- About this item.
- 4.3x super tele-zoom 3 ED lens elements for excellent quality Compact & lightweight.
Product Description
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D1) Oylmpus 70-300MM F4-5.6 ZUIKO
Manufacturer's Description
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Standard Lenses:The standard lenses are ideal for
all-round applications for advanced amateurs and ambitious hobby
users. They are special dedicated digital lenses with a near
telecentric design for perfect image quality
ZUIKO DIGITAL Lenses:ZUIKO DIGITAL lenses meet the high demands
of digital SLR photography providing edge-to-edge sharpness and
high light utilisation.
They feature near telecentric optics for high image quality.
Based on the Four Thirds standard they feature bright, compact
and lightweight design.
Four Thirds Standard:Four Thirds is the answer to the
uncompromising demands of professional photography. It represents
a break from the past and frees digital SLR photography from the
confines of conventional camera technology.
Angle of View:When you use the lenses designed for 35mm film with
digital camera bodies that incorporate sensors smaller than film
there is the potential problem of a loss of wide-angle
capability.
When you use lenses designed for 35mm film with digital camera
bodies that incorporate sensors smaller than film there is the
potential problem of a loss of wide-angle capability.
Four Thirds solves this phenomenon. As the lens if always fully
optimised to suit the sensor, you don't have to contend with
expensive wide-angle lenses that do not attain their intended
specification - the angle of view you expect is the angle of view
you get.
The standard focal lens of the Four Thirds standard is around
25mm.So to compare for the 35mm format with a standard focal
length of around 50mm, you have to use the factor 2 to have the
angle of view compared (50mm = 100mm related to 35mm equivalent
focal length).
Lens Resolution & Corner-shading:Because the medium of film is
very tolerant, there was no need to equip lenses with very high
resolving power in the past. But with digital sensors, this has
changed.
Conventional lens systems simply do not deliver the lens
resolution necessary for electronic sensors.They often have a
resolution of only around 10 microns. However, because modern
multi-megapixel cameras often have a pixel pitch of just 5 or 6
microns or less, overlapping and quality losses are the result.
Therefore, the full theoretical performance of the sensor cannot
be used. The problem is exacerbated with a greater number of
pixels and a smaller sensor size.
All lenses designed for the Four Thirds standard ensure the image
sensor is not left wanting. The ultra-fine resolution attained
through special manufacturing processes guarantees full sensor
performance.
For Edge to Edge Clarity:All Four Thirds-optimised lenses feature
so-called near telecentric optics.
Due to the nature of the electronic sensor construction, image
data is lost and there is a susceptibility to interference if
light hits the pixels at a high angle of incidence. IT causes a
situation called corner-shading, a loss in quality at the edge of
the frame. This is associated particularly with cameras using
full-format sensors, where lenses must spread the light widely to
reach each corner.
However, the near telecentric construction of lenses optimised
for the Four Thirds standard ensures light hits the sensor at
right-angles. This guarantees edge-to-edge colour, clarity and
brightness.
Standardisation:Four Thirds is a technological standard dedicated
to the needs of digital SLR camera systems. It has been designed
to maximise the performance of both image sensors and lenses. To
achieve this, it sets definitive standards on three
levels:Mechanical, Optical and Communication.
Mechanical Standards:The type, size and shape of the bayonet
and bore are standardised to permit lens
inter-changeability. Also the distance between the focal plane
and the lens flange surface (flange back) and the position of the
image sensor in relation to the rear of the lens have been
defined.
Optical Standards: The Four Thirds Standard fixes the size of the
image circle, i.e. the diameter of the circle projected by the
lens onto the focal plane. The lens is roughly twice as big
as the image circle, a feature necessary to allow the light to
fall at almost perpendicular angles onto the entire image sensor
via the near telecentric lens elements, thus virtually
eliminating corner-shading.
A Communication Standard:The lens and body are no longer separate
entities. now, through the standardised communications protocol
established by Four Thirds, the two can communicate and exchange
information.
An Open Standard:The Four Thirds standard has been deliberately
designed as an open stnadard.That means the more body, lens and
accessory manufacturers adopt the standard, the greater will be
the degree of product compatibility. As a result, the range of
equipment and options available to photographers will be greater
General Advantages of the Four Thirds System:No decrease in image
resolution caused by inappropriate lenses - full use of the
sensor's performance;No loss of wide angle
capability;Significantly reduced incidence of
corner-shading;Smaller, lighter lenses and bodies;Brighter lenses
by approximately two f-stops with same depth of field as 35mm
lenses (plus solutions to provide shallow depth of field if
required);Designed to remain compatible with future sensor
developments;Cross-manufacturer interchangeability;Perfect
harmonisation of lens and body due to communication
standard;Secure investment due to future-oriented design
