Resin Exposure Settings Calculator
Created by: Ethan Brooks
Last updated:
Calculate adjusted resin exposure times based on resin type, layer height, temperature, and screen age for SLA and MSLA printers.
Resin Exposure Settings Calculator
3D PrintingCalculate adjusted resin exposure times based on resin type, layer height, temperature, and screen age.
What is a Resin Exposure Settings Calculator?
A resin exposure settings calculator determines the optimal UV exposure time per layer for SLA and MSLA resin 3D printers based on your specific resin, hardware, and environmental conditions. Getting exposure right is critical for resin printing — too little and layers fail to adhere, too much and you lose detail and dimensional accuracy.
Unlike FDM printing where a wrong setting usually just degrades quality, wrong resin exposure often causes complete print failure. Under-exposed prints fall off the build plate or delaminate into a blob of partially cured resin in the vat. Over-exposed prints cure too broadly, filling in fine features and making supports nearly impossible to remove.
The ideal exposure time depends on multiple variables: the resin's photosensitivity (which varies dramatically between standard, tough, and flexible formulations), the layer height (thicker layers need more UV energy), the UV LED power and screen type (mono screens transmit more UV than older RGB screens), screen age (UV output degrades over time), and ambient temperature (cold resin cures more slowly).
This calculator starts with baseline exposure values for each resin type at 50μm on a mono LCD, then applies adjustment factors for layer height, temperature, screen age, and UV power level. The result is a calibrated starting point that is significantly more accurate than generic manufacturer recommendations, which assume ideal conditions.
How the Resin Exposure Settings Calculator Works
The calculation begins with a base exposure time from a lookup table for each resin type at the standard 50μm layer height on a mono LCD screen. Standard resin starts at 2.5 seconds, ABS-like at 3.0 seconds, tough at 4.0 seconds, and so on. These baselines assume a new screen at room temperature.
Layer height adjustment scales the exposure: 30μm layers multiply by 0.7 (less resin to cure), while 100μm layers multiply by 1.8 (much more resin to cure). Temperature adjustment adds exposure if the ambient temperature is below 20°C, at a rate of 5% per degree below 20°C. Screen age adds a percentage based on estimated use: 0% for new, ~8% for moderate age, and ~15% for aging screens.
For RGB LCD screens, the base exposure is approximately doubled because RGB screens block a significant portion of UV light compared to monochrome screens. The calculator also provides bottom layer settings — typically 10-15× the normal layer exposure — and recommends bottom layer count, lift speed, and rest time between layers.
Exposure Time Adjustment Formulas
Base Exposure = Resin lookup value (at 50μm, mono LCD, 25°C)
Layer Adjust: 20-30μm ×0.7 | 50μm ×1.0 | 100μm ×1.8
Temp Adjust = Base × (1 + max(0, (20 - temp) × 0.05))
Age Adjust = Base × (1 + (months/18) × 0.15)
RGB Screen = Mono exposure × 2.0 (approximate)
Bottom Exposure = Normal × 12-15 (for plate adhesion)
Example Calculations
Standard Resin — Optimal Conditions
Standard resin at 50μm on a new mono LCD at 25°C: base 2.5s, no adjustments needed. Bottom exposure: 35s for 6 layers. These are near-ideal conditions — if your calibration test looks good at these settings, no further adjustment is needed.
ABS-Like Resin — Cold Garage
ABS-like resin at 50μm, mono LCD, 15°C ambient: base 3.0s + 25% cold adjustment = 3.75s normal exposure. Bottom exposure: 50s. The cold temperature significantly increases cure time. Consider using a space heater to bring the room to 20°C+ for more consistent results.
Tough Resin — Aging Screen, Fine Layers
Tough resin at 30μm on a 20-month-old mono LCD at 22°C: base 4.0s × 0.7 (layer) × 1.17 (age) = 3.28s per layer. The fine layer height reduces per-layer exposure, but the aging screen requires more time to compensate for reduced UV output. Consider replacing the screen if approaching 2000+ hours.
Common 3D Printing Applications
- New resin testing — when trying a new resin brand or type, the calculator provides an informed starting exposure before running calibration prints.
