Originally posted by stevebrot DeadJohn knows his stuff (
examples of his astro work) and if he says amp glow, it may well be amp glow.
Sorry to be so stern, but the example frame at top right is telling. The ghost head by the arrow tells me that there was precious little to pull. The short answer regarding an artifact at high ISO + severe intentional underexposure + high ambient temperature + deep shadow pull is simply, "Don't do that!"
Steve
Steve, thanks for all the questions, I'll try to answer tomorrow. Just one thing: those shadow are pulled
only to better show the magenta strip; usually I don't underexpose and then pull the shadows (and never to that extent, unless needed, but it should really be on the event of an alien landing in the woods near my house...
), I expose "normally" for my subject: in the ballet scene I could just cut away that part of the frame, there was just an invisible coreographer who could just remain invisible... I only noticed a bit of magenta shifting in the shadows there, but thought it was a faint reflection of the lights on the stage.
---------- Post added 07-13-19 at 04:56 PM ----------
Originally posted by stevebrot Link? No link => not even a rumor.
Steve
Steve, are you stating that I'm a liar or what? She sent me the originals, shot the way I asked (she's a member of the Pentaxians group on FB).
BTW, have you got a KP? Would you be so kind to try and duplicate the kind of setting to see if the noise pattern shows in the same way? Camera in a dark room, finder covered and lens with cap, 1/15s and ISO ranging from 800 to 12800. RAW, of course...
if you like to check for yourself, I've uploaded four dng files here:
WeTransfer
There is one of mine (one of those shown above) and three from the Texan KP owner. Sorry if I took so long to reply, but the upload speed is not what I may call fast, here...
PS: I didn't find anything about the temperature of the sensor in the Exif, just the WB Kelvin temperature. Where exactly should I look?