What is a 'Four Thirds' sensor?

[ajf_2005]

What are the so called Four Thirds sensors in the Olympus and new Panasonic cameras?

Do they have advantages over (for example) the current Canon sensors in the likes of the 350D?

Andrew
--
http://www.pbase.com/ajfarmer

 

[jfinite]

--

 

[Kelly Mackey]

Here's a web site for the Four Thirds system:

http://www.four-thirds.org/en/index_01.htm

 

[Norm Neely]

Hi Andrew

The following link show the sensor sizes.

http://www.dpreview.com/learn/?/Glossary/Camera_System/sensor_sizes_01.htm

You might want to check out the glossory. A lot of usefull information on cameras.

--
Norm

 

[tbcass]

Personally I see no advantage at all. It doesn't fit any common print sizes I can think of but it does double lens focal length I believe.
--
Tom

http://www.flickr.com/photos/25301400@N00/

 

[Paul Pasco]

8x10?
--
Lili's Dad

http://www.pbase.com/lilis_papa

 

[ajf_2005]

Thanks for the links and feedback.

Have read their wesbite but still not absolutely convinced as to the point of it. I can see the idea if it is an 'open' standard but will the likes of Canon and Nikon really move to it?

Also, it mentions about the fact the lenses are designed to make light hit the sensor straight on etc. Is this really something that current DSLRs CANNOT do?

Andrew
--
http://www.pbase.com/ajfarmer

 

[Joseph S Wisniewski]

Thanks for the links and feedback.
Have read their wesbite but still not absolutely convinced as to
the point of it. I can see the idea if it is an 'open' standard but
will the likes of Canon and Nikon really move to it?

No. First, there's no real advantage over any other system. Second, it's not all that "open". It's patented and trademarked by Olympus, and all press releases and marketing literature (like that four-thirds website that Kelly mentioned) are copyrighted by Olympus.

Also, it mentions about the fact the lenses are designed to make
light hit the sensor straight on etc. Is this really something that
current DSLRs CANNOT do?

No. It's something that other DSLRs were doing before Olympus. The Nikon 17-35mm f2.8 was the first lens built to have light striking the sensor at a more perpendicular angle than conventional lenses. Nikon designed that lens back when the only DLSRs were those outrageously expensive Kodak DLSRs built on Nikon bodies.

It's also not particularly necessary. For years, I've been promoting the concept of offsetting the microlenses on a sensor. Kodak actually built a sensor of this type for the Leica Modul-R, and it performs very well with "conventional" lenses. Supposedly, Canon also uses this concept in their 1Ds II.

--
The Pistons led the NBA, and lost in the playoffs.
The Red Wings led the NHL, and lost in the playoffs.

It's up to the Tigers now...
Leading the league, and going all the way!

Ciao!

Joe

http://www.swissarmyfork.com

 

[Lemming51]

8x10?

 

[Lemming51]

It does have 2x crop factor relative to 35mm film frame. That simply means the sensor is about 1/2 the size.

Personally I see no advantage at all. It doesn't fit any common
print sizes I can think of but it does double lens focal length I
believe.

 

[Joseph S Wisniewski]

Personally I see no advantage at all. It doesn't fit any common
print sizes I can think of but it does double lens focal length I
believe.

There's a tremendous advantage to Olympus. A patent has to be something unique, or a unique (not obvious) combination of existing technologies. Their four thirds patent hinges on a combination of three things: interchangeable lenses, a mount diameter to sensor diagonal ratio of 1.8:1, and a 4:3 aspect ratio. Without the 4:3 aspect ratio, the original Kodak DSLR built on a Canon EOS chassis back in the late 90's would meet the interchangeable lens and mount diameter requirements.

--
The Pistons led the NBA, and lost in the playoffs.
The Red Wings led the NHL, and lost in the playoffs.

It's up to the Tigers now...
Leading the league, and going all the way!

Ciao!

Joe

http://www.swissarmyfork.com

 

[stephenmelvin]

Personally I see no advantage at all. It doesn't fit any common
print sizes I can think of but it does double lens focal length I
believe.

The standard 35mm format doesn't fit any common enlargement sizes, either. Just the 4x6 size, which came into being once 35mm became the dominant consumer format. The 4:3 format more closely fits the standard print enlargement and frame sizes, with less cropping. It's very close to the same ratio as 11 x 14" (working out to 11 x 14.67"). To get any other dSLR to an 11" print size, the other dimension is 16.5", meaning you lop off an additional 2" compared to 4:3. You can do the same exercise for other enlargement sizes: 16 x 20, 20 x 24, 24 x 30, etc.

The crop factor does make the math easier, which is certainly an advantage. But it also makes for a tiny viewfinder. Man, I tried out an E500, and it looked like trying to view a 35mm slide at the end of a 12" long tunnel. Ugh.

--
Tom

http://www.flickr.com/photos/25301400@N00/

 

[Glen Barrington]

Ignore the hype about 4/3s sensors. They are really no better or no worse than APS sized sensors. Judge the cameras on other more typical decision points. I think the Oly cameras will come out on top as often as they come out in second or third place.

