M42
    Prime
    Full frame

    Schneider-Kreuznach Edixa-Laudar 50mm f/2.8

    4.0
    (2 reviews)
    Optical: 5.0
    Mechanical: 5.0
    Value: 4.0
    Focal Length
    50mm
    Aperture
    f/2.8-22
    Mount
    M42
    Weight
    128g
    Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 is a manual focus prime lens for full frame cameras.

    Optical design

    Has 14 aperture blades, this lens has a beautiful bokeh. Bright lens thanks to the high aperture value

    Physical characteristics

    With a lens filter diameter of 35.5 mm you are one step from the next standard filter size, buy step-up ring and bigger filter but you can chose from plenty options. 32 mm long, this small lens should be always in the camera bag. Weights 128 grams so convinient to carry.

    Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 purchase history

    eBay Price HistoryeBay Auction (high-low)

    Purchases (518)

    • Aug 14, 2025$139.00
    • Aug 13, 2025$372.00
    • Aug 13, 2025$37.00
    • Aug 11, 2025$186.00
    • Aug 9, 2025$53.00
    • Aug 5, 2025$56.00
    • Aug 5, 2025$158.00
    • Aug 3, 2025$73.00
    • Aug 1, 2025$162.00
    • Aug 1, 2025$92.00
    • Jul 29, 2025$162.00
    • Jul 29, 2025$37.00
    • Jul 28, 2025$42.00
    • Jul 27, 2025$46.00
    • Jul 25, 2025$46.00
    • Jul 23, 2025$45.00
    • Jul 17, 2025$927.00
    • Jul 16, 2025$45.00
    • Jul 16, 2025$70.00
    • Jul 14, 2025$40.00
    • Jul 11, 2025$377.00
    • Jul 11, 2025$372.00
    • Jul 10, 2025$31.00
    • Jul 9, 2025$56.00
    • Jul 8, 2025$738.00
    • Jul 8, 2025$747.00
    • Jul 6, 2025$176.00
    • Jul 6, 2025$178.00
    • Jul 3, 2025$825.00
    • Jul 3, 2025$835.00
    • Jul 1, 2025$88.00
    • Jul 1, 2025$89.00
    • Jun 30, 2025$19.00
    • Jun 29, 2025$329.00
    • Jun 28, 2025$147.00
    • Jun 28, 2025$149.00
    • Jun 27, 2025$57.00
    • Jun 23, 2025$67.00
    • Jun 23, 2025$68.00
    • Jun 23, 2025$46.00
    • Jun 23, 2025$3758.00
    • Jun 23, 2025$47.00
    • Jun 22, 2025$348.00
    • Jun 22, 2025$343.00
    • Jun 19, 2025$49.00
    • Jun 19, 2025$50.00
    • Jun 19, 2025$51.00
    • Jun 18, 2025$66.00
    • Jun 18, 2025$67.00
    • Jun 18, 2025$212.00
    • Jun 18, 2025$214.00
    • Jun 18, 2025$56.00
    • Jun 18, 2025$58.00
    • Jun 18, 2025$220.00
    • Jun 15, 2025$74.00
    • Jun 15, 2025$75.00
    • Jun 15, 2025$77.00
    • Jun 13, 2025$145.00
    • Jun 13, 2025$139.00
    • Jun 13, 2025$141.00
    • Jun 12, 2025$1408.00
    • Jun 12, 2025$1444.00
    • Jun 12, 2025$1391.00
    • Jun 10, 2025$96.00
    • Jun 10, 2025$97.00
    • Jun 10, 2025$99.00
    • Jun 9, 2025$22.00
    • Jun 9, 2025$23.00
    • Jun 9, 2025$59.00
    • Jun 9, 2025$60.00
    • Jun 9, 2025$61.00
    • Jun 8, 2025$240.00
    • Jun 8, 2025$250.00
    • Jun 8, 2025$243.00
    • Jun 6, 2025$145.00
    • Jun 6, 2025$139.00
    • Jun 6, 2025$141.00
    • Jun 5, 2025$589.00
    • Jun 5, 2025$612.00
    • Jun 5, 2025$597.00
    • Jun 4, 2025$250.00
    • Jun 4, 2025$260.00
    • Jun 4, 2025$254.00
    • Jun 2, 2025$35.00
    • Jun 2, 2025$260.00
    • Jun 2, 2025$37.00
    • Jun 2, 2025$36.00
    • Jun 2, 2025$250.00
    • Jun 2, 2025$254.00
    • Jun 1, 2025$1315.00
    • Jun 1, 2025$1349.00
    • Jun 1, 2025$74.00
    • Jun 1, 2025$75.00
    • Jun 1, 2025$77.00
    • Jun 1, 2025$1299.00
    • May 28, 2025$325.00
    • May 28, 2025$135.00
    • May 28, 2025$232.00
    • May 28, 2025$329.00
    • May 28, 2025$234.00
    • May 28, 2025$136.00
    • May 28, 2025$140.00
