ssscomp

Many people by fast lenses, i.e. 1.4, to use the narrow depth of field, and in low lighting conditions with no intention of ever using the same lens at 5.6 since they have other lenses that do well At 5.6. I certainly use my 1.4 lens in that "mode" 99% of the time. So if that is true, why don't they make a lens that is simply 1.4? No adjustable aperture, no built-in stabilization just superb quality glass to shoot at one focal length and one f-stop. They could save the money from the aperture mechanisms and auto focus and provide a superb piece of great glass. I would certainly be online to buy one. Anyone else?

jerryc41 Loc: Catskill Mts of NY

I bet they do - for specialized purposes. Such a lens would have a very narrow audience and would be expensive. Controlling exposure would be more difficult if an f/1.4 lens were always wide open. I don't like the term "constant aperture lens" because it isn't constant. It simply has the ability to be constant. As you said, an f/2.8 lens doesn't always shoot at f/2.8.

http://improvephotography.com/19360/constant-aperture-lens/

breck Loc: Derbyshire UK

I purchase fast lenes but use all available apertures dependent on the result I want and available lighting.
I doubt anyone only uses any lens at its widest aperture, they are just way more adaptable that small aperture lenses, and usually far better quality at all settings

speters Loc: Grangeville/Idaho

While I do have some fast glass, I do not use it all the time at wide open, more often I use it at way smaller apertures, appreciating it's IQ and knowing I can enjoy that quality at low light levels as well. But if they would offer same lens with a fixed aperture, I sure would not buy it (it would pretty much render it useless for me). The use of many primes is already somewhat restricted to certain uses, but that would just be too much!

rook2c4 Loc: Philadelphia, PA USA

I don't think I'd want a lens like that; one would need to use ND filters to have any real control over shutter speed selection.

Jim Bob

Simple: no real market for it.

Carlo Loc: Maryland, NW.Chesapeake Bay

I am not sure they have exactly what you are describing ....but you may want to review / explore Samyang lenses...FYI...

phyprof

I feel that there would be few people wanting a lens that can't be stopped down for times when they want greater depth of field, or the light is too bright so a much faster shutter speed would have to be used. If few lenses are made (relatively few) the cost would be more. It is an interesting concept, however.

This being said, I shoot most of the time, 90% at least, with fixed focal length lenses. While zoom lenses are more convenient, I prefer the quality and lighter weight of the primes.

dennis2146 Loc: Eastern Idaho

In my opinion your thought that people buy fast lenses only to use the fast aperture is mistaken. I have owned many fast lenses and while they were useful for low light conditions, they were also just as useful for many other photographic subjects as well. For me a 35mm f1.4 makes a great all purpose lens on a full frame camera.

Dennis

Cdouthitt Loc: Traverse City, MI

A 1.4 is still sharper stopped down a bit. Just because you can, doesn't mean you should.

WayneT Loc: Paris, TN

I remember I used an f1.2 50mm lens on my old Nikon F1 and it was my go to lens. I loved it for low light but I used it a higher f stops as well. I don't think I would want a set f-stop lens like that just not versatile enough.

lamiaceae Loc: San Luis Obispo County, CA

One lens for one highly specific use, no way. That is what accessories are for, for occasional use (now in this case I can't think of how you could make a large iris with a lens accessory). You must realize the entire dynamic in use marketing is different. Most of you (those that have only done photography during the digital age and/or zoom lens dominant age, autofocus age). Back during the film days shorter lenses most often were relatively fast, it was more about being able to focus and the ISO for best results being typically 25 - 400 (during when I was shooting film). Nifty-fifties were usually f/1.7, 1.8, 2, faster ones f/1.2 or 1.4. Shorter lenses other than "normal" lenses were in the range of f/2, 2.8, 3.2, 3.5; this was for say lenses in the range of about 24mm to 105mm. f/4.5 to 5.6 lenses were more or less reserved for really long or zoom lenses. Remember film lenses have the greater coverage of FF or FX digital lenses. if a lens only had a stop at one F-stop, say 1.4 how could you use the camera in Shutter Priority mode. And again it would have too limited a use for its price or cost. The iris is not the most expensive part of a lens assembly. Also if you have a lens of f/1.4 with its probable high cost and high quality you are missing a lot if you only shoot it at only f/1.4, it is most likely your sharpest lens at all stops. That is why they are Nifty. These days for new "normal" lenses you are probably looking at fast 35mm lenses (for the far more common CF or DX cameras). This obsession with bokeh is a relatively new thing and largely driven by the aesthetic of Japanese photographers. Wow, a lens with one fixed stop, that is taking photo technology back a long ways. Good luck with that product idea. If you were trying to be rhetorical, I understand and agree more.

lamiaceae Loc: San Luis Obispo County, CA

The 35mm lens is popular among film street photographers. And in urban settings with long shadows a fast 35mm is just the thing. For CF digital the equivalent would be about 24mm.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

An F1.4 lens is usually (but not always) very good in the center of the lens, but "marginal" at best at the corners and edges, when used wide open. But stop it down to F2.8 or F4, and it usually beats the pants off an F2.8 lens used wide open or even at F4.

You do have a point, though. Some lenses, like F2.8 or F4 long (300, 400, 500, and 600mm) telephotos are engineered to provide their best results used wide open, and don't necessarily improve much at smaller apertures - because most who use these will use them at or close to their max aperture. But you would need the adjustment to allow for different lighting conditions, otherwise you'd need a bunch of cameras and even more lenses to cover all the lighting variations.

Leitz Loc: Solms

No serious photographer would buy it!!