A jól bevált helyen, Szelicsén partiztunk. Külön köszönetet érdemel Ilarie, akinek a 20 centis tubusával bolygóztam a 15 centisénél több fény reményében.
A csíkhúzós fotó Magic-Lantern-nel hajtott Canon 1100D-vel készült 97 képkockából egy „ha fényesebb” php-szkripttel.
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We were at a star party on our well known spot near Sălicea.
Special thanks to Ilarie for letting me try his scope (20 cm) which is a bit larger than mine (15 cm) so I hoped for more light for planetary imaging with my webcam.
The star trails have been shot with a Canon 1100D powered by Magic Lantern. 97 frames were included, F/4 18 mm, ISO 800, 20 seconds each and then added with a „keep the lighter pixel” filter in a PHP script.
<?php /* Trivial code to create a startrails picture from individual frames depicting pointlike (or slightly elongated) stars by using a final_pixel[x,y] = max(input_image[0].pixel[x,y], ... input_image[input_image_count-1].pixel[x,y]) function. Progress is also saved. */ set_time_limit(6000); $list = glob('input/*.*'); function pixel_to_luminance($i){ $r = $i >> 16; $g = $i >> 8; $g = $g % 256; $b = $i % 256; $l = $r + $g*2 + $b; return $l; } $output = imagecreatefromstring(file_get_contents($list[0])); $c = 0; for ($q=1; $q<min(500, count($list)); $q++){ $i = imagecreatefromstring(file_get_contents($list[$q])); for ($y=0; $y<imagesy($i); $y++) for ($x=0; $x<imagesx($i); $x++){ $pix_o = imagecolorat($output, $x, $y); $pix_i = imagecolorat($i, $x, $y); $l_o = pixel_to_luminance($pix_o); $l_i = pixel_to_luminance($pix_i); if ($l_o < $l_i) imagesetpixel($output, $x, $y, $pix_i); } imagedestroy($i); if ($q % 5 == 0){ $c++; $c_ = $c; if ($c < 10) $c_ = '0'.$c_; if ($c < 100) $c_ = '0'.$c_; imagejpeg($output, 'output_'.$c_.'.jpg', 90); }; } imagejpeg($output, 'output_final.jpg', 90); imagedestroy($output); ?>





