DPI/Pixe density

[Rawfa]

I was reading an article (http://www.sphoto.com/techinfo/dslrsensors/dslrsensors.htm) and the part about pixel density got me curious. The way they relate it to DPI (Dots Per Inch) gave me the impression that if you set the E-P1 settings to lower DPI should decrease the pixel density. I'm not too technical so maybe I got it wrong. Is this right? What I still don't really get is if it's good or bad to have high or a low pixel density. On another thread it was said that the DP1 was the winner because it had like 1.6pixel density...

"Pixel density is nothing more than the dpi (Dots Per Inch) rating of the sensor where each dot is an individual photo receptor on the sensor that will produce one pixel. Higher sensor dpi numbers = higher pixel density."

 

[kevinparis]

Rafa

You cant change the pixel density... that is locked in when the sensor is made.

General theory is that higher pixel density means smaller individual pixel sensors which are less sensitive to light so they have to have their signal amplified which leads to noise.

The reason why the D700 has such good High ISO performance is that the pixel density is low - only 12 million pixels in the area of a full frame sensor. On the otherhand something like a G10 crams 15 million pixels onto a much smaller sensor.

Changing the image resolution on the camera just gives YOU less pixels to play with - the camera always captures all the pixels it can

hope this helps

K

 

[pellicle]

this subject always seems to confuse so many ... here's my brief attempt to clarify it.

 

[pellicle]

reviewing that (written some time ago) I find one of my wishes is already granted:

So to Mr Camera maker, please, consider that not everyone wants ONLY a DSLR, and that if you put decent sized sensor in compact camera and give us back decent compact cameras, you might just sell more of them.

and when a GF 1 comes I'll have it even more granted

 

[Rawfa]

One fo the reasons why I asked is because I've found a DPI setting that can be changed on the E-P1. What will that do then? I know I use it when I want quality scans or prints, but camera wise I don't know what it does.

 

[woodmancy]

One fo the reasons why I asked is because I've found a DPI setting that can be changed on the E-P1. What will that do then? I know I use it when I want quality scans or prints, but camera wise I don't know what it does.

I thought that they gave you less DPI by summing neighboring pixels, in which case you would get less resolution but also less noise. I did not know you could do this on the EP-1, I'll have to try it.

Keith

 

[kweide]

That has NO influence on pixel density. It is a given fact frozen in silicium on the chip. You cannot alter that. The DPI settings in the menue is for matching print output only....

 

[barjohn]

If it provided pixel binning (the combining of pixels to reduce noise and improve signal) it would be beneficial. This isn't easily done and requires very sophisticated algorithms. Phase has such an algorithm for the P65+ which they hod a patent on (if I remember correctly). I think in the E-P1 they are just reducing the pixels in the jpg files to reduce file size. I could be wrong as I haven't tested it.

 

[kweide]

It is for print output only. I just checked it with the manual.... sorry no pixel binning !

 

[Rawfa]

So it has no influence what so ever over the IQ. Thanks guys. A good forum is like a good school