... And the display Magnifier is used on other cameras

There is a thin magnetic metal frame which codes for 3 '' display, such as Canon Mark II, Nex 5R fits etc.. All screen magnifiers, not only of cinema technology, but also the many (cheaper) Chinanachbauten can be placed. I have one of those.

The frame is made accurately. It is a thin, tough adhesive layer applied (not uhuartig!), Which is protected by a paper cover during delivery. This paper strip should be carefully pull off so that the adhesive is not removed. The mounting frame fits exactly. Is best to select a bright image in order to put him exactly can. In operation without a magnifying glass, the frame is barely perceptible. The magnetic closure between the frame and magnifying glass keeps very well. May elevation at the camera of course not on the magnifying glass. I've tested it also on a display protective glass underneath. Worked well. However, then you have 2x adhesive and an increased release probability.