What is a Pixel ?

[Eifion Williams]

Pixel : Basically, pixels are the amount of dots used to cover an area. Pixels are stored on the sensor inside the camera.
Manufacturers use different sized sensors and different amounts of pixels, with most cameras these days having 6 million or more which is plenty to produce a print of A4 size.
The problem now in my opinion is that the race to get as many pixels as is possible has gone too far, and sensors which were initially designed to take 6 million pixels are now being crammed with well over double that amount, with picture quality suffering.

Please feel free to comment. :camera:

[TonyHoward]

I guess that one is simply looking at a moment in time in the evolution of the digital sensor. There is a good section on sensor technology and its relationship to noise production in this quarter's EOS magazine for those that subscribe to it. It highlights that image quality is delendent on a range of factors that include the nature of the pixels, the number, the microlenses above the pixels, the pixel size, the sensor size, the electronics surrounding the pixels and the quality of the processor. I have three canon cameras with megapixel numbers ranging from 8.2 to 21.1. The image quality and noise performance improves as the pixel numbers increase; however, I suspect that this is a resultant of all of the factors mentioned above rather than a direct relationship to pixel numbers alone. What I have appreciated though with the increase in pixel number is the extra editing capacity it provides and, particularly the ease with which one can print cropped images in large format.

[Paul Smith]

it was certainly interesting that Canon scaled back the G11's pixel count from the G10. They've also kept the new 1D mk IV at a reasonable 16MP on an APS-H (1.3 crop) sensor. This to me says they know that the pixel density on the 50D and 7D are on the high side.

The other area that I'm constantly amazed at is ISO. My 30D only goes to 3200 and is pretty useless above 800. I notice Canon and Nikon now go to 102,400 which is staggering. Even more amazing is the results that you actually get at something like 6400. Take this new short film shot on a 1Dmk IV at 6400 using only available light.

nocturne (http://vincentlaforet.smugmug.com/Laforet-Videos/Nocturne-Canon-1DMKIV-Video/10024122_sqhwE#686345820_EeDCa)

[Marian J]

Not sure about the cramming pixels into a space originally designed for less (I am not vey techy), but can say that as I have progressed up the pixel count ladder my pictures have improved :) (for some reason i am now thinking 'it's not about size, it's what you do with it' ) and the reality is that if you are a crap photographer then you can still take a crap pic with the best equipment.

It is about the ability of the sensor to resolve detail; more pixels = greater ability to resolve detail. This resolving ability needs to be matched by the lens resolution, which can be lacking in kit and 'less expensive' lenses. Unless you use the best glass then the results might not be significantly better than you would achieve with a sensor with a lesser pixel count.
(sooooo....... I now need L lenses ;))

But until there is a major step forward in lens technology, I think that the pixel count for sensors has probably gone as high as it needs to .....

[Lee Iggulden]

HUH ;) !!!

Think I will stick to having "ideas" much simpler :) Even if it does create more "Work" for me.

[JohnTudor]

It seem to me to be Canon and Nikon that are upping the pixels in ever new camera, for me they should be working on fps,

As for lenses all us canon users know that canon make the best! :D

[Paul Smith]

I think Canon are quite keen to separate the studio and wildlife/sports bodies and only appear to be obsessed with fps on the crop bodies.

Oh and another vote for L glass being lovely. One day I'll get the body to use it to the full.

[TonyHoward]

Paul mentions Canon's reduction in pixel count from 14.7m to 10m on the same size sensor in moving from the G10 to the G11 (plus providing larger diodes and advances in analogue-to-digital signal processing). An interesting technical review in JBP (21/10/09) analyses the consequences and provides some useful light on the topic of this thread. It concludes that the new sensor provides significantly better noise control through all ISOs than the earlier versions. The downside is that resolution is decreased at base ISO (100). This prompts some concern regarding future applicability for stock photography. As always, life is a compromise.