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3G iPhone could arrive overseas by early 2008 - Page 3

post #81 of 91
Quote:
Originally Posted by TenoBell View Post

The more MP they squeeze onto a sensor the ASA sensitivity can go down if not supplemented with faster lenses and better digital processing.

With more MP you will take a larger picture but that does not automatically translate into a picture with more sharpness or detail. You need a proper lens that can resolve that detail and digital processing that can maintain that detail.

MP numbers don't linearly translate as to what is better or worse. Two sensors with the same number of pixels don't necessarily provide the same quality.

yes yes , we all know that more mp's doesn't necessarily mean better quality photos,
BUT IT USUALLY DOES

camera manufactures are always improving their products,
so mp's go up
data transfer rate goes up
sensor density goes up
features go up
etc etc

i see an improvement in mp's (which is the only advertised measure of it's " performance ") and know that there are improvements to handle the extra megs
post #82 of 91
Quote:
Originally Posted by iconsumer View Post

nice

i thought a noob is something u you put on a sprout

You're right! - that must be it, I'm a noob of butter!

well thats a relief, I have been called far worse than that
post #83 of 91
Quote:
Originally Posted by JDW View Post

While this line of discussion is quickly getting off-topic, I will say this: most digital "consumer level" cameras are junk. I've not seen a serious competitor to my Canon PowerShot G5 to date, and the G5 is far from new! The manufacturers are putting out the first technology the see to grab dollars. They are not putting out better quality. They keep adding more MP's to tiny little CCD's. The average consumer is mislead in thinking this is better than older cameras, so they shell out the cash. I've got friends here in Japan that shell out the cash for almost every new model of a given brand they like, but the quality isn't getting better despite those pixels and fancy NR engines. The solution is NOT better processing to filter the noise, nor is a better lens. The solution is a bigger CCD -- which is what the pro cameras have. This is why a 5MP cell phone is largely irrelevant to me. The CCD is so tiny anyway, by the time you get to 5MP or higher, you lose pixel data to noise. For more information on the subject, direct your browser to the following site:

http://www.dpreview.com/

Totally.
post #84 of 91
Quote:
Originally Posted by iconsumer View Post

...i see an improvement in mp's (which is the only advertised measure of it's " performance ") and know that there are improvements to handle the extra megs...

Usually. One needs to do their homework nonetheless for prosumer/ pro/ enthusiast stuff. 8)

NOW ALL OF YOU GET BACK ON TOPIC BEFORE WE ALL GET A GOOD SPANKING !!!11!!
post #85 of 91
Quote:
Originally Posted by gregmightdothat View Post


I'm not really sure what you mean by "faster lenses" and how they're relevant here. Are you referring to shutter speed?

Even cheap plastic lenses have quite a bit of resolving power. That said, in the short term, lenses will always be sharper than the sensor.

You're right about the digital processing, at least on cellphones. I'm always pissed off that my RAZR decides to save all photos with the lossiest, blockiest JPEG compression possible.

However, more megapixels, properly handled for in terms of lenses and processing, is always better, unless file size is an issue.

A lens' speed is the ratio of its maximum aperture to its focal length. The speed is usually represented by an f number such as f2, f2.8, f3.5, etc. A 'fast' lens is one which has a wide maximum aperture relative to its focal length. The wider the maximum aperture the more light can be let through. With a wide aperture, more light is being let through so you can use a faster shutter speed. So the terms 'speed 'and 'fast' are really refering to the shutter speed.

If you have a lens with a focal length of 200mm and the maximum aperture is f3.5, then the diameter of the front lens will be 'roughly' 57mm. Now if you want a 'really fast' 200mm lens, say f1.8, the front lens will have to be about 111mm in diameter! The cost of such a lens can be more than a car, if it is for a 35mm film camera!

fast is good (bit like greed) because with a higher shutter speed you can freeze rapid action - say if you are a pro sports photographer - or of more relevance to most people - you can reduce the effects of camera shake.

Camera shake has a huge impact on the sharpness of results - it might be why some peoples 10mp camera appears to take worse photos than a 5mp one if the latter had a much faster lens the photos are more likely to be sharp on average.

I guess I am just greedy (therefore I must be good!) - I want 5mp in an iPhone with at least a f2.8 lens. I have a Sony Ericsson K750i and it has a very nice f2.8 lens and a 2mp sensor. It takes very impressive photos considering. The focal length is 4.8mm so the front lens must be about... 1.7mm!
post #86 of 91
Quote:
Originally Posted by nvidia2008 View Post


NOW ALL OF YOU GET BACK ON TOPIC BEFORE WE ALL GET A GOOD SPANKING !!!11!!

we all need a new topic
the weekend is getting longer the more this story stays last on ai
post #87 of 91
Quote:
Originally Posted by cnocbui View Post

You're right! - that must be it, I'm a noob of butter!

well thats a relief, I have been called far worse than that

noober mind what people may call you
post #88 of 91
Quote:
Originally Posted by cnocbui View Post

A lens' speed is the ratio of its maximum aperture to its focal length. The speed is usually represented by an f number such as f2, f2.8, f3.5, etc. A 'fast' lens is one which has a wide maximum aperture relative to its focal length. The wider the maximum aperture the more light can be let through. With a wide aperture, more light is being let through so you can use a faster shutter speed. So the terms 'speed 'and 'fast' are really refering to the shutter speed.

