Compur shutter speed sequences

[Chuck Peacock]

Hi,

Does any one out there know when Compur switched from to old style 1-2-5-10-25-50-100-... shutter speed sequence to the modern, geometric 1-2-4-8-15-30-60-125-...?

It seems to me that Leica changed over in the early 1950s, but I see a bunch of Schneider lenses with serial numbers into the mid-1960s that still have the old numbers.

[Ted Harris]

The serial numbers on the lens cells don't tell you the age of the shutters in which they are set.

[Gordon Moat]

Compur shutter numbering:
1920 450000
1922 500000
1925 600000
1926 750000
1927 850000
1928 950000
1929 1000000
1930 1150000
1931 1500000
1932 1800000
1933 2250000
1934 2700000
1935 3200000
1939 5400000


I have this from a site, which unfortunately I no longer have the link. It might help a little dating older Compur shutters.

Ciao!

Gordon Moat Photography

[Emmanuel BIGLER]

I have a #2 Synchro-Compur shutter with the old sequence 1-2-5-10-25-50-100-200.
I have it fitting a 2.8-100mm Zeiss planar (for a baby Linhof 6x9).
Probably end of the fifities, beginning of the sixties.
So I agree, this kind of shutter sequence was still sold with new lenses in the sixties. However, this might have been "new old stock" so I do not know actually the last date of fabrication of the last synchro compur 1-2-5-10....

I have attached below a bar-chart that will give you the correspondence between odl and new sequence just at a glance, by increments of 1/3 stop.

[Per Madsen]

I have a Carl Zeiss 150/4.5 in a Syncro Compur from 1958 which have the old sequence (1- 2- 5- 10- 25- 50- 100- 200), and I have a Schneider-Kreutznach 90/8 in a Syncro Compur from 1961 which have the new sequence (1- 2- 4- 8- 15- 30- 60- 125- 250- 500). Both lenses are in the original shutters.

I could imagine that the change ocurred somewhere around 1960 for new production Syncro Compur shutters.

[Chuck Peacock]

I certainly understand that the lens and the shutter don't have to be made at the same time. And in many cases it's obvious that lenses have been remounted into a different shutter.

Before I started looking at Schneider serial numbers, I'd have guessed that rim-set Compur shutters with the old sequence dated to the mid-1950s or earlier. However, I've recently seen a number of Schneider lenses with serial numbers that date them to 1965-1966 with old sequence shutters.

I'm probably overthinking this, but I'd think that if this is caused by shutters wearing out and being replaced, the tendancy would be for the shutter to be newer than the lens.

Is it maybe the case that if you look at the total population of #0 or #1 rim-set Compur shutters, most of them have the old sequence?

Other than (perhaps) a bit of inconvenience, is there any reason to think the old sequence Compurs are any less reliable than the newer geometric versions?

This also brings up another question. Does anybody have a good idea when Compur switched from dial-set to rim-set? I've always avoided the dial-set shutters since I figured they were ancient and hence unreliable, but maybe this isn't really correct. Any comments?

Chuck

[al olson]

I have a Kodak Retina IIIc that has the sequence 1-2-4-8-15-30-60...etc., on a Compur Synchro shutter. I purchased the camera in August of 1955.

I would presume that this sequence was first designed for the IIc and IIIc cameras which introduced the Light Value System (later changed to EVS). These cameras had external built-in light meters that measured light intensity with needle match to the LVS value. The photographer then transfered this value to the appropriate LVS value on the shutter ring which then coupled the aperture settings to the shutter settings so that he could select the desired exposure pair by turning the rim.

I believe these cameras were introduced only a few months before I purchased my IIIc.

[swdphoto]

I've got a Kodak Ektar 207mm from 1962 with a Sychro Compur with the old 1,2,5,10,25,50,100,200,400 speeds. I think Compurs were last used by Linhof so a Linhof expert might know the answer.