Fujinon 250mm Soft Focus

[Bogdan Karasek]

Since we are on the topic, and I am sitting in front of my newly found Fujinon-SF 180mm and -SF 250mm, I have a few questions. Very interesting thread, I might add. Maybe someone can tell me the purpose of large red dot on the grill? Does it have to be oriented a certain way, thus aligning the grill a certain way?.... I`m guessing here. I do notice that the red dot is the same size as the holes in the grill. Is that supposed to tell me something? Otherwise, concidence???

[mdarnton]

The red dot is just to identify which grid you are using. There's another one that's yellow. And they match up with the f numbers indicated by the yellow or red scales. One involves more of the outer edge of the lens, which is where the unsharpness comes from, than the other. The disk is a way to give less exposure without stopping down and losing the unsharpness--by the time you get down to f11 with these lenses they lose most of the soft focus and become essentially normal at f22. With the disks you can use the lens wide open or just one stop down, but get a smaller effective f-stop, as indicated on the appropriate scale for your disk.

I'm not fond of my 250 at all--so far it just seems like a bad lens, not a classical SF lens, but I'm still figuring it out, so that could change.

[BrianShaw]

The disks are used to control the amount of diffusion. No disk - maximum diffusion, yellow disk - moderate diffusion, red disk - more subtle diffusion. ...

No disk - DOF per normal aperture and least diffusion (minimal... almost none... just what one would expect from a triplet design lens)

[BrianShaw]

Your lens must be different than mine, then. I can easily get my hands on one and have had my hands on it for quite a while.

[BrianShaw]

Well, what I experience is that without a disk, wide open (f/5.6), there is a lot of OOF due to shallow DOF. Any diffusion present is, as you say, due to the spherical aberration left in the design... but I think the "diffusion" is buried by the regular OOF. The strainers add diffusion with the outer holes, which cease adding diffusion when stopped down two stops from the f/stop associated with each disk... because the outer holes are no longer admitting light. Perhaps we are using the terms 'diffusion' and 'OOF' differently when no strainer is in place. The instruction sheet posted earlier in this thread interestingly states that the lens is designed to be used with a strainer and the strainer is used to maximize diffusion. I'm thinking that we are using some terms differently. I find OOF to be very different to the diffusion of any SF lens.

[BrianShaw]

Ah. I've never considered anything I've seen when shooting without disk to have noticeable glow. I'll have to look harder, perhaps. The pic I posted earlier is typical of when I use SF so may be very different from your shots.

[russyoung]

I own an 180 and 250 and have simply looked at a ground glass image of the 420. Have put an easy 50 sheets of 4x5/5x7 behind the 180 & 250. Like BrianShaw, I am unable to find any diffusion whatsoever. Its just 'not sharp'. I use Veritos, SemiAchromatics, Spencer Portlands, Imagons, Plasticcas, etc., with desired effect. But not the Fujinons... ymmv.

[mdarnton]

Yes, I completely agree with that. Here's an example, no screen at between 5.6 and 8, and you can click through for a larger version--for me, it's just a lens that won't focus, not anything special. It doesn't show the wirey sharpness surrounded by haze or the added DOF of a real soft focus lens. If you want a SF lens that doesn't break the bank and acts like one should, there are better choices . . . heck, I like my Reinhold Wollaston a lot better.

This is just an aside, and I'll probably build a post around it later, but a lens I like a lot is the 15" Wollensak tele-Rapter in shutter. Screw out the back, stash it in a safe place, and move the front around to the back. It will look funny, like a Kodak Portrait Lens, and it works great, f5.6 at around nine inches. It's the poor man's Verito.

But the Fujinon? Here it is:



Dan K
by Michael Darnton, on Flickr

[Jim Andrada]

Wouldn't the strainers increas diffraction effects?

[BrianShaw]

That, exactly, is our differing opinion. The instructions say so as does my experience but TAG has different experience.