They do tend to be a bit noisier at high ISO (say over iso 400) than APS based cameras. Only you can decide if that is important. I have found that the increase in noise is quite manageable at iso 800 with Noiseware and OK at iso 1600 with noiseware. I wouldn't want to use a 4/3s camera for concert or astronomical photography, but for the kind of light duty occasional use that I would need high iso for, the Oly cameras work quite well especially considering they generally cost less than the competition.

4/3s image quality is quite high at the lower iso settings (iso 400 and below). and the Olympus lenses are as good as the Japanese lens makers can do. Many people feel that the Olympus kit lenses are a bit better than the competition's kit lenses but if they are, it is by a very small increment. The OLY cameras are competitive in every way.

Like I said, I'm quite satisfied with my 4/3s Oly camera. But I DON'T think the 4/3s sensor had all that much to do with my satisfaction nearly as much as the fact that I bought a well made and well designed camera at a good price. It probably would have been just as good with an APS sensor.

http://www.photo.net/photodb/photo?photo_id=4573512
--

Some see the cup as half empty, others see the cup as half full. Personally, I see the cup being knocked over.

 

[Forrest41926]

The standard 35mm format doesn't fit any common enlargement sizes,
either. Just the 4x6 size, which came into being once 35mm became

8x12"
16x24"
20x30"

 

[Tom_N]

The 4:3 aspect ratio comes from NTSC TV sets and the other electronics (camcorders, computer monitors, etc.) built around them. That, in turn, comes from the "Academy Ratio" of 4:3 that is the OAR for old films.

Common aspect ratios

1.25:1 -- 8 x 10 prints, 4 x 5 medium-format film cameras
1.33:1 -- NTSC TVs, digital P&S cameras, Four-Thirds system
1.40:1 -- 5 x 7 prints
1.41:1 -- European paper sizes (SQRT(2):1 is real convenient for scaling)
1.50:1 -- 35mm film, APS film, DSLRs with those sensor sizes, 4 x 6 prints
1.60:1 -- Widescreen Apple monitors (HDTV picture + menu bar on top)
1.66:1 -- Some Disney films
1.78:1 -- Widescreen HDTVs (16:9).
1.85:1 -- Many widescreen films. On disc, might be cropped to 16:9.
2.35:1 -- Many Westerns (e.g., "The Good, The Bad, & The Ugly")

 

[stephenmelvin]

The standard 35mm format doesn't fit any common enlargement sizes,
either. Just the 4x6 size, which came into being once 35mm became

8x12"
16x24"
20x30"

I said common. Just try finding frames for those sizes. Yes, it can be done, but 8 x 10, 11 x 14, 16 x 20, etc. are much, much more common. Heck, square frames are more common at most shops I've been to.

 

[stephenmelvin]

The 4:3 aspect ratio comes from NTSC TV sets and the other
electronics (camcorders, computer monitors, etc.) built around
them. That, in turn, comes from the "Academy Ratio" of 4:3 that is

1.85:1 -- Many widescreen films. On disc, might be cropped to 16:9.

Most current widescreen films are 1.85:1.

2.35:1 -- Many Westerns (e.g., "The Good, The Bad, & The Ugly")

That's the ratio of Panavision (by far the best known widescreen process), as well as a number of other processes. I believe VistaVision is the same ratio. The difference? VistaVision actually uses 35mm film running sideways, as in most 35mm film cameras. This allows for widescreen movies to be shot on 35mm with 70mm quality.

BTW, you forgot 1:1, format of artists and astronauts!

 

[yesfan02]

The standard 35mm format doesn't fit any common enlargement sizes,
either. Just the 4x6 size, which came into being once 35mm became

8x12"
16x24"
20x30"

I said common. Just try finding frames for those sizes. Yes, it can
be done, but 8 x 10, 11 x 14, 16 x 20, etc. are much, much more
common. Heck, square frames are more common at most shops I've been
to.

--I just did two 8x12's and can't find a matt to fit. Nothing common here either.

Soon! Oh Soon the light. Ours to shape for all time, ours the right. The sun will lead us, our reason to be here.

 

[poliscijustin]

Just means it is a 4:3 aspect ratio instead of 3:2. Matter of personal preference mostly. The 3:2 ratio is a little wider and perfectly matches a 4x6 print. I prefer it. 4:3 is a little taller and requires slightly less cropping to make an 8x10. While some tout this as an advantage, it isn't like any 3:2 camera has trouble making an 8x10 if you know what you are doing when you shoot the pic.
--



A small but growing collection of my photos can be seen at
http://www.pbase.com/poliscijustin

 

[poliscijustin]

I said common. Just try finding frames for those sizes. Yes, it can
be done, but 8 x 10, 11 x 14, 16 x 20, etc. are much, much more
common. Heck, square frames are more common at most shops I've been
to.

http://www.framesbymail.com
http://www.americanframe.com

They will make you any size you want, for cheap and good quality. OR, it is easy enough to crop either 3:2 or 4:3 to pretty much any print size you want.