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Old Jan 23, 2007, 9:33 AM   #11
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Corpsy,
While that sounds like it should be true in theory, it isn't actually true in practice. (I realize you were hedging your bets by saying "will tend to have" - so I'm partially playing the role of devils-advocate here. I'm helping educate the readers with this position.)

A lot of things create noise and companies are getting quite good at reducing/supressing it. For example, the noise between the Canon 10D and the 20D between ISO100 & ISO400 were roughly equal (at least, to my memory - I took several thousand pictures with both cameras) but the 20D is a higher resolution camera.

On the other hand, I find the noise on the 1D MkII N to be worse than on the 20D, even though they have the same resolution and the 20D's sensor is smaller! So don't just go by the resolution, actually look at sample pictures online. www.imaging-resource.com is one of the old places I know that actually posts full-resolution images online for you to look at. That is really the only way to see what the noise will be at any given ISO.

I will say that I would be more likely to agree if the two cameras were released at the same time. In other words, all other things being equal, the camera with the higher resolution will have more noise. But in the real world, "all other thing being equial" is never true... other parts of the camera get better as well and help keep noise in check. And I certainly hope so! I look forward to the day that I can shoot at ISO400 at the same noise quality as I do now at ISO200.

Eric
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Old Jan 23, 2007, 11:19 AM   #12
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eric s wrote:
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....A lot of things create noise and ....
What are you referring to when you say noise?
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Old Jan 23, 2007, 8:38 PM   #13
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Compare the test photos on http://www.dpreview.com/reviews/sonyh5/page10.asp shot at ISO 1000 with http://www.dpreview.com/reviews/sonyh5/page8.asp shot at ISO 80. Look in particular at the photos with lots of dark areas such as the picture of the lens. The coloured mottled hash on the page 10 photos is noise.
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Old Jan 24, 2007, 11:30 PM   #14
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Eric, I'm not saying it's a simple rule that lower megapixels means less noise, but it is a rule that on different sensors built using the same technology, the one that has the most surface area per pixel will produce the least noise.

There are other factors that contribute to the amount of noise that appears, but often times the technology that goes into a sensor doesn't change until several generations of cameras have passed. It's why for Panasonic, the 6MP FZ20 has less noise than the 8MP FZ30, which has less noise than the 10MP FZ50, assuming you're comparing unprocessed RAW images. The technology for reducing noise in the processed JPGs has certainly improved over the years, but this is mostly irrelevent to more professional users who process RAW images for maximum quality and detail.

There are plenty of sites online that can explain the causes of image noise further. Here's one:

http://www.photoxels.com/tutorial_noise.html

"Each photosite itself generates electrical noise that can contaminate its neighbor. In a larger image sensor, the photosites can be physically further apart and thus be less affected by that contamination. "A larger image sensor also means that the photosite can be larger, thus have a larger light gathering capacity. It is therefore able to generate a larger signal to noise ratio.
"That is why a digital camera with 6 million pixels crammed into a 1/1.8 in. image sensor has more noise (especially at high ISOs) than a 6MP digital camera using the much larger half-frame (APS-sized) image sensor."
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Old Jan 25, 2007, 10:48 AM   #15
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4x6 print 2mp (any more does little to help image quality)
8x10 print 4-5mp (any more does little to help image quality)
16x20 print 18mp (any more does little to help image quality)

Lenses make a MASSIVE difference, camer resolution *sometimes* makes a *little* difference.

Cropping is an INVALID argument. You can only crop a THIN SLICE off a 10mp image before it's the same resolution as 6mp, plus the higher pixel density will show degredation from poor lenses earlier… so you might actually lose out going this route. There is NO substitute for getting it right in camera.

Noise between different TYPES (SLR, Compact) of cameras is significant, the differences between MODELS is minor.

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Old Jan 25, 2007, 11:23 AM   #16
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So how do Leica lenses rate?
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Old Jan 29, 2007, 1:02 PM   #17
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Corpsy,
I'm not talking about noise reduction software, I'm talking about different technologies put into the cameras themselves. Things like better insulation in the traces on the boards. Or better isolation of the sensor from the rest of the chips. Or better designs for getting the data of the sensor. I've worked in companies that made electronic hardware before, and spent much time with the people who design ICs. There are many things effecting noise in a digital image beyond just photosite size and density. That is a big one, but it is absolutely *not* the only one.

This is why even through there are smaller photosites on the Canon 20D, it has less noise at 200ISO than the 10D. Both of those cameras had *exactly* the same physical size sensor but the one with smaller more densely packed photosites had less noise! And the 1D MkII N has a larger sensor, with less-densely packed photosites (but the same resolution) compared to the 20D, yet the noise at 20D is higher in the "N" than in the 20D.

