Lens question

[Mikoh4792]

What's the difference/benefit of owning a lens that have these different labels? f/1.2,1.4,3.5.....etc

[red ink]

Those numbers refer to apertures... the smaller the number the bigger the maximum aperture.

[formica]

smaller f numbers = bigger aperture size

bigger aperture = faster lens, more light hits the CCD/film and you can use faster shutter speeds or less sensitive film/CCD setting which can improve picture quality and reduce noise, it also reduces the depth of field, giving a much tighter focus


wide aperture is especially useful for dark scenes (allows more light), macro shots (tighter focus) and action shots (faster shutter speed)

[Mikoh4792]

Awesome thanks guys.

Formica in that case wouldn't you want to get smaller f aperatures all the time then?Since if you want to go bigger in f number you can always just do that on your manual setting. Why would people just get a lens that will limit them in aperature size? In other words why even get a lens that is not the smallest f number?

[formica]

no because it reduces the focal length, and sometimes you want a wide focal length, and for very bright situations, you may need a slower shutter speed for eg to take action shots to show up movement

allot of lens come with a wide range in a single lens, so its less restrictive i guess, its at the extreme ends of photography where it becomes important, very dark/very bright, extreme macro/wide landscape etc etc

[Mikoh4792]

If I were to pick a lens solely for the purpose of shooting my snakes would I want one with a bigger or smaller f stop?

I'm talking about shooting mainly in ambient light(mostly in the shade) and in "studio" type setups with studio boxes...etc

[red ink]

Originally Posted by formica

no because it reduces the focal length, and sometimes you want a wide focal length, and for very bright situations, you may need a slower shutter speed for eg to take action shots to show up movement

allot of lens come with a wide range in a single lens, so its less restrictive i guess, its at the extreme ends of photography where it becomes important, very dark/very bright, extreme macro/wide landscape etc etc

Focal length is not affected by aperture... All aperture does is control depth of field. You can get low end lenses that have a maximum aperture of 5.6 but have a focal length of 200mm and you can get 200mm lenses that have a maximum aperture of 2.8.

In bright situations you want faster shutter speeds to control your exposure if your not going to close your lens aperture down - which will change your depth of field. You will blow out the image if you don't.

@Mikoh

Why would people just get a lens that will limit them in aperature size? In other words why even get a lens that is not the smallest f number?

The reasoning is simple.... the bigger the maximum aperture the bigger the price tag.

[Mikoh4792]

Originally Posted by red ink

Focal length is not affected by aperture... All aperture does is control depth of field. You can get low end lenses that have a maximum aperture of 5.6 but have a focal length of 200mm and you can get 200mm lenses that have a maximum aperture of 2.8.

In bright situations you want faster shutter speeds to control your exposure if your not going to close your lens aperture down - which will change your depth of field. You will blow out the image if you don't.

@Mikoh


The reasoning is simple.... the bigger the maximum aperture the bigger the price tag.

Ah I see. So you can basically do the same with a bigger aperature lens...it's just you have more options with a bigger aperature lens?(since you can always lower aperature with your camera)

[formica]

yeh depth of field is what i ment!

[loud]

Originally Posted by Mikoh4792

Awesome thanks guys.

Formica in that case wouldn't you want to get smaller f aperatures all the time then?Since if you want to go bigger in f number you can always just do that on your manual setting. Why would people just get a lens that will limit them in aperature size? In other words why even get a lens that is not the smallest f number?

red ink already said it (price tag), but just to put it into perspective -

Canon 85mm f/1.2 costs $2,199
Nikon 85mm f/1.4 costs $1,599
Canon 85mm f/1.8 costs $419 (Nikon equivalent is $496)

Originally Posted by Mikoh4792

Ah I see. So you can basically do the same with a bigger aperature lens...it's just you have more options with a bigger aperature lens?(since you can always lower aperature with your camera)

Yes, exactly