Q1: Does a specialist like you see these problems you mentioned very often in pictures taken casually by people with their camera phones?
A: Yes that's something we see quite easily. It's quite common, and though it might appear to be something only for experts to see, that's a matter that everybody would want to check on quality lenses.
Q2: That's my next question: Will the average Joe really see the difference between an average camera phone and a better one?
A: The average Joe might not see the problem in one picture, but when pictures are side by side, he will see that one picture will look better than the other.
Q3: In your opinion, why is it that camera phones still don't have optical zooms? Is it that the phones are too small or optical zoom would be too much of a battery hog?
A: It's because of the size of the unit itself. Phones are too thin
Expert Quote
"Camera phones are too thin to accommodate any optical zoom gear."
to accommodate any camera zoom optics.
Q4: I assume that optical zooms require movable parts, right?
A: Yes, you need motor drive, you need gears, you need more lenses because you want to have a focal length range. So, all of that together would be too big for a camera phone.
Q5: The new iPhone 4S, which has generated so much media attention, boasts about its backside-illuminated camera. To the inexperienced ear, it sounds like something new, but is it really new or just something new in camera phones?
A: Backside illumination is a technology used in the sensor. It
What we learned
Backside-illuminated sensors allow better low-light photography. (Photo: the iPhone 4S)
was in fact developed by Sony and first released in 2009. Since Sony is a big manufacturer of sensor devices, a lot of companies buy their sensors for their devices. That's the case for the iPhone 4S - it uses the Sony backside illumination sensor for its camera. This sensor allows you to gather more light and allows more sensitivity than a regular CMOS sensor. It's a big improvement for low-light photography.
Q6: But it's hard for the layman to comprehend how it works because of the feeling that just adding light to the picture will interfere with the natural light of the image. Is there a simple way to explain that?
A: It does not add light at all to the imaging sensor. A standard CMOS sensor is built with some wiring that prevents all the light from the lens to strike the sensitive part of the sensor. A backside illumination sensor is kind of build upside down, so all the light that comes from the lens strikes the sensitive part of the sensor without being blocked by any wiring - the light that used to be wasted isn't wasted anymore.
Q7: So, in a nutshell, it wastes less of the available light that comes naturally from the image?
A: Exactly. It is about 2 times more sensitive
Q8: About the iPhone 4S again: what about its five-element optics? They claim it makes the image sharper. Are camera experts like you impressed with that or is it commonplace?
A: From what I've seen online from the iPhone 4S pictures, those
Expert Quote
"From what I've seen online from the iPhone 4S pictures, those pictures seem to be quite good for a camera phone."
More:
iPhone 4s pros and c
pictures seem to be quite good for a camera phone. Even the pictures took by end users. I didn't zoom into the images to see how soft they were, but overall, the brightness, distortion, and contrast was very good. And it could be due to the lens and the sensor itself. So the five-element optics could be a big plus because making simple lenses is of course cheaper and smaller but more elements in a lens will allow better control on the problems we mentioned earlier. Those issues can be better controlled within the lens itself.
Q9: Is it really safe to look at the samples provided by the manufacturer? One would think that they enhance the pictures a bit...
A: Let's just say that it is not always faithful
Q10: Apple also says that the larger aperture lets more light in, but is there a drawback?
A: There isn't much of A drawback to a larger aperture aside from its weight which would be heavier than a smaller aperture lens. A bigger aperture is a plus for any photographer but there is one possible drawback to a larger aperture and that is a shallower depth of field. That means the subject in focus can appear more detached from the background. But that's rarely a problem, unless you want to do landscape photography.
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