Loss of detail from wrong exposure (overexposure or underexposure)

Symptom

Fine details come out blurred or are lost: thick or merged letters, small holes filled in, lines thicker than they should be; or pillars, tips and thin areas are missing, or holes and deformations appear.

Likely causes, from most to least likely

1. Normal layer exposure time is not right for that resin on your printer: detail is lost whether it is too short or too long.
2. You are using the profile of another resin or another colour.
3. The layer height does not suit that resin: not every resin works well at every layer height.
4. The room is cold, which changes the exposure time needed.

Checks to tell which one it is

• Print an exposure test: the same model at several times, and compare which one reproduces the details best.
• Signs of overexposure: letters and details thickened or merged, holes filled in, pillars or lines thicker.
• Signs of underexposure: missing pillars, tips or the dot on the i, holes or deformations.
• Check that the profile matches your exact resin, its colour and your layer height.

Before you start

Uncured resin irritates skin and eyes: wear nitrile gloves and safety glasses, ventilate the room and do not look at the UV light. Before taking anything apart or cleaning it, switch the printer off and unplug it, unless a step says otherwise. If in any doubt, stop and ask a professional.

Step-by-step fix

1. Load the official profile

   Use the resin manufacturer's profile for your printer and layer height. If there is none, start from the closest one and run an exposure test.

   Check: The part reproduces small details without thickening them.

   If that does not fix it: Run an exposure test.

2. Run an exposure test

   Print your manufacturer's calibration part (for example Prusa's resin calibration or Phrozen's XP Finder) at several times. Change only the exposure and leave the other settings at their defaults. If unsure about layer height, Prusa suggests 0.05 mm.

   Check: You find the time that forms every detail without thickening or merging them.

   If that does not fix it: Widen the range of times and repeat the test.

3. Apply the chosen time

   Set that time for the normal layers in the profile. For real parts, Phrozen recommends as a guide adding at least 10%, and 20% if the part is over 12 cm.

   Check: The part comes out with the same detail as the test.

   If that does not fix it: Control the temperature.

4. Print at a stable temperature

   Print at a temperature similar to the one of the test: in the cold, the exposure time the resin needs changes.

   Check: Results repeat from one day to the next.

   If that does not fix it: If details are always missing in the same area, check the film and the screen (cured debris in the vat and LCD screen and UV light sheets).

Prevention

• Run an exposure test every time you change resin, colour or layer height.
• Always print in similar temperature conditions.

Still not fixed?

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Printers it applies to

Any resin (MSLA/SLA) 3D printer, from any brand.

Official sources

This guide summarises the official documentation linked here:

• Resin Calibration (SL1/SL1S) · Prusa Research
• Object missing details · Prusa Research
• How to Dial in Resin for Optimal Results · Phrozen
• Ambient temperature too cold #10703 (SL1/SL1S) · Prusa Research