Reply to thread

Message

<blockquote data-quote="WayneF" data-source="post: 205717" data-attributes="member: 12496">To each his own, but my guess is you just heard someone show these numbers:D800:&nbsp;&nbsp; 36.3 mp,&nbsp; Image width 7360 pixels,&nbsp; Sensor width: 35.9 mm -&nbsp;&nbsp; density 205 pixels per mm.D7100:&nbsp; 24.1 mp,&nbsp; Image width 6000 pixels, Sensor width: 23.5 mm -&nbsp; density 255 pixels per mm.And 255 is more than 205, more density on the chip.&nbsp; &nbsp; Seemingly, this is the only number anyone wants to discuss.However, so what? Smaller pixels is just more noise.1.&nbsp; We don't/can't look at the chip.2.&nbsp; 36.3 mp is more than 24.1 mp&nbsp; (simply greater resolution in the image). You can't see effect of this?3.&nbsp; 7360 pixels width is 1.23x more than 6000 pixels (simply more&nbsp; pixels, more resolution, more detail, across the width of the image).&nbsp;&nbsp; You can't see effect of this?4.&nbsp; 35.9 mm width is&nbsp; 1.5x larger than 23.5 mm (needs less enlargement into any image that can be viewed).&nbsp; The DOF formula works from enlargement (and aperture and focal length, but NOT density).5.&nbsp; The DX 255 pixels per mm becomes only 170 pixels per mm after enlargement to same size as FX.&nbsp; The density per mm maybe be greater on the D7100 &quot;chip&quot;, but its image is smaller (objects occupy fewer mm), so there are instead FEWER pixels across its smaller object dimensions. Less detail, not more.6. If density is the foolish goal, then the Nikon Coolpix P310 compact point&amp;shoot camera specs are:P310: 16.1 mp, Image width 4608 pixels, Sensor width 7.66 mm - 856.9 pixels per mm.&nbsp; Wow!&nbsp; 856.9 pixels per mm!&nbsp;&nbsp; We should try that one.&nbsp; <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile&nbsp; &nbsp; :)" loading="lazy" data-shortname=":)" />&nbsp; &nbsp; But it has to be enlarged about 5.6x more.&nbsp;&nbsp; This is only 153 pixels per mm after enlargement to same size as FX.&nbsp; And there are also other factors, like noise and poor high ISO performance, due to the tiny pixels.So chip density is wrong thinking. The good stuff is about pixel size and count instead.&nbsp; Chip density can be counter productive.&nbsp; I would instead suggest more resolution, more pixels instead.FX does use a longer focal length than DX, and DX is longer than compact (to fill frame with same view).This longer lens does reduce FX DOF, but it does not reduce resolution.Small sensor sizes reduce resolution.</blockquote>

[QUOTE="WayneF, post: 205717, member: 12496"] To each his own, but my guess is you just heard someone show these numbers: D800: 36.3 mp, Image width 7360 pixels, Sensor width: 35.9 mm - density 205 pixels per mm. D7100: 24.1 mp, Image width 6000 pixels, Sensor width: 23.5 mm - density 255 pixels per mm. And 255 is more than 205, more density on the chip. Seemingly, this is the only number anyone wants to discuss. However, so what? Smaller pixels is just more noise. 1. We don't/can't look at the chip. 2. 36.3 mp is more than 24.1 mp (simply greater resolution in the image). You can't see effect of this? 3. 7360 pixels width is 1.23x more than 6000 pixels (simply more pixels, more resolution, more detail, across the width of the image). You can't see effect of this? 4. 35.9 mm width is 1.5x larger than 23.5 mm (needs less enlargement into any image that can be viewed). The DOF formula works from enlargement (and aperture and focal length, but NOT density). 5. The DX 255 pixels per mm becomes only 170 pixels per mm after enlargement to same size as FX. The density per mm maybe be greater on the D7100 "chip", but its image is smaller (objects occupy fewer mm), so there are instead FEWER pixels across its smaller object dimensions. Less detail, not more. 6. If density is the foolish goal, then the Nikon Coolpix P310 compact point&shoot camera specs are: P310: 16.1 mp, Image width 4608 pixels, Sensor width 7.66 mm - 856.9 pixels per mm. Wow! 856.9 pixels per mm! We should try that one. :) But it has to be enlarged about 5.6x more. This is only 153 pixels per mm after enlargement to same size as FX. And there are also other factors, like noise and poor high ISO performance, due to the tiny pixels. So chip density is wrong thinking. The good stuff is about pixel size and count instead. Chip density can be counter productive. I would instead suggest more resolution, more pixels instead. FX does use a longer focal length than DX, and DX is longer than compact (to fill frame with same view). This longer lens does reduce FX DOF, but it does not reduce resolution. Small sensor sizes reduce resolution. [/QUOTE]

Verification