Reolution and sensorsize

[hoogw photo]

<p>For the pocket I bought a camera, but with the small sizes of the sensor, you mostly get free noise with them.<br>

I have a camera with 12 m pixels, but its possible to reduce it to 8 m or 5 m. When i take pics I notice that the picture has the same contense, but the resolution differs ofcourse. My question is:<br>

Does the camera use then the whole sensor or just a part of it? The crop factor seems the same, so does the camera combine several pixels to one? In that case is it possible to have less noise?</p>

<p> </p>

[Mattman944]

<p>The worst effect of the P&S megapixel wars is to clog up everyones harddrives with unnecessary data. The tiny lenses and sensors cannot resolve 10 megapixels. So, your idea is a good one. The good quality 3 megapixel camera my wife uses takes better pictures than the 10 megapixel camera I won as a prize.</p>

<p>Depending on the algorithm they used, when the camera downsizes it may reduce the noise some. Averaging nearby pixels will average out some of the noise. But, starting with full resolution and downsizing yourself is mostly likely better. </p>

<p>When buying a P&S, a quick way to estimate image quality is the diameter of the lens. Bigger lens equals bigger sensor. </p>

[Spearhead]

<p>What camera are you using? Is the reduced image the result of a lower jpeg setting?</p>

[bill_tuthill]

Most P&S cameras simply downsample the smaller (fewer megapixel) images from the largest size. In the majority of cases, you can do better with good downsampling software such as Photoshop or GIMP. Some, such as Fuji EXR, do pixel binning that actually improves results at lower megapixel settings. Several Panasonic cameras use different portions of the sensor for various aspect ratios (2:3, 4:3, and 16:9). I do not know of any P&S cameras that use a much smaller sensor area for reduced size.

 

SD cards and DVD blanks are cheap now, so I believe it's best to shoot at largest size with maximum JPEG quality. It is true that most P&S images are just as good downsampled 50% then upsampled 200% as they are at original 100%. In other words, too many megapixels for the actual resolution data. Smaller images are also easier to email and view from email.

[henryp]

<p>Interesting sensor-size article in today's NY Times:<br>

http://www.nytimes.com/2010/12/23/technology/personaltech/23pogue.html</p>

<p>Henry Posner<br /><strong>B&H Photo-Video</strong></p>

[hoogw photo]

<p>Thank you all for your kind response.<br>

Just for the pocket I bought Lumix TZ8 (12MP), because of the lens. I searced fo the TZ7 (10 MP), but they were sold out.<br>

Mathiew and Bill, now I understand what they are doing with the pictures. I wished that all manufacturers used the Fuji EXR system. <br>

Fuji used longer the 1/1.7 sensor (F11) at a comfortable price, and only the more expensive LX5, S95, use something like that. Too many pixels on too little sensors.<br>

My wife made pictures with the D40 (6 mp) at the Philipines and its was surprising that they are better than my D80. Except the cropping.<br>

Conclusion: Maybe I had to buy the Fuji FX80 EXR for less noise.</p>

[scottelly]

The 12 megapixel Nikon D2x shoots 5 megapixel photos in "crop" mode, and the D3 does something similar, but

those are the only cameras I know of that do what you're talking about. And that is for shooting "zoomed" and faster (8

fps instead of 5 fps on the D2x and 11 fps instead of 9 fps on the D3) instead of for just making photos that take less

memory on memory cards, though that is a positive side affect. Those two Nikon DSLR cameras are in effect shooting

with a much smaller sensor by using only about half their sensor for capturing photos when in "crop mode" - weird

huh? Of course, in the D3 it's like switching from a fast full-frame sensor camera that shoots 12 megapixel photos to a

super-fast D70 in a bigger body - not so bad at all. It's a little different with the "crop mode" in the D2x, since you're

starting with a 1.5 crop factor sensor (APS-C).

[bill_tuthill]

Jan, the Fuji F80EXR has been replaced by the F300EXR, which is better in almost all respects.

 

Thanks Scott, I forgot about DX mode in Nikon FX cameras.