How different are Tessars from different companies?

[Jimi]

Over time the 4.5ers were recomputed and their coverage grew.

When did this happen, is there some way to distinguish the 4.5ers? I have a 1920 Tessar, a 150/4.5, that I have yet to actually test, but I hope it covers 4x5" (or at least 9x12 cm) straight-on.

[Dan Fromm]

As with many vintage designs, someone decides to remake one, even though there are millions of used ones out there. https://www.kickstarter.com/projects...&ref=discovery

I find it interesting that in 35mm sizes, there are not that many Tessars. In LF, there were plenty.

Interesting assertions about sharpness, whatever that means, no MTF or resolution measurements to support them.

[Dan Fromm]

When did this happen, is there some way to distinguish the 4.5ers? I have a 1920 Tessar, a 150/4.5, that I have yet to actually test, but I hope it covers 4x5" (or at least 9x12 cm) straight-on.

Sorry, can't help you. Look for a copy of A Lens Collector's Vade Mecum, which gives some chronology, or, better yet, Hartmut Thiele's Fabrikationsbuchs.

I believe that the various vintages all look much the same.

[John Kasaian]

Greater than usual coverage is the biggest difference that I can see.
Kodak Commercial Ektars have it, while other Tessars don't.

The lyrics were supposed to go:
Mamma don't take my fourteen inch Kodak Commercial Ektar away
but Paul Simon couldn't get it to rhyme

[Dan Fromm]

Greater than usual coverage is the biggest difference that I can see.
Kodak Commercial Ektars have it, while other Tessars don't

f/6.3ers have more coverage than f/4.5ers but I'm not aware that Commercial Ektars have more coverage than f/6.3ers.

[mdarnton]

The thing about the run of the mill 4.5 Tessar is that they are sharpest in the center and get gradually unsharp as you move out. Combine that with a wide circle of illumination that lights the film well beyond any sharpness at all and it will be up to you if it covers well enough for you, based on how picky you are at the corners. 6.3 versions are somewhat better in this regard.

For instance, this one is probably marginal for some, but OK for me:
https://www.flickr.com/photos/michae...posted-public/
It's asking a lot of a 190mm Tessar formula to cover 5x7.

[Bernice Loui]

Could be related to the innate differences as to how a LF (not press 4x5 camera) -vs- 35mm roll film still image camera would be used.

35mm film camera and it's modern digital equivalent is typically used for "decisive moment" images where the lens ability to capture light, increase shutter speed, brighter image in the view finder to aid in focusing and all related would favor large aperture lens designs like a Gauss. This evolved the typical 35mm lens into a 50mm f1.4 to be common offering.

In the world of LF (not press camera 4x5) Images produced would be more conceived, planned or crafted. Typical LF camera sits on a tripod where shutter speed or exposure time is typically longer than a hand held 35mm camera. This would put the need for large aperture lenses into the lesser importance category with other aspects of lens design primary like image circle and image quality and other aspects of lens design that might not be as significant for a 35mm hand held camera.

As for Tessar lens formulations for LF, they have become favored for most image making (Kodak Ektar due to Lanthium glass and their image results due to the design being "tweaked" by designers and image makers who understood very well what is required for high quality prints. Lens aperture used would be f4.5 to about f22). They are a trade off design like all designs. They do not have the largest aperture, largest image circle and more, but if one were to consider the overall LF image making needs, they are a extremely excellent compromise of the MANY factors and demands for a LF lens design.

There is NO ideal LF lens for ALL image makers, only way to know what specific LF lens works for your print making needs is to try them LOTS.



Bernice

I find it interesting that in 35mm sizes, there are not that many Tessars. In LF, there were plenty.

[mdarnton]

There are plenty of 35mm Tessars, but they are all on cheap cameras, mostly non-interchangable, with 1/10 ‐ 1/200 type shutters for home hobby shooters (Kodak Retina, Ansco Memo, etc.) With 35mm the glass is so small it probably was not a big deal to make a faster lens, earlier.

[Drew Wiley]

Less elements meant less flare, particular in older days. Also less complicated to mfg.

[John Kasaian]

f/6.3ers have more coverage than f/4.5ers but I'm not aware that Commercial Ektars have more coverage than f/6.3ers.

Interesting. Does it have anything to do with having the more open aperture of 6.3s? But then how would that explain the f9 450 Nikkor M which covers 12x20 with coverage to spare?