The flux of narrow 5007 Å [OIII] forbidden line during last 20 years is accepted as a bench-mark for calibration of the continuum and broad-lines fluxes in AGN. But one can not get away from the problem of the forbidden lines variability in these objects. The first report were published by Bardin et al. (1967). Some of the results are revieved by V. Pronik, I. Pronik (1988, 1992). There were 4 years monitoring of [OIII] fluxes variability in the Seyfert galaxy NGC 1275 nucleus (Pronik et al., 1990). Now we reexamine the published data of W. Zheng et al. (1986, 1987, 1988), discussed earlier in supposition of forbidden lines constant in spectra of 11 low-redshifted QSOs. Maximal calibration coefficients adopted by W. Zheng et al. in supposition of [OIII] lines constant were in the interval 2.0–3.6. On the other hand the fluxes errors are about 15%. Disagreement is very high. This is one of the arguments in the forbidden lines variability Tightness.
Integral Field Spectrography of Active Galaxies with TIGER