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In a project aimed at measuring the optical Extragalactic Background Light(EBL) we are using the shadow of a dark cloud.We have performed, with the ESOVLT/FORS, spectrophotometry of the surface brightness towards thehigh-galactic-latitude dark cloud Lynds 1642. A spectrum representing thedifference between the opaque core of the cloud and several unobscuredpositions around the cloud was presented in Paper I (Mattila et al. 2017a). Thetopic of the present paper is the separation of the scattered starlight fromthe dark cloud itself which is the only remaining foreground component in thisdifference. While the scattered starlight spectrum has the characteristicFraunhofer lines and the discontinuity at 400 nm, typical of integrated lightof galaxies, the EBL spectrum is a smooth one without these features. Astemplate for the scattered starlight we make use of the spectra at twosemi-transparent positions. The resulting EBL intensity at 400 nm is $I_{\rmEBL} = 2.9\pm1.1$ $10^{-9}$ erg cm$^{-2}$s$^{-1}$sr$^{-1}$\AA$^{-1}$, or$11.6\pm4.4$ nW m$^{-2}$sr$^{-1}$, which represents a 2.6$\sigma$ detection;the scaling uncertainty is +20%/-16%. At 520 nm we have set a 2$\sigma$ upperlimit of $I_{\rm EBL} \le$4.5 $10^{-9}$ ergcm$^{-2}$s$^{-1}$sr$^{-1}$\AA$^{-1}$ or $\le$23.4 nW m$^{-2}$sr$^{-1}$+20%/-16%. Our EBL value at 400 nm is $\ge 2$ times as high as the integratedlight of galaxies. No known diffuse light sources, such as light from Milky Wayhalo, intra-cluster or intra-group stars appear capable of explaining theobserved EBL excess over the integrated light of galaxies.

Extragalactic background Light: a measurement at 400 nm using dark cloud shadow II. Spectroscopic separation of dark cloud's light, and results