    • May 28, 2025$337.00
    • May 27, 2025$64.00
    • May 27, 2025$1156.00
    • May 27, 2025$1127.00
    • May 27, 2025$232.00
    • May 27, 2025$235.00
    • May 27, 2025$241.00
    • May 27, 2025$245.00
    • May 27, 2025$1175.00
    • May 27, 2025$1113.00
    • May 27, 2025$60.00
    • May 27, 2025$61.00
    • May 27, 2025$63.00
    • May 26, 2025$81.00
    • May 26, 2025$82.00
    • May 26, 2025$84.00
    • May 26, 2025$85.00
    • May 25, 2025$88.00
    • May 25, 2025$83.00
    • May 25, 2025$85.00
    • May 25, 2025$87.00
    • May 23, 2025$32.00
    • May 23, 2025$33.00
    • May 23, 2025$34.00
    • May 22, 2025$56.00
    • May 22, 2025$25.00
    • May 22, 2025$58.00
    • May 22, 2025$59.00
    • May 22, 2025$28.00
    • May 22, 2025$29.00
    • May 22, 2025$24.00
    • May 21, 2025$160.00
    • May 21, 2025$97.00
    • May 21, 2025$96.00
    • May 21, 2025$99.00
    • May 21, 2025$164.00
    • May 21, 2025$101.00
    • May 21, 2025$166.00
    • May 21, 2025$158.00
    • May 19, 2025$48.00
    • May 19, 2025$49.00
    • May 19, 2025$46.00
    • May 19, 2025$47.00
    • May 17, 2025$64.00
    • May 17, 2025$65.00
    • May 17, 2025$66.00
    • May 17, 2025$162.00
    • May 17, 2025$164.00
    • May 17, 2025$260.00
    • May 17, 2025$263.00
    • May 17, 2025$169.00
    • May 17, 2025$171.00
    • May 17, 2025$270.00
    • May 17, 2025$274.00
    • May 13, 2025$72.00
    • May 13, 2025$73.00
    • May 13, 2025$70.00
    • May 12, 2025$52.00
    • May 12, 2025$53.00
    • May 12, 2025$54.00
    • May 11, 2025$42.00
    • May 11, 2025$43.00
    • May 11, 2025$44.00
    • May 11, 2025$19.00
    • May 11, 2025$20.00
    • May 8, 2025$70.00
    • May 8, 2025$71.00
    • May 8, 2025$72.00
    • May 8, 2025$47.00
    • May 8, 2025$48.00
    • May 8, 2025$49.00
    • May 7, 2025$33.00
    • May 7, 2025$34.00
    • May 6, 2025$18.00
    • May 5, 2025$64.00
    • May 5, 2025$65.00
    • May 5, 2025$66.00
    • May 4, 2025$164.00
    • May 4, 2025$169.00
    • May 4, 2025$171.00
    • May 4, 2025$172.00
    • May 4, 2025$113.00
    • May 4, 2025$116.00
    • May 4, 2025$117.00
    • May 2, 2025$96.00
    • May 2, 2025$98.00
    • May 2, 2025$75.00
    • May 2, 2025$77.00
    • May 2, 2025$78.00
    • May 2, 2025$79.00
    • May 2, 2025$94.00
    • May 1, 2025$194.00
    • May 1, 2025$354.00
    • May 1, 2025$356.00
    • May 1, 2025$199.00
    • May 1, 2025$203.00
    • May 1, 2025$204.00
    • May 1, 2025$979.00
    • May 1, 2025$340.00
    • May 1, 2025$984.00
    • May 1, 2025$348.00
    • Apr 28, 2025$866.00
    • Apr 28, 2025$680.00
    • Apr 28, 2025$684.00
    • Apr 28, 2025$653.00
    • Apr 28, 2025$848.00
    • Apr 28, 2025$862.00
    • Apr 28, 2025$82.00
    • Apr 28, 2025$84.00
    • Apr 28, 2025$85.00
    • Apr 28, 2025$86.00
    • Apr 28, 2025$827.00
    • Apr 28, 2025$670.00
    • Apr 25, 2025$235.00
    • Apr 25, 2025$241.00
    • Apr 25, 2025$117.00
    • Apr 25, 2025$245.00
    • Apr 25, 2025$246.00
    • Apr 25, 2025$120.00
    • Apr 25, 2025$122.00
    • Apr 25, 2025$123.00
    • Apr 24, 2025$963.00
    • Apr 24, 2025$344.00
    • Apr 24, 2025$329.00
    • Apr 24, 2025$943.00
    • Apr 24, 2025$337.00
    • Apr 24, 2025$343.00
    • Apr 24, 2025$920.00
    • Apr 24, 2025$958.00
    • Apr 20, 2025$137.00
    • Apr 20, 2025$131.00
    • Apr 20, 2025$134.00
    • Apr 14, 2025$49.00
    • Apr 13, 2025$58.00
    • Apr 13, 2025$59.00
    • Apr 12, 2025$66.00
    • Apr 12, 2025$68.00
    • Apr 11, 2025$74.00
    • Apr 11, 2025$75.00
    • Apr 9, 2025$116.00
