Flatten negatives under books before scanning session

Wrong Focus Point

Flatbed scanners:

• Different film heights may require focus adjustment
• Some scanners have adjustable focus; others don't
• Wrong holder height = wrong focus plane

Dedicated film scanners:

• Usually autofocus; may occasionally miss
• Manual focus point selection often available
• Focus on an area with fine detail (grain, sharp edge)

DSLR scanning:

• Focus on the film grain, not on a feature
• Use focus peaking if available
• Live view magnification for critical focus
• Consider focus stacking for very curved film

Scanner Optical Issues

Symptoms:

• Focus consistently soft across all scans
• Softness appears after a period of working fine
• Soft in corners even when centre is sharp

Causes:

• Dust on internal optics
• Lens misalignment
• Scanner damage

Solutions:

• Clean scanner glass (both sides if accessible)
• Check for dust on underside of glass
• Professional cleaning for internal optics
• If persistent, scanner may need service or replacement

Resolution Issues

Understanding resolution helps you get optimal results without oversized files.

Optimal Scanning Resolution

The principle: Scan at a resolution that captures all the detail in the film—but not higher, because you're just enlarging grain at that point.

General guidelines:

The test: Scan the same negative at multiple resolutions. If you can't see more detail at the higher resolution—just bigger grain—the lower resolution is sufficient.

Optical vs Interpolated Resolution

Optical resolution: The actual resolution of the scanner's sensor and optics. This is real resolving power.

Interpolated resolution: Software-enlarged resolution. The scanner scans at optical resolution, then software adds pixels. No new detail is captured.

Always use optical resolution for quality work. Interpolation can be done later in Photoshop if needed and gives identical results.

Example: A scanner with 3200 DPI optical resolution might offer 6400 or 12800 "interpolated." The 6400 and 12800 settings just produce larger files with no more detail.

When More DPI Doesn't Help

Film grain is the limit. Once you're resolving individual grain particles, more resolution just makes grain bigger. This is especially true for:

• Fast films (ISO 400+)
• Push-processed film
• Older film emulsions
• Some motion picture films

Scanner optics are the limit. Many flatbed scanners don't actually resolve their claimed optical DPI. A flatbed claiming 6400 DPI optical might actually resolve 2400-3200 DPI of real detail.

Lens quality in original image limits final sharpness. A soft lens on the camera can't be fixed by scanning at higher resolution.

Software-Specific Issues

Different scanning software has different quirks.

Negative Lab Pro

Common issues:

Colours look wrong after conversion:

• Try different colour model settings
• Check source profile matches camera
• Sometimes re-converting with different settings helps

Results vary frame to frame:

• Adjust black and white clipping per frame
• Use consistent lighting when DSLR scanning

SilverFast

Common issues:

NegaFix profiles don't match:

• Try different film profiles for same stock
• Custom profile adjustment often needed

Slow performance:

• High-resolution preview causes slowdown
• Reduce preview resolution in preferences

VueScan

Common issues:

Colours inconsistent:

• Lock film base color between frames
• Create custom profiles for your film stocks

Image too dark or too light:

• Adjust "Analog gain" in the Input tab
• Check black and white points

Dust removal not working:

• Ensure infrared clean is enabled
• Check scanner supports infrared channel
• B&W silver negatives won't work with infrared

Epson Scan / Epson Scan 2

Common issues:

Banding in shadows:

• Disable "Unsharp Mask" in software
• Try different quality settings

Digital ICE greyed out:

• Only available for film, not reflective scanning
• Check correct scan type selected

File Format Problems

Colour Space Issues

Symptoms:

• Colours look different in different applications
• Vibrant on screen, dull in print
• Shifts between editing and export

Solutions:

• Use consistent colour space throughout workflow
• sRGB: Safe for web, most displays
• Adobe RGB: More colours, good for printing
• ProPhoto RGB: Widest gamut, requires careful handling
• Embed colour profile in scanned files
• Enable colour management in all applications

Bit Depth Recommendations

8-bit:

• 256 levels per channel
• Small files
• Fine for web and casual use
• Can posterise with heavy editing

16-bit:

• 65,536 levels per channel
• Much larger files
• Best for archival and heavy editing
• Maintains smooth gradations when adjusting curves

Recommendation: Scan at 16-bit (48-bit colour) if your scanner supports it. Convert to 8-bit only at final export if needed.

TIFF vs DNG vs JPEG

TIFF:

• Lossless compression option (LZW)
• Widely compatible
• Large files
• Good for archival scans

DNG (for DSLR scans):

• Raw file with all camera data
• Smaller than uncompressed TIFF
• Requires raw converter
• Best for DSLR scanning archival

JPEG:

• Lossy compression
• Small files
• Fine for web/sharing
• Never use for archival master scans

Troubleshooting Checklist

When scans don't look right:

Summary

• Dust is universal—prevent it, use ICE when available, clean up what's left
• Newton rings require anti-Newton solutions (ANR glass, tensioned holders, or wet mounting)
• Colour problems usually trace to film profile or mask removal issues
• Banding is often related to LED light sources or electrical issues
• Focus problems are usually film flatness issues
• Resolution should match the detail in your film—more isn't always better
• Work in 16-bit for editing flexibility, with proper colour profiles

Good scanning is part technology and part technique. Once you understand the common issues and their solutions, you can consistently produce excellent scans from your negatives.