360mm Sironar vs. Sironar-S and Sironar-N?

[bbauer]

There's a good chance I didn't word my query correctly, but searching lfphoto and google for everyone else didn't turn up the difference between an older 360mm Sironar and the later Sironar-S and Sironar-N...I'm mainly looking for info on coverage for the older lens.

Bob

[Sdrubansky]

Actually, I've been wondering the same thing myself only in regards to the 300mm.
Finding any info on the older Sironar (not S or N) is not so easy. Are they even coated?

M

[Dan Fromm]

<snip> Are they even coated?

M

This is a strong contender for question of the week.

Yes they're coated. All of the major lens makers started coating "not long" after 1945. The oldest of the lenses under discussion, the jes' plain Sironar with no suffix, seems to have been introduced in 1968.

According to the VM, the Sironar covers 60 degrees wide open, 70 degrees two stops down. The -S covers 72 degrees two stops down.

The big risk with jes' plain Sironars is separation, at the time they were made Rodenstock used cements that didn't last ...

[IanG]

The coating on the plain Sironar's is very good indeed, not far off the later Multi coated Sironar N & S versions.

The separation of the early plain Sironar is not so good as Dan says, my 150mm is due back off loan this week to possibly have the problem fixed, if it's got worse. They almost all suffer as do many other Rodenstock lenses made around the same time. I have separation just starting on two older Rodagons.

There's misconceptions about pre-MC coating of LF lenses and I found that my experiences of early coated 35mm lenses wasn't matched in the LF field where manufacturers seemed to think good coatings were more important. So I've changed my opinions in recent years after only using MC LF lenses for about 20 years.

So called Single coating is a misnomer, as many lenses had a number of coatings Zeiss developed the technology before WWII, of course applications vary some may be a simple single coating but others are either mixed coatings or more than one coating layer, some almost as sophisticated as the Super Multi-Coating technology launched by Pentax in cooperation with Zeiss with their SMC lenses.

Ian

[bbauer]

thanks for the info.

bob

[Sdrubansky]

Yes, thank you.

Shame about the separation, must be why a lot of these lenses can be
found at very low prices.

M

[IanG]

Not sure about the 360mm but the smaller plain Sironar's were not symmetrical like the later N or S versions (and the Symmar's) and could be split, the shutters carry two sets of apertures.

These older Sironar's are far less common than the later versions and I don't think they were in production that long, the N & S versions are a different optical design.

The separation issue is due to an early synthetic replacement for Balsam and the problem was solved by the time teh N & S versions were produced.

Ian

[Bob Salomon]

The original Sironar was not MC and was convertible. Rodenstock's literature from 1975 called in "nearly symmetrical" and, by using the front group only, it became a 1080mm F22 lens. At f22 the 360mm at infinity covered a 435mm circle.

This lens was replaced with the Sironar N which originally was not a MC lens but later versions were. It was not convertible and also covered a 435mm circle at infinity at f22.

The Sironar N MC was replaced by the Apo Sironar N which is not convertible and also covers a 435mm circle at f22 at infinity. Like the other earlier versions this lens covered 64° at f22 at infinity.

The Apo Sironar S covers a 468mm circle at infinity at f22. This is a 68° coverage lens at f22 at infinity.

There has never been a Sironar S lens. Only the current Apo Sironar S.