Jump to content

“1/2.3 – in., square-pixel CCD with primary color filter” what does it mean?


Recommended Posts

<p>I was considering a new compact camera and was comparing spec with D-SLR and compact but when it came to sensor size the D-SLR gave width and hight of sensor but with the two compacts I have been using it say “1/2.3 – in., square-pixel CCD with primary color filter” with Fugi and similar with Casio 1/2.5 and try as I will these figures don't seem to bare any relation to the focal length and the equivalent focal length for a 35mm film camera.<br>

Working on basis film is 24 x 35 mm giving a diagonal of around 42 mm I wrote a program which would show me how this related to a D-SLR and what an old for example Pentax lens would do with a new cropped sensor SLR. Since many gave the equivalent size I could also work back to give sensor size from the real focal length and 35mm focal length together with pixals the latter to give aspect ratio.<br>

Works it would seem A1 with D-SLR data but however I try to convert the compact data it just does not seem to compute. My calculator http://gw7mgw.co.nf/Camera-Lens.html is here it was at first rather simple but I just can't seem to find what that “1/2.3 – in., square-pixel CCD with primary color filter” means. If the area was 1/23 of an inch then it would be some where near but can't see both Casio and Fugi making a mistake with decimal point so has to refer to something I can't see.<br>

Eric</p>

 

Link to comment
Share on other sites

<p>Hello Eric,<br>

I can't help you with what "primary colour filter" means, whoever I do have a link that may help in understanding sensor sizes, their dimensions and aspect ratios. See here<br>

http://www.dpreview.com/glossary/camera-system/sensor-sizes<br>

See under the heading of "<strong>Sensor Type Designation</strong>" for an explanation of where figures such as 1/2.3" are worked out. It is not a straight forward diagonal measurement of the sensor - as you will read.<br>

Hope this helps.<br>

Laurie</p>

Link to comment
Share on other sites

<p>Hi Eric<br>

It is an antiquated standard from the 1950's based on the outside diameter of a video vacuum tube whose internal video sensor is about 2/3 the diameter of the tube.<br>

So divide out the fractional number e.g. 1/2.3 in = .435 in and that would be the size of that outside vacuum tube diameter to hold that diagonal size of sensor. Real helpful right.<br>

For the actual calculations I have seen two different approaches used by manufacuturers (the best I can tell)<br>

Approach 1<br>

- divide out the inch fraction of sensor spec e.g 1/2.3 in = .435 in<br>

- multiply by 25.4 to convert to mm<br>

- divide by 1.59 to find the actual diameter of the sensor in mm compared to mythical round vacuum tube diameter<br>

Approach 2<br>

- divide out the inch fraction of sensor spec<br>

- multiply by 25.4 to convert to mm<br>

- divide by 1.5 to find the actual diameter of the sensor in mm compared to mythical round vacuum tube diameter<br>

- This number actually represents the sensor diagonal if it were a square sensor with the same total area as the sensor in question<br>

<br />------------------------------<br>

Since there does not appear to be exact formulas that are an industry standard don't expect the numbers from each manufacturer to exactly represent the same think. The closest link for a reference that I have found is about Optical Format: http://en.wikipedia.org/wiki/Optical_format <br>

Hope his helps some.</p>

Link to comment
Share on other sites

<p>"Square pixel with primary color filter" sounds like the marketing department needed some more buzzwords... Nearly all sensors use a filter consisting of the three primary colors - the Bayer filter being the most common by far, but Fuji has a different one (Trans-X). Based on this description, could still be both, though they do use the Trans X designation in their marketing materials. <br />Square pixels - again the only one I can recall that did use non-square pixels was Fuji (Super-CCD or whatever it was called). Sounds to me like they're trying to say "Bog standard CCD with Bayer filter".<br>

Note that these sensors in compact sizes typically have a 4:3 aspect ratio, instead of 3:2 for film and DSLRs.</p>

Link to comment
Share on other sites

<p>hank you all I was beginning to think my maths was even worse than I thought. I could not believe how small compact sensors were and so was thinking I had made a huge error somewhere.<br>

Since the calculation is not a precise figure but just approximation not sure if really worth altering program to work with the approximate value. <br>

As to the way colours are done I have seen the normal and special sensor the latter to give high dynamic range and that was not a problem.<br>

I have seen such an improvement from my Old Pentax with CCD and my Nikon with CMOS I do realise how important the sensor is. However still love my Pentax I just feel at home with it.<br>

I inherited the Casio EX-Z600 and I have been rather impressed so small and easy to take anywhere. Always feel even the K10D Pentax says mug me and the Nikon D7000 with a Tamron 18 - 270 mm lens is really only used when I have some one with me. A few draw backs with the Casio EX-Z600 are no RAW files and no view finder and auto focus often fails to find the subject however the Nikon D7000 with the Tamron lens is not that good either I thought the Pentax K10D was bad until I started using the Nikon but I suppose with such a huge zoom only to be expected.<br>

