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).
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
As I have no idea what ads will display here, they
are not necessarily endorsed by me but you may well find them
useful and by clicking on them it helps to pay to keep this website
alive:
