Why do they say PRIME lenses are good for LOW LIGHT?

[tigidig4x]

Hi guys, I just want to ask why do people say that prime lenses are good for low light? I am thinking that because of the small apertures, the more light it could detect and you could use the extra light to use higher shutter speed. Am i thinking right? Or there is more something technical? Thanks guys.

 

[Buckster]

Close. Just change "because of the small apertures" to "because of the large apertures".

 

[o hey tyler]

Hi guys, I just want to ask why do people say that prime lenses are good for low light? I am thinking that because of the small apertures, the more light it could detect and you could use the extra light to use higher shutter speed. Am i thinking right? Or there is more something technical? Thanks guys.

Yeah bro. When you got mad diameter up in yo' aperture diaphragm, more of them light molecules be hittin' yo sensor.

Prime lenses be like "Yo this the hoover dam, letting in mad light flow. Whereas your kit lenses be letting in some skeezy little trickle of light, ya heard."

 

[EIngerson]

A zoom lens has multiple elements for the light to pass through before it reaches the sensor. A prime lens only has one. Therefore, If you used a 24-70 at 50mm F8, ISO 200 @ 1/200 SEC and a 50mm prime lens with the same settings, more light would make it to the sensor on the 50mm prime.

 

[Buckster]

A zoom lens has multiple elements for the light to pass through before it reaches the sensor. A prime lens only has one. Therefore, If you used a 24-70 at 50mm F8, ISO 200 @ 1/200 SEC and a 50mm prime lens with the same settings, more light would make it to the sensor on the 50mm prime.

Umm... No. Not even.

You need to do a bit more research on this topic.

 

[o hey tyler]

A zoom lens has multiple elements for the light to pass through before it reaches the sensor. A prime lens only has one. Therefore, If you used a 24-70 at 50mm F8, ISO 200 @ 1/200 SEC and a 50mm prime lens with the same settings, more light would make it to the sensor on the 50mm prime.

Prime lenses don't necessarily have 1 element. (I can't think of one that does.) The Canon 50/1.4 has 7 elements in 6 groups for example. You're correct though, they do generally have less elements/groups than zooms.

 

[EIngerson]

A zoom lens has multiple elements for the light to pass through before it reaches the sensor. A prime lens only has one. Therefore, If you used a 24-70 at 50mm F8, ISO 200 @ 1/200 SEC and a 50mm prime lens with the same settings, more light would make it to the sensor on the 50mm prime.

Umm... No. Not even.

You need to do a bit more research on this topic.

I will, but maybe throw me the cliff notes.

 

[EIngerson]

A zoom lens has multiple elements for the light to pass through before it reaches the sensor. A prime lens only has one. Therefore, If you used a 24-70 at 50mm F8, ISO 200 @ 1/200 SEC and a 50mm prime lens with the same settings, more light would make it to the sensor on the 50mm prime.

Prime lenses don't necessarily have 1 element. (I can't think of one that does.) The Canon 50/1.4 has 7 elements in 6 groups for example. You're correct though, they do generally have less elements/groups than zooms.

Hmmm, I might have to beat up a liar. lol

 

[Buckster]

Look at cross-sections of prime lenses, and you'll find few, if any, that have only one element.

50mm @ f/8 lets through the same amount of light, no matter which lens you achieve that with, whether it's a prime or a zoom. That's why hand-held light meters work regardless of which lens you're using.

 

[EIngerson]

Look at cross-sections of prime lenses, and you'll find few, if any, that have only one element.

50mm @ f/8 lets through the same amount of light, no matter which lens you achieve that with, whether it's a prime or a zoom. That's why hand-held light meters work regardless of which lens you're using.

It appears I've been mis-lead, but thanks. So aperture is the only reason they are better in low light?

 

[Buckster]

Look at cross-sections of prime lenses, and you'll find few, if any, that have only one element.

50mm @ f/8 lets through the same amount of light, no matter which lens you achieve that with, whether it's a prime or a zoom. That's why hand-held light meters work regardless of which lens you're using.

It appears I've been mis-lead, but thanks. So aperture is the only reason they are better in low light?

For the most part, yes. Some have better/faster/quieter motors for faster/quieter auto-focus as well, but mainly it's the wider aperture diameter that gives better performance in low light.

 

[EIngerson]

Look at cross-sections of prime lenses, and you'll find few, if any, that have only one element.

50mm @ f/8 lets through the same amount of light, no matter which lens you achieve that with, whether it's a prime or a zoom. That's why hand-held light meters work regardless of which lens you're using.

It appears I've been mis-lead, but thanks. So aperture is the only reason they are better in low light?

For the most part, yes. Some have better/faster/quieter motors for faster/quieter auto-focus as well, but mainly it's the wider aperture diameter that gives better performance in low light.

Thanks, I know it's a pretty redundant topic, but I've been a believer in the elements idea for quite a while now. A photographer I know and respect explained it to me that way quite a while ago. The light meter point makes perfect sense though.

 

[KmH]

Look at cross-sections of prime lenses, and you'll find few, if any, that have only one element.

50mm @ f/8 lets through the same amount of light, no matter which lens you achieve that with, whether it's a prime or a zoom. That's why hand-held light meters work regardless of which lens you're using.

It appears I've been mis-lead, but thanks. So aperture is the only reason they are better in low light?

As far as light goes, but there are still optical quality issues (chromatic aberration, sharpness, distortion, etc) to consider, particularly if a wide aperture prime lens is used at or near wide open.

http://en.wikipedia.org/wiki/Doublet_(lens)
http://en.wikipedia.org/wiki/Achromatic_lens
http://en.wikipedia.org/wiki/Lens_(optics)

 

[GooniesNeverSayDie11]

Keep in mind that larger apertures also assist in AF speed and accuracy. If you are using a 50mm f/1.4 but stopping it down to F/5.6, your camera will still benefit from more light during metering and focusing.

 

[Steve5D]

Some have better/faster/quieter motors for faster/quieter auto-focus as well, but mainly it's the wider aperture diameter that gives better performance in low light.

Whether a lens can be heard when it focuses has nothing to do with whether or not it will perform well in a low light situation. A lens could sound like a farm tractor and still perform well in low light.

I would be happy to hear an explanation to the contrary, though...