RA4 Colour Head Calculator

A simple calculator for determining CMY filtration values for RA4 colour printing. Upload a reference image of your negative, select your film base and paper stock, then adjust the sliders to calculate your starting filtration values.

This tool provides baseline recommendations - always make test strips to verify filtration for your specific setup, as enlarger light source, paper age, and chemistry conditions will affect results.

Reference Image

ⓘ

Upload an image and adjust filtration to preview the final RA4 print.

Film Type / Grade

For colour: different film bases need different filtration. For B&W: grade controls contrast.

Enlarger Type

Different enlargers use different CMY scales for multigrade filters.

Paper Stock

Select B&W paper for multigrade printing, or colour paper for RA4.

Quick Guide

  • Add Cyan: Reduce red cast
  • Add Magenta: Warmer tones, reduce green cast
  • Add Yellow: Reduce blue cast
  • Remember: These are starting values. Always make test strips!

Baseline Filtration

Film + Paper Starting Point:

0C 80M 50Y

Adjust Filtration

0
80
50
±0

Your Filtration

0C 80M 50Y

Colour Preview: