Fujinon W 250 mm f6.7 on 7x17 camera

[luca_3797]

Hello I would to know if a lens such as a Fujinon 250 f.6.7 with a IC of 398 mm at f 22 focused on infinity could be used on a 7x17 or 11x14 camera if the lens is stopped down to f /64 and focused at the same distance or on Hiperfocal distance...... I really don't know how to calculate the IC of a lens with different aperture in use..... Is there any fomula around how to calculate the IC of a lens set a different apertures and focused at a definite distance? Any answer or useful info will be very appreciate. Thank you very much. Cheers Luca Marchesin

[Ernest Purdum]

Unfortunately, there is no formula, since the amount of image circle change as the aperture is reduced varies greatly from one lens design to another. Some user of the Fujiinon 250 f6.7 may provide the information here as might be the case with another specific lens.

[Jason Greenberg Motamedi]

Would you like your 250/6.7 back? I would love to send it to you, since I can't use it for anything.

[Steve Sherman]

Rated image circle and actual coverage can vary. I have a Dagor 9 1/2 inch which does not quite cover my 7X17 negative. On the other hand I have a 240mm Nikor W lens which does cover the negatvie nicely. The lens is not rated to cover that much of a diagonal yet the negative shows no fall off. I doubt there is much room for movement, however it is a nice angle of view with that camera. Hope this helps.

[luca_3797]

Thanks to everybody (included Jason) .The Fujinon 250 W f/67 is a very nice lenses for the true "gourmet" of photography...... cheers Luca

[sanking]

Bear in mind that the actual diameter of the circle of illumination does not increase as you stop down, though overall performance at the corners usually improves, to a point.

In the case of the Fujinon-W 250 f/6.7 the actual circle of illumination is about 404 mm. This is not a conservative figure provided by the manufacturer, but a real figure. This amounts to almost 80 degrees of coverage but leave you well short of the 465mm or so circle of coverage needed to cover 7X17. To cover 7X17 with a 250 mm lens you would need a minimum of about 86 degrees of coverage. Obviously the 250 Fujinon-W falls well short.

In vintage lenses you could get this coverage with a wide angle Dagor of 9.5" (240mm), and with luck, a regular of the same focal length Dagor just might cover.

[luca_3797]

Sandy, thanksfor the info but the IC for the 7x17 format is not 459 mm ?Ok 6 mm is nothing ..... If the Pitagora rule with the square root give me that size will be ok with the Dagor as you said but not with the Fujinon ....I'll make a test soon with paper negative and I'll post an answer ASAP. In case I can't use the Fujinon I'll buy soon a Dagor... luca

[sanking]

It depends on how you calculate the diagonal. If you do so based on a full 7X17" the diagonal is 467 mm. If you assume a loss of about 1/8" of image area on all four sides from the film holder the diagonal is 458 mm.

Either way the 250mm Fujinon-W will not come close to covering 7X17" if it is anything like the one that I tested a few years ago because it had a maximum circle of illumination of 404mm.

If you decide to buy a 240mm Dagor try to get one of the older ones as they tend to have a full 86 or 87 degrees of coverage when stopped down, whereas many of the modern ones (after about 1950) don't cover much more than 80 degrees, if that.

A really great 240mm lens for the 7X17" format is the 240mm f/9 Computar but it will probably (and should ) cost you more than an old Dagor of the same focal length.

[luca_3797]

Thanks again, I'll will consider that.

[luca_3797]

The Fujinon W 250 f6.7 will cover the format if stopped down at f/64.I got a splendid picture with this lens last week.So I don't need to buy a similar one for that.....