How come they make such a big deal about compact camera F numbers?

[snapsnap1973]

Why do they seem to make such a big deal about compact camera's F number's when average lens sold for DSLR's, etc have worse F numbers on average? I mean they're always saying things (in reviews) like "well it's only an f3.5 lens on this compact camera so it's not that great" when I watch reviews of lens sold for DSLR's and it's got an F5.6 lens and they say "well it's a good lens".

Do you need better F numbers on compact camera lenses in comparison to DSLR cameras?

 

[Overread]

Compact cameras generally render photos with a much greater depth of field than those from cameras with larger sensors/film. As a result you need a much much wider aperture to start being able to create a background blur effect. Combine that with the fact that smaller sensors are typically more noisy than larger ones and you've also a desire to have wider apertures so that you can let in more light without having to raise your ISO

 

[snapsnap1973]

thanks

 

[bribrius]

as stated excellently. smaller sensors in cc cameras need faster glass to make up for it.

 

[Derrel]

Lower f/number values (like f/3.3 or f/2.8, etc.) are also somewhat an indicator of the quality of the lens and as a result, of the camera. Sony's new RX-10 for example, has a constant aperture of f/2.8, all the way from widest to most telephoto. It's a very high-end compact camera. The lens is high-spec, and the camera makes fine images. Lower-spec'd cameras have lower-spec'd lenses.

 

[JerryLove]

Lower f/number values (like f/3.3 or f/2.8, etc.) are also somewhat an indicator of the quality of the lens and as a result, of the camera. Sony's new RX-10 for example, has a constant aperture of f/2.8, all the way from widest to most telephoto. It's a very high-end compact camera. The lens is high-spec, and the camera makes fine images. Lower-spec'd cameras have lower-spec'd lenses.

For example: The IPhone 4S has an f/2.4 lens, making it better than the Sony RX-10?

 

[ShaneF]

you mean i did not have to spend thousands of dollars on my camera equipment, all i had to do was buy an IPhone?...Damn and even then i have an Andriod. JK

 

[sashbar]

Lower f/number values (like f/3.3 or f/2.8, etc.) are also somewhat an indicator of the quality of the lens and as a result, of the camera. Sony's new RX-10 for example, has a constant aperture of f/2.8, all the way from widest to most telephoto. It's a very high-end compact camera. The lens is high-spec, and the camera makes fine images. Lower-spec'd cameras have lower-spec'd lenses.

For example: The IPhone 4S has an f/2.4 lens, making it better than the Sony RX-10?

all the way from wide to telephoto? Are you saying the iPhone has a constant f zoom?

 

[ann]

Lower f/number values (like f/3.3 or f/2.8, etc.) are also somewhat an indicator of the quality of the lens and as a result, of the camera. Sony's new RX-10 for example, has a constant aperture of f/2.8, all the way from widest to most telephoto. It's a very high-end compact camera. The lens is high-spec, and the camera makes fine images. Lower-spec'd cameras have lower-spec'd lenses.

For example: The IPhone 4S has an f/2.4 lens, making it better than the Sony RX-10?

But, because of the sensor size it is closer to a f22, which is why there are so many tilt and shift apps

 

[WayneF]

Do you need better F numbers on compact camera lenses in comparison to DSLR cameras?

It seems very doubtful that there is any compact camera with a f/3.5 maximum aperture? At least not if it is adjustable.

Stated another way, the crop factor of the tiny sensors on compact cameras is so great that images taken stopped down greater than say f/4 suffer badly from diffraction. In auto mode in bright sun, it will never be stopped down more than f/4. This makes f/1.8 be seriously important. Also makes f/1.8 quite easy to design and build, compared to larger cameras and lenses.

 

[Judobreaker]

Lower f/number values (like f/3.3 or f/2.8, etc.) are also somewhat an indicator of the quality of the lens and as a result, of the camera. Sony's new RX-10 for example, has a constant aperture of f/2.8, all the way from widest to most telephoto. It's a very high-end compact camera. The lens is high-spec, and the camera makes fine images. Lower-spec'd cameras have lower-spec'd lenses.

For example: The IPhone 4S has an f/2.4 lens, making it better than the Sony RX-10?

all the way from wide to telephoto? Are you saying the iPhone has a constant f zoom?

The iPhone doesn't have optical zoom at all which makes it pretty likely the lens has a fixed aperture as it also has a fixed focal length...

 

[JerryLove]

For example: The IPhone 4S has an f/2.4 lens, making it better than the Sony RX-10?

all the way from wide to telephoto? Are you saying the iPhone has a constant f zoom?

The iPhone doesn't have optical zoom at all which makes it pretty likely the lens has a fixed aperture as it also has a fixed focal length...

Constant fixed focal length

Yes. I was making a simultaneous claim and proof of claim that f value cannot be reliably used as an indicator of the quality of the camera.

Lenses are all about which compromises to make. Price, quality, zoom, aperture, etc all have to compete with one another.

 

[table1349]

Why do THEY make a big deal out of F numbers. Simple...........They took marketing and business classes in college. Same reason they make a big deal about #X zoom range, Same reason they make a big deal out of Megapixels, same reason they make a big deal about LCD size. In a word MARKETING.

The smart phone is killing the P&S market. They have to do something to try and salvage it.