 Facility |
 Imaging |
 Spectroscopy |
| La Silla | EFOSC2 SUSI WFI | EFOSC2 HARPS NIRPS |
| Paranal UT1 | FORS2 (old ETC) | FORS2 (old ETC) KMOS |
| FORS2 (new ETC) | ||
| Paranal UT2 | VISIR | UVES (new ETC)
UVES (old ETC)
UVES-FLAMES
GIRAFFE VISIR |
| Paranal UT3 | SPHERE-IRDIS SPHERE-ZIMPOL | X-SHOOTER
SPHERE-IFS
CRIRES |
| Paranal UT4 | HAWK-I | MUSE |
| ERIS | ||
| Paranal ICCF | ESPRESSO | |
| Paranal VLTI | GRAVITY MATISSE VisCalc CalVin | |
| Paranal VISTA | VIRCAM | 4MOST |
| Paranal VST | OmegaCAM | |
| ELT | ELT imaging | ELT spectroscopy |
ESO Exposure Time Calculators
Documentation and Tools
- Support: https://support.eso.org
- Frequently Asked Questions
- Formula Book
- Database of efficiency profiles
- Deprecated ETCs
- SkyCalc Sky Model Calculator
- with advanced Almanac
- command-line interface skycalc_cli
News and Notes
March 4, 2025
Sky signal correction in the CRIRES ETC
A bug has been fixed where the factor slitwidth × extraction aperture was not applied to the sky signals, leading to an overestimation of sky counts and maximum pixel values. The sky background computation is now correctly scaled.
February 27, 2025
ETC2.0 updated for P116, see the change log
Featuring UVES ETC2.0
VLTI tools VisCalc, CalVin, GRAVITY, MATISSE:
A new medium configuration A0-B5-D0-G1 replaces the former K0-G2-D0-J3 configuration.