These examples directly *violate* what you're saying. That a camera with more densely packed photosites should have more noise. That is true, if everything else were the same in the cameras... but everything else isn't the same.

Eric
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Old Jan 29, 2007, 1:09 PM   #18
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Graphico wrote:
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So how do Leica lenses rate?
In general, they make very, very good lenses. They are usually quite expensive, but very good.

One of the problems that Canon is facing with their 1Ds MkII is that the sensor out resolved all but their best lenses (From what I've read.) In other words, the image is "lens limited" not "sensor limited" - the sensor can capture more detail than the lens can project on to it. And this is really a serious problem (if the megapixel race keeps going the way that it is.)

Good lenses are already expensive (more expensive than most people are willing to spend.) So ramping up the MP even more is not really worth it once you can't actually produce a lens that will resolve enough detail for it. Once it becomes possible to put 15 or so megapixels into a reasonably priced DSLR then things will get interesting.

Other than creative cropping (which tmoreau points out isn't the best reason if you're making prints) what will they do to separate one model from another? The images won't show any more detail (unless the lenses get better) so hopefully they'll start to work on something like capturing a wider range of darks and lights. Who knows?

Eric
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Old Jan 29, 2007, 6:43 PM   #19
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Eric, where do you get your information? The only site I've seen that compares those two cameras directly is here: http://www.dpreview.com/reviews/cano...kii/page19.asp

At high ISOs, the 20D does indeed have about half the noise of the 1Ds. It also has about half the detail level, quite consistent with images that have recieved a higher degree of in-camera noise reduction processing. It's consistent with comparisons of the Pentax K100d to Pentax *ist cameras, which use the exact same sensor but have less noise and less detail. There are many such examples out there.
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Old Jan 29, 2007, 8:12 PM   #20
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At high ISOs, the 20D does indeed have about half the noise of the 1Ds. It also has about half the detail level, quite consistent with images that have recieved a higher degree of in-camera noise reduction processing. It's consistent with comparisons of the Pentax K100d to Pentax *ist cameras, which use the exact same sensor but have less noise and less detail. There are many such examples out there.
I'm sorry, but I never suggested that a comparison be made between the 20D any of the cameras you listed in that paragraph (specifically the 1Ds, Pentax K100d to Pentax *ist cameras) or any other camera other than the 10D, the 20D, and the 1D MkII N. I don't know why you're suggesting that is what I meant (and I just re-read my post to make sure.)

I never comparied noise on the 20D to the 1Ds (of any version), nor did I say anything about comparing detail between the 20D and the 1Ds (of any version.)

If I'm missunderstanding your comments, then I appoligise ahead of time.

I get my information from a variety of places. Which information are you wondering about? The out-resolving?

The information about the 1Ds MkII out-resolving lenses came from an article on http://www.luminous-landscape.com, I believe (foggy memory, but my memory of the writing in it would fit the style of Michael Reichmann.)

A little searching turned up this article, that suggests that the 1Ds (the original) already was pushing that problem:
http://www.luminous-landscape.com/es...el-count.shtml
I seem to remember the comment refering to the 1Ds MkII, but I didn't see that article with some more searching on his site. Maybe I'm mixing up the bodies?

He isn't refering to the 17-40 or the 16-35, which are both good/great lenses (well, the 17-40 can have problems on the short end - but it seem to be sample dependent.) He's talking about putting a 28-135 on the camera. It's a handy lens, but it really isn't that sharp and eventhough its a "L" lens, it really isn't as good as either of those (and it shouldn't be, it costs a lot less.)

The 20D only has 8MP. I certainly would not suggest that it can out-resolve Canon lenses. If Canon couldn't make a lens which out-resolves the 20D, then it doesn't deserve to be at the top of the DSLR food chain.

So again, which comments of mine are you questioning? Then I can directly address them. If I'm wrong, I'd like to correct my memory/thinking. If I'm right, I'd like to defend my points. But most of what you said in your post are not reflected in what I said - so I don't know where you're coming from to comment properly.

Eric

ps. Just re-read your post. I know little about Pentax K100d and Pentax *ist cameras. It seems like you're saying that they use the same sensor, but one shows less detail and less noise. If it was just less detail, I might blame a change in lens quality. Instead it sounds like over-aggressive incamera noise reduction to me. I'm not talking about software ('cause I assume the difference is in a RAW as well.) It could easily be steps taken in hardware to reduce noise... which had the bad effect of reducing image quality as well. Pure speculation, I admit, but it would fit the points you made.
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