35mm SLR with M42 mount and automatic exposure

[hannes]

Hello:

One of my focus in collecting old cameras is on 35mm SLRs with M42 mount and automatic exposure. There are not so many cameras falling into this group because many producers switched to bayonet mount to allow transfer of aperture values to camera electronic.

I will start with 2 cameras of my collection and hope that others will be added to this thread.

Yashica Electro AX

It was built from 1972 to 74. (correct me if I'm wrong)

It has electronic controlled Copal shutter

It is a fully automatic camera without feedback which time it chooses. There are only lamps in the view finder to indicate over or under exposure. This is very similar to the Electro 35 G rangefinder camera.

The lamp on top of the camera is light when the shutter is open, giving you a very rough indication about used time. Manual says that for times faster than 1/60 sec the shutter function cannot be determined by this lamp very well. This is because such a lamp does not fully glow when turned on for such short times. But it works well for longer exposure times.

It has an aperture open button, instead of a step down button, because by default aperture is allways stepped down. For composing the image you have to press this button to open the aperture for brighter view.

When you switch to manual mode the light meter is turned off.

There is also a limitation in the lenses you can use. You cannot use Yashinon DX 21mm f/3,3, Auto Yashinon DX 28mm f2.8 and 50mm f/2, F/1,8 f/1,4 due to the construction of the mirror. It would collide with these lenses.

All together this camera is not very user friendly, but an important member of a Yashica Electro collection.







Hannes

[hannes]

Chinon CE Memotron and derivates

It started with the Memotron CE in 1974, followed by the CE II in 1977. The last one was the CE-3 Memotron 1979.

They have an electronically controlled metal focal plane shutter. Speeds from 2 to 1/2000 sec. plus B (1/90 sec flash sync.) Manual mode has 12 mechanical speeds. Exposure control by an automatic aperture preferred exposure system... simply set aperture by turning f-stop ring and the camera sets the shutter speed automatically. The CE-3 has a smaller body and top speed was reduced to 1/1000s.

Depressing the shutter release button halfway activates meter. Memory exposure control switch lets you take a meter reading for a subject and lock it in so, that extreme contrast or strong back light will not misguide exposure system.
Multiple exposure button allows double or multiple exposures on one frame.

Any M42 lens with or without automatic aperture can be used.

Revueflex 4004 and 5005
Are based on the Memotron CE II but the Memotron function is missing. The body of the 4004 and 5005 is the same. The only difference is that the 5005 has the faster lens: Auto Revuenon 1:1.4/55 mm instead of 1:1,7/55 mm.

Revueflex AC-1 is a relabeld CE-3 Memotron

I own a Revueflex 5005. This is my favourite M42 camera when I'm to lazy to use external light meter.





Hannes

[belgiumreporter]

If i am not mistaken,the Pentax electro spotmatic or ES was the first auto exposure M42 35mm single lens reflex. It was launched in 1971.
It has aperture priority auto, speeds under 1/60th are fully automatic controlled and can not be set manual. The complete range of speeds is set stepless in auto mode. Speeds faster than 1/60th can be set manual.

[hannes]

Yashima Osanon Digital 750

Who can help me out with information about this camera?
There is not much to find in the net, except one site in Japanese.

I have one in working condition but cannot find how to use some of the controls on the body. Using it in AE mode with the original lens works fine.

This is the only camera I know which displays the exposure time in seconds and not in 1/xx sec. If it measures 1/500 it displays 0.002 in the view finder. At 100 ISO it sets time between 4 sec and 0.001. At long time exposure one can watch the remaining time of open shuter running down to 0.

Hannes

[hannes]

Dec 19, 2017 16:19:07 GMT -5 belgiumreporter said:

If i am not mistaken,the Pentax electro spotmatic or ES was the first auto exposure M42 35mm single lens reflex. It was launched in 1971.
It has aperture priority auto, speeds under 1/60th are fully automatic controlled and can not be set manual. The complete range of speeds is set stepless in auto mode. Speeds faster than 1/60th can be set manual.

