Does A Cameraphone Really Need 41 Megapixels?

No 'cos the lens is prob' cr4p.
Next!
Del

Not so fast!

The lens is made by none other than Carl Zeiss! They make some of the best lenses on the planet. F-number is 2.4, which is a fast lens with good low light capacity.

This LINK explains the sensor better.

As I argued in another post, it still produces a 5 to 6 mp file, but it uses the extra pixel sites to reduce noise and improve light gathering. The net result is a superior camera that you can slip into your shirt pocket and still make a phone call if you need to.

Just ignore the Rayleigh limit for the resolution of a lens, and the Nyquist limit for digital sampling -- and you can have the best (albeit useless) camera on the market.

Reminds me of those department-store telescopes claiming '1,000 X' magnification.

"Does a cameraphone really need 41 megapixels?"

Sure, why not?

Consumers are a fickle lot. Some consumers simply HAVE TO have the hottest goodest fastest bestest awsomest stuff that is available. When new stuff comes out, these people are a built in customer base.

I recently had a request for proposal from an apartment house (new building) for an electronic access control system for the building. The performance criteria sheet from the owner was absolutely ridiculous... the building automation system (which the access control system would slave under) was absolutely ridiculous. During due diligence I discovered the owner LOVES gadgets... crazy about them.

No detail or upgrade was missed, right down to the apartments having doors that not only unlock when you approach (active RFID), an electromechanical operator will open the door for you as well.

So, not only does the building owner love his gadgets, he had no trouble finding gadgety people to populate this automated utopia... at an upscale price.

I think you nailed this one. It's not about high quality photos - that would require a lens with a bigger aperture. Plus I don't think many folks could hold the phone still enough for all that extra resolution to matter much. Might need an Inspector Gadget style built-in-automatically-extendable-voice-activated tripod run by cloud-based software.

I think you are wrong on this and here is why.

What is important here is not the high number of pixels, but how those pixels are employed.

First, the actual rsulting image is only 5 to 6 mp, not 41. The 41 are used internally to allow digital zoom (up to 2.8X giving you a 28-78mm equivalent zoom compared to a 35mm camera) and to improve image quality and lower both the sensor read noise and dark noise in low light.

The sensor's high pixel count allows software to couple those pixels together to produce superior light gathering power and to cancel out the random noise generated from the sensor.

Here is a link to a sample image. Have a look for yourself and see if this is simply a marketing ploy.

Note that Carl Zeiss is making the optics for this camera and they are a first rate lens manufacture. This is not a cheap plastic lens, but a fast (F2.4) quality optic.

Numerous marketing studies show a large and growing market for quality cameras that are small and easy to use that also serve as a phone. So while you may be cultivating Good Answers for your point of view here, the manufactures are smiling all the way to the bank.

Lastly, this technology will no doubt filter its way upward into regular point and shoot cameras and DSLRs in the near future. That is another reason that this news is an important announcement.

This is all about marketing, 100%. And you fell for it. The marketing goal is not to get the consumer to buy this camera or that camera phone. The marketing goal is to get more pictures shuffled across the net for little real value.

Ralph: Hey Jimmy, look at this picture of Mary at the bar. My new phone camera is high of a resolution you can blow up the image and see the pores on her face.

<6 megabytes>

Jimmy: Big deal, my cell phone camera takes 6 megabyte pictures, too. Look at Helen at the beach.

<6 megabytes>

Ralph: Yeah but if you blow up my picture you can see greater detail. Look I'll send you a close up.

<6 megabytes>

Jimmy: Why do I want to see a close up of Mary. You're the one dating her.

Viola. The network has now obtained revenue for not 18 MB but 36 MB because up and down links are paid for.

You AH immediately fell for this little mind game by linking to another picture to make your point. I needed to see a picture of free climber just as much as you need to hear LP playing "Into The Wild". "Somebody left the gate open...."

Oh, come on.

Of course there is revenue in data transfer. However, the idea of a 41 mp camera is going to be responsible for a spike in data transfer volume is a big stretch. No, it is simply a rip in the fabric of reality.

Again, if I read your original post correctly, you are claiming that the 41 mp sensor is going to increase revenue for wireless data transfer time. However, the image size of this sensor produces a 5 to 6 mp sized file, which is relatively small compared to some of the other phones.

