Screenshots API: Opacity of LASCO mask depends on spatial scale

[Daniel Mueller]

Compare the following two calls:

(a)
http://helioviewer.org/api/index.php?action=takeScreenshot&date=2099-01-01T00:00:00Z&imageScale=31&layers=[SOHO,LASCO,C2,white-light,1,100],[SDO,AIA,AIA,304,1,100],&x0=0&y0=0&width=256&height=256&display=true

(b)
http://helioviewer.org/api/index.php?action=takeScreenshot&date=2099-01-01T00:00:00Z&imageScale=32&layers=[SOHO,LASCO,C2,white-light,1,100],[SDO,AIA,AIA,304,1,100],&x0=0&y0=0&width=256&height=256&display=true

The former one generates a composite image with a transparent coronagraph mask, while the latter one (and other with imageScale > 31) result in the attached screenshot.

It would be great if transparency would be handled as in case (a) for all image scales.

Thanks!