in 2003, a consortium of manufacturers including Olympus, Panasonic and Kodak
agreed on the development of standards based on a new digital sensor size
"four thirds" (4/3rds)
which has a crop factor of 2 when compared to the
35mm film standard and thus the sensor area is one quarter the size and thus
much cheaper to make. Leica joined this consortium.
The impetus behind development of the 4/3rds standard is
production of lenses which have an MTF of at least 200 lines/mm (4x
the usual 35mm full frame lenses which tend to be 50 lines/mm) and are
potentially smaller (but not ultra wide angles due to design issues), lighter, faster and cheaper
than lenses designed for 35mm film cameras. This is based on the
concept that 35mm film camera lenses are needlessly large, heavy and
expensive for meeting the needs of digital imaging. Moreover, the
lenses designed for the 4/3rds format are "near-telecentric"
- which helps avoid vignetting, color fringing, and softness at the
edges of the image.
in August 2008, Olympus and Panasonic agreed to extend the system by introducing
a new ultracompact dSLR standard called "Micro
Four Thirds" which uses the same size sensor but because it does
away with the SLR mirror, it allows even more
compact bodies and lenses whilst still retaining compatibility with existing
Four Thirds system including its lenses via an adapter:
~50% shorter flange distance (sensor to lens mount distance) AND back
focus distance (rear lens element to sensor)
will enable smaller lenses, in particular, wide angle lenses which
had to be bigger with Four Thirds design.
will potentially enable use of short flange lenses such as Leica M
and Canon FD.
6mm smaller diameter lens mount
maintain the principle of telecentricity in lens design.
11 electrical contacts on lens mount instead of 9 to allow for more
future proofing, but in particular, the ability to more rapidly extend
new lenses and AF with more accuracy - presumably to optimise contrast
detect AF.
ability to use normal Four Thirds lenses via an adapter
no SLR mirror thus:
slim, compact and light camera body designs
no through-the-lens optical viewfinder -
potential for a Leica rangefinder style though
some models will probably only have LCD
viewfinder as with current point and shoots, while other models may
have EVF (electronic viewfinders).
relies on contrast detect AF with
presumably face detect AF option, but this will be slower than dSLR
AF by necessity in design.
almost silent function, thus discrete for
weddings, classical music concerts
movie mode for those that like this in some
models
potential for very high burst rates perhaps
60fps at 10mp
unlike the Four Thirds, it is not an "open standard"
emphasis will be on edge-to-edge image quality rather that
super-compactness for its own sake
hints at what the 2 extra lens mount pins are for - better AF
control of the lens
timing of the announcement more related to improvement in
contrast-detect AF technology as shown in the E-420 which as it
improves further over time will make M4/3 cameras more usable.
possible use of EVF or rangefinder viewfinders to supplement LCD
live preview
likely expansion of movie capability
Leica M lens usage possible
will not be replacing the 4/3 system
more 4/3 bodies coming out this year - presumably will be
announced Sept 2008.
As can be seen here, by removing the SLR mirror, the Micro
system now enables thin body design and lenses that can be made much
smaller by bringing them closer to the sensor.
This shows the difference in diameters of the two mounts
which suggest the Micro lenses will have narrower diameters and not jus at
their mounts.
And for compatibility, what more could you expect?
While a Micro lens will only fit a Micro body, you will be able attach
a Four Thirds lens via an adapter onto the Micro body, and hence almost
any lens that one currently can fit onto a Four Thirds dSLR body.
My take of the Four Thirds Micro System:
this is quite an exciting development and is consistent with my
prediction that Olympus/Panasonic will eventually dominate the compact
dSLR market
with a digital camera potentially the not much bigger than current digitals such
as a Canon G9, but with the enormous advantage of not only having a
bigger sensor and thus more dynamic range and lower noise, but ability
to use almost ANY lens on it via adapters.
such cameras will mean that they can also be used as back up cameras
to semi-pro Four Thirds cameras and would be portable enough and easy
enough so that the non-photographers of the family will be comfortable
using them instead of having a plethora of non-compatible systems in the
household.
possibilities for Four Thirds Micro camera bodies:
dedicated infrared
body
with the IR blocking filter replaced by a IR pass filter.
SLO-MOTION video cameras
eg. 1000fps capable of using the Four
Thirds lenses to give unique possibilities:
super wide angle video
super macro video
super telephoto video
astrophotographic video
narrow depth of field video using the 50mm f/2 macro or the
50-200mm f/2.8-3.5 SWD lenses
there is no reason why a camera body with functionality of the
new Casio FH20 with its 40fps at 9mp or up to 1000fps in movie
mode can't be made:
Leica fans pay a LOT of money for their toys - see Leica M
obviously, Leica owners get some unique features if they can
afford these unique lenses, but a Four Thirds Micro user may get
similar functionality with extra functionality (see next) and
have a choice of new high quality Micro 4/3 lenses or the high
quality 4/3 lenses (although
many will not AF on a micro body, but then Leica lenses are MF
anyway).