My Father-in-law has the Fugifilm Finepix S2900 Series and I was impressed. Really odd manual warns about aerial erection and one wonders what that has to do with a camera? But I have got use to the idea of only a casual glance at the display when taking photos and any colour correction or similar can be done latter even if done in camera. I always take RAW pictures so was looking at the idea of a compact with RAW and a reasonable ISO and f-stop for the lens.<br>

The 4/3 has a lot going for it keeping the interchangeable lens option but my K10D has been a problem with dust. My own fault treated like a film camera and did not appreciate how careful one needs to be about dust and so not being able to remove lens does have some advantages the lens has never been removed from my Nikon D7000 and likely never will be.<br>

Seeing the size of sensor on a compact at least explains the poor ISO but the K10D is not that good only the D7000 has a CMOS sensor and a really good ISO capability. But in the main using a tripod I get away with the slow exposures. Although the Nikon sensor is really good the Pentax anti-shake leaves the Nikon well behind and so simply reading reviews does not really help.<br>

Main reason for Nikon and Canon is being able to hire a lens since I have no intention of hiring a lens there is really no need to pay the extra for the pair and money better spent getting a good camera. <br>

I expect it to be a few years before I buy but still try to keep abreast of developments. I was rather surprised at Nikon finding it would not work with CS4 even with CS5 it needed an upgrade to be able to read the RAW files but then I realised Nikon is 14 bit where Pentax is only 12 bit with RAW files. As to if the 2 bits really make a difference I don't know? But as a result I would not dream of converting Nikon RAW to DNG but have used the DNG save option with the Pentax.<br>

With so much to consider it will take years before I have the skill required to select the next camera I had the Ricoh XR7 45 years before I upgraded to the K10D and in the main selected as it could use all the old lenses.<br>

I still have a IBSOR D.R.P. bellows compact camera my dad bought for 6D in 1945 so I am a little slow to catch up with technology. <br>

</p>

<p> </p>

<p> </p>

Link to comment
Share on other sites

<p>Just not really related to your original topic, but to pick up on some of your points;<br>

It is a myth that dust mainly enters while changing lenses, and that superzooms are a remedy against this. All those superzooms extend considerably and push and pull quite a lot of air, and they're not sealed against dust (which is pretty much impossible anyway). A friend of mine with a long-range zoom after 6 months had loads more dust on his sensor than I had on mine - and I use primes and changes lenses pretty much all the time. Sensor-cleaning is simply part of the deal, and no big issue. Removing the dust-spots from photos is also easy with good software.<br>

Both K10D and D7000 are truely excellent DSLRs. Superzooms do not match their capabilities; I am convinced both your DSLRs are miles ahead of any compact. Just put on a better lens and you'll see.<br>

The difference between CMOS and CCD is mainly technical, and I wouldn't make a fuzz over it. It is not the main reason why one camera is better than another at high ISOs - the D7000 is simply about a generation later and high ISO performance of cameras accelerated a lot in those times; plus the D7000 is known to be an excellent high ISO camera. That doesn't make the K10D a poor performer in any way; it is actually quite good too.</p>

<p>Choose the camera you prefer using, and pair it with really good lenses. There is little use in spreading money over two different systems and not being able to get really decent lenses. Lenses are more important than the body (they last longer, and define more of your creative possibilities) - all the more reason to not cripple an excellent $1000 DSLR with a mediocre $400 superzoom.</p>

<p>As for Photoshop - the requirement to upgrade to get support for newer DSLRs - it has got nothing to do with 12-bit or 14-bit files, but it is simply a policy of Adobe. They end support and updates fairly quick after they release a new version, and as a result the older versions cannot read files from newer cameras. Unfortunately, nearly all software suffer these forced (paid) upgrades.</p>

<p>Do not make things too complex. Find a system that suits you best (by the sound of it: Pentax), invest properly into it, and get software that works with it and that you like working. All the technical details in the background aren't all that relevant in the end to make compelling good photos, so don't get lost into it.</p>

Link to comment
Share on other sites

<p>Thank you <a href="/photodb/user?user_id=5189561">Wouter Willemse</a> I had not really thought about the working of zoom sucking in dust but it does make sense. The Pentax was my selection as can use old lenses bought for Ricoh XR7 the Nikon was my sisters given to me by my dad when my sister died. As a result it's kept in the bag most of the time.<br>

Although I should know better when using the zoom lens with the Nikon the Tamron B008 18-270mm I tend not to realise how much I have zoomed in and go past the point where it can be used hand held. With the Pentax 28mm prime is hardly used mainly use the Pentax-DA 18-55mm which is only coupled lens. The 95 - 210 is rather old and like the 28mm using without being wide open is a lot of messing around. The 400mm pre-set is very basic but as a result very long which I find a great aid to holding steady where tripod is not used. With tripod it is connected to lens not camera. Also have bellows for Pentax K and reversion ring for 95 - 210 and close-up filters for Pentax-DA 18-55mm. Remote cable release and wireless release for Pentax plus 3 batteries (2 for Nikon) so yes the Pentax is used far more than the Nikon. So with Pentax still using lenses bought in early 1980's.</p>

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...