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New T5i vs old 400D , pics no better on T5i ?

Started Sep 9, 2014 | Questions thread
Rob Bernhard Senior Member • Posts: 1,872
18MP is not "almost twice the resolution" of 10MP

18MP is not almost twice the resolution of 10MP. A sensor has an area: length and height. For every doubling of MP you only get 40% more linear resolution.

The T5i sensor is 5184 x 3456. The 400D sensor is 3888 pixels x 2592 pixels.

The T5i has 33% more resolution of the 400D on the long side and 33% more the resolution of the 400D on the short side.

If you want to double the linear resolution you need to multiple both numbers by 2.

3888 * 2 = 7776

2592 * 2 = 5184

5184 * 7776 = 40MP

A 40MP sensor has twice the resolution of a 10MP sensor.

As others have said, looking at 200% views (in DPP or any other application) is not telling you anything about the images or the image quality. You need to look at the actual output: prints. If you don't print and only post to the web, then your comparison needs to be something other than pure detail. (Dynamic range, the ability to crop, noise levels, etc.).

You may also be interested in this article: http://www.gdanmitchell.com/2011/05/01/why-your-21mp-file-looks-softer-than-your-12mp-image-at-100

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