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View Full Version : U43 format - why 1/4 FF


Ricoh
19th November 2015, 01:00 PM
When the U 4/3 format was conceived I wonder why Olympus and Panasonic chose 1/4 of the the 35mm FF. It would seem more logical to have chosen FF, like other Mirrorless formats, eg Sony and Leica.

SteveJ
19th November 2015, 01:22 PM
To make a compact interchangable lens camera system.

Steve

Graham_of_Rainham
19th November 2015, 01:45 PM
Size matters! It always has to Olympus.

I was shooting with a Fuji X100T yesterday and while not FF, it was noticeably larger than my E-P5. Not by much, but when you look at the FF CSCs they really are considerably bigger and heavier.

It's also worth remembering the 4/3rds system was designed from scratch, rather than evolving from 35mm lenses with digital bodies made to fit.

Ultimately it can only ever be the final product, on which judgment is made, so the quality of the print or the image on your HiRes screen, is the one true test.

Having "played" with a lot of different systems, my choice of Olympus has always been based on the way it works for me, and the end results.

*chr

OM USer
19th November 2015, 02:53 PM
The 4/3rds system was designed (I believe) around a telecentric model whereby light at the edges of the frame was (nearly) perpendicular to the sensor as CCD sensors suffered severe performance loss with incident light. This meant that the exit lens and the sensor must be of similar size. To have gone for a bigger sensor would have meant that the rear of the lens would be much bigger and so impact the overall compactness of the system. The telecentric design meant that the system punched well above its weight in terms of sensor size. The switch to CMOS sensors half way through the system lifespan meant that incident light falloff is not so much an issue but it was too late by then to change. MFT specifications are based on the 4/3rds specifications hence the same size sensors.

Ricoh
19th November 2015, 02:54 PM
Hi Graham,
I'm aware of capabilities myself as I'm able to compare the u43 next to my FF (35mm) digital. Certainly for web use or indeed for normal monitor size and resolution it's hard to see much difference. Perhaps the distinction I would draw would be noise, especially at high ISO. However I wasn't trying to elicit any sort or format war, I'm just curious how u43 came into being. I doubt the clever designers in Japan came up with the format without first conducting some market research, but perhaps not. The Sony Walkman was a good of example of technology driving the market, and likewise the iPad.

Ricoh
19th November 2015, 02:57 PM
Can't seem to 'thank you' using the buttons OM User, so I'll do it this way!

Graham_of_Rainham
19th November 2015, 03:29 PM
One of the more comprehensive "reasoning" can be found: HERE (http://www.four-thirds.org/en/fourthirds/index.html)

The image sensor in a digital camera can be compared to a "deep well." You cannot see the bottom of the well unless you lean over it. In the same way, light inclined at an angle cannot reach the image sensor (i.e. the bottom of the well). Many of the current interchangeable-lens D-SLR cameras using traditional 35 mm film camera lenses are very susceptible to loss of sharpness, chromatic aberration, and shading of peripheral areas.

http://www.four-thirds.org/en/common/img/c_ft_standard_bene_vi_03.jpg

Wide-angle type lenses are especially problematic since oblique light inclined at a large angle tends to enter the peripheral areas.
ZUIKO DIGITAL 14-54mm F2.8-3.5, at 14mm (28mm : 35mm equivalent) 35mm film camera zoom lens, at 28mm

With the Four Thirds system, the diameter of the lens mount exceeds the sensor size and the digital-dedicated lens design allows all the light (even on the periphery) to travel perpendicularly to the surface of the image sensor. The result is a sharp, clear image reproduction throughout the image plane.
Linear propagation of light and the high imaging performance made possible by the digital-dedicated design are the biggest features of the Four Thirds lenses.

Ulfric M Douglas
19th November 2015, 07:34 PM
When the U 4/3 format was conceived I wonder why Olympus and Panasonic chose 1/4 of the the 35mm FF. It would seem more logical to have chosen FF, like other Mirrorless formats, eg Sony and Leica.
At the time (hugely important factor!) the 35mm sensors were very very expensive, certainly a niche market, not consumer.
Using a 4:3 ratio at least made better use of the image circle while the sensor size allowed the E-1 to maybe be profitable considering sensor cost.

These days I think they would have used a bigger sensor but still the excellent 4:3 ratio.

C'mon Olympus, DO IT.

:|

Olympus 35mm would be a larger sensor then "full frame". Think about it.

DerekW
19th November 2015, 08:30 PM
Remembering back to the heady days when 4/3rds came out there was some mention of the mount diameter (hole for the lens) being compatible with TV / video cameras.

Naughty Nigel
19th November 2015, 11:09 PM
When the U 4/3 format was conceived I wonder why Olympus and Panasonic chose 1/4 of the the 35mm FF. It would seem more logical to have chosen FF, like other Mirrorless formats, eg Sony and Leica.

I thought 4:3 was half the size of a 35 mm film frame? :confused:

Ricoh
20th November 2015, 12:44 AM
I thought 4:3 was half the size of a 35 mm film frame? :confused:
On the diagonal, yes, but 1/4 in terms of area. I was referring to the latter as I believe the comparison is more meaningful in such terms.

Ricoh
20th November 2015, 12:55 AM
At the time (hugely important factor!) the 35mm sensors were very very expensive, certainly a niche market, not consumer.
Using a 4:3 ratio at least made better use of the image circle while the sensor size allowed the E-1 to maybe be profitable considering sensor cost.