This matches what I could find about the Spotmatic ES.

Now we should have the list almost complete. I read that the ES ist the only one which also has mechanical times that work without battery.

It uses an additional control on the SMC Auto Takumar lens to tell the body which aperture is set on he lens. That is identical to the mechanism which his used by Yashima. I wonder if the SMC Auto Takumar can be used on my Yashima.

I hope to find time to take pictures of my Yashima during next days

The Spotmatic ES and Chinon Memotrons are not cheap nowadays. So I have to be patient till I find a good one to a reasonable price.

Hannes

[hannes]

This is my Yashima OSANON Digital 750 with OSANON 55mm f1:1,8 lens

Digital describes the way shutter speed is shown in the view finder. Red digital numbers showing the time in seconds from about 4 down to .001 for the shortest time with is 1/1000s. It was also sold under a few more names.



It is a very rare camera, never heard of it before I got this good looking one which is fully working.

Similar like Pentax with the ES series they added an additional control to the lens to tell the electronic the selected aperture. I do not know if Pentax SMC lenses can be used on this body



It has electronic controlled Copal shutter with Auto exposure mode. It has manual mode too but this is awful to use. I did not find out how yet.



There is almost no information about the camera in the internet, I found one blog in Japanese with images. The writer has the same unanswered questions I have after playing with the camera for some hours.

Shooting with the original lens in Auto mode works fine once you realize it does open aperture measurement with exposure lock. So if you change the aperture while shutter is half pressed time does not change. Release shutter and half press it again.

I did not yet find out how to shoot with other automatic lenses. There are controls to set the max aperture and the used aperture. I assume you have to enter the max aperture first, then set the used aperture on the lens and on the body every time you change aperture.



I'm not surprised that this was the only camera Yashima made before they went bankrupt.

Finally I found another camera which falls into this category, Cosina Hi-Lite ECL and EC. They look very like the Chinon CE-3. I'm not the only one who wanders how much parts do they have in common.

So now this is the full(?) list of cameras with automatic exposure for today is:

Pentax ES and ES II
Yashica TL Electro AX
Yashima OSANON digital 750
Chinon Memotron series up to CE-3 and derevates
Cosina Hi-lite ECL and EC
Praktica EE2 and EE3


Hannes


So, if you have more information about that strange stage in camera development, please contact me.

[belgiumreporter]

That Yashima Osanon is a remarkable camera, it's got some strange design features and from what i can see in the pics it seem to have a removable prism as well (the little latch left of the viewfinder secures the prism in place i guess??) this would make it even more unique as being the only M42 auto slr with removable prism ever made.
On the Pentax ES there's a third model (or variation) on the first models "Electro Spotmatic" was written in full, later models had the abreviation "ES" on them.

[hannes]

Dec 28, 2017 6:47:52 GMT -5 belgiumreporter said:

That Yashima Osanon is a remarkable camera, it's got some strange design features and from what i can see in the pics it seem to have a removable prism as well (the little latch left of the viewfinder secures the prism in place i guess??) this would make it even more unique as being the only M42 auto slr with removable prism ever made.
On the Pentax ES there's a third model (or variation) on the first models "Electro Spotmatic" was written in full, later models had the abreviation "ES" on them.

As far as I could find out till now, the prism is fixed. I'll investigate closer next week, but I'm pretty sure it is fixes.

But meanwhile I found out who manual works and how to operate it with "normal" automatic lenses.

Manual mode: light meter is turened off when you switch to manual. You need handheld meter like with Yashica Electro AX. The camera displays the choosen time in the view finder. There are no time markings on the time knob.

Using "normal" automatic lenses:

1) set max aperture on the knob,
2) chosse aperture and set it on the lens
3) set choosen aperture also on the body
4) shoot in autmatic mode.

Never forget to perform step 3 when you change aperture on the lens :-)

PS: I added Praktica EE2 and EE3 to the list above

Hannes