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Old Oct 28, 2004, 8:40 PM   #1
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I recently purchased the Panasonic Z20 and was very disappointed in the image quality. I did notice in Photoshop, and I believe Steve's Digicam's (or one of the other major camera review sites) EIF information on the gallery picturesthat the Z20's resolution is only 72 pixels per inch, even at the highest quality. My Canon G3 is 180 pixels per inch and that's a pretty old camera in tech years. Does anyone know if this is the reason why the pictures are so noisy. Any way to increase it? Thanks in advance!
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Old Oct 28, 2004, 8:49 PM   #2
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This question gets asked a ton.

I forget the whole deal, but it all boils down to that the 72dpi is a meaningless number. You can change it around to whatever you like and it does not change any of hte image. What really matters is the resolution (800x600, 1024x768, etc.)

I am sure someone here knows the details (I believe it has something to do about how large an image it will make, like 4MP picture will make 7x5 at xxDpi. Or something like that)



Anyway, that number makes no difference to how much detail is in your image



EDIT:

I found someone on the forum who explained it
Quote:
Originally Posted by Mikefellh
Until you get to printing, this number is really meaningless. 72dpi is a left over from the original Mac days, but an image will be taken and displayed the same way on a monitor whether it has a dpi of 10, 100, or 1000, becuase the image would still have the same number of pixels across and horizontally (say 1600x1200).

But when I go to print, that 1600x1200 prints different sizes depending on the dpi assigned to it, or if it's changed through the resizing option in photo editing software. For example, using that 1600x1200 dpi the way the camera took it at 72dpi:
At 72dpi it prints a 22.2x16.6"
At 180dpi it prints an 8.8x6.6"
At 300dpi it prints a 5.3x4"

That's the relationship. In my case with my 2mp camera that's what I get (which is enough for me for now). With changing it that way you aren't adding or subtracting information from the image itself, merely telling it how to print with the information already in the picture.
That post was foudn at http://www.stevesforums.com/forums/v...273&forum_id=9

hope this helps
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Old Oct 28, 2004, 8:59 PM   #3
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Anyway, that number makes no difference to how much detail is in your image



Wow! Thanks! I was always under the impression that the more pixels per inchthe smoother and more detailed the picture. I was praying that if there was a to increase the resolution in the camera, the better the pictures would be. Oh well, I guess I can't have it all. Thanks again for the info.
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Old Oct 28, 2004, 9:16 PM   #4
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jazzisit wrote:
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I recently purchased the Panasonic Z20 and was very disappointed in the image quality. I did notice in Photoshop, and I believe Steve's Digicam's (or one of the other major camera review sites) EIF information on the gallery picturesthat the Z20's resolution is only 72 pixels per inch, even at the highest quality. My Canon G3 is 180 pixels per inch and that's a pretty old camera in tech years. Does anyone know if this is the reason why the pictures are so noisy. Any way to increase it? Thanks in advance!
Are you saying that you are disappointed with the image quality because of the 72dpi? Or because of the way the images look?

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Old Oct 29, 2004, 12:34 AM   #5
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When you import a picture into Photoshop, its default is set to 72 pixels per inch (ppi). That's because most pc monitors can only reproduce images at this pixel density. A PC's monitor can not - literally, display beyond its own resolution (pixel density) capabilities. This has nothing to do with the camera at all. An image taken from any camera will be viewed at 72 ppi, since that's the max resolution of most monitors.

When you import and image into PC, using Photoshop (or not), it will size a 2 megapixel image - for example to 22 inches in width, 16.67 inches in height for a 1600 pixel X 1200 pixel image (by the way, 1600 pixel width X 1200 pixel height = 2 mega, or million, mega = million, pixels) If you divide 1600 (pixels)by 72 (your screen's ppi resolutions), you get a 22 inch wide image. Ditto for its height. The more pixels an image has, the larger it will be on your screen, not more detailed do to higher resolution. (Photoshop will reduce the image size in you monitor to about 33% so you can see what's goint on.) The larger a digital image file is, the larger it will be seen in your monitor. Just divide the number of pixels of the images width by 72 to determine how many inches wide. The image will not - can not, be more than 72 ppi.

This is why it's a farce to get a digicam with lots of megapixels if you mainly view your pictures on your monitor. A 1 megapixel camera is fine. You actually throw 75% of the pixels away if you resize a 4 megapixel image to a normal size - say 6X4, for viewing on a standard 72 ppi monitor.

Printing is another matter, however. When you resize an image in Photoshop for printing, you take the 22 inch wide image and shrink it to 6 inches, say, your pixel density will increase proportunately to around 267 pixels per inch for the image file sent to your printer.

This is not the same - however, as the dpi (dots per inch) your printer will reproduce the print. That depends on what your printer settings are set to. Think of the image file as "input resolution" and your printers dpi as "output resolution"

For all intents and purposes, 250 and above is considered "photoquality" input resolution for a digital image file. Any resolution gains above 300 ppi is considered nearly imperceptable to the naked eye from a normal viewing distance - that is to say, wasted. And, any image you see on your monitor will be 72 ppi image, since that's the max resolution your monitor can display the image, usually, depending on your monitor and how it's set.
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Old Oct 29, 2004, 9:15 AM   #6
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Thanks NickTrop! I think I wasconfusing ppi and dpi . Now if only I can print some decent pics I will be okay because I so want to keep this camera.
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Old Oct 30, 2004, 1:09 AM   #7
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NickTrop wrote:
Quote:
The more pixels an image has, the larger it will be on your screen, not more detailed do to higher resolution.
The larger the image is, the more detail it has. Resolution is detail.

