Resin 3D Print Exposure Calculator
Select your printer and resin type, set your layer height, and get a starting exposure time for normal and bottom layers - plus lift speed and anti-aliasing recommendations. Use the RERF guide below to fine-tune your exact settings. Everything runs in your browser, nothing uploaded.
Printer
Resin
Layer height
Recommended exposure times
These are starting estimates. Print a RERF test to dial in your exact resin batch - see the guide below.
Anti-aliasing ?
-RERF test guide ?
A RERF print is a matrix of small objects printed at several exposure levels in one go. Find the level that produces the sharpest details and thinnest walls without delamination.
- Download a RERF file for your printer from the Elegoo, Anycubic, or Phrozen support pages (search "[your printer model] RERF test file").
- Open the RERF file in your slicer (Chitubox, Lychee Slicer, or the printer's own app). Do not re-slice it - use it as-is.
- Set your slicer's normal exposure to the value shown above. The RERF file will print a range of exposures around that starting point (typically ±0.5 s in 8 steps).
- Print and inspect: the correct column will show crisp lettering, thin walls without breakage, and no over-cure blooming.
- Note the winning exposure time and use it as your normal layer setting going forward. Repeat if you switch to a different resin brand or colour.
Resin 3D printer exposure time calibration
Why exposure time matters and how to find the sweet spot
Resin 3D printers (DLP, LCD, and other projection systems) cure liquid resin using UV light. Exposure time controls how much energy each layer receives. Too little exposure leaves the resin under-cured, producing brittle parts with weak walls and detail loss. Too much exposure causes over-curing, blooming (the part grows larger than designed due to excess shrinkage), and extreme brittleness. The ideal exposure time produces crisp fine details, thin walls without breakage, and smooth surfaces. This sweet spot varies with resin type, color, printer model, and age of the resin. An exposure test (also called a "ramp test") is the standard way to find it: print columns with increasing exposure times, then choose the column that looks best under a magnifying glass.
How to perform an exposure ramp test and interpret results
A ramp test file contains multiple vertical pillars, each exposed for incrementally longer times - for example, 6, 6.5, 7, 7.5, 8, 8.5, 9 seconds. After printing and washing, the columns progress from under-cured (thin, fragile) through over-cured (bloated, brittle). The winning column is the one with crisps lettering, minimal wall thickness variation, and no visible blooming or excessive shrinkage. Note the exposure time and use it as your layer setting going forward. Repeat the test whenever you change resin brand, color, or if the resin has been exposed to light/heat, as these factors shift the ideal exposure window.
FAQ
What is the difference between layer exposure time and initial layer exposure?
Initial layer(s) typically need more exposure than subsequent layers because they must stick to the build platform. Typical settings: initial 10-12 seconds, then 6-8 seconds for normal layers. Under-exposing initial layers causes print failure (parts peel off the platform). This calculator focuses on normal layer exposure; you may need to test initial exposure separately.
Does the printer's light source type affect exposure time?
Yes. DLP projectors and monochrome LCD systems output different wavelengths and intensities. An exposure time optimal for one printer may not work on another, even with the same resin. When switching printers or upgrading, run a new ramp test to find the new optimal exposure.
Should I adjust exposure time for different layer heights?
Yes, generally. Finer layer heights (25-50 microns) can use shorter exposure times because the laser passes through less resin thickness. Thicker layers (100+ microns) may need proportionally longer exposure. Start with a ramp test at your target layer height to avoid guessing.