Irix 15 mm f/2.4 User manual

Extended User Manual
Irix 15 mm f/2.4

Extended User Manual – Irix 15 mm f/2.4
Thank you for choosing an Irix lens. You hold in
your hand the fruit of the dedication and experien-
ce of the combined forces of engineers and photo-
graphers.
Using the nest available materials, state-of-the
-art technologies and cooperation, our team has
created an excellent tool for both professional and
amateur photographers.
The Irix 15 mm f/2.4 is an ultra-wide-angle, rectilinear, manual
focus lens, designed for full-frame DSLR cameras. It is also com-
patible with many crop-sensor models.

Extended User Manual – Irix 15 mm f/2.4
[3 ]
TABLE OF CONTENTS
FRONT LENS CAP 4
FRONT FILTER THREAD 5
LENS HOOD 6
FILTER WINDOW 7
FOCUS SCALE CALIBRATION 8
FOCUS RING LOCK 9
FOCUS RING 10
DEPTH OF FIELD SCALE 11
HYPERFOCAL SCALE 15
REAR GELATIN FILTER SLOT 17
HOW TO ATTACH THE LENS TO THE CAMERA 18
REAR LENS CAP 19
APERTURE CONTROL 20
HARD LENS CASE 21
MAINTENANCE 22
SAFETY PRECUTIONS 23
TECHNICAL SPECIFICATION 24
TEMPLATE FOR CUTTING GELATINE FILTERS 25

Extended User Manual – Irix 15 mm f/2.4
[4 ]
FRONT LENS CAP
The front lens cap protects the front lens element
from possible contamination and impact damage.
The cap should always be attached when the lens
is not in use.
To attach or remove the front cap, hold the lens
body rmly in one hand and grasp the cap with
your thumb and nger by the recesses in the front
of the cap. Squeeze gently toward the center of the
cap to release the latches.
Additional lens caps may be purchased through
the Irix Online Store www.irixlens.com.

Extended User Manual – Irix 15 mm f/2.4
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Your Irix lens can accept 95 mm screw-in lters via
the front threads. Due to the wide angle of view,
the use of “slim” lters is advisable to prevent
vignetting. Filters with a low prole of 5.3 mm or
less are recommended. Stacking multiple lters
may also cause vignetting.
Irix Edge lters are highly recommended, as they
are engineered to be fully compatible with the lens
design.
To attach a threaded lter, align the threads care-
fully and rotate it clockwise while facing the front
of the lens. The lter should turn smoothly and
with very little eort. If it appears to be crooked or
binds, reverse the rotation to remove and realign
the lter.
Excess pressure or misaligned threads may permanently dama-
ge the lens and lter.
Before tightening the lter, ensure that it does not come into
contact with the front element of the lens Contact between the
surfaces may cause permanent damage to both.
FRONT FILTER THREAD

Extended User Manual – Irix 15 mm f/2.4
[6 ]
LENS HOOD
The removable and reversible lens hood helps
prevent unwanted sidelight from the sun or other
sources from entering the lens. It also helps pro-
tect the lens from accidental impact damage. We
recommend having your lens hood attached at all
times.
There is no need to remove the lens cap when re-
moving or attaching the lens hood.
To remove the lens hood from its storage (rever-
sed) position, rotate it counterclockwise (when
facing the lens) until it releases (approximately 1/8
turn).
To attach the hood for use, align the white line on
the hood with the corresponding line on the end of
the lens. Slip the hood gently over the mount and
rotate it clockwise until it clicks rmly into place.
The alignment mark should now align directly with
the line on the angled portion of the lens barrel.
To reverse-mount the lens hood prior to storing the lens in its
transport case, use the same procedure with the lens hood
facing the opposite direction.

Extended User Manual – Irix 15 mm f/2.4
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FILTER WINDOW
The lter window in the lens hood provides access
to the edge of lters that rotate, such as circular
polarizers, graduated lters and variable ND l-
ters. This feature allows you to adjust those lters
without removing the lens hood.
To open the lter window, push the raised portion of the blind
toward the front of the lens hood, sliding the blind until it clicks
into place. To prevent unwanted side light from striking the
lens, close the blind when the window is not in use.

Extended User Manual – Irix 15 mm f/2.4
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FOCUS SCALE CALIBRATION You Irix lens has been engineered to exacting stan-
dards. The focus scale is factory calibrated and
should be accurate. In some cases, however, you
may nd that the innity mark on your lens does
not correspond to the optimum focus setting for
distant objects. While the focus ring will rotate past
the innity setting to allow you to compensate for
this, it may be more convenient to re-calibrate the
innity setting on your lens. You can make this ad-
justment yourself or contact the Irix support team
for help.
To calibrate the focus ring:
1. Remove the calibration window cover by unscrewing the T6
Torx screw and sliding the cover outward.
2. Set the focusing ring at the innity position and rotate the
focus lock ring to the locked position. The internal calibration
ring and at head locking screw should be visible.
3. Using a at head screwdriver, loosen the screw on the cali-
bration ring. Be careful not to allow the screws to fall into the
lens housing. A screwdriver with a magnetic tip is recommen-
ded.
4. Using your camera’s Live View and LCD zoom, rotate the cali-
bration ring to focus carefully on a distant subject (farther away
than 50m/164ft).
5. Lock the calibration ring by re-tightening the screw and re-
place the calibration window cover.

Extended User Manual – Irix 15 mm f/2.4
[9 ]
FOCUS RING LOCK
The focus ring lock allows you to x the focusing
ring in a selected position. This innovative feature
helps prevent accidental movement, resulting in
focus shift.
You may want to use the focus lock during long
exposures, time-lapse imaging, or whenever re-
petitive shots are called for. You can also use it to
avoid changing the focus setting while mounting
or removing the lens or to retain the focus setting
when storing it in a bag, case or backpack.
Landscape photographers, street photographers
and journalists can utilize the focus lock to keep
the lens at the innity setting or hyperfocal distan-
ce for a given aperture.
To use the focus lock, focus the lens, then rotate
the locking ring in the direction of the “lock” arrow
until you meet resistance. Don’t over-tighten. To
unlock, rotate the ring in the opposite direction
until “unlock” aligns with the top of the lens.
CAUTION: Forcefully rotating the focus ring with the lock enga-
ged may cause permanent damage to your lens.

Extended User Manual – Irix 15 mm f/2.4
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FOCUS RING
The focusing ring moves the internal focusing
elements of the lens to achieve the desired focal
point. You can focus visually while looking at your
subject in the viewnder or LCD screen or by using
the distance, depth of eld or hyperfocal scales on
the lens barrel.
Your Irix lens allows you to set the focus at innity without the
need to look at the scale. While rotating the focus ring, innity is
indicated by a click and a denitive stop in the rotation.