Fujinon 300mm & 360mm W puzzle

[Bernice Loui]

Got to wonder, what the criteria was for rating image circle? Yes, the marketing ad common is image circle at f22, what about actual lens performance at the edge of the "spec" image circle_?_

Here it's always been chose the lens required to meet the image needs, then apply the camera as needed. If LOTs of camera movement is required, lens to be used follows. This this methodology becomes a problem as sheet film size goes up. larger the sheet film lens choices and possible lens optical performance becomes increasingly limited in many ways. Or one of the many reasons 8x10 was given up decades ago.

As for Fujinon view camera lenses, seems they gained popularity with increased web searches with the passage of web based information time. Yes, Fujinon lenses are good, have several. Yet, they are not superior to any of the others here like Rodenstock, Schneider, Kodak.. Having owned and used many, not convinced Fujinon offers a significant advantage over other similar lens designs from other view camera lens brands.

The obsession with Fujinon view camera lenses continues.. IMO, Fujinon and others are mere tools to achieve an image goal.


Bernice

[neil poulsen]

The numbers in the EARLY W series literature might be wrong, but as Maris (above) points out, it seems the 300mm has a very large IC. The IC numbers -- if the coverage is really 80 degrees for all lenses seems accurate:

210mm -- 352
250mm -- 398
300mm -- 420
360mm -- 485

Nothing seems unusual there.

The IC is proportional with focal length, if the angle of coverage stays the same. (80 deg.) There's a 20% jump in focal length between the 250mm and 300mm lenses. There should also be a 20% jump in IC. But, the jump in IC between the two lenses is less than 6%. So, it's inconsistent.

There's another source of information on the world wide web that included statistics on many Fuji lenses, and I noticed this same inconsistency. I also purchased a 300mm with inside lettering quite some time ago. (I just sold it.) But, I didn't take time to determine the actual IC. An image circle of 420mm isn't bad. But if the lens actually covers 80 degrees, we would expect an image circle of about 478mm.

[Bob Salomon]

The IC is proportional with focal length, if the angle of coverage stays the same. (80 deg.) There's a 20% jump in focal length between the 250mm and 300mm lenses. There should also be a 20% jump in IC. But, the jump in IC between the two lenses is less than 6%. So, it's inconsistent.

There's another source of information on the world wide web that included statistics on many Fuji lenses, and I noticed this same inconsistency. I also purchased a 300mm with inside lettering quite some time ago. (I just sold it.) But, I didn't take time to determine the actual IC. An image circle of 420mm isn't bad. But if the lens actually covers 80 degrees, we would expect an image circle of about 478mm.

As long as the image circle isn’t chocked down by the shutter.

[rawitz]

As long as the image circle isn’t chocked down by the shutter.

The shutter size limits the max f-stop, not the image circle. The Fuji 250WS has f6,7 and shuttersize 1, the 300 has f5,6 and shuttersize 3, the 360 has f6,3 and shuttersize 3, they all have 80 angle of coverage (illumination).

[Bob Salomon]

The shutter size limits the max f-stop, not the image circle. The Fuji 250WS has f6,7 and shuttersize 1, the 300 has f5,6 and shuttersize 3, the 360 has f6,3 and shuttersize 3, they all have 80 angle of coverage (illumination).

Check Rodenstock specs. Long lenses in barrel have, with some lenses, larger circles then the same lens in Copal 3 shutter.

[Bernice Loui]

Schneider 1100mm f22, "fine art", Copal# 3 shutter. Spec image circle is 900mm @f22.
https://www.badgergraphic.com/index....roduct_id=4315

Schneider 770mm f16, "fine art", Copal# 3 shutter. Spec image circle is 900mm @f22.
https://www.badgergraphic.com/index....roduct_id=4266

Image circle of 900mm is not small, does not appear to be limited by the copal# 3 shutter.


Rodenstock APO sonar, 480mm f11, Copal# 3 shutter, spec image circle is 396mm @f22.
http://www.prograf.ru/rodenstock/largeformat_en.html


All three share the Copal# 3 shutter, their spec image circle differs.


Bernice

As long as the image circle isn’t chocked down by the shutter.

[ic-racer]

I have an 'Outside Lettered' Multicoated Fujinon 300/5.6 as my main 8x10 lens. I have never measured its exact coverage. However, on the Shen-Hao, it is almost impossible to adjust the camera to the limits of the lens coverage. In fact it covers too much, I really need a compendium (I have a thread out there on internal bellows reflections with this lens).

[xkaes]

The shutter size limits the max f-stop, not the image circle. The Fuji 250WS has f6,7 and shuttersize 1, the 300 has f5,6 and shuttersize 3, the 360 has f6,3 and shuttersize 3, they all have 80 angle of coverage (illumination).

One would think that the image size -- rated at f22 -- would not be impacted by the shutter, but Fujinon has always listed the 300mm W as having a 420mm IC -- not the 490mm as would be expected for an 80° lens. But they finally did adjust it to be a 68° lens -- bless their souls.

[Drew Wiley]

Fuji LF lens literature seems to have always been afflicted with a few illogical typos here and there. For example, the 1981 brochure realistically gives the image circle of the 360/f10 A series lens as 504 mm in relation to a nominal 70 deg angle of view, but for the 360/6.8 W just 485 mm for its alleged 80 degrees (both at f/22).

But in real world usage, the usable image circle can indeed be significantly affected by strong tangential tilts and swings, or maximum rise, due to "mechanical vignetting". Having a number 1 shutter (which I love for its compactness and lighter weight), the 300A and 360 A lenses are inherently more prone to mechanical vignetting than their big brother W and WS counterparts in no. 3 shutters, unless smaller shooting apertures are used. On the other hand, the A's seem to be better optically corrected in that respect. But unless you're shooting larger than 8x10 film, you'll get plenty of surplus coverage regardless.

[Maris Rusis]

Thanks for the response.
I've never seen a W lens with inside lettering that is multi-coated. Can you provide a picture?
The original 300mm is listed with an IC of 420mm (80°) at f22.

Sorry, don't have the gear to do colour pictures. When I shine a light source at the front of my lens I see faint purple, brown, and yellow reflections. The back of the lens shows only brownish reflections. Multicoated? Now I don't know.

If a lens has an image coverage of 80 degrees then half the coverage is 40 degrees. To turn this into a linear measure just multiply the focal length of the lens by the tangent of 40 degrees to get the radius of the image circle and then multiply by two to get the diameter of the image circle.

Example:
300mm X 0.84 (= tan 40 degrees) = 251mm (= radius of image circle) X 2 = 503mm (diameter of image circle)

Working the other way a 300mm lens with an image circle of 420mm implies an image coverage of 70 degrees not 80 degrees. Maybe the mis-match of numbers is down to the difference between the circle of illumination and the circle of good definition all hinging on the opinion of some optical engineer.