    • Apr 9, 2025$117.00
    • Apr 9, 2025$118.00
    • Apr 8, 2025$76.00
    • Apr 8, 2025$77.00
    • Apr 8, 2025$78.00
    • Apr 7, 2025$72.00
    • Apr 7, 2025$73.00
    • Apr 7, 2025$74.00
    • Apr 7, 2025$76.00
    • Apr 3, 2025$24.00
    • Apr 3, 2025$25.00
    • Apr 2, 2025$43.00
    • Apr 2, 2025$44.00
    • Apr 2, 2025$46.00
    • Apr 2, 2025$21.00
    • Apr 2, 2025$22.00
    • Mar 30, 2025$82.00
    • Mar 30, 2025$83.00
    • Mar 30, 2025$84.00
    • Mar 30, 2025$87.00
    • Mar 26, 2025$536.00
    • Mar 26, 2025$525.00
    • Mar 26, 2025$555.00
    • Mar 26, 2025$533.00
    • Mar 23, 2025$24.00
    • Mar 23, 2025$25.00
    • Mar 22, 2025$193.00
    • Mar 22, 2025$322.00
    • Mar 22, 2025$196.00
    • Mar 22, 2025$324.00
    • Mar 22, 2025$197.00
    • Mar 22, 2025$204.00
    • Mar 22, 2025$335.00
    • Mar 22, 2025$274.00
    • Mar 22, 2025$275.00
    • Mar 22, 2025$285.00
    • Mar 19, 2025$122.00
    • Mar 19, 2025$117.00
    • Mar 19, 2025$118.00
    • Mar 15, 2025$34.00
    • Mar 15, 2025$35.00
    • Mar 14, 2025$1120.00
    • Mar 14, 2025$257.00
    • Mar 14, 2025$259.00
    • Mar 14, 2025$268.00
    • Mar 14, 2025$1077.00
    • Mar 14, 2025$1113.00
    • Mar 14, 2025$1082.00
    • Mar 13, 2025$1416.00
    • Mar 13, 2025$1377.00
    • Mar 13, 2025$1426.00
    • Mar 13, 2025$1371.00
    • Mar 12, 2025$152.00
    • Mar 12, 2025$20.00
    • Mar 12, 2025$151.00
    • Mar 10, 2025$611.00
    • Mar 10, 2025$587.00
    • Mar 10, 2025$556.00
    • Mar 10, 2025$590.00
    • Mar 10, 2025$560.00
    • Mar 10, 2025$538.00
    • Mar 10, 2025$541.00
    • Mar 10, 2025$607.00
    • Mar 8, 2025$297.00
    • Mar 8, 2025$299.00
    • Mar 8, 2025$287.00
    • Mar 8, 2025$289.00
    • Mar 7, 2025$936.00
    • Mar 7, 2025$140.00
    • Mar 7, 2025$141.00
    • Mar 7, 2025$145.00
    • Mar 7, 2025$146.00
    • Mar 4, 2025$34.00
    • Mar 4, 2025$35.00
    • Mar 4, 2025$36.00
    • Mar 4, 2025$273.00
    • Mar 4, 2025$274.00
    • Mar 4, 2025$282.00
    • Mar 4, 2025$284.00
    • Mar 1, 2025$70.00
    • Mar 1, 2025$72.00
    • Mar 1, 2025$73.00
    • Mar 1, 2025$74.00
    • Mar 1, 2025$76.00
    • Feb 27, 2025$13.00
    • Feb 25, 2025$80.00
    • Feb 25, 2025$49.00
    • Feb 25, 2025$51.00
    • Feb 25, 2025$77.00
    • Feb 20, 2025$1126.00
    • Feb 20, 2025$1158.00
    • Feb 20, 2025$1166.00
    • Feb 16, 2025$98.00
    • Feb 16, 2025$101.00
    • Feb 16, 2025$102.00
    • Feb 16, 2025$105.00
    • Feb 16, 2025$1163.00
    • Feb 16, 2025$1131.00
    • Feb 16, 2025$1171.00
    • Feb 16, 2025$1212.00
    • Feb 14, 2025$192.00
    • Feb 14, 2025$197.00
    • Feb 14, 2025$206.00
    • Feb 14, 2025$199.00
    • Feb 13, 2025$40.00
    • Feb 13, 2025$37.00
    • Feb 13, 2025$39.00
    • Feb 7, 2025$32.00
    • Feb 7, 2025$29.00
    • Feb 7, 2025$30.00
    • Feb 7, 2025$31.00
    • Feb 5, 2025$112.00
    • Feb 5, 2025$108.00
    • Feb 5, 2025$116.00
    • Feb 5, 2025$111.00
    • Feb 2, 2025$25.00
    • Feb 2, 2025$26.00
    • Feb 1, 2025$66.00
    • Feb 1, 2025$69.00
    • Jan 29, 2025$224.00
    • Jan 29, 2025$232.00
    • Jan 29, 2025$303.00
    • Jan 29, 2025$305.00
    • Jan 29, 2025$316.00
    • Jan 29, 2025$223.00
    • Jan 26, 2025$20.00
    • Jan 26, 2025$21.00
    • Jan 23, 2025$545.00
    • Jan 23, 2025$538.00
    • Jan 23, 2025$516.00
    • Jan 23, 2025$519.00
    • Jan 22, 2025$36.00
    • Jan 22, 2025$37.00
    • Jan 22, 2025$38.00
    • Jan 22, 2025$20.00
    • Jan 22, 2025$21.00
    • Jan 21, 2025$64.00
    • Jan 21, 2025$27.00
