Lenses Question

[JeremyLangford]

Theres one thing I've never understood.

I never get it when people talk about their new 50mm f/2 or their 50mm f/2.8.

Why are slower 50mm lenses like these good? Why would someone not just get a 50mm f/1.4. Its seems like the f/1.4 is a ton more versitle when it comes to shallow depth of fields and you can always go to a f/2 or f/2.8 if needed. Right?

I kno price is usually a big issue, but most of you guys have manual focus lenses, which usually cancels out the price issue.

Is there just something I'm missing that would make a 50mm f/2 better than a 50mm f/1.4?

 

[markinlondon]

The doubling of aperture requires a much greater degree of correction adding bulk to the lens, not to mention cost. An f2 lens will usually give far better performance and cost and weigh a lot less. In Leica terms, until the ASPH 50 Summilux, the Summicron was always streets ahead in the performance stakes. See Erwin Puts' Leica Lens Compendium for a detailed discussion of this.

 

[BillBingham2]

In RF world not looking through the lens to focus and compose frees the user to have slower and smaller lenses. Also, the depth of the mirror box limits an SLR from several designs that are very good and may not cost as much.

You can not say that a 2.8 will always out perform a 1.4. While often it does, there are some great fast lenses that kick butt of everything. Nikkon 50/1.4 that was released with the S3 2000 kickes a lot of other 1.4, 2.0, 2.5 lenses butt in sharpness, look and feel.

On the other hand, the Nikkor 28/2.8 AIs lens is one of the best 28s Nikon has ever made (2.0 or 3.5).

B2 (;->

 

[pvdhaar]

While it's true that some great fast fifties do exist, they definately do not always 'kick butt of everything'. There's more to an image than sharpness alone. To name but a few, slower lenses are more rectilinear, have better contrast, and are less prone to ghosting.

Besides the whole image quality thing, slower lenses can be built lighter and more compact, which makes them more fun to carry around all day..

 

[Laforet]

In the example mentioned above, AIS Nikkor 28/2.8(not the AI version, which has its own, unique credits) has less flare than the 2.0 counterpart, while the 3.5 is sharp, but a tad slower for a SLR in terms of viewfinder brightness and the ablity to close focus.

I own both AI Nikkor 50/2 and MC Rokkor-X 50/2, both of them are extremely fine lenses, and the f/1.4 versions give marginally usable image at f/1.4, so I went for the f/2 ones for the reduced flare and bulk.

 

[Dr. Strangelove]

I own both AI Nikkor 50/2 and MC Rokkor-X 50/2, both of them are extremely fine lenses, and the f/1.4 versions give marginally usable image at f/1.4, so I went for the f/2 ones for the reduced flare and bulk.

My wife has both the original non-AI Nikkor 50/2 and non-AI Nikkor 50/1.4. The 50/2 is a great little lens even by modern standards and it performs very well wide open. In fact the 50/1.4 at f/2.0 is not sharper than the 50/2.0 wide open and of course the faster lens is more prone to flaring and ghosting; being from the 1960s it does not have multicoating. So she only uses the much heavier 50/1.4 for low available light handheld photography with fast negative film.

 

[oscroft]

Hi Jeremy,

Why are slower 50mm lenses like these good? Why would someone not just get a 50mm f/1.4. Its seems like the f/1.4 is a ton more versitle when it comes to shallow depth of fields and you can always go to a f/2 or f/2.8 if needed. Right?

People have talked about different lens factors already, but the simple answer is that there is far more to lens performance than focal length, maximum aperture and cost - sharpness, contrast, various kinds of aberration (distortion), different quality of out of focus areas (bokeh), different tonality (perhaps a bit controversial that one), susceptibility to flare, etc all contribute to the final image. It simply isn't the case that a 50/1.4 will necessarily produce better quality images than a 50/2 - as someone has pointed out, it is often the reverse.