Posts Tagged: Canon
Wrestling with Printer-Induced Roller Marks on Paper
Problems with the mechanics of how printers handle fine quality paper for printing
Canson BKF Rives 310gsm paper loaded into Canon iPF8400 printer, showing pinch roller marks. This is equivalent to the worst-case scenario with my first iPF8400 if the paper was passed under the rollers about 5 times or more. For some reason, my documentation from seven years ago was lost, so I had to re-create equivalent roller pressure on the paper. Illumination is indirect sunlight from the balcony to the right, somewhat diffused but sufficient to notice the problem. The dents running vertically down the paper correspond perfectly to the roller positions. Note the grey lever mechanism in the lower right, which the user manually operates to raise and lower the pinch rollers (the little grey cylinders about 13mm wide running horizontally on the far side of the visible portion of the paper).
This is what the problem looks like, is totally unacceptable and one way or another, I had to make it go away.
Your Cameras and Lenses are Crooked and How to Adjust Them
Plus a bunch of tidbits about some of the challenges in making astro-landscape photographs
Silver River Shimmers, 2017
Photograph notes: This is a composite of 4 vertical frames stitched for the sky and another 4 vertical frames stitched for the land for a total of 93.8 million pixels, using a Sony a7R II at ISO 800 and Canon EF 35mm f/1.4L II USM. Each of the sky frames was stacked and averaged from nine 32-second exposures at f/2.8. The land frames were stacked and averaged from four 32-second exposures at f/4 made 23 mins later at predawn to avoid shadows from the sun. 52 exposures were used in all. The sky exposures were tracked with a Sky-Watcher Star Adventurer.