Larger size picture = worse quality?

[Braveheart]

Another newbie question. :)

I noticed when I take the biggest size pictures with any digital camera, and view them on my PC, they appear very poor quality, not sharp at all.

Now when I view this same picture but 50% of it's original size, it apears a lot more sharp.

Could somebody please explain this to me?



I already asked similar questions a few threads below, but I still dont get it. Shouldnt the largest picture have the best quality? yet most of the higher end cameras producerather poor quality pics when viewed at full size, which sucks because in order to see the pics CLEAR, I have to view them all at 50% of their size, or less.

[Morden]

It's probably just an effect of the way the software on your PC is reducing the images to fit on the screen. At some sizes, it will work well, at others, it won't. You might get blurring, moire patterns, jagged edges and other artefacts, If you can view the images 'actual size', they should look fine.

If the larger photos print OK, there's no problem. :)

Hope this helps.

Neil D.

[henkbos]

OK, here we go: the size of the picture is not THAT important, it's the resolution. If you view to pictures that have the same size on SCREEN but one has twice the resolution as the other one, you WILL see a difference, unless the size on the screen is too small to note that difference.
BUT: that ALL pictures need some form of processing onthe PC. One part of this procedure is sharpening of the pic. Have a look at Fred Miranda's or Roger Cavanaugh's websites. They will give examples.

Good luck!

[Gibbs]

Assuming that the image has been correctly taken (exposure, focus, etc.) the lack of sharpness on the monitor will be the result of the image reduction applied by the software in order to fit it onto the desktop for display. This will be particularly apparent on diagonals which will display 'jaggies'. These will disappear when the image is viewed at 'actual size'.

[Braveheart]

Nope, even when I view the pictures taken by pros, and view them in full size, meaning I have to scroll up and down, side to side to see it all, the picture is not clear at all, only when you reduce it 50% it becomes very crisp and clear.

[Gibbs]

Strange.

One would assume that most 'pro's' would never put soft work on the net.

I would imagine that it has to do with your monitor resolution, dot pitch, and other wonderful issues like that. Do a test - get one of these images professionally printed and see if it is still poor.

[Braveheart]

When I say pro, I mean the sample images I looked at here:

http://www.dpreview.com/


and



http://www.dcresource.com/



Maybe it is my monitor or my Video card, which is not that good I might add.

[Gibbs]

OK - got ya.

Do remember that any stuff you are viewing on the net will tend to have been heavily reduced to allow it to load up quickly. Typically some of these files will only be about 40 - 60k in size.

The key question is - are the pictures you are taking at a high res on your G2 appearing soft when you view them. If not - then blame it on the Internet.

[Braveheart]

Gibbs wrote:
The key question is - are the pictures you are taking at a high res on your G2 appearing soft when you view them.

Unfortunatelly they do appear soft, not sharp. :(

[dn7elson]

Take a look at the EXIF data in either the image or as listed. You will find that the images are at 72 dpi (compared to the G2 180 dpi) with high compression. The 3.5MB file has been reduced to 213k and likely reduced in size too.

This is typical for web images as those without broadband connections don't want to download 3.5MB images just to take a look.

You need to make sure that you have all the details to go along with the assumptions ;)

[Braveheart]

dn7elson wrote:

You need to make sure that you have all the details to go along with the assumptions ;)



I do know what you mean, but you have to understand that details mean nothing when it comes to EYES. My eyes are enough to tell me if the picture is good or not.

[phogy]

Since the sensors found in today's digital cameras (excluding the Sigma SD9, released yet?) interpolate the GRGB-pixels the 'full resolution' pictures will look soft. Interpolation always introduces softness, that's the whole point.

When shooting at the maximum resolution your camera is capable of, this softness due to bayer interpolation is more obvious than when shooting in lower resolutions.

Braveheart's eyes are correct; images look sharper at 50% since it takes 4 'photo detectors' (referred to as pixels when we say 'mega pixels') to fully describe the color of one RGB pixel. This is where the Foveon technology has its advantages: each 'photo detector' is in fact a full RGB pixel. Hence the term 'mega pixels' will actually mean 'mega pixels' and not 'million photo detectors'.

[Braveheart]

phogy wrote:
Since the sensors found in today's digital cameras (excluding the Sigma SD9, released yet?) interpolate the GRGB-pixels the 'full resolution' pictures will look soft. Interpolation always introduces softness, that's the whole point.

When shooting at the maximum resolution your camera is capable of, this softness due to bayer interpolation is more obvious than when shooting in lower resolutions.

Braveheart's eyes are correct; images look sharper at 50% since it takes 4 'photo detectors' (referred to as pixels when we say 'mega pixels') to fully describe the color of one RGB pixel. This is where the Foveon technology has its advantages: each 'photo detector' is in fact a full RGB pixel. Hence the term 'mega pixels' will actually mean 'mega pixels' and not 'million photo detectors'.




Ok, this sounds like the answer I was looking for, but you are too technical for me, I do not understand these terms and technology that good so could you please put it in more simple "for dummies" explanation? If possible :) hehe

please.

[phogy]

I'll give it a try ;-)

The photo sensor found in digital cameras (the digital 'film') is color blind. (Now, Foveon is a new technique that isn't but we'll put it aside for now.)
Okay, but you still get color images out of it, right? The magic is in the red, green and blue filters. (Some cameras use yellow, cyan, magenta and green filters). Every photo detector (a 4 MP camera has approx. 4 million photo detectors) is still color blind, but when seeing the world through a red, green or blue filter, it registers the red world, the green world and the blue world. As you know, red + green + blue is white, and RGB images are no news either - your color tv, computer screen etc is made up of tiny red, green and blue elements that your brain interprete as one full color dot.

I'll take the G2 as the example now. The CCD has 1 million red filtered pixels, 2 million green and 1 million blue. Since 3 is an odd number, one color needs to be over represented to make the whole thing even up. Choosing green as the over represented color is no coincidence, the green light defines contrast better.

Okay, I hope I'm not too technical so far. Anyway, these 1+2+1 mega pixels are about to define a 4 mega pixel full color photo. To achieve this, each full color RGB pixel in the final photo must be calculated from, at least, three surrounding red, green and blue pixels. This is the Bayer interpolation, I don't know how it works in detail, but this is what it does: It combines the 1+2+1 mega pixels to a 4 mega pixel photo.

To perhaps understand this a little better: Had the 1+2+1 mega pixels been monochrome, that is no color filter applied, you would have a sharp image (as sharp as the lens/focus etc allows) at 100%. Imagine averaging each pixel from the value of 3 surrounding pixels, and you end up with a softer image. This is exactly what happens in the color case.

[newpoint]

I had the same problem. I am also very new to digital photography. I had called the Canon support and they told me that the photo is probably at it's highest quality but it really depends on the monitor. My NEC LCDmonitor is great at 1280x1024 but then the pictures get a little fuzzy. I was ready to give the camera back but the Canon group said if the monitor was even bigger and higher quality I would see the difference. Also, he said it to print it poster size and it should be OK..I will have to try that and see.

[dn7elson]

We have a lot of apples and oranges going on here.

The specific references to images were to web reduced resolution and increased compression. Both lead to vastly reduced sharpness, clarity and detail.

Then there is the esoteric (albeit generally factual) discussion of the color mask vs. multi-color pixels. This also has to do with ultimate sharpness of images, but is not really the issue with web adjusted images (reduced resolution, color depth and/or increased compression) that allow for less required bandwidth, storage space and download time.

Then of course there is the viewing hardware. You will generally not get the best nor sharpest image on a low end monitor (regardless of size) or a video card that excels at 3D but blurs 2D images such as photographic images.