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Old May 28, 2003, 1:48 AM   #11
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Dizzy and Eric (and everyone else) I realy appreciate the extra effort you went to in answering my questions, all the extra info you gave me helps a lot and I'll read it over and over again till it sinks in, (I always thought an image looks better on the comp than a print out even though it has less resolution)

Like I said I'll copy all this info and read it again to make sure I understand it all, It's so anoying when you don't know the answer to something and you are afraid to ask because you don't want to look stupid, but coming to these forums and asking people who know these things helps so much and it's great to be able to get the answers you need without feeling dumb :shock:

again thanks very much for your time and effort in answering my questions,

Steve
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Old May 28, 2003, 5:55 AM   #12
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Quote:
Originally Posted by Colt-45
(I always thought an image looks better on the comp than a print out even though it has less resolution)
That's not unusual as you are dealing with two colour models (methods of generating colour). On the print you start out with white and you add pigments of cyan, magenta, & yellow, and when those three are mixed together you get black...on the monitor you start out with black and you add coloured "lights" of red, green, & blue, and when those three are mixed together you get white.

I have a lightbox that I use for looking at slides (rather than holding up each slide to a lightsource), but if you print a picture on normal copy paper, and put it in the lightbox it makes the colours much more vivid, and if I'm having guests I would to that and hang it on the wall as a converation piece.
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Old May 28, 2003, 9:24 AM   #13
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Just to further clarify - the screen uses a different method of generating colours to the printer. But that has nothing to do with clarity and resolution. It just means that the colours on a screen look better.

Screens use light to generate colours using what is known as an "additive" process. The screen is naturally black, and the more lights you mix together, the brighter the colour gets until it becomes pure white.

Printers use ink to generate colours using what is known as a "subtractive process" meaning they start out with a white page and the more colours that are printed onto the white, the darker it gets until it becomes pure black.

So screens and printers are the exact opposite, One starts out black and gets brighter, the other starts out white and gets darker.

All the colours on a screen are generated with different combinations of red green and blue (these are known as the primary colours).

Whereas all the colours on a printed page are generated with different combinations of cyan, magenta and yellow (these are known as the secondary colours).

You can get black by mixing all three secondary colours together, however, in printing, black is always used as a seperate fourth colour, because it's a very commonly used colour so it saves on ink. And also, most text is black, so it needs to be very sharp, which it wouldn't be if all the black were made out of three different colour processes, because they are usually slightly out of alignment.
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Old May 28, 2003, 9:33 AM   #14
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Originally Posted by lg
Take into consideration also the magnification of the image on the CCD. All other factors being the same, at full zoom, a 2MP camera with a 10x optical zoom will provide a better image than a 3MP camera with a 3x zoom even if the 3MP image is enlarged and then cropped.
I don't actually understand what you're saying here. Can you clarify for me?
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Old May 28, 2003, 11:27 AM   #15
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What he is trying to say is that a long lens will put more pixels of a distant object than a (cropped) image taken with a shorter lens. It really has nothing whatsoever to do with zoom - take a look at the brief note at Imaging Resources about on 3x zoom http://www.imaging-resource.com/NEWS/1047935077.html

Looks like an interesting camera, but I'd like my 3x to go from 8-24mm (equiv).
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Old May 28, 2003, 12:15 PM   #16
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Mike and Dizzy, thanks for the extra info, every bit extra helps me so much, I realy appreaciate it.
I know a lot of this would be resolved by just doing some test printing but that's a bit of a problem for me right now as I don't have a printer , so i guess I have a lot more research to do on that as well before I buy

Thanks again

Steve
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Old May 28, 2003, 12:26 PM   #17
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Quote:
Originally Posted by BillDrew
What he is trying to say is that a long lens will put more pixels of a distant object than a (cropped) image taken with a shorter lens. It really has nothing whatsoever to do with zoom
Aren't zoom and focal length the same thing?

I'm still not 100% sure what this means. Are you saying that cropping a 2272x1704 photo down to 1280x960 is not the same as a 3x zoom?

How can that be?

Assuming there are no jpeg artifacts on the image, it should be identical.. right?

My camera is 3x zoom, but I consider it to be 9.5x zoom if I crop the photo down to 1280x960.

Colt, I don't have a printer either. I've never needed one.

Maybe when I get rich I'll buy a really good one. But most the printers on the market don't appeal to me at all. I'm fussy about print outs so I'd rather do without. For now.
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Old May 28, 2003, 12:47 PM   #18
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Col45, I don't think I actually answered your question effectively yesterday.

You asked how come if photos look perfect on a big computer screen, why can't they be printed out at that size.

I gave you a lot of "interesting" technobabble explaining that computer screens are much lower resolution than print outs, and not very precise. But I forgot to actually answer the question.

The answer is that it is kinda a trick of the eye. Although images may seem very crisp and clear on your computer screen, the screen really is incapable of showing images at the level of detail of a printer. But because you look at that computer screen all the time and you're used to seeing it, you are not aware of how "bad" the picture is.

It's a bit like this... when you look at the black on this screen, it seems very very black. But really it's not that black. There are much blacker things. But when you're looking at the screen your brain is telling you that that is "black" because you know that that's as black as it can get.

In the same way, your brain says that a good quality photo on a screen is "very good quality" because it knows that that's as good as it can get.

You probably know yorself that the images on a computer screen are much crisper and clearer than images on a TV. But if you look at pictures on a big TV, they still seem good quality. Even though we know that they can be much better.
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Old May 28, 2003, 1:54 PM   #19
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Again Dizzy thanks for the extra info, and don't worry about the answer you gave me yesterday it was great, it helped me a lot to understand these things, that's true about being used to seeing an image a certain way and thinking it's good even though it's not as good as it can get, I would realy need to see a side by side comparison to realy see the difference, similar to a film pic taken with a "cheap" lens and a top of the line lens.

I'm wondering if I was to print out a pic at the same size and resolution as I have on the screen (is it 72 or 120 DPI?) would it look the same or close to it?

You said you don't have a printer, do you have any of your images printed? or do you just have them on your comp?

Thanks for all you answers, they help a lot

Steve
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Old May 28, 2003, 3:20 PM   #20
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Quote:
Originally Posted by Grand Dizzy
Aren't zoom and focal length the same thing?

I'm still not 100% sure what this means. Are you saying that cropping a 2272x1704 photo down to 1280x960 is not the same as a 3x zoom?
No it isn't the same thing. Even negleting the difference in resolution, that change would be an effective increase in focal length by a factor of 1.775 - the ratio of the linear dimensions.
Quote:
Originally Posted by Grand Dizzy
Assuming there are no jpeg artifacts on the image, it should be identical.. right?
No - beyond any JPEG artifacts it will be lower resolution
Quote:
Originally Posted by Grand Dizzy
My camera is 3x zoom, but I consider it to be 9.5x zoom if I crop the photo down to 1280x960.
You might consider it to be a 9.5x zoom, but no one else would.
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