Ars Acon 35 model II

This is a small Japanese rangefinder camera from 1956 to 1958 (according to Interweb sources). The general styling is very like a Zeiss Ikon of the period – square with heavily champhered corners. The camers measures 117 by 77 mm and by 60 mm deep. It weighs 588g without film.


lens: Vita Anastigmat
focal length:  45 mm
apertures: f/3.5 to f/16
focus range: 3.5 feet to infinity
lens fitting: fixed
shutter: Signa leaf
speeds: 1/10 to 1/200
flash: PC socket
film size: 35 mm

On the right hand end of the top plate is the film advance knob – this is a knob and not a lever which is already a bit old fashioned by the mid-1950s. This camera dates from the period when knobs were being replaced with levers but not yet on this camera. The knob is not on a ratchet which would make advancing the film easier. Rather, it is necessary to turn the knob a complete rotation to advance the film one frame. This is not difficult but does slow down the rate of photographing. In the centre of the advance knob is the frame counter. This counts up from one and needs to be set to zero by hand. It will count up to 39 frames. Just behind and to the left of the film advance knob is a button. This is not the shutter release button (no prizes for guessing what I was trying to do with it!) but the button to enable the rewinding of the film – there is no shutter release on the top plate.

“The actual shutter release is a lever on the right side of the shutter/lens housing with a fairly large knurled knob on the end”

Left of the film advance knob, the top plate is raised. This raised portion houses the rangefinder. The rangefinder is coupled to the lens and is operated by the lens focus ring – more later. On top of this raised portion is the accessory shoe – this has no electrical contacts. In front of the accessory shoe is the name of the camera – ACON 35 MODEL-II. Beside the accessory shoe is the camera serial number – 63208.


On the back of the rangefinder part is the viewfinder eyepiece. This incorporates the rangefinder eyepiece. On many early rangefinder cameras there were separate viewfinder and rangefinder  eyepieces. The eyepiece is round, it has a diameter of 5 mm. This is pretty standard for the time but is very hard to use while wearing glasses. On the front of the rangefinder part of the top plate are two windows. The larger one is the viewfinder window and measures 16 by 11 mm. The smaller window is the rangefinder window. It is smaller as it is only providing the central rangefinder spot in the viewfinder image.

On the left of the top plate is the film rewind knob. Later in the 1950s these got replaced by a small crank but, to be honest, I find a knob to be much easier to use. Inside the rewind knob is a film reminder. This is entirely a mnemonic and has no effect on the functioning of the camera. The options here are : empty; panchro; h.s. pan; colour; inf red.


As always, the front of the camera is dominated by the lens/shutter housing. This is offset to the left and is mounted on a satin-plated brass square. The shutter is a Signa which is a make I have never heard of before. It is a between the lens leaf shutter and is clearly modelled on the Compur/Prontor design from Germany. It offers speeds from 1/10 to 1/200 seconds and B – a fairly standard and eminently usable range.

“The lens is a Vita Anastigmat which (like the Signa shutter) I have never heard of before”

The aperture is controlled by an iris diaphragm with ten blades – this will give an almost circular aperture with implications for bokeh. Apertures range from f/3.5 to f/26. The setting lever for the aperture is on the underside of the shutter/lens housing right where the delay action lever usually is. There is no delay timer lever on this shutter.

Focusing the lens is by a lever that is also below the shutter/lens housing. This moves through something like 70° to focus from 3.5 feet to infinity . The lever is attached to the rangefinder in the top plate (so it is a coupled rangefinder. The focus lever moves the entire shutter/lens assembly which maintains the integrity of the multi-element lens and is a superior method of focusing. Many cheaper camera only move the front element which will change the optical characteristics of the lens.

To use the rangefinder, you look through the viewfinder at the small yellowish square in the centre of the image. If the image is out of focus, the image in the small square will be double. You move the focus lever until the double image moves to become one single image at which point the lens is in focus. This works best if there is a strong vertical in the image but that is not essential. Incidentally, the rangefinder square is made yellowish by using a thin layer of gold on the internal rangefinder mirror rather than using silver.  This increases local contrast and makes the rangefinder easier to use.

Shutter release


Focus lever



Before the shutter can be fired, two conditions must be met. First, the film must be advanced. This is to prevent accidental double exposures. Secondly, the shutter must be manually cocked by pulling a lever on the top of the shutter/lens housing to the right. The actual shutter release is a lever on the right side of the shutter/lens housing with a fairly large knurled knob on the end. This is pressed down to fire the shutter. A word or warning – if you advance the film but do not cock the shutter and then press the shutter release you will reset the double exposure mechanism. You would then need to advance the film a second time before you can take a picture thus wasting a frame of film.

The lens is a Vita Anastigmat which (like the Signa shutter) I have never heard of before. It was quite common for camera makers to buy-in lenses from specialist optical companies and use their own names for them. Focal length is 45 mm which is normal for 35 mm photography.

The base of the camera is satin-plated brass and has two 25 mm bright plated, serrated discs – one at each end. Together, these discs act as feet and allow the camera to sit stably on a level and even surface. One of the discs has a tripod boss in the centre. This is 1/4 inch UNC as is standard. It is right at one end of the camera so bodes badly for level attachment to a tripod.  The other disc has an arrow beside it and the legends ‘O’ and ‘C’. To open the camera you turn this disc from ‘C’ to ‘O’. The base plate and back will then come away in one piece.


Inside is standard. The chamber for the film cassette is on the left. The film gate is next – this is smaller than usual. Of course, the actual gate is 24 by 36 mm but the surrounds are smaller. The film sits on 3 mm either side of the film gate rather than the 10 mm in my Zeiss Ikon Contina Ic. The wider the surround to the film gate, the flatter the film will sit which has implications for image quality.  Keeping these areas small allows the camera to be smaller as well (117 mm wide compared to 123 mm with the Zeiss Ikon Contina Ic) and this is a compact camera (not as compact as a Rollei 35, perhaps, but smaller than most).

Interior of camera
film gate

All parts of this camera seems to work well so I shall be trying it with film – results soon.


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