Talk:Four Thirds system

message: Quoting the footnote at the bottom of http://www.four-thirds.org/en/about/benefit.html (as of 13:36 30 Jan 2008 UTC)
*	Details of the Four Thirds System standard are available to camera equipment manufacturers and industry organizations on an NDA basis. 
Full specifications cannot be provided to individuals or other educational/research entities.
:I had read this exact quote on the official website and I too wondered how they could call this an "open" standard. However, this statement also clearly states that any company may enter in an agreement with them to get the full specification; I guess that is what they see as "open". I find it most intriguing that they would prohibit individuals and other researchers to access the standard... Anyway, back to the "citation needed", I think what is controversial about the marked phrase is the "commonly accepted definition" statement. Maybe this could be rephrased with something such as this: "This is claimed to be an open standard; it is however accessible only to companies and under a non-disclosure agreement." (and then link the page mentioned above). AlexFicelle (talk) 17:43, 10 November 2008 (UTC)
thread_title:  Why it's not an "Open Standard" 

message: Can anyone explain the connection between the name "four-thirds" and the size of the sensor? The article presently contains the text The name of the system comes from the size of the imaging sensor. The sensor used is a "4/3 inch" type sensor. The length is based on the diameter of particular size of Vidicon tube—the actual light sensitive area being smaller. The actual length of the sensor diagonal is 22.5mm. So more specifically, my questions are: In what way does the name come from the size? In what way is the length based on the diameter of some Vidicon tube? Note that 4/3 inch = 33.9 mm, which is much bigger (50% bigger) than 22.5 mm. That is, the sensor is nowhere near 4/3 inch in diagonal. Fg2 04:56, August 11, 2005 (UTC)
:Indeed it's not the physical dimension of the sensor.  There's a good explanation of the confusing fractional definitions camera manufacturers use here: http://www.dpreview.com/learn/?/Glossary/Camera_System/Sensor_Sizes_01.htm. 203.132.65.32 08:45, 23 December 2005 (UTC)
thread_title:  Name explanation 

message: have removed this link - the four thirds system covers aspects in addition to just the sensor format - its more about the imaging circle and the lens mount than the sensor size. 
For the record, I don't think the separate page is warranted - but that's probably a discussion left until after the issue of whether to delete the "full frame" page is decided. --Hmette 06:56, 7 April 2007 (UTC)
replies: text: Agree that the standard covers aspects in addition to just the sensor format... but it does cover the sensor format, not just the imaging circle. So why you'd remove the link escapes me. Expand the description by all means but don't remove useful content is my advice. Andrewa 09:55, 7 April 2007 (UTC)
thread_title:  Image sensor format 

message: "Four Thirds is not an open standard, however, as it does not meet the "allowing anyone to use" criterion commonly accepted as the definition of an open standard." This sounds like point of view as there's no citation. On wikipedia's own Open Standard page it appears that the term itself has a broad array of interpretations and there is no clear definition of the term at all. I recommend removing this line or citing a source which shares the author's criticism as a way to highlight criticism of the standard's closed nature.
Reply to the above- this is not just a point of view, as the standard is only available to companies.  Wikipedia definition of Open Standard, first line "An open standard is a standard that is publicly available".  Fails even this 1st generally accepted "open standard" criterion.  It is only open when compared to the "trade secret" approaches camera manufacturers normally take.  Some viewpoint from authors must be accepted on Wikipedia otherwise a manufacturer can claim anything is "open" in a press release and the Wikipedia entry just parrots the press release!  Claims which are not substantiated by reality should be pointed out.  --124.169.30.248 (talk) 04:51, 5 December 2009 (UTC)
thread_title:  Open Standard? 

message: The explanation that a 300 mm lens has the same angle as a conventional 600 mm lens was bogus.  The difference in angle is a direct result of the ratio of sensor size on many Olympus SLRs to a standard 35 mm frame.  I suspect, but don't know, that telecentricity might make for a shorter 300 mm lens, but that doesn't change its focal length.  
Groogle 23:20, 3 December 2007 (UTC)
replies: text: I've tried to restore the comparison in a more correct way. Let's talk about it here if you think I'm wrong. Thanks. --RenniePet 16:10, 4 December 2007 (UTC)
thread_title: 300 = 600?

