can i define higher settings for specific objects?

[max montana]

hi there,
i face a problem with artefacts on my balcony balustrade, over all in the houses i the back
i use a material with opacity map there. with "medium settings" (medium preset - noise treshhold 0,005), i get nice results and good rendertimes for my scene, but artefacts on the balcony balustrade. i can handle that with higher settings (high preset - 0,002 noise treshhold) for the price of much higher rendertimes.
question: can i define higher settings, material- or object wise, as i can handle it with the subdivisions for refl - refr?
thx

[idtools]

maybe by reducing blur of the opacity map or changing the mode of filtering not pyramidal but
summed area

[max montana]

thanks for the suggestion idtools. tried 0,01blur and summed area filtering, but both without bettering.

[rmejia]

What Antialiasing image sampler type are you using?

[max montana]

i use adaptive qmc with area antialiasing filter