Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It only takes a minute to sign up.
Sign up to join this community
I'm looking for super wide angle lenses, ideally 50mm and below. I'm only interested about decent rise/fall movements because I do mostly architecture, and I'd like to be very close to the subject.
However, I cannot find suitable lenses for it. Meaning, super wide angle lenses image circles are usually around 160mm.
Is there a viable alternative that would allow me to do rise/fall movements?
They don't exist. They can't exist, really. 120 degrees is about as far as rectilinear designs seem to go.
If you wanted that Super Angulon 47XL to cover more than 166mm it'd have to be wider than 120 degrees.
Shift is identical to off-center cropping.
But somehow people understand "cropping narrows your field of view" better than they understand "shooting a lens on a format small enough to permit shift narrows your field of view"
All lenes project a circular image of the outside world. This image is sharpest and brightness in the center. As you examine this image, you will discover that it has reduced sharpness and it dims thus the fringes are substandard as to image quality. This is called a vignette.
As a rule, we match lenses to format size. We generally select focal length based on the corner-to-corner measure (diagonal) of the format. The 4x5 inch format has a diagonal of 5.4 inches = 160mm. in other words, a 160mm focal length lens projects an image with a circle of good definition that properly covers the entire 4x5 frame.
Lenses shorter than the diagonal are classified as wide-angle. It takes a special lens design when it comes to expanding the circle of good definition so that it adequality covers the frame size. Making a 50mm that will work with a 4x5 format would be a challenge. Making one that will accommodate a rising / falling front is likely wishful thinking.
Why the vignette? Imagine a miniature you is waking on the 4x5 frame looking up at the lens. When you are at the center of the frame, you will see a circular opening when the shutter is snapped. Now walk towards one of the corners of the frame and look up again. As you move more and more off-axis, what you see is an oval lens aperture, not a circle. This oval opening will pass less light due to the fact at it appears to have a reduced area. Thus, the further off-axis, the weaker will be the image. Additionally, all lenses have residual defects called aberrations and distortions. I fear that a 50mm on a 4x5 will have too small a circle of good definition. Now add rising and falling front and you likely entered the realm of the impossible.
The image circle is usually specified at a specific aperture. Often f16. Smaller apertures will produce a larger image circle unless the lens is designed with a baffle or similar element that limits the image circle.
In addition, high quality lenses typically give a conservative image circle size. The amount of vignetting may be acceptable for a particular use (and unacceptable for others).
In addition, wide angle large format lenses are often used in conjunction with center weighted neutral density filters due to the longer light path to the corners relative to the center of the film plane. This is another way to mitigate light falloff outside the specified image circle.
It is also worth noting rear tilts and swings do not require a larger image circle because the skewed film plane presents a smaller area perpendicular to the lens axis.
Finally, the right tool for extremely wide angle architectural photography might be a smaller format. A somewhat similar field of view can be achieved off the shelf using a 35mm format camera with a 17mm tilt-shift lens...so long as you are willing to forgo rear movements.
