Featuring in this week’s “Full Frame” is the movement of the Grand Seiko 4580-7010. A slightly smaller – yet no less impressive – image than usual, since when tilting and swinging the focal plane to the extent that it is in this shot, I can’t get as much magnification.
Before getting onto the photograph itself, this is probably a good opportunity to clear up some confusion that is out there as to the number of 4580 movements that were created, and where they ended up.
Following the end of the Neuchatel Observatory Chronometer trials, Seiko submitted for certification a number of 4520 and 4580 movements in the years 1968 through to 1970.
In 1968, 103 examples of the 4520 caliber were submitted, of which 73 passed certification.
In 1969, 30 examples of the 4580 caliber were submitted, of which 25 passed certification.
In 1970, a further 150 examples of the 4580 caliber were submitted, of which 128 passed certification.
That much is widely written up and accepted. Where the confusion lies is how these movements were cased up and sold.
Continue reading “Full Frame – Grand Seiko 4580-7010 VFA movement”