Rich, a silly question: why should be the sampling area aligned with axes? transformations of a sampling area save a lot of computations: otherwise you would have to sample and compute the whole area of a bounding box of a stretched / skewed / rotated zoom box.. transformations of a computed image result into interpolations, blurring the originally 'incorrect'/'imperfect' image even more the chain is: transform coords > sample > compute > transform pixels > render what Fractint does: transform coords > sample > compute > visualise what real-time rendering layer would add: loop {transform pixels > render} so, even if you plan to substitute the plain visualisation with a real-time rendering layer, the coords transformation is still needed for efficiency and versatility.. /charlie/