very compact, near silent EVF camera kits
may yet be an improvement on the Leica M8 as EVF technology
improves
the main problems with optical rangefinder-style
viewfinders are:
inability to assess adjustment of polariser and
gradient filters
inability to assess depth of field effects
parallax and focus errors - although the rangefinder
technology is reasonably accurate
no AF mechanisms
no ability to pre-visualise super-telephoto field of
view or focus (max. is for 90mm lens)
as yet, the Leica bodies do not have image stabilisation
or live preview built in, and no spot metering, and for
backwards compatibility, have used in-camera technologies to
reduce vignetting instead of designing telecentric lenses as
with the 4/3 system.
not to be under-estimated is the convergence of technologies bringing
near silent operation to the digital SLR world, thus for instance, you
could photograph your child playing at a classical music concert with a
Four Thirds Micro camera body attached to either a Four Thirds Micro
lens or a Four Thirds wide aperture telephoto such as a ZD 50-200mm
f/2.8-3.5 SWD via an adapter.
I do not see the Micro system replacing the Four Thirds system but
augmenting it.
Imagine you are on an African safari and have your Olympus E3
dSLR with Olympus ZD 150mm f/2 lens and 2x TC giving a 600mm
telephoto reach at f/4 but you decide you want some really rapid
burst shots or a movie. Just swap the E3 for a Micro body which you
carry in your shirt pocket and once you lock in focus, away you go.
The AF speed, handling and optical viewfinder of the Four Thirds dSLR
will be unlikely replaced by a Micro system within the next decade,
although the ne contrast AF seems as good as entry-level dSLR AF.
BUT the Micro system will bring many point and shoot photographers to
the Four Thirds dSLR world while filling niche functionalities because
of its portability, silence, movie mode, high burst modes and ability to
use almost any lens.
the biggest hurdle of the Micro system is AF speed and it will be
interesting to see how this pans out and it may be that reasonable
contrast detection AF speed is only possible with 11pin lenses - ie.
Micro Four Third lenses (and perhaps future Four Thirds lenses).
Four Thirds Micro camera bodies:
Olympus E-P1:
coming July 2009; $US899 incl. 17mm f/2.8 and VF-1 viewfinder;
similar to an Olympus Pen camera style targeting the
street photographers and landscape photographers
metal slim-line body; 12mp; 3fps; similar features as E-620 including
art filters and full manual control but more image detail due to weaker
AA filter.
optional optical viewfinder (VF-1) and flash (FL-14)
720p stereo video with 4stop IS and art filters; minHDMI out but no
mic in. SD/SDHC memory cards;
new 12mp sensor - can shoot at four different aspect ratios (4:3, 3:2,
16:9 and 1:1) with a similar angle of view and effective pixel count of
around 12Mp, by using different portions of the sensor in a similar
fashion to the DMC-LX3.
AVCHD video-enabled version of the G1 with live, silent AF during
video capture and dedicated video on/off button.
7 blades, circular, close focus 1m, 52mm filter, 380g
Lumix G Vario14-45mm f/3.5-5.6 ASPH Mega OIS:
announced late 2008
7 blades, circular, close focus 0.3m, 52mm filter, 195g
unfortunately this lens suffers from a bit of distortion, but then it
is a kit lens.
Four Thirds lenses via MFT-FT adapter:
these will allow full aperture control and they all have circular
apertures for nice bokeh - image quality should be comparable to that on an
equivalent Four Thirds camera.
AFS contrast-detect AF will only be possible if the lens is designed for
contrast-detect AF
AFC (continuous AF) contrast detect AF is currently NOT possible on
these even if designated as contrast-detect AF capable
furthermore, it is unlikely these lenses will be made to be HD video AF
capable as presumably this needs the extra electronic coupling pins on the
lens mount as for MFT lenses.
AFS contrast-detect capable Four Thirds lenses to date:
these lenses cannot be used on any dSLR with a mirror unless the adapter
has optical component to adjust focus, BUT they can be used fully
functionally on MFT cameras with a Canon FD to MFT adapter.
Canon EOS EF lenses:
can be used with an EOS - MFT adapter BUT due to the electronic control of
EOS lenses, can only be used at the widest aperture.
Lens Baby lenses for EOS of course have their own aperture disks so these
can be used with aperture control by changing the disks.
Nikon G lenses:
the newer Nikon lenses are similar to the Canon EOS in that they can be
used with a Nikon-FT adapter plus FT-MFT adapter but must be used wide open
aperture.
Practically any other 35mm SLR lens via the correct adapter with full
aperture control:
includes Nikon, Pentax, Minolta, Konica, Leica R, Carl Zeiss Contax
Practically any 35mm rangefinder camera lens via the correct adapter with
full aperture control:
Olympus Pen (adapter not yet available)
Canon for Leica M
35mm moving picture PL lenses via PL to MFT adapter with full aperture
control:
see here
for example of GH-1 videos using the Zeiss PL lenses
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