    • Jan 21, 2025$28.00
    • Jan 21, 2025$61.00
    • Jan 21, 2025$63.00
    • Jan 15, 2025$320.00
    • Jan 15, 2025$96.00
    • Jan 15, 2025$303.00
    • Jan 15, 2025$92.00
    • Jan 15, 2025$305.00
    • Jan 15, 2025$91.00
    • Jan 15, 2025$316.00
    • Jan 15, 2025$95.00
    • Jan 14, 2025$73.00
    • Jan 14, 2025$76.00
    • Jan 14, 2025$77.00
    • Jan 13, 2025$265.00
    • Jan 13, 2025$274.00
    • Jan 13, 2025$278.00
    • Jan 13, 2025$263.00
    • Jan 12, 2025$32.00
    • Jan 12, 2025$1922.00
    • Jan 12, 2025$2029.00
    • Jan 12, 2025$1935.00
    • Jan 12, 2025$2003.00
    • Jan 12, 2025$30.00
    • Jan 12, 2025$31.00
    • Jan 8, 2025$66.00
    • Jan 8, 2025$69.00
    • Jan 7, 2025$120.00
    • Jan 7, 2025$114.00
    • Jan 7, 2025$119.00
    • Jan 6, 2025$738.00
    • Jan 6, 2025$708.00
    • Jan 6, 2025$748.00
    • Jan 1, 2025$961.00
    • Jan 1, 2025$949.00
    • Jan 1, 2025$910.00
    • Dec 30, 2024$8.00
    • Dec 26, 2024$1265.00
    • Dec 26, 2024$1282.00
    • Dec 26, 2024$1214.00
    • Dec 26, 2024$1814.00
    • Dec 23, 2024$32.00
    • Dec 23, 2024$30.00
    • Dec 22, 2024$132.00
    • Dec 22, 2024$137.00
    • Dec 22, 2024$843.00
    • Dec 22, 2024$139.00
    • Dec 22, 2024$878.00
    • Dec 22, 2024$890.00
    • Dec 20, 2024$450.00
    • Dec 20, 2024$123.00
    • Dec 20, 2024$116.00
    • Dec 20, 2024$469.00
    • Dec 20, 2024$121.00
    • Dec 20, 2024$90.00
    • Dec 20, 2024$475.00
    • Dec 20, 2024$94.00
    • Dec 20, 2024$95.00
    • Dec 19, 2024$74.00
    • Dec 19, 2024$75.00
    • Dec 19, 2024$71.00
    • Dec 18, 2024$961.00
    • Dec 18, 2024$40.00
    • Dec 18, 2024$1001.00
    • Dec 18, 2024$42.00
    • Dec 18, 2024$43.00
    • Dec 18, 2024$1015.00
    • Dec 17, 2024$640.00
    • Dec 17, 2024$606.00
    • Dec 17, 2024$631.00
    • Dec 16, 2024$398.00
    • Dec 16, 2024$404.00
    • Dec 16, 2024$22.00
    • Dec 16, 2024$23.00
    • Dec 16, 2024$382.00
    • Dec 15, 2024$227.00
    • Dec 15, 2024$132.00
    • Dec 15, 2024$133.00
    • Dec 15, 2024$230.00
    • Dec 15, 2024$972.00
    • Dec 15, 2024$76.00
    • Dec 15, 2024$45.00
    • Dec 15, 2024$79.00
    • Dec 15, 2024$80.00
    • Dec 15, 2024$217.00
    • Dec 15, 2024$921.00
    • Dec 15, 2024$126.00
    • Dec 15, 2024$959.00
    • Dec 14, 2024$320.00
    • Dec 14, 2024$316.00
    • Dec 14, 2024$303.00
    • Dec 12, 2024$132.00
    • Dec 12, 2024$133.00
    • Dec 10, 2024$132.00
    • Dec 10, 2024$133.00
    • Dec 8, 2024$1282.00
    • Dec 8, 2024$105.00
    • Dec 8, 2024$107.00
    • Dec 8, 2024$1265.00
    • Dec 8, 2024$189.00
    • Dec 8, 2024$191.00
    • Dec 3, 2024$59.00
    • Dec 3, 2024$60.00
    • Dec 1, 2024$21.00
    • Nov 25, 2024$94.00
    • Nov 25, 2024$95.00
    • Nov 21, 2024$64.00
    • Nov 21, 2024$63.00
    • Nov 19, 2024$109.00
    • Nov 19, 2024$107.00
    • Nov 19, 2024$100.00
    • Nov 19, 2024$101.00
    • Nov 18, 2024$55.00
    • Nov 16, 2024$75.00
    • Nov 15, 2024$91.00
    • Nov 13, 2024$1175.00
    • Nov 11, 2024$91.00
    • Nov 11, 2024$2207.00
    • Nov 10, 2024$1281.00
    • Nov 10, 2024$69.00
    • Nov 10, 2024$103.00
    • Nov 10, 2024$529.00
    • Nov 10, 2024$1265.00
    • Nov 9, 2024$101.00
    • Nov 7, 2024$48.00
    • Nov 7, 2024$961.00
    • Nov 7, 2024$53.00
    • Nov 7, 2024$319.00
    • Nov 5, 2024$30.00
    • Oct 31, 2024$27.00
    • Oct 30, 2024$43.00
    • Oct 30, 2024$22.00
    • Oct 16, 2024$239.00
    • Sep 11, 2024$1018.00
    • Aug 3, 2024$184.00
    • Jul 30, 2024$949.00
    • Jul 30, 2024$910.00
    • Jul 17, 2024$37.00