If 2 shots where taken of the same subject. 1 at 1280 x 960 (1mp), and the other at 2560 x 960 (5mp), each detail in the larger image would consist of twice as many pixels as the smaller image. Thus have twice as much detail.

Don't get confused about all this ppi, screen resolution vs print size, dpi stuff. The plain and simple fact is the number of pixels that the image contains. Not how it looks in the camera, on the monitor, or out of the printer.

Fact of graphics...

Bigger image = more pixels = more pixels per detail = more detail

Smaller image = less pixels = less pixels per detail = less detail

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Old Oct 30, 2004, 1:34 AM   #8
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jazzisit wrote:
Quote:
I recently purchased the Panasonic Z20 and was very disappointed in the image quality. I did notice in Photoshop, and I believe Steve's Digicam's (or one of the other major camera review sites) EIF information on the gallery picturesthat the Z20's resolution is only 72 pixels per inch, even at the highest quality. My Canon G3 is 180 pixels per inch and that's a pretty old camera in tech years. Does anyone know if this is the reason why the pictures are so noisy. Any way to increase it? Thanks in advance!
I have been reading many reviews over the past couple of nights. I am doing this in an effort to actually try and find a better big zoom camera than the FZ20. I have looked at reviews of cameras that where over $1,000.00. Some had much bigger sensors and yet more noise, purple fringing, poorer image quality, or some other problems.

Every time I thought I found one, I found something in the review that was not as good as the FZ20.

The problems that the FZ20 has are... A little higher noise level... EVF/LCD darken in manual mode... Takes a little practice to focus... And thats it...

This camera was said to be one of, if not the best digital zoom camera on the market by a proffessional review.

I have posted over 250 posts on this site, and have read many more. I have posted many pictures as well, and all where from the FZ20, and all where straight out of the camera shots (no touch ups what so ever).

I also read a lot of complaints about the camera, but see no proof. I saw the noise comparison in a thread compairing the 10 to the 20. I know it's got more noise, but surprisingly even with the noise produces sharper and better images than the ones with less noise.

I say... Lets run some tests. If someone has an FZ1, lets see some pics at each ISO setting. And I mean straight out of the camera at 100% crop in low light.

If someone has an FZ10... Same thing.

FZ15... Same thing...

Lets put our pictures where our mouths are, and show eachother results. And if anyone has another camera they want to compare with the panasonics, post some pics and lets put all this stuff to bed so we can all go out and enjoy taking some pictures...

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Old Oct 30, 2004, 7:13 AM   #9
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bobc wrote:
Quote:

Fact of graphics...

Bigger image = more pixels = more pixels per detail = more detail

Smaller image = less pixels = less pixels per detail = less detail

bobc
Completely incorrect, Bob. Sorry, have to disagree:

1) Pixel ->density<- is what resolves image resolution, and allows for fine detail. How many pixels are there per inch?

2) Pixel density inversely related to - and determined by, image size. If you increase the size of an image, the pixels are less dense. Decrease the dimensions of an image, pixel density increases.

Now, why megapixels are overrated:

1. Beyond a certain pixel density, the differences become microscopic. That density - and it's really a "rule of thumb" is around 250 pixels per inch. Think of it logically, what detail of your picture is 1/250th of an inch? At this density, you need a microscope to see the differences. So, you can't actually see the differences in detail, however:

A. You spend way more money for more pixels to add invisible detail to your picture.
B. Increasing pixels without increasing sensor size results in noise. The noise comes from - literally, electronic interference cause by adjacent pixels on the sensor. They are too close to each other, and cause electronic interference when they are fired, just like your vacuum interferes with your TV reception when it gets too close. So, you spend more money, for a noisier image, to resolve detail you can't see.
C. In the case of PC viewing, you can NOT display an image that has a higher resolution than your monitor is capable of. If your monitor's resolution is the standard 72 ppi, it can not display a 300 ppi image. This is why digital images are measured in pixels, 1600X1200 pixels - never in inches or meters. When you resize an image to fit onto a computer screen you throw the pixels away. The 3500X2700 pixel image of your expensive 5 megapixel camera is reduced to an image of say 800X600 (that's even pretty large) to view on a monitor. How is the image reduced? The pixels are pitched, discarded, erased, destroyed. You could produce an 800X600 image with a sub-one-megapixel camera.

Bob - you know this!

The reason I say, take a look at the FZ-1 all the time, is that - as a consumer or hobbiest, you DON'T NEED ALL THOSE $&^@* MEGAPIXELS!!! Unless you make large prints, or do a lot of cropping where you will lose density. If you view mostly on a PC? You only need a "sub" megapixel camera. 6X4? Standard snap shot? 2 megapixels - that's it, for 35 mm photoquality resolution.

To your "put up" or shut up point. Here, take a quiz instead. Was the image below taken with a cell phone, a sub-one megapixel camera, 2, 4 megapixel camera or a 6 megapixel DSLR?



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Old Oct 30, 2004, 7:29 AM   #10
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Nick

Nice pic ! From that shot, from its size there's no way to tell what MP camera been used , no way a cellphone though !

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