Relations between goodliness of photographic prints and slope of tone reproduction curves is studied. Experiment were carried out with samples having various negative sizes which correspond to 8mm, 16mm and 35mm motion picture negative. Decreases of the negative size yield decreases of the slope of tone reproduction curve which derived directly from original luminance and print density, therefore, optimum developing time which estimated with categorical- and comparative-judgement is found longer for small negative than large one. And, in this case, density-response in various negative sizes was consisted with the spacial frequency which correspond to maximum response of eye.