Enlarger Fundamentals

An enlarger is the heart of the darkroom—an optical projector that shines light through your negative onto photographic paper, creating a print. The enlarger is the heart of the darkroom printing process. After you've developed your negatives, the enlarger projects them onto light-sensitive paper to create prints. Understanding your enlarger is the first step to making quality prints.

This guide covers enlarger types, key components, popular models, lenses, and setup fundamentals.

Key Terms

Before diving in, here are the essential concepts you'll encounter:

Contrast grades: A numbering system (0-5) indicating how much contrast a paper or filter produces. Grade 2 is "normal"—lower numbers give softer results with more grey tones; higher numbers give harder, more contrasty results with starker blacks and whites.

Callier effect: The phenomenon where condenser enlargers produce higher contrast than diffusion enlargers from the same negative. Dense areas of the negative scatter light differently in condenser systems, amplifying contrast. In practice, you may need to use a lower contrast grade with condenser enlargers to achieve the same print contrast as with diffusion.

Condenser vs diffusion enlargers: The two main types of enlarger light systems. Condensers use lenses to focus light directly through the negative—sharper but less forgiving. Diffusion systems scatter light before it passes through—softer, more even illumination that minimises dust and scratches.

How an Enlarger Works

The basic principle is simple: a light source illuminates your negative from above, a lens focuses that image onto the baseboard below, and you expose photographic paper placed on the baseboard.

Raise the enlarger head for larger prints, lower it for smaller ones. Focus using the lens stage. Control exposure with a timer and the lens aperture.

Enlarger Types

The most important distinction is how light reaches the negative.

Condenser Enlargers

Condenser enlargers use glass lenses (condensers) to focus light directly through the negative.

Characteristics:

• Higher contrast (0.5-1 grade more than diffusion)
• Sharper grain structure
• Shows dust and scratches prominently (every speck prints as a white spot)
• Can create hot spots if misaligned
• Traditional design, many classic enlargers use this system

Best for: Photographers who want maximum sharpness and don't mind spotting prints

Diffusion Enlargers

Diffusion enlargers scatter light before it passes through the negative, either via a diffusion chamber, frosted glass, or a mixing box.

Characteristics:

• Softer, more forgiving contrast
• Minimises appearance of dust, scratches, and grain
• More even illumination
• Easier to match negatives to paper grades
• Common in colour printing (colour heads are diffusion type)

Best for: Most photographers, especially those printing colour or scanning-grade negatives

Cold Light Enlargers

A variant of diffusion using fluorescent tubes instead of incandescent bulbs. Popular for large format printing.

Characteristics:

• Very even illumination over large negative areas
• Lower contrast than condensers
• No heat (important for long exposures)
• Can require VC filter compatibility modifications
• Typical in fine-art B&W darkrooms

Examples: Aristo cold light heads, Zone VI modified heads

Key Components

Light Source

Incandescent bulbs: Traditional choice. Opal or frosted bulbs reduce hot spots. Must be correctly rated for your enlarger (typically 75-150W).

Halogen bulbs: Brighter and more consistent colour temperature. Found in many modern enlargers. May require voltage regulation.

LED conversions: Emerging option for older enlargers. Cooler, longer-lasting, but colour spectrum may affect multigrade paper response.

Colour heads: Contain cyan, magenta, and yellow filtration dials for colour printing. The magenta and yellow settings also control contrast on multigrade paper.

Negative Carrier

Holds the film flat in the light path. Two main types:

Glass carriers: Two pieces of glass sandwich the negative. Ensures absolute flatness. Adds four more surfaces that can attract dust and create Newton rings (interference patterns from glass-film contact).

Glassless carriers: Metal frames with a cut-out window. No glass dust issues, but negatives can pop (buckle from heat) during long exposures. Standard choice for most work.

Anti-Newton ring (ANR) glass: Special textured glass that prevents Newton rings. A good compromise for large negatives that need glass support.

Lens Stage and Focusing

The lens mounts on a stage that moves up and down for focusing. Most enlargers use a rack-and-pinion mechanism operated by a knob.

Bellows vs fixed tubes: Some enlargers (like the Beseler 23C) use bellows between the head and lens stage, allowing more flexible movements. Others have fixed tubes.

Autofocus systems: Rare and generally not worth the complexity. Manual focus with a grain focuser is standard practice.

Baseboard and Column

Baseboard: The flat surface where you place paper and easels. Should be stable and level.

Column: Supports the head and allows vertical movement. Height determines maximum print size at closest focus.

Column types:

• Standard vertical column
• Tilting column (for perspective correction)
• Wall-mounted (saves space, allows floor projections for very large prints)

Timer

Controls exposure duration. Options:

Basic timer: Manual dial, starts exposure when you turn it on. Must watch and stop manually.

