Dumb lens question

[j-dogg]

How come there is no lenses below 50mm with a max aperture of like f1 or f1.4, 1.8 etc. you would think it would be super easy to make a 28mm f1 or a 35mm f1, is it because of no depth of field at those apertures?

 

[MattKing]

But there are.

For example:

http://www.the-digital-picture.com/reviews/canon-ef-35mm-f-1.4-l-usm-lens-review.aspx

or:

http://www.cameraquest.com/voigt3512.htm

 

[tkamiya]

Well... there are such lenses. Nikon has 35mm f/1.4 and it can be yours for mere 1800 dollars!

 

[DWThomas]

I think those shorter focal lengths get into retrofocus designs which add complexity (AKA "money") to the design when trying to simultaneously cover a large image circle. There's a Canon EOS 24mm f1.4L for a mere $1699.95 at B&H.

 

[2F/2F]

1) There are some fast wides that have f stops like f/1.4, f/1.8, f/1.9, and f/2.0.
2) F/1 wides would not have much of a market, and they would be entirely unaffordable for most people.
3) Wide lenses do not need to be as fast as normal or long lenses, because you can get away with slower shutter speeds without capturing a lot of camera shake. For example, my 28mm f/2.0 lens can gather just as much light hand held as my 50mm f/1.4, because I can reliably shoot with it hand held at '30.
4) Perhaps super fast wides are extremely difficult to design in a way that provides good-enough optical quality. It was hard enough even with Canon's EF 50mm f/1.0, a normal lens, which is relatively simple to design.
5) Looking to the future, the need for new fast lenses decreases every time a new generation of digital cameras with higher and/or cleaner ISOs comes out. With what I tend to shoot, I need my 1.2 lens for film, or for my 8-year-old 6 Mpix ISO 1600 maximum (and a dirty 1600 at that) 10D; the f/1.0 would be ideal, but I cannot afford it. But I will be able to get by just fine with a 1.4 lens when I get my next digital camera, a D700.

 

[Wade D]

I have a Minolta MC 35mm f/1.9. Very sharp even wide open. I don't know what it cost new but I picked it up at a swap meet for $5.

 

[dnjl]

The further you move away from the normal range (50-ish), the harder it becomes to design well-performing lenses. If you want a sub-1000 dollar large aperture wide, there's the FD 24mm f/1.4.

 

[ic-racer]

These lenses were marketed for the "35mm is my normal lens size" crowd. They are big and heavy, though.

 

[Rol_Lei Nut]

These lenses were marketed for the "35mm is my normal lens size" crowd. They are big and heavy, though.

But the one in the picture is quite wonderful - when I can be bothered to carry it around...

 

[j-dogg]

Well that explains a few things.

I have a 50 1.4, 1.8 and my new favorite, 50mm f2, tack sharp. I have a 35 2.8 and 28 2.8, great lenses, just couldn't figure out why super fast lenses aren't so common.

 

[elekm]

That's a beautiful Distagon. How do you like shooting with it?

 

[elekm]

And to answer the question as to why there aren't superfast wide angles?

As the lens gets faster, the front element gets larger to collect more light. Then you have to begin to correct for this and correct for that. And pretty soon you're correcting your corrections.

Plus, fast wides also can have problems with flare, which multicoating can help to suppress.

By the time you're finished, you're looking at a $1,200 or $1,500 lens. And with today's consumer wanting $19 DVD players, getting a consumer to play more than $1,000 for a non-zoom lens is a challenge.

Then it becomes: Can they sell enough lenses to recoup R&D and production costs? That larger front element requires a larger glass blank, more polishing and probably results in a higher rejection rate, although some makers might have a wider tolerance for what's acceptable.

Can they design superfast lenses? Definitely. Will they? Only if they can turn a profit.

 

[j-dogg]

Yep that's another reason I had figured.

Gotta love APUG. Learn something new every day.

 

[pinhole_dreamer]

My Kowa has a 1:2.8 48 mm lens.