Enlaged photographs

Photograph can be enlarged so that people with normal eyesight are able to see them properly, without magnifying glass. It can be done, merely by using cameras having lenses with a long focal length. You already know that a photograph obtained with the aid of a lens having a focal distance of 25-30 cm will appear in relief when viewed with one eye from the usual distance away. One can obtain photographs that won’t seem flat even when looked at with both eyes from quite a distance. You already know that our brain blends two identical retinal images into one flat picture. However, the greater the distance from the object, the less the aid of a lens having a focal distance of 70 cm can be looked at with both eyes without losing the sense of depth. Since it is incommoding to resort to such lenses, let me suggest another method, which is to enlarge the picture you take with any ordinary camera. This increases the distance at which you should look at photographs to get the proper effect. A four fold enlargement of a photograph taken with a 15 cm lens is already quite enough to obtain the desired effect. Cinema goers have most likely noticed that some films seem to spring into unusually clear relief to such an extent at times that one seems to see real scenery and real actors.