If you have a lens with a focal length of 200mm and the maximum aperture is f3.5, then the diameter of the front lens will be 'roughly' 57mm. Now if you want a 'really fast' 200mm lens, say f1.8, the front lens will have to be about 111mm in diameter! The cost of such a lens can be more than a car, if it is for a 35mm film camera!

fast is good (bit like greed) because with a higher shutter speed you can freeze rapid action - say if you are a pro sports photographer - or of more relevance to most people - you can reduce the effects of camera shake.

Camera shake has a huge impact on the sharpness of results - it might be why some peoples 10mp camera appears to take worse photos than a 5mp one if the latter had a much faster lens the photos are more likely to be sharp on average.

I guess I am just greedy (therefore I must be good!) - I want 5mp in an iPhone with at least a f2.8 lens. I have a Sony Ericsson K750i and it has a very nice f2.8 lens and a 2mp sensor. It takes very impressive photos considering. The focal length is 4.8mm so the front lens must be about... 1.7mm!

It's not how long your lens is, it's how you use it...
post #89 of 91
Quote:
Originally Posted by iconsumer View Post

we all need a new topic
the weekend is getting longer the more this story stays last on ai

Dude, tell me about it. Well, 24 hours to a New York morning, so maybe some Nasdaq action will give us something new to obsess about. That and maybe some new Apple news. ... In the meantime, in a few hours, Arsenal vs Chelsea !!!!11!! ( http://en.wikipedia.org/wiki/Carling_Cup ) .... I'm undecided on who to support. Hmmm...
post #90 of 91
Quote:
The more MP they squeeze onto a sensor the ASA sensitivity can go down if not supplemented with faster lenses and better digital processing.

Respectfully, this is almost entirely untrue.

Directly from Canons website.

Reducing pixel size to increase pixel density leads to poorer sensitivity and a narrower dynamic range. Canon has realized both high resolution and enhanced sensitivity despite pixel-size reduction by closing the gaps between its microlenses. Furthermore, Canon gave these smaller pixels a higher light storing capacity by boosting the circuit density inside each. This has expanded the signal output range in low ISOs. Thanks to this expanded range and high sensitivity, EOS DIGITAL cameras have a wider selection of ISO settings.

Quote:
Even cheap plastic lenses have quite a bit of resolving power. That said, in the short term, lenses will always be sharper than the sensor.

From a technical paper on Lens Modulated Transfer Function.

Some exceptionally good machine vision lenses have a resolving power of 100 lp/mm which corresponds to a horizontal pixel resolution of 1280 pixels (for 1/2" format). In this case, the lens will achieve megapixel resolution, but not more. If resolution is important to you, you will need to ensure that your lens resolution is capable of achieving at least the resolution of the camera that you are using.

Most machine vision lenses are not capable of achieving higher than megapixel resoluion. The resolving power of a lens is usually quoted in line pairs per millimeter (lp/mm) if it is quoted at all. Most inexpensive machine vision lenses offer an optical resolution of around 50 lp/mm which corresponds to a horizontal pixel resolution of about 700 pixels. Such a lens is adequate for use with a VGA resolution camera, but will not acheive megapixel resolution.


Lens MTF charts clearly show the sensor would receive the most visual information if there were no lens at all. The lens is needed because there needs to be some way of focusing and controlling the amount of light that hits the sensor. You always loose some visual information simply because it has to pass through glass before it hits the sensor. The best lenses are able to control flare, light reflections, chromatic aberration, barrel distortion, rounded bokeh. Most of these anomalies effect the sharpness and dynamic range of a picture. The best lenses that achieve high MTF are hand made and cost $10,000 to $40,000.
post #91 of 91
Quote:
Originally Posted by gregmightdothat View Post

While each pixel records less incident light in a higher-megapixel camera, the sensor as a whole picks up just as much light. At small sizes, the noise is irrelevant. At large sizes, more detail will always trump a blurry image, even if that detail does have some noticeable noise.

The same number of photons are still spread over the same area, and that number of photons is limited by the lens. A greater number of cells under the same lens means that fewer photons will hit a cell, therefore, with all other things being the same, the dynamic range per cell goes down when the number of photo cells goes up.

More cells behind a 1mm lens does nothing, because the 1mm lens simply can't be done well and done cheaply at the same time, so it's going to be just as blurry.
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