The only way that this camera could increase net traffic is the wow-factor, which is a very shaky argument and very transitory because people lose interest quickly.

As I said, there is a large and growing market for better cameras in small packages.

Actually, it is an explosion. You have every manufacture on the block getting into mirrorless, point and shoot, phone cameras, and small format lens mounts. Even Leica is in the market with rebadged Panasonic point and shoots and their own X1.

I don't think this is the manufactures driving the market, but the market driving the manufactures. With recent advances in sensor technology and the microprocessors to manage the signal processing and data manipulation the ability to get serious photographic quality in images is making huge advancements.

Digital SLR cameras have only been around for about 12 years and they were big clunky, low resolution. In that time we have seen digital equal and now surpass film in quality (that is not limited to simply pixel resolution, but much lower noise and and light sensitivity). Film is dead for the average consumer.

The links you provided show me that I have to revise my previous comments. The key being that the chip size used is really quite large - much larger than the typical miniscule chip used in phones.

Here are some calculations I've done that show the 41 M pixels claim is maybe not the stretch I first thought. The following are all reasonable, though slightly rough calculations.

The chip size is 1/1.2, which means it has a diagonal length of 13 mm.
This 13 mm would be the image size for a 'normal' photographic image, which typically covers about 40 degrees horizontal, or 50 degrees diagonal.
For a 50 degree image yielding a 13 mm image size, the focal length would be 11 mm. [S = f*tan(Φ); so if S = 13 mm and Φ = 50 degrees, then f = 11 mm.]
If f = 11 mm and the f/ratio is 2.4, then the lens diameter is 4.6 mm.
The limiting resolution, in arcsec, of a lens (the Rayleigh limit) is 141/ [image size in mm]. So Reslim = 141/4.6 = 30.6 arcsec. This means there will be 50 degrees/30.6 arcsec resolvable features, or 50 deg/0.0085 deg = 5882 resolvable features across the diagonal. The Nyquist limit requires at least 2 pixels per resolvable feature, so 11764 pixels are needed.
The actual number of pixels across the diagonal is 9409 (7728 x 5368). This is 80 percent of the number needed to meet the Rayleigh limit. The effective number of useable pixels in each axis would thus be 6182 x 4294, and this gives a total of 26.5 M pixels.

So as it turns out, by making some assumptions it looks like the camera will produce at least 26.5 million pixels, which is really quite good. If the lens is slightly wider than the 4.6 mm diameter I calculated, i.e., closer to 6 mm, then it may in fact come close to yielding 41 Megapixels.

Oops minor correction. The statement:

The limiting resolution, in arcsec, of a lens (the Rayleigh limit) is 141/ [image size in mm],

should be:

The limiting resolution, in arcsec, of a lens (the Rayleigh limit) is 141/ [lens diameter in mm]. The numbers I used were correct, just the wording was in error.

Nice work. The only thing that I am not sure about is the 50° you cited. I think the angle for a normal 35 mm equivalent lens is closer to 57° or am I off track?

Thanks.

As I said, these were rough but reasonable assumptions.

For film cameras the image size was fixed for given camera type, like an SLR, but there were some variations in FOV due to the various manufacturers' lenses (f/2, f/1.7, etc.) From Wikipedia: Normal lens: angle of view of the diagonal about 50° and a focal length approximately equal to the image diagonal.

I don't think the field of view changes with aperture, only with changes focal length. The focal length of this camera with its fixed lens has a roughly 35 mm equivalent.

I can take my DSLR and change the aperture to any value on any lens and the FOV in the viewfinder never changes.

I don't think the field of view changes with aperture, only with changes focal length.

True. I didn't mean to imply that it did. My first SLR was a Minolta with a 55 mm f/2 lens. A few years later I got a new Minolta with a 50 mm f/1.7 lens. I also bought a 28 mm, f/2.8 'wide angle' lens for it. My brother had a Nikon with a lens that could open to f/1.4; I believe it had a 50 mm lens - and it would have yielded the same FOV as the f/1.7 lens. Any of these lenses could be set to f/22, thus changing the effective aperture of each lens but without changing the FOV each one provided.