why

[Ray]

Is it just to print a larger picture?

You got it in one.  

However, you should not draw the conclusion that a D60 has therefore no advantage over a D30 for owners of an A4 printer. There may be circumstances where substantial cropping of the image is required before printing and this could mean you are trying to get an 8x11" print from a 2MP image. In the same circumstances the D60 would give you 4MP to work on, resulting in a noticeably sharper print (all else being equal).

The smaller-the-pixel-the-greater-the-noise principle only applies when all else is equal. It rarely is. The D60 has lower noise than the D30, despite its smaller pixel pitch.

[george]

The previous posters probably covered your logical question about the "need for a "better" camera, say the D60". Your reasoning is valid, but you should also think what will happen if we keep increasing the pixel size? The pixel size of D30 is 10,2 microns (meters E-6). If we increase the pixel size, say for example, at 20 microns, we will not get lower noise. Increasing the pixel size improves noise, but reduces resolution.
It so happens, due to present technical improvements / limitations, that the ideal pixel size is somewhere between 6,5 and 8 microns. And that field covers the pixel dimensions for most popular dSLRs, D60, 300D, D70, D100, D1x etc.
regards,
George

[BJL]

it seems to me that all I gained was the ability to make a bigger print.

To twist it slightly, images that still look good when examined more closely: bigger prints, same size prints viewed more closely, more cropping from file to print, or all of the above.

About noise, a trend I have seen lately is that pixel sizes are often reduced and pixel counts increased about in step with improvements in technology so that there is little or no worsening of noise levels or of the camera's processing speed (frame rate etc.) Note the transition of the Canon 1D to "Mark II": more, smaller pixels, yet the same frame rate and about the same or better noise levels.

[lenzzzcap]

Thank you,
This was what I was looking for, some facts to work with. I am just not happy with my D60. And the only way out, without a divorce, is to swap off for a D30. Now I did like my d30 and only upgraded to the d60 because of hype, not in hand facts. I am leaning towards the 1600iso advantage of the d30 over the higher pixel count of the d60. These two seem to be the only cameras in the same price range. I would move on up if I could, but can't. The light is pretty bad here most of the time and the faster iso could be handy, but to crop out half of an image is pretty handy too. I wish I could just be happy with what I have. But NOOOOO!
Just in a want mood.

[BJL]

[font color=\'#000000\']I did read that the more megapixels, the more noise. ...[/font]

[font color=\'#000000\']cristianomc,

   mostly right I think, but I am bit unsure of some of your wording, so let me say it differently.

On one hand,
a) a sensor with smaller pixel pitch built with the same basic technology will give a worse signal to noise ratio at each pixel. Roughly, the S/N ratio would scale with pixel area.

On the other hand,
 technology has improved enough since the D30 that newer sensors of the same pixel size can have far better pixel S/N ratio, and new sensors with significantly smaller pixel pitch can have the same or better pixel S/N ratio than earlier models.

c) the effective S/N ratio seen on a print (or on-screen) depends on the size at which each pixel is displayed; printing the pixels smaller does some "smearing" or averaging of noise over nearby pixels, improving the S/N ratio. Roughly, once the pixels are printed small enough to be at or below the limits of the eye's resolution, perceived S/N ratio improves in proportion to the number of pixels per unit area on the print ("pixel density").

Items a) and c) alone suggest a rough balance in perceived noise levels on prints of a given size from sensors of a given size; doubling the pixel count halves the pixel area and rougly halves the per pixel S/N, but prints of the same size have about twice the print pixel density, roughly doubling the perceived S/N ratio, cancelling the previous halving.

Then item , technological progress, probably makes D60 prints of a given size better in perceived noise levels. Go to an even newer camera and it is probably no contest.[/font]

[bobme]

[font color=\'#000000\']

Of course, the 1Ds uses a CCD whereas the D30 and D60 use CMOS sensors which have to make room for additional processing components.

The 1Ds is CMOS too.[/font]

[lenzzzcap]

I am wondering. If a three meg camera, say a d30, gives me a great pciture at 10x15 then what would be the need for a "better" camera, say the D60. If 3mp works and Iget 1600 ISO, then what is the reason we all moved to the 6mp camera. Is it just to print a larger picture? Point is, I realy liked my d30 but went up to the d60 when it came out. A year later I am still confused about why I did it. I ony have 1000 iso and the noise is no better than the d30. so it seems to me that all I gained was the ability to make a bigger print.
Please tell me the reasons I did this, make me feel better. what is it that makes the 6mp camera, D60, a better camera than the 3mp.
I heard it said that a larger pixel is a good thing, that when the pixels get smaller you get more noise. If this is so and the sensor in the 30 is the same size asthe 60 then twice the pixels must make them smaller= more noise???

