Anyone here own a Leicina Special?...

[slashmaster]

I thought the Mekel was only a polavision camera?

There are two versions of the camera. They're described here: http://super8wiki.com/index.php/Visual_ ... e_8_Camera and http://super8wiki.com/index.php/Mekel_300. The cameras were designed by Mekel Engineering and both have pin registration.

Oh ok!.... Did not know that was the same company that made both. Hey, can you tell me something else?... It did come from the factory with those 4 knurled knobs to get the front off fast right? Why would they do that? Just to make the prism easier to clean? Did they make a different front cover so the reflex prism can be removed and you can use non-reflex lenses?...

[slashmaster]

[possibly there are even more cameras with the little ramps I know the R8 an dR10 do have them. So does the Nikon 8x Super Zoom and the Minolta D10. Clearly Japanese designers and engineers then already had a clear understanding and insight of the working and troubles of super-8 cartridges.

This air-channel, which I only came to understand the importance of later, makes all this pressure-plate fanatism laughable and the collimation obsession an illusion. These have no purpose. Don't use lenses at aperture 1.0 or 1.2 and think to reduce the air-channel, it will wreck the pick-up drive in the worst case

I don't understand the air channel, can you tell me about it?..

[sciolist]

Hey, can you tell me something else?... It did come from the factory with those 4 knurled knobs to get the front off fast right? Why would they do that? Just to make the prism easier to clean? Did they make a different front cover so the reflex prism can be removed and you can use non-reflex lenses?...

The lens plate can be removed quickly, but that feature is intended to allow access to the manually-adjustable shutter (having a range of 10° to 160°). The viewfinder optics can't be cleaned simply by removing this plate (the beam splitter is only 0.005 inches thick and, according to instructions supplied with the camera, shouldn't be touched). I'm unaware of other kinds of lens plates for the camera.

[aj]

[possibly there are even more cameras with the little ramps I know the R8 an dR10 do have them. So does the Nikon 8x Super Zoom and the Minolta D10. Clearly Japanese designers and engineers then already had a clear understanding and insight of the working and troubles of super-8 cartridges.

This air-channel, which I only came to understand the importance of later, makes all this pressure-plate fanatism laughable and the collimation obsession an illusion. These have no purpose. Don't use lenses at aperture 1.0 or 1.2 and think to reduce the air-channel, it will wreck the pick-up drive in the worst case

I don't understand the air channel, can you tell me about it?..

When the cartridge-plate-notches interlock with the camera-gate knobs it does so that there is room/distance between the gate and the plate. It is a channel. The distance is by design larger then every film-thickness available. Hence, the film is free to move as it is frictionless. You could test this with a separated plate from a cartridge Put a strip of film over the gate, put a plate over it and notice that the film can easily be moved up or down...
The films travels through this channel when the claw pushes it. Should the pickup be to too strong it will yank the film through even when the claw is not pushing. Should the supply be blocked the claw possibly might not advance it enough or at all. It is a delicate balance
An early problem with this was the bump caused by the roller in the film when the film had been still in cartridge some time. This bump would cause an unsharp image when it passed the gate as the film suddenly moves forward to the lens and goes out of the focal field. Especially notable with wide open aperture of course. An attempt to remdy this was the framemaster plate which reduces the space in the channel. It is an illusion to think every camera could be adapted to work with a channel where the film is not free. The pickup drive isn't suitable for that And the claw may suffer too.

[slashmaster]

[possibly there are even more cameras with the little ramps I know the R8 an dR10 do have them. So does the Nikon 8x Super Zoom and the Minolta D10. Clearly Japanese designers and engineers then already had a clear understanding and insight of the working and troubles of super-8 cartridges.

This air-channel, which I only came to understand the importance of later, makes all this pressure-plate fanatism laughable and the collimation obsession an illusion. These have no purpose. Don't use lenses at aperture 1.0 or 1.2 and think to reduce the air-channel, it will wreck the pick-up drive in the worst case

I don't understand the air channel, can you tell me about it?..

When the cartridge-plate-notches interlock with the camera-gate knobs it does so that there is room/distance between the gate and the plate. It is a channel. The distance is by design larger then every film-thickness available. Hence, the film is free to move as it is frictionless. You could test this with a separated plate from a cartridge Put a strip of film over the gate, put a plate over it and notice that the film can easily be moved up or down...
The films travels through this channel when the claw pushes it. Should the pickup be to too strong it will yank the film through even when the claw is not pushing. Should the supply be blocked the claw possibly might not advance it enough or at all. It is a delicate balance
An early problem with this was the bump caused by the roller in the film when the film had been still in cartridge some time. This bump would cause an unsharp image when it passed the gate as the film suddenly moves forward to the lens and goes out of the focal field. Especially notable with wide open aperture of course. An attempt to remdy this was the framemaster plate which reduces the space in the channel. It is an illusion to think every camera could be adapted to work with a channel where the film is not free. The pickup drive isn't suitable for that And the claw may suffer too.

Oh ok!.. Yeah, I have taken the rear pressure plate from a cartridge I cracked open and put it up to a camera plate with a piece of film in between before. It has very little drag, most of it from the two spring loaded guide pins. I wonder if maybe the spring loaded guide pins in the Leicina have more spring pressure than most? Therefore better registration? I've been wanting one of those framemasters! Been trying to find out what all the dimensions are so I can grind my own out of a piece of stainless. How does the gate in a polavision work? Is it like a super 8 cartridge?. No drag except for the guide pins?