On 28/02/2014, David Mann <dmann...@gmail.com> wrote: > On Mar 1, 2014, at 2:14 am, Mark C <pdml-m...@charter.net> wrote: > >> It looks like a 3 or 4 color separation offset print so my guess would be >> with Paul that it is a photo of an image printed in a magazine. >> >> Is the same pattern visible if you look at the print directly under a >> loup? I assume it is there. If not it would probably be a scanning >> artifact. > > We had to pop into my wife's work on the way home from her mother's place to > check on the leaky roof after a rain storm (it's leaking because it's > undergoing repairs). > > I took the opportunity to bring the slide along so we could look at it under > the microscope and we managed to get a photo by holding her iPhone up to the > eyepiece. I was skeptical but it came out rather well. This is a crop of > the full-size photo to preserve as much magnification as I can get. > > http://gallery.multi.net.nz/photo/779/ > > It's a stereo scope so I was able to see that the blue layer is at the > bottom, with the green in the middle and red on top. I think the > magnification is 100x (10x objective, 10x eyepiece). Plus whatever > magnification I'm getting from cropping the phone pic. We couldn't get the > 40x objective to focus through the glass but I don't think we needed it. > > The dark splotch is part of the image. You can just make out the grainy > appearance (it was much sharper to the eye). The grain is present even in > bright parts of the image but it's incredibly fine even under this > magnification. > > I'm not sure what caused the bleeding between the red bits but it looks like > a hair on the image. Here's a link to a smaller thumbnail where you can see > that more clearly. That might give a clue to the process by which it was > produced. > http://gallery.multi.net.nz/img/thumbs/779-sz4pqpbs.jpg > > Under a 10x loupe I can only barely make out that there are separated > primary colours so this detail is is incredibly fine. If it is a photo of a > print then it's a really very seriously bloody sharp one.
In contrast, a closeup of Polachrome: http://farm8.staticflickr.com/7262/7471683282_f914422824_m.jpg Yours looks more like a copy of a printed image, to me. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
