fujinon 250 W (S) 6.7?

[Colin Graham]

Is the WS version the same as a regular W 6.7? I just bought one advertised as a 250 W (which is supposed to have an I.C in the 390mm range) and it seems to have the same circle as a fujinon 240 A, which is like 330 or so. I put it on my 5x12 and ran a corner out of coverage, left the standard locked and switched to the 240 and refocused slightly to account for the shorter length and have the same dark crescent in the corner of the glass. It seems weird because this lens is like 4 times the size and weight of the 240 A. It has the same 67mm front rim as the W and the same aperature scale...(I know there is a 6.3 out there with a smaller circle but this is positively a 6.7) Any help most welcome. Thanks

[Colin Graham]

here's a shot

[tim atherton]

hmmm - I had one that looked itedntical until I got the slightly later version in a Copal 1

It seemed to have the same coaverage as the one I have - around 400mm

What aperture did you use? presumably f22 or such?

Does you GG have corner cutoffs? Have you checked by looking through the corners and seeing where you clip the iris circle (or second best, doing it in reverse and looking through the lens/iris back up into the gg corners

[Colin Graham]

Hi Tim-
I stopped down until the cutoff looked sharp while under the darkcloth- probably f32 or so. I dont have clipped corners on the glass, I'm just going by WYSIWYG on the glass. More than likely I am doing someting wrong. (I should probably check for bellows clipping too) The diagonal of 5x12 is about 330 mm and I seem to be running out of circle with fairly modest front movements. Thanks.

[tim atherton]

hmmm - try this

stop down to say f22 or so

with no dark cloth on peer through the front of the lens/iris aperture from an angle - easiest from below, until you can see the opposite top corner of the ground glass.

You should still be able to see the full circle of the iris

now apply some rise (I think... - it'll make sense hopefully) always making sure you have a line from your eye through the aperture to the corner of the GG. Keep doing so until you start to run out of image circle. . - this will show itself by part of the aperture becoming obscured by the front barrel/filter ring begining to cut off a part of the aperture circle

Hope that makes sense. it will show you how much rise you are getting and you can compare the lenses as well

[Sheldon N]

One thing you might try to do is stop down to f/22 and check the outer portions of the image circle with a good loupe for sharpness. I think that the Fuji A actually puts out a larger circle of illumination than its specificied image circle, but that sharpness falls of pretty dramatically outside the spec'd range. I'm not sure whether the Fuji W does the same thing, but if you checked with a loupe you could figure out which one had a more useable image circle.

I had both of those lenses for a short while, and found that the circle of illumination on the Fuji W 250mm f/6.7 was only slightly larger than the Fuji A 240mm. I was a little surprised by this, but didn't think to check with a loupe at the time.

[Colin Graham]

That's what I was starting to think Sheldon. But at this point I had to pack everything up for a trip tomorrow. I guess I'll proceed as if this is the case and hope for the best. I did try what you suggested Tim but had already put the 240 back on the 4x5 board so couldnt compare. I really like it on 4x5 anyway so probably I'll keep both. Thanks for the suggestion.

[Colin Myers]

Are you using a 5 x 12 back, or is it a dedicated 5 x 12 camera? Is this a compatabilty
problem with a back and have you experienced similar cut off problems with other lenses, whose theoretical I.C. should cover the format?
Colin Myers

[Colin Graham]

It's a dedicated 5x12. The lens covers just fine, I was just expecting considerably more circle than the 240 A, that's all. I guess mainly I wanted to be sure that the seller wasnt pulling a fast one, as I was not familiar with the WS version of this lens. I do like the lens. Had time for a couple of exposures yesterday and it looks great. Great sharpness to the edges, so I'm pretty much convinced Sheldon's line of thinking is right on... Cant tell about flare yet as it was rainy all day but contrast looks good.