    Auctions (24)

    • Aug 14, 2025High: $1400.00 / Low: $30.00
    • Jul 13, 2025High: $3999.99 / Low: $19.99
    • Jun 20, 2025High: $1400.00 / Low: $19.99
    • May 28, 2025High: $544.63 / Low: $19.99
    • May 4, 2025High: $979.00 / Low: $12.95
    • Apr 7, 2025High: $550.00 / Low: $12.95
    • Mar 14, 2025High: $950.00 / Low: $7.50
    • Feb 17, 2025High: $950.00 / Low: $7.50
    • Jan 25, 2025High: $909.99 / Low: $7.50
    • May 25, 2023High: $149.99 / Low: $149.99
    • May 18, 2023High: $149.99 / Low: $149.99
    • Oct 14, 2021High: $60.00 / Low: $60.00
    • Oct 7, 2021High: $60.00 / Low: $60.00
    • Sep 30, 2021High: $60.00 / Low: $60.00
    • Sep 23, 2021High: $60.00 / Low: $60.00
    • Sep 16, 2021High: $60.00 / Low: $60.00
    • Sep 9, 2021High: $60.00 / Low: $60.00
    • Sep 2, 2021High: $60.00 / Low: $60.00
    • Aug 26, 2021High: $60.00 / Low: $60.00
    • Aug 19, 2021High: $60.00 / Low: $60.00
    • Aug 12, 2021High: $60.00 / Low: $60.00
    • Aug 5, 2021High: $60.00 / Low: $60.00
    • Jul 29, 2021High: $60.00 / Low: $60.00
    • Jul 22, 2021High: $60.00 / Low: $60.00