[lenzzzcap]

This is true. I was quite able to crop out a good half of the image in capturing football players. I could get 200mm close and then trim down further giving the effect of a longer lens. So what I would also trade off is the crop factor. I would not be able to zoom in like I do now unless I used interpalation, wich we all know the downfalls of. Thanks for the input. This would all be a mute point if I just had a spare 3,000 fr 1D

[BJL]

It so happens, due to present technical improvements / limitations, that the ideal pixel size is somewhere between 6,5 and 8 microns.

That range seems reasonable I suppose, but what is your basis for it? A lower limit based on adequate dynamic range, an upper limit from wasting lens resolution and having to work harder to control digitization artifacts like moiré?

I would put in a small voice for the possible value of smaller pixels if one accepts that this gives more resolution at a trade off of being more restricted in the subject brightness range and low light/high speed conditions that one can handle. The same sort of trade-off that one makes when using fine grained, high resolution, high contrast, low ISO slide films like Fuji Velvia.

[Sfleming]

Well ... if I had a top notch 600mm Canon lens and a Wimberly gimble  mount  I wouldn't need a 1Ds (or an Imacon back on a Contax or Hassy MF body).  But I don't.  

Compromise compromise compromise.

Someday I'll have a 1Ds Mk2 AND a 600 mm lens.  Then you will know my name.

[Ray]

Now I did like my d30 and only upgraded to the d60 because of hype, not in hand facts. I am leaning towards the 1600iso advantage of the d30 over the higher pixel count of the d60.

I don't think we've done a good job explaining the issues. I can't imagine any circumstances where a D30 would have an advantage over a D60. The advantages of the D60 are real - not hype.

I think part of your confusion might be due to the frequent use of pixel pitch for pixel size, and the methods by which reviewers such as dpreview compare the noise in different sensors.

I've never seen any published pixel size specs for any of the Canon cameras, but many months ago Michael R gaves us some actual sizes for the D30 and 1Ds. From memory, the total area of all 3M D30 pixels covers about 25% of the sensor. That is, whilst the pixel pitch of the D30 is around 9 microns, the actual size of the pixels is around 5 microns (don't hold me to exact figures). On the other hand, the actual pixel size of the 1Ds is very close to the pixel pitch, ie. virtually no space between one pixel and the next. Of course, the 1Ds uses a CCD whereas the D30 and D60 use CMOS sensors which have to make room for additional processing components.

For all I know, the actual pixel size of the D60 might be no smaller than that of the D30, or only slightly less. The main differences might be in the size of the additional processing components on the D60' sensor, allowing more pixels to be incorporated into the chip.

If you check out the dpreview comparison of the D60 and D30, you'll find that noise levels are very similar with the D30 having a slight edge. But this can be very misleading unless you think about what's really going on. Each of the sample grey squares in the comparison is exactly the same size on your screen. That means they are composed of the same number of pixels (90x80 I believe).

Pixel for pixel, the D30 might appear to have a slight edge, but in practice, when taking photos and making prints, the D60 gives you 2 pixels for every one D30 pixel, and the facts of life are; two D60 pixels (as a unit) are less noisy than one D30 pixel.

This leads us to the possible advantage of the D30 having a 1600 ISO setting as opposed to the D60's maximum of 1000. Don't let this fool you! Since we've already established that the D60 produces less noise, an underexposed D60 image at ISO 1000 with exposure compensation applied at time of conversion, should be no noisier (and probably less noisy) than a correctly exposed D30 image at ISO 1600.

[cristianomc]

[font color=\'#000000\']Ok, folks.... I did not understand anything....

I did't understand the noise question.

I did read that the more megapixels, the more noise.
Also did read that the reason you get less noise, and better dynamic range, is because the photosites for each pixel are larger and the larger photosites sites can gather more light, so less ampliation of the signal (which adds noise) is needed for an equivalent ISO sensitivity.

So the noise is connected with the size of the photosite and the sensor. But the photosite of the D30 is equal on the D60. So the noise is also connected with the size of the pixels in microns (dot pitch), correct? So, larger the dot pitch smaller the noise (less ampliation needed), smaller the print, and smaller the resolution (contrast, brightness, saturation)  right? Cause there's less pixels to build the image... And smaller the dot pitch larger the noise (more ampliation needed), larger the print, and larger the resolution (there's more pixels to build the image).

Is it correct?

Thank you all![/font]

[lenzzzcap]

[font color=\'#000000\']I couldn't have said it better. No, really. I couldn't.
Thanks that is the answer I wanted[/font]

[Ray]

[font color=\'#000000\']You're quite right. It's the 1D that has a CCD sensor.  [/font]