Kenko 0.16x Fish-eye Converter

How nice it is to see "prime" used correctly for a change! Thank you for
that!

You're right, the first series of numbers are obviously aperture settings.
The second series are obviously focal length settings for 35mm camera
lenses, as they include familiar focal lengths that single-focal-length
lenses used to come in, such as 200mm, 135mm, 100mm, 85mm, etc. as well as a
few non-standards.

I presume that second ring is supposed to be set for the focal length of the
prime lens it's used with on a 35mm camera. If the prime lens is a zoom, the
converter should be set for whatever focal length was in use, within that
range of 30-200mm. The aperture ring I presume controls a diaphragm within
the fisheye converter itself. Your description seems to confirm this.

N.


"Gisle Hannemyr" wrote in message
...
I've just aquired an old Kenko 0.16x fish-eye converter with 52mm
thread.

While modern WA converters usually have no controls, this Kenko model
(long since discontinued) has /two/ control rings. The first displays
a series of decimal numbers from going 3.5 up to 90 that look very
much like aperture settings. The second is a series starting at 200
and going down to 30.

An picture of the converter, with the two control rings, and the
number series on them are at:

http://heim.ifi.uio.no/~gisle/photo/wa.html

When I experiment with these controls, they appear to control
aperture, angle of view, and vignetting - but not in an (at least not
to me) obvious way. Whatever documentation that came with the lens
is long lost.

What I want to do, is to figure out the /optimum/ setting for the
converter (ie. the setting that gives the least vignetting, largest
angle of view, and best overall sharpness. In order to do that, I
would like to know what the control rings on the converter are, and
how they are intended to be used. If anyone reading this are familiar
with this lens and its controls, what sort of prime it is supposed
to me used with, etc. - please post an explanation here.
--
- gisle hannemyr [ gisle{at}hannemyr.no - http://folk.uio.no/gisle/ ]
================================================== ======================
«To live outside the law, you must be honest.» (Bob Dylan)

By the way, the usual practice with that sort of device, as I recall, was to
always shoot with the prime lens wide open. Aperture adjustments were to be
made entirely at the converter. This of course will mean putting the camera
into aperture-priority or full manual mode, whichever seems most appropriate
or works best.

N.


"Nostrobino" wrote in message
...
How nice it is to see "prime" used correctly for a change! Thank you for
that!

You're right, the first series of numbers are obviously aperture settings.
The second series are obviously focal length settings for 35mm camera
lenses, as they include familiar focal lengths that single-focal-length
lenses used to come in, such as 200mm, 135mm, 100mm, 85mm, etc. as well as
a
few non-standards.

I presume that second ring is supposed to be set for the focal length of
the
prime lens it's used with on a 35mm camera. If the prime lens is a zoom,
the
converter should be set for whatever focal length was in use, within that
range of 30-200mm. The aperture ring I presume controls a diaphragm within
the fisheye converter itself. Your description seems to confirm this.

N.


"Gisle Hannemyr" wrote in message
...
I've just aquired an old Kenko 0.16x fish-eye converter with 52mm
thread.

While modern WA converters usually have no controls, this Kenko model
(long since discontinued) has /two/ control rings. The first displays
a series of decimal numbers from going 3.5 up to 90 that look very
much like aperture settings. The second is a series starting at 200
and going down to 30.

An picture of the converter, with the two control rings, and the
number series on them are at:

http://heim.ifi.uio.no/~gisle/photo/wa.html

When I experiment with these controls, they appear to control
aperture, angle of view, and vignetting - but not in an (at least not
to me) obvious way. Whatever documentation that came with the lens
is long lost.

What I want to do, is to figure out the /optimum/ setting for the
converter (ie. the setting that gives the least vignetting, largest
angle of view, and best overall sharpness. In order to do that, I
would like to know what the control rings on the converter are, and
how they are intended to be used. If anyone reading this are familiar
with this lens and its controls, what sort of prime it is supposed
to me used with, etc. - please post an explanation here.
--
- gisle hannemyr [ gisle{at}hannemyr.no - http://folk.uio.no/gisle/ ]
================================================== ======================
«To live outside the law, you must be honest.» (Bob Dylan)

By the way, the usual practice with that sort of device, as I recall, was to
always shoot with the prime lens wide open. Aperture adjustments were to be
made entirely at the converter. This of course will mean putting the camera
into aperture-priority or full manual mode, whichever seems most appropriate
or works best.

N.


"Nostrobino" wrote in message
...
How nice it is to see "prime" used correctly for a change! Thank you for
that!

You're right, the first series of numbers are obviously aperture settings.
The second series are obviously focal length settings for 35mm camera
lenses, as they include familiar focal lengths that single-focal-length
lenses used to come in, such as 200mm, 135mm, 100mm, 85mm, etc. as well as
a
few non-standards.

I presume that second ring is supposed to be set for the focal length of
the
prime lens it's used with on a 35mm camera. If the prime lens is a zoom,
the
converter should be set for whatever focal length was in use, within that
range of 30-200mm. The aperture ring I presume controls a diaphragm within
the fisheye converter itself. Your description seems to confirm this.

N.


"Gisle Hannemyr" wrote in message
...
I've just aquired an old Kenko 0.16x fish-eye converter with 52mm
thread.

While modern WA converters usually have no controls, this Kenko model
(long since discontinued) has /two/ control rings. The first displays
a series of decimal numbers from going 3.5 up to 90 that look very
much like aperture settings. The second is a series starting at 200
and going down to 30.

An picture of the converter, with the two control rings, and the
number series on them are at:

http://heim.ifi.uio.no/~gisle/photo/wa.html

When I experiment with these controls, they appear to control
aperture, angle of view, and vignetting - but not in an (at least not
to me) obvious way. Whatever documentation that came with the lens
is long lost.

What I want to do, is to figure out the /optimum/ setting for the
converter (ie. the setting that gives the least vignetting, largest
angle of view, and best overall sharpness. In order to do that, I
would like to know what the control rings on the converter are, and
how they are intended to be used. If anyone reading this are familiar
with this lens and its controls, what sort of prime it is supposed
to me used with, etc. - please post an explanation here.
--
- gisle hannemyr [ gisle{at}hannemyr.no - http://folk.uio.no/gisle/ ]
================================================== ======================
«To live outside the law, you must be honest.» (Bob Dylan)