    What is the Schneider-Kreuznach Edixa-Laudar 50mm f/2.8?

    Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 is a camera lens with 50mm focal length, a maximum aperture of f/2.8/22, for the M42 mount, supporting the Full frame format, weighing 128g.

    Prices and availability are sourced from eBay sold listings and live auctions at request time.

    eBay Auctions

    No active auctions found.

    Technical Specifications

    Optical
    Focal Length50mm
    Aperturef/2.8-22
    Min Focus Distance0.8m
    FocusingManual Focus
    Physical
    Weight128g
    Length32mm
    Filter Thread35.5mm
    MountM42
    FormatFull frame

    Reviews

    Gabriel Roux3.4/5

    Reviewer did not give any comments for Schneider-Kreuznach Edixa-Laudar 50mm f/2.8

    Gabriel Roux4.7/5

    Reviewer did not give any comments for Schneider-Kreuznach Edixa-Laudar 50mm f/2.8

    Frequently Asked Questions

    What is the Schneider-Kreuznach Edixa-Laudar 50mm f/2.8?

    Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 is a camera lens with 50mm focal length, a maximum aperture of f/2.8/22, for the M42 mount, supporting the Full frame format, weighing 128g.

    What mount is the Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 compatible with?

    Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 uses a M42 mount and supports the Full frame format.

    How much does the Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 cost?

    Based on recent eBay sold listings the Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 typically sells for around $7.50. Actual prices vary with condition and seller.

    Is the Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 a good lens?

    Schneider-Kreuznach Edixa-Laudar 50mm f/2.8 has a community rating of 4.0/5 from 2 review(s).

    Which lenses are similar to the Schneider-Kreuznach Edixa-Laudar 50mm f/2.8?

    Similar lenses include Carl Zeiss Ultron 50mm f/1.8 (Icarex 35), MC Carl Zeiss Jena Pancolar 50mm f/1.8, Meyer-Optik Gorlitz Primotar 50mm f/2.8.

    Current Pricing

    Latest Price
    €213.00

    Review Summary

    Overall Rating
    4.7
    Optical5.0/5
    Mechanical5.0/5
    Value4.0/5
    Bokeh5.0/5
    Usability4.5/5
    Based on 2 reviewers