The PRAKTICA M42 camera's web
  Main   Camera's   Lenses   Accessories   History      Tech. info   Classifieds   Contacts   Photo gallery   Links   

The shutter system. More items will follow.

The hart of every camera is and will always be the shutter. It is not only designed to let light through, but also has to devide it equally over the surface of the film. This is done by all models Praktica (except the L-serie) with a curtainshutter. This can be best described as two curtains sliding with the same speed from left to right across the filmsurface. When sliding across there is a small opening between them to let the light fall on to the filmsurface.So the bigger the opening, the more light falls on the film. One can also regulate the speed of the curtains (shutterspeed) to make it go slower or faster and to controle the amount of light comming on the filmsurface.


The opening between the curtains is aprox.: at 1/250s - 8mm, 1/125s - 16mm and from about 1/60s it is about the same or bigger then 36mm, which is very important with flashphotography, because the whole filmsurface has to be lighted in a very short period. For the slower speed (1/2s, 1/4s, 1/8s) a delay device is build in the camera to controle this. The older models Praktica until the Nova 1 have a separate switch near the shutterspeedbutton to engage this mechanism. The curtain shutter has proved to be very relliable for many years. It could work without any problems by temparatures from -5� to +45�. The only real problem is when you leave your camera in the sun without a lenscap on the lens because then the lens will work as a magnifying lens and burn a hole through the shutters curtain.

 

The Praktica L serie has a completely different type of shutter made out of 6 steel shades working 3 by 3 as a curtain. The shades are only 0.07mm thick and mounted on a mechanism. This system has a very high speed (about 4m/s), and because this model runs vertical instead of horizontal the distance the shutter has to travel becomes shorter which results in faster shutterspeeds. Also the flashsync.speed can be set higher to 1/125s instead of the former 1/60s. There is also a delay mechanism that regulates the speeds in three fases ( 1 - 1/15s, 1/30 - 1/125s and 1/250 to 1/500s) the speed of 1/1000s is not beeing reduced.

So in conclusion whe might say that this model was quite an improvement for Praktica and is still working quite well in the models I use these days.

Any additional information, questions or comments just mail me: [email protected]