SCIENCE- G OS SIP. 



rising front for both horizontal and vertical pic- 

 tures, and is fitted with two levels. The 5x4 

 " De Luxe " is precisely the same in every detail, 

 except that it is fitted with the No. 7 Ross-Zeiss 

 lens of two 11-| in. foci, giving in the combined 

 lens a focal length of 6J in. The price of the 

 J-plate camera is £21 10s., and of the 5x4 £32 10s. 

 The Adams "Reflex" camera is quite a different 

 type of instrument, the principal feature being a 

 full-size finder on the reflex system. This consists 

 of a reflector working on a spring inside the camera, 

 which reflects the rays coming through the lens on 

 to a piece of ground glass inserted in the top of the 

 camera. This receives the image in exactly the 

 same condition that it will be thrown upon the 

 sensitive plate when the mirror is released. Thus 

 the identical view in respect to sharpness, amount 

 of view, size of object, and position it will occupy 



Fig. 3. Adams' "Reflex" with focussing hood raised. 



on the plate is clearly seen in the finder. The 

 ground glass is shaded from the light by means of 

 a deep funnel arrangement, as shown in fig. 3, which 

 enables the operator to see the image clearly in the 

 most brilliant light. There is not any other system 

 for focussing and arranging the picture in hand 

 camerawork with such accuracy and precision as can 

 be attained by this method. This particular camera 

 is so constructed that the picture . can be taken 

 either vertically or horizontally by simply inserting 

 the double dark slide according to the way the 

 picture is required. The camera is fitted with a 

 focal plain shutter giving exposures varying from 

 ^th to ig^th part of a second. This shutter con- 

 sists of a rollable blind which when making an 

 exposure carries a slit of varying size across the 

 sensitive plate and close to its surface. The 

 various exposures are obtained by altering the size 

 of the slot, which in this case is achieved by 

 simply turning a small mill-head screw outside the 

 camera until the desired exposure is seen registered 

 on the shutter itself. The lens best adapted for 

 this class of camera is one with a large working 

 aperture, such as the " Zeiss Planar," working at 

 F. 4, the " Unar," F. 5, the " Convertible Anastig- 



mat," F. 6-3, the " Cooke," F. 6'5, the •• Dallmeyer 

 Stigmatic," F. 6, or other lenses of this type. 

 Those in this camera are easily interchangeable, 

 so that one or more of different foci can be used 

 on the same instrument. For instance, the 5x4 

 size is capable of taking any lens of an equiva- 

 lent focus between 7 and 14 inches ; thus, if the 

 No. 10 Ross-Zeiss Anastigmat lens is fitted, the 

 combined lens will be 8 inches and the single 

 lens 14 inches, which would gain a wide choice of 

 angle of view. In addition to the ordinary work, 

 the camera can be used for telephoto lenses. The 

 Reflex camera is made for |- plate, 5x4 and 

 | plate. 



The "Nydia" is a neat folding pocket-camera, 

 fitted with the Newman and Guardia pneumatic 

 shutter working between the lenses, having a 

 range of speeds from xoo tn to | a second, and time 

 exposures. It is fitted with the N. and G. 



The " Nydia " Camera, open and closed. 



changing system, the box practically forming the 

 body of the camera. When in use it is rigid and 

 easily worked. It has a very neat focussing 

 arrangement which permits of adjustment from 

 two yards to the utmost limit. When closed, as 

 seen in the illustration, it measures only 1\ inches x 

 4j inches x If inches, and when loaded' weighs 

 28 ounces, thus being easily carried in a j>ocket. 

 The box is constructed to carry eight plates, or 

 twelve flat films. This camera is made only in 

 quarter-plate size. It is fitted with lenses by four 

 different makers — viz. a Rapid Rectilinear, work- 

 ing F. 8 ; Wray's Rapid Rectilinear, F. 8 ; Ross 

 New Symmetric Anastigmat F. 8 ; and Zeiss-Saty 

 Anastigmat F. 63. The focal length of all these 

 lenses is the same — 5| inches. The iris diar 

 phragm in each case is scaled up to F. 45. 

 The finder is of the real image type, ground glass, 

 and can be relied upon to give a true representa- 

 tion of the picture on the plate. In addition to 

 the above features the " Nydia" is provided with a 

 swing back. The prices of the " Nydia " range from 

 £1 10s. to ±°15 10s., according to the lens selected. 

 The "Adams" cameras, working with the bag- 

 changing, are made somewhat upon the same lines, 

 that is, so far as concerns the manufacture. Both 

 these firms are makers only of the highest class 

 instruments. 



(To be continued.') 