Enlarger timer: Connects to the enlarger, turns light on/off automatically for set duration. Essential for consistency.

Digital timer: Precise to 0.1 seconds, often with footswitch support. Examples: GraLab 300, Time-O-Lite, Omega.

Popular Enlargers by Format

35mm Enlargers

Entry-level enlargers handle 35mm only. Compact and affordable.

Medium Format Enlargers (35mm + 6x6/6x7)

The most versatile choice—handles 35mm and medium format.

Large Format Enlargers (4x5 and up)

For sheet film printing. Substantial equipment requiring dedicated space.

Enlarger Lenses

The lens is critical—it determines print sharpness across the frame. Enlarger lenses are optimised for flat-field reproduction at close distances.

Focal Length by Format

Match focal length to negative size:

Why focal length matters:

• Too short: Vignetting, uneven illumination
• Too long: Requires raising head higher for same print size, may exceed column height

Recommended Lenses

Premium (best optical quality):

• Rodenstock Rodagon — Exceptional, the industry reference
• Schneider Componon-S — Equally excellent, slight colour difference
• Nikon EL-Nikkor — Outstanding, discontinued but available used

Good value:

• Fujinon EP — Excellent quality, often overlooked
• Rodenstock Rogonar — Entry-level Rodenstock, still very good
• Meopta Anaret — Budget option, decent sharpness

Avoid:

• Unbranded or "kit" lenses included with cheap enlargers
• Lenses with visible scratches, fungus, or haze

Optimal Aperture

Like camera lenses, enlarger lenses are sharpest stopped down from wide open:

f/5.6 - f/11: Optimal range. Best corner-to-corner sharpness. Wide open (f/2.8 - f/4): Useful for focusing, but print at smaller apertures. f/16 and smaller: Diffraction begins to soften the image. Avoid unless you need very long exposures for burning.

Setting Up Your Enlarger

Alignment

The negative, lens, and baseboard must all be parallel. Misalignment causes focus falloff across the print.

Checking alignment:

1. Use a laser alignment tool (ideal but expensive)
2. Use a precision bubble level on each surface
3. Test print a detailed negative and check focus in all four corners

Common misalignment causes:

• Baseboard not level
• Negative carrier not seated properly
• Column not perpendicular to baseboard
• Worn or loose lens stage

Height and Space

Plan for:

• Ceiling height: Column extension plus your height when using the focuser
• Table depth: Baseboard plus chemistry trays if in same room
• Safe distance: Enlarger should be away from wet chemistry area

Light-Proofing

The darkroom must be completely dark—any stray light fogs paper. Check:

• Door seals
• Ventilation covers
• Any indicators or LED lights on equipment
• The enlarger head itself (some leak light at seams)

Focus Aids

The eye isn't reliable for critical focus. Use a grain focuser—a small magnifier that shows the film grain projected on the baseboard.

Grain Focusers

Peak 1: Classic, affordable, works well Micromega: Higher magnification, critical focus Scoponet: Excellent optics Paterson: Budget option, adequate

Technique:

1. Place the focuser on the baseboard where your print will be
2. Look through the magnifier
3. Adjust focus until grain snaps into sharp clarity
4. Check focus in the centre and at least two corners

Buying Used Enlargers

Most enlargers on the market are used. Here's what to check:

What to Examine

Electrical: Does it power on? Is wiring frayed or damaged? Are switches functional?

Mechanical: Column moves smoothly? Head locks securely? Focusing is smooth without play? Bellows (if present) are light-tight?

Optical: Lens clear and free of fungus/haze? Condenser lenses clean? No cracks in diffusion glass?

Negative carrier: Correct format included? In good condition?

Common Problems

Stripped gears: Focus mechanism slips or has dead spots Bellows holes: Light leaks visible when shining a torch inside (bellows-equipped models) Missing parts: Condensers, negative carriers, red filter, timer Electrical issues: Intermittent power, flickering light

Fair Prices (approximate, 2026)

Prices vary hugely by location and condition. As a rough guide:

A good lens is often more valuable than the enlarger body. A mint Rodagon 50mm might cost more than a Beseler 23C.

What You'll Need Beyond the Enlarger

A complete printing setup also requires:

Summary

• Condenser enlargers produce higher contrast and sharper grain; diffusion enlargers are more forgiving
• Match enlarger format to your largest negative size, plus some headroom
• Match lens focal length to format: 50mm for 35mm, 80mm for 6×6, 150mm for 4×5
• Optimal lens aperture is f/5.6 to f/11
• Alignment between negative, lens, and baseboard is critical
• Always use a grain focuser for precise focus
• Buying used is standard; check electrical, mechanical, and optical condition

Your enlarger is a precision instrument. Treat it well, keep it aligned and clean, and it will produce beautiful prints for decades.