message: The article says "Its area is ... around 15× larger than the 1/2.5" sensors typically used in compact digital cameras". Looking at the diagram, the area of the Four Thirds sensor is 225 mm², and the area of a 1/2.5" sensor is 25 mm². So shouldn't it say "9x larger"? Matthewk (talk) 17:01, 23 December 2007 (UTC)
replies: text: Correct, thanks. --RenniePet (talk) 17:17, 23 December 2007 (UTC)
thread_title:  Sensor size comparison 

message: I'm a fan of the Four Thirds System, but in the interests of honesty I think the statement about noise problems should say that it begins to be relevant from above ISO 400. It previously said "ISO 400 and up". Another editor changed that to "ISO 1600 and up". Wish that was true. Anyway, I've now changed it to "above 400", and added a link to a brand-new review of the Olympus E-3 in DPReview, where it says, for that model at least, "Noisier results than most competitors above ISO 400 (usable up to ISO 1600)". --RenniePet (talk) 00:24, 23 February 2008 (UTC)
thread_title:  Smaller sensor = more noise 

message: :Feel free to state your position on the renaming proposal by beginning a new line in this section with *Support or *Oppose, then sign your comment with ~~~~. Since polling is not a substitute for discussion, please explain your reasons, taking into account Wikipedia's naming conventions.
* Support as nominator.  The offical site has it as "Four Thirds system". Dicklyon (talk) 06:00, 16 February 2009 (UTC)
thread_title: Survey

message: The article says that the Four Thirds flange to focal plane distance is significantly shorter than a number of "competing" brands. In the case of Canon FD (hardly a competitor) the difference is actually only 3.4mm, which is not enough to allow an adapter to be made that allows infinity focus. FD lenses can be converted to fit a Four Thirds mount but it is a destructive process that prevents the lens from being used again with an FD body. A Canon FD to Micro Four Thirds adapter is, however, available. 83.104.249.240 (talk) 18:54, 24 March 2009 (UTC)
thread_title:  Advantages section 

message: First off statement had no sources.
First statement was that one of the disadvantages stated that as of 2009 only olympus is the only manufacturer of four third system cameras.
Panasonic dSLR cameras are all four third and has also started releasing Micro Four Third System Cameras (http://panasonic.net/avc/lumix/systemcamera/gms/index.html)
Leica
As for saying that the orginal supporters have distanced themselves from four third, again where are the sources.
All the supporting companies are still listed as supporters on the official fourthird website. --Unsungheroz83 (talk) 08:37, 4 August 2009 (UTC)
replies: text: You were right to remove the paragraph. Contained mostly WP:Original research (e.g. "have seemingly distanced"). Unrelated: it seems you logged out between edits, that's a bit confusing.... Rror (talk) 12:31, 4 August 2009 (UTC)
replies: text:  Yeah for some reason my wiki occassionally logs out and I have no idea why. --Unsungheroz83 (talk) 07:05, 5 August 2009 (UTC)
thread_title:  Removed one of the disadvantages 

message: I think the paragraph about adapters for old mounts is too long, and the reference to a website on OM legacy lenses far too specialized (and non-notable in the WP sense) to bother mentioning.  I would suggest instead something like:
:Because the flange-to-film distance is small, lenses from other systems can often be fitted to Four Thirds cameras with simple mechanical adapter rings.
Comments? --macrakis (talk) 20:34, 18 January 2010 (UTC)
thread_title: Discussion of older mounts

message: Admitting to not being an expert on this up front, I wonder how much of this article makes sense when written in the present tense.
In the last 10-12 years, the resolution/size ratio of digital sensors has skyrocketed. We now have obscenely high pixel counts in sensors much smaller than any four thirds camera. Much of the "advantages/disadvantages" section here is just addressing the subject of small sensors, but that's general information applicable to any small sensor, of which there are countless varieties now, and I'm sure modern optics technology has far surpassed the resolution issues that might have affected these cameras in their heydey. As far as I can tell that was literally decades ago - dpreview says the last Four Thirds camera (from Olympus at least) was sold in 2011.
We would probably have to find newer external references to confirm and properly update this, which might be tough if nobody has bothered to do a retrospective on "the whole Four Thirds issue" (which I recall being a bone of contention between photographers for many years), but would it make sense to attempt to rewrite this article to make it clear that these concerns were in greater focus years ago when this technology was new? Gravislizard (talk) 20:59, 30 December 2021 (UTC)
thread_title:  Historical relevance, etc.