- Seasonal adjustment — printers in garages or unheated rooms need different exposure settings in winter versus summer.
- Screen replacement planning — tracking how much exposure increase your aging screen needs helps decide when replacement is cost-effective.
- Layer height optimization — comparing exposure times at different layer heights helps choose the best resolution for your time budget.
- Troubleshooting print failures — if prints are suddenly failing, checking whether temperature or screen degradation has shifted your optimal exposure helps diagnose the root cause.
- Multi-resin workflow — users who switch between standard and engineering resins need different exposure profiles for each type.
Tips for Better 3D Printing Results
Always run a calibration test print (like the Resin XP2 validation matrix) when dialing in a new resin. This calculator provides a starting point, but every printer and resin batch has slight variations. The calibration print lets you fine-tune within a narrow range rather than searching from scratch.
Keep your printing environment above 20°C (68°F) for consistent results. Below this temperature, exposure adjustments become large and less predictable. A small enclosed space with a low-wattage heater is more effective and economical than heating an entire room.
When your screen reaches 1500-2000 hours of cumulative UV exposure, you will notice exposure times creeping up significantly. Track your screen hours (some printers display this in the menu) and budget for a replacement screen. A worn screen produces uneven UV distribution that no amount of exposure adjustment can fully compensate.
Frequently Asked Questions
How do I find the right exposure time for my resin?
Start with the manufacturer's recommended settings for your specific printer and resin combination, then fine-tune using an exposure calibration test print (like the Resin XP2 validation matrix or AMERALABS Town). This calculator provides adjusted starting points based on resin type, layer height, temperature, and screen age.
What is the difference between normal and bottom layer exposure?
Bottom layers (first 4-8 layers) use much longer exposure times (30-60 seconds) to ensure strong adhesion to the build plate. Normal layers use shorter exposure (2-5 seconds) for proper curing without over-exposure. Bottom layers are critical — if they fail, the entire print detaches from the plate.
Why does cold temperature affect resin exposure?
Resin cures through a photochemical reaction that is temperature-dependent. Below 20°C (68°F), the reaction slows significantly, requiring 10-30% longer exposure per layer. Below 15°C, printing becomes unreliable. The ideal printing temperature is 20-28°C. Use a space heater near the printer or an enclosure in cold environments.
How does screen aging affect exposure times?
LCD/LED screens lose UV intensity over time. A mono LCD screen may lose 10-15% brightness after 1000+ hours of use. This means exposure times need to gradually increase as the screen ages. After 1500-2000 hours, most mono screens need replacement. The calculator adds a percentage based on estimated screen age.
Does layer height affect exposure time?
Yes, significantly. Thinner layers (30μm) need less exposure because there is less resin to cure. Thicker layers (100μm) need much more — typically 1.5-2x the 50μm baseline. The relationship is not perfectly linear because UV light penetrates through some depth, so very thin layers are proportionally easier to cure.
What happens if I over-expose my resin prints?
Over-exposure causes loss of fine detail (features fill in or merge), dimensional inaccuracy (parts print larger than designed), difficulty removing supports, and potential layer lines becoming more visible. Over-exposure is the most common beginner mistake and is worse for print quality than slight under-exposure.
What happens if I under-expose my resin prints?
Under-exposure causes weak layer adhesion (layers separate or delaminate), soft or tacky surfaces that do not fully cure even after post-curing, failed supports that cause print failures, and dimensional inaccuracy. Under-exposed prints may also have a cloudy or matte appearance instead of the expected surface finish.
Sources and References
- Elegoo — "Resin Exposure Settings Guide for Mars and Saturn Series" (baseline exposure recommendations by resin type).
- CHITUBOX — "Exposure Time Settings Guide" (layer height and resin type exposure matrix).
- Anycubic — "Photon Mono Series Resin Settings" (mono LCD exposure baselines and calibration procedures).
- All3DP — "Resin 3D Printing Settings: The Complete Guide" (exposure adjustment factors for temperature and screen age).
- AMERALABS — "Resin Exposure Calibration Methodology" (systematic calibration test procedures).