I present the results of multi-component decomposition of V and R broadband images of a sample of 17 nearby galaxies , most of them hosting bars and active galactic nuclei ( AGN ) .
I use budda v2.1 to produce the fits , allowing to include bars and AGN in the models .
A comparison with previous results from the literature shows a fairly good agreement .
It is found that the axial ratio of bars , as measured from ellipse fits , can be severely underestimated if the galaxy axisymmetric component is relatively luminous .
Thus , reliable bar axial ratios can only be determined by taking into account the contributions of bulge and disc to the light distribution in the galaxy image .
Through a number of tests , I show that neglecting bars when modelling barred galaxies can result in a overestimation of the bulge-to-total luminosity ratio of a factor of two .
Similar effects result when bright , type 1 AGN are not considered in the models .
By artificially redshifting the images , I show that the structural parameters of more distant galaxies can in general be reliably retrieved through image fitting , at least up to the point where the physical spatial resolution is \approx 1.5 Kpc .
This corresponds , for instance , to images of galaxies at z = 0.05 with a seeing FWHM of 1.5″ , typical of the SDSS .
In addition , such a resolution is also similar to what can be achieved with HST , and ground-based telescopes with adaptive optics , at z \sim 1 - 2 .
Thus , these results also concern deeper studies such as COSMOS and SINS .
This exercise shows that disc parameters are particularly robust , but bulge parameters are prone to errors if its effective radius is small compared to the seeing radius , and might suffer from systematic effects .
For instance , the bulge-to-total luminosity ratio is systematically overestimated , on average , by 0.05 ( i.e. , 5 % of the galaxy total luminosity ) .
In this low resolution regime , the effects of ignoring bars are still present , but AGN light is smeared out .
I briefly discuss the consequences of these results to studies of the structural properties of galaxies , in particular on the stellar mass budget in the local universe .
With reasonable assumptions , it is possible to show that the stellar content in bars can be similar to that in classical bulges and elliptical galaxies .
Finally , I revisit the cases of NGC 4608 and NGC 5701 and show that the lack of stars in the disc region inside the bar radius is significant .
Accordingly , the best fit model for the former uses a Freeman type II disc .