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tokens: free of atmospheric perturbations, regularly produced by the 50 cm Solar Optical Telescope (SOT) on-board the satellite HINODE between November 2006 and February 2016, are now available. These images have been used in this paper to investigate the variation of the solar granulation over the activity cycle with more accuracy than before. After a presentation of the HINODE/SOT synoptic program in Sect. 2 , the method of analysis of the blue continuum images is described in Sect. 3 . The results are presented in Sect. 4 and discussed in Sect. 5 . 2. Observations: HINODE/SOT synoptic program The HINODE synoptic program provided broadband images obtained at the disk center with the Optical Solar Telescope (e.g., Tsuneta et al. 2009 ). They were taken a few seconds apart in blue, green and red continuum windows at 450.45, 555.05, 668.40 nm respectively, in the G -band lines of the CH molecule at 430.50 nm, in the CN band head at 388.35 nm and in the Ca II H line at 396.85 nm, in general once or twice a day. In this work we have only used the blue continuum images. During the observations, the focus position was controlled in the G -band; when optimized in this wavelength, it is also optimized in the nearby blue continuum 0.4 nm window. But unfortunately, this set of images is not as homogeneous as expected, because a significant number of them appear to be blurred to a varying degree; the cause of blurring may be inaccurate focusing or/and optical aberrations as one will see in Sect. 4 . Consequently, great care is taken in this investigation to only select the sharpest images, in order to get the most homogeneous set of high resolution granulation images currently available, spanning nearly one solar cycle (although the minimum of activity between cycle 23 and cycle 24 was longer than usual). Before February 2008, when a serious telemetric problem occured, between two and four images were taken every day in each wavelength; after that month and until September 2009 the cadence was reduced to about one image taken every two days, but then on increased again to a cadence of about one observation per day. Two adjacent cameras with 2048 × 2048 square pixels of nominal scale 0′′̣055, took rectangular images of nominal size 228′′ × 114′′. We have taken into account the annual variation of the Earth-Sun distance by changing the pixel scale accordingly. After the telemetric problems which occurred in January 2008, the images of the synoptic program were binned by a factor of two. Fortunately, this is not a problem in this work, since the images taken before this date were binned by a factor of two for analysis. So the size of all the analyzed images is 2048 × 1024 pixels. The program ended in February 2016, when both cameras broke down. All images were calibrated with the standard solar reduction software distributed under SSWIDL, which corrects for bad pixels, readout errors, dark current and flat field. A 1024 × 512 pixel subfield of a calibrated image is