What is a prime lens?

Bo Malicious

Can anyone please explain what a prime lens is in simple English!?

Thnks.

Creamy Goodness

basically it's a lens that just has one focal length.

the most popular example would be the 50mm that any good photographer should have.

Ghost Train

no zoom

DK32

http://en.wikipedia.org/wiki/Prime_lens

I find wikipedia can be a great jargon buster

democrates

There's no zoom on it.

If you want more of the scene to appear in your photo you have to step back until it all appears on the screen/viewfinder, or alternatively if you want less of the scene to appear in your photo you have to walk forward until just the section you want will be in the photo.

The advantage of a standard lens is generally higher quality, there are fewer pieces of glass inside compared with a zoom. Before shelling out it costs nothing to ask for feedback and recommendations here, then you can buy second-hand on adverts.ie where your boards.ie login also works.

PS, strictly speaking it's called a 'standard' lens but few people are nerdy enough to correct you on that...

Bo Malicious

thanks fellas.


And a prime/standard lens focuses just as any other lens would - or are there inherent restrictions?

Creamy Goodness

Bo Malicious wrote: »

thanks fellas.


And a prime/standard lens focuses just as any other lens would - or are there inherent restrictions?

well it depends really on who makes the prime lens and also how old the lens is.

older lenses may be manual focus only whereas newer primes will be both automatic and manual focusing. but the mechanisms behind each will be the same.

ie. a prime lens in manual focus will focus the same as a zoom lens in manual focus. ditto for automatic focus mode

DaireQuinlan

democrates wrote: »

PS, strictly speaking it's called a 'standard' lens but few people are nerdy enough to correct you on that...

Actually, if we're going to be all nerdy and pedantic, a standard lens normally only refers to a prime thats of a focal length roughly equal to the diagonal of the format you're shooting on. IE, 45/50mm on 35mm or FF digital, 80mm on 6x6 medium format etc etc. It results in an image thats about as normal perspective as possible for that size format.

Ghost Train

DaireQuinlan wrote: »

Actually, if we're going to be all nerdy and pedantic, a standard lens normally only refers to a prime thats of a focal length roughly equal to the diagonal of the format you're shooting on. IE, 45/50mm on 35mm or FF digital, 80mm on 6x6 medium format etc etc. It results in an image thats about as normal perspective as possible for that size format.

And to be even more pedantic, was reading something today that for 35mm standard lens is more like 40-45mm. This wasn't the article I read but is sort of along the same lines
http://blog.dpreview.com/editorial/2009/03/what-is-a-standard-lens.html

democrates

Thanks guys you've just armed me for the 'wipe that got me on it

kumate_champ07

Ghost Train wrote: »

And to be even more pedantic, was reading something today that for 35mm standard lens is more like 40-45mm. This wasn't the article I read but is sort of along the same lines
http://blog.dpreview.com/editorial/2009/03/what-is-a-standard-lens.html

yes its more like 45mm, 50mm is easier/cheaper to design!

WedPhoto

a prime lens is a lens with a fixed focal lengt (i.e 35mm, 50mm, 85mm, etc...). they have a better image quality than the zoom lenses because they use less optical elements inside, thus reducing the amount of glass the light has to pass through, thus less light degradation...they can be quite expensive. the medium format cameras use only prime lenses (as far as i know)

sineadw

WedPhoto wrote: »

the medium format cameras use only prime lenses (as far as i know)

Nah - they have zooms as well

petercox

Actually the reason primes tend to be higher quality is not due to less glass directly, but due to the fact that the design is simpler. Zoom lenses have many more variables for optical designers to think about and as a result are a compromise design. They sacrifice design perfection to get acceptable results across the whole zoom range. Some do this better than others.

A prime lens only has to do one thing well, and that's a single focal length.

And yes, medium format cameras can use zooms, although historically it's mainly been primes. Large format lenses are all primes, no zooms there.

Cheers,
Peter

the_tractor

If you get a decent prime, with a large max aperture then it will be worth it's weight in gold in low light conditions where you can't/don't want to use a flash.