These days I think they would have used a bigger sensor but still the excellent 4:3 ratio.

C'mon Olympus, DO IT.

:|

Olympus 35mm would be a larger sensor then "full frame". Think about it.

I suspect cost was a significant factor, the result was probably a workaround.

Harold Gough
21st November 2015, 06:44 PM
I'm grateful that the short flange to sensor distance (20mm) allows just about any legacy film lens to be used on a body, via suitable adapters and tubes, as required.

Harold

pdk42
22nd November 2015, 12:19 AM
It's a reflection of design decisions made in the early to mid 2000s. Back then big sensors were expensive and tele-centricity was important (as Graham's post has illustrated above). Would they make the same design decisions today? I doubt it, but for me it's still a highly relevant standard since it delivers an excellent blend of compactness and performance.

Internaut
22nd November 2015, 04:07 PM
Ultimately, it was just an arbitrary design decision that through luck, and the the later decision to go with a new mirrorless mount, is still relevant. Size matters to me, but I'm still looking into a modest full frame kit to complement Micro Four Thirds.

ian p
22nd November 2015, 05:40 PM
If you follow the 4/3 diagonal to the edge of a full frame sensor, it's more like 1/3 of the area and not 1/4. The remaining 25% of the long thin sensor is generally a waste, unless you need a panoramic format.

As FF bodies and lenses tend to be very big, it would make sense to make a 4/3 ratio full frame sized sensor. FF bodies and lenses could then be 25% smaller.
Most sensor sizes are 4/3 ratio

Ricoh
22nd November 2015, 05:57 PM
Oh, from my googling I observed the linear dimensions, x and y, are half that of the FF 35mm, therefore 1/4 of the area.

ian p
22nd November 2015, 06:05 PM
1/4 of the whole long thin sensor. But about 1/33 of the useful 4/3 part. The FF sensor is a weird legacy shape that on average will not be fully used. Actually, FF lenses are capable of covering a bigger sensor than they do, if only they made a shorter sensor, it could then be taller. If you don't have a mirror, there is no need to stick to a fixed ratio.

Simon Bee
22nd November 2015, 06:32 PM
From my point of view, where Micro 4/3 really excels is in the telephoto department, such M4/3 optics are so much smaller and lighter than those for a 24x36mm sensor dSLR.

If however you have no need for a lens above 135mm ( 35mm terms ) then M4/3 compactness does not always win out. My Leica M-E has a 24mm x 36mm sensor .... in other words one with a surface area 4x larger and IMO at least, is not very much larger than an E-P5 plus the 35mm F2 Summicron is a TINY F/frame lens.

Take a look here...... http://camerasize.com/compare/#459,388

Admittedly the Leica costs a heck of a lot more ( my M-E & 35mm F2 set me back almost 6k ) and is not for everyone, also native lenses do not go beyond 135mm. However for those who may not be familiar with a Leica 'M' the above comparison may well be an eye opener.

I am sure that Olympus ( and Kodak remember;) ) chose a 17x13mm sensor because as already said back in the early 2000's sensors were very expensive plus a comprehensive range of new optics of the necessary quality to cover a 24x36mm sensor would have cost Olympus an awful lot in R&D.

The IQ out of my M-E at low ISO is simply breathtaking and it has quickly become my 'walk-about camera' of choice when I want a 'digital' option ( film is still my preferred choice ). However I am definitely going to get back into M4/3 for extreme-telephoto use. I have thought of getting another 5mk2 although TBH the E-P5 is such a bargain S/H I think that is the route I'll take, it's still a great camera and typically one can buy a S/H E-P5 & 75-300mk2 for 500.00 ... that is one hell of a lot of camera and reach for the money;)

Kind regards, Simon

ian p
22nd November 2015, 06:40 PM
Keep an eye on EM5ii prices. There are huge savings already.

Ricoh
22nd November 2015, 06:49 PM
Hi Simon, have to agree with the M-E, well I would wouldnt I :)

I was just about to post this http://photoseek.com/2013/compare-digital-camera-sensor-sizes-full-frame-35mm-aps-c-micro-four-thirds-1-inch-type/ but you got in first.

Actually, I'm thinking about selling my 'black' E-P5 plus VF-4, if you're interested. At a guess I think it has less that 500 clicks (I will check) and is in absolutely pristine condition, like new in fact. Purchased from SRS and is still in warranty.

pdk42
22nd November 2015, 09:35 PM
Hi Simon, have to agree with the M-E, well I would wouldnt I :)



Steve - I've just been to your Flickr site and I must say you're using your Leica to great effect! There are some stunning street images you've taken there. This one just has to be my favourite though (I guess it's OK to post links to your image here!!??):

https://farm1.staticflickr.com/498/19972240961_5d07f6cb36_b.jpg (https://flic.kr/p/wqSXq6)
Hard work museums (https://flic.kr/p/wqSXq6) by Steve Wales (https://www.flickr.com/photos/steves_flickr/), on Flickr

(even if it's taken with a GM5!)

Ricoh
22nd November 2015, 10:27 PM
Hi Paul, thanks for the nice comments :)
The image linked above was actually taken with a u43 camera, the trusty, stealthy GM5 coupled with the brilliant PL 15mm f/1.7
It was a picture begging to be taken, although I don't think the mum was too pleased with me taking her passport photo, or maybe she was ?