Spiratone Fish-Eye Converter Heritage

Overview

The Spiratone Fish-Eye Converter is an afocal auxiliary lens sold under the Spiratone brand (and rebadged under names like Weltblick, Kenko, and Soligor), designed not as a standalone prime but as a 0.15X converter that mounts on the front of a host lens via an adapter plate. Spiratone was known for inexpensive, innovative, and sometimes quirky photographic accessories, and this fisheye fits that mold: reviewers describe it as 'exceptionally well thought-out' for its class. Its clever afocal design meant it could adapt to a wide variety of cameras and host lenses, converting the host focal length to 0.15X of the original (e.g. a 50mm host becomes roughly 7.5mm effective). It even includes an adjustable built-in aperture and a ring to set the host lens focal length so the effective combined aperture is indicated. On APS-C, it reportedly pairs well with a 40mm-class host lens to render nearly the full circular fisheye image at approximately 180 degrees in a compact package. No established nicknames or community jargon are evidenced in the reviews. Its cult appeal is summed up by the recurring sentiment: 'like so many Spiratone things, it's fun, innovative, and perfectly usable' — a cheap route to a true circular fisheye look rather than a tool for pristine image quality.

Verdict: The Spiratone Fish-Eye Converter is for the experimenter who wants a genuine, fun circular fisheye look on the cheap rather than pristine optics. It rewards you with a true ~180-degree image and good central sharpness, but demands you accept soft edges, vignetting, and a strong tendency to flare. Innovative and perfectly usable — a playful creative tool, not a precision instrument.

Optical Character

Sharpness wide open

Center sharpness is good, but the extreme edges are very soft.

Flare resistance

Quite prone to flare according to multiple reviewers, treated as a limitation to manage.

Vignetting

Suffers from vignetting, sometimes worsened by a wobbly mount, and affected by the host lens aperture.

Community Insights

What people love

A cheap and accessible way to get a circular fisheye image, especially near-full-circle results on APS-C with a suitable host lens
Clever, well-thought-out afocal design with a built-in adjustable aperture and a ring to indicate effective combined aperture
Universal adaptability to many cameras and host lenses, converting to 0.15X of the host focal length
Good center sharpness and a relatively clean masked edge on the circular image
Genuinely fun, innovative, and perfectly usable in the classic Spiratone spirit

What people dislike

Prone to flare
Very soft extreme edges
Vignetting, sometimes worsened by a wobbly or loose mount
Not capable of really great image quality
Field of view can be reduced if the host lens aperture isn't set wide enough (f/2 or larger)

Pro Tips

Set the host (intermediate) lens to f/2 or wider — a narrower aperture reduces the resulting field of view
Note that the built-in adjustable aperture affects vignetting, so experiment with it to control the circular image
Because it flares easily, shade the front element and avoid strong light sources in or near the frame
Expect and compose around very soft extreme edges — keep your subject toward the center where sharpness is good
For a near-full circular fisheye on APS-C, use a compact ~40mm-class host lens
Ensure the converter is seated firmly to minimize the wobble-related vignetting

Sources (1)

Web-grounded synthesissecondary

The Spiratone Fish-Eye Converter is an afocal auxiliary lens sold under the Spiratone brand (and rebadged under names like Weltblick, Kenko, and Soligor), designed not as a standalone prime but as a 0.15X converter that mounts on the front of a host lens via an adapter plate. Spiratone was known for inexpensive, innovative, and sometimes quirky photographic accessories, and this fisheye fits that mold: reviewers describe it as 'exceptionally well thought-out' for its class. Its clever afocal design meant it could adapt to a wide variety of cameras and host lenses, converting the host focal length to 0.15X of the original (e.g. a 50mm host becomes roughly 7.5mm effective). It even includes an adjustable built-in aperture and a ring to set the host lens focal length so the effective combined aperture is indicated. On APS-C, it reportedly pairs well with a 40mm-class host lens to render nearly the full circular fisheye image at approximately 180 degrees in a compact package. No established nicknames or community jargon are evidenced in the reviews. Its cult appeal is summed up by the recurring sentiment: 'like so many Spiratone things, it's fun, innovative, and perfectly usable' — a cheap route to a true circular fisheye look rather than a tool for pristine image quality.

https://www.pentaxforums.com/userreviews/spiratone-auxiliary-fish-eye-lens.htmlhttps://www.dpreview.com/forums/post/58096580https://www.dpreview.com/forums/post/59380857https://photo.stackexchange.com/questions/134788/what-is-wrong-with-my-0-15x-fisheye-adapter-by-weltblick-a-kenko-soligor-spirahttps://lens-db.com/accessory/spiratone-auxiliary-fisheye-lens-015x/