Has the mania for ultra-fast lenses hit a peak? Will it now subside and allow lens makers to concentrate on better compromises?

another portrait. 

I'm the first to admit that I've been suckered into the wild enthusiasm camp about lenses with very fast apertures for most of my time in photography. When we shot with film cameras a faster lens meant a brighter viewfinder which meant easier focusing. An added benefit of focusing with a fast aperture lens at its widest setting was very narrow depth of field which also helped with nailing focus. 

Since everyone (most people?) were able to focus their faster lenses more accurately a mythology about the lenses existed. Since the lenses were better focused the resulting images at any aperture were sharper so they looked better. This led people to believe that the faster and more expensive lenses were also capable of higher overall performance. It made sense to people because they were, daily, judging the results of more accurate focusing and mistaking at least some of the benefit as coming from a better designed lens when compared to slower lenses. 

In the mid-1990s autofocus technology got better and better and camera makers didn't need to make focusing screens that were optimized for highest acccuracy (at the expense of brightness). Since nearly everyone buying newer and newer cameras used AF for almost every shot the camera makers looked at the compromise matrix of focusing screen engineering and changed the mix to favor super bright screens at the expense of manual focusing discrimination. All in all it's a compromise that makes the most sense for the most users. 

Now lenses both fast and slow would benefit from the same accuracy in autofocusing because the focusing was no longer done on the screen but buy an AF sensor instead. So, essentially, the need for super fast lenses for higher focusing accuracy was cancelled. But the mythology continued. 

I read an article which I can't source at the moment but it was about lens design. It may have been written by Irwin Puts about Leica lens manufacturing but it essentially made the point that more modest aperture lenses were much easier to manufacture with consistency and high quality than faster lenses. 

It seems that every time you need to increase the diameter of the lens elements to increase the speed of a given focal length a doubling of diameter requires many times more manufacturing accuracy than a slower lens. Also, fewer elements are required for optimal correction. 

For the first ten years of mass acceptance of interchangeable lens digital cameras (roughly 2000-2010) the one reason to own faster lenses was the rather poor noise performance of then available sensors. On my Nikon D2Xs any ISO over 400 was mostly unusable for commercial work. Noise reduction apps for post processing proliferated like bunnies. An argument could be made that companies like Sigma started designing their ultra-fast Art series line of primes in order to provide a sharp, wide open aperture to compensate for the low ISOs we needed to use at the time. But that never meant that fast lenses could be designed to out perform slower lenses for things like: contrast, sharpness, resolution and lower distortion. 

And those are all the things needed in most lenses to make them successful.

Now we've entered a new age with digital. It's the age of miraculous ISO performance in cameras. One no longer has a rationale, beyond the look of a particular lens design, to splash out two or three times (or more) money to buy a faster lens if an f2.0 lens offers all the performance of an f1.2 or f1.4 lens that weighs three times as much and takes up a lot more real estate in your camera bag. 

I write this because I'm trying to reform my bad lens buying habits by introducing some rational thought into the process. I guess my epiphany came when I struggled with the weight, size and ponderous AF of the original Sigma 85mm f1.4 Art series lens. It was a monster to handhold, and, if truth be told, it, like most ultra-fast lenses, was a one trick pony. It could do really great zero depth of field images. But after you've seen a few years worth of strangely narrow depth of field you come to realize that it's not a vital part of usual and successful imaging. Better to concentrate on shooting at apertures that let one actually see the majority of a subject clearly and with acceptable focus. 

Another rude awakening has been my odd dance with the Panasonic S-Pro 50mm f1.4 lens. Optically, it's magnificent. At f1.4 it's as sharp and contrasty as any Leica or Zeiss super star lens I've ever tested. When you stop it down it gets better and better. But it's ponderously large and also weighs a ton. I find that I very rarely take it out and shoot it for pleasure. Though I've had it well over a year I can count on my fingers and toes the number of times I've actually needed its particular performance envelope in the work that I do. And the work I see most commercial photographers pursue. 

When I head out the door for fun I look into a drawer filled with lenses and ponder. I like the 40-60mm range and at first I look to the 50mm lens and fantasize about how wonderful all the subjects I photograph will look by dint of the lens's amazing performance. Then I quickly become more rational, realize that I'll mostly be shooting at f4 or f5.6 and move on to finding a more comfortable and more than adequate alternative. Usually it's something like the Contax/Zeiss 50mm f1.7 or the Sigma 45mm f2.8. Lately, I've been shooting more often with the Sigma 65mm f2.0 and am finding it to be a powerful imaging tool. Very sharp at f2.0 and among the very highest performance long normal lenses extant, when used at f4.0 and f5.6. Why carry the weight if the f-stops at which you'll be photographing are in the middle of the range?

Even older lenses made for film cameras, if well designed and built, are delivering surprisingly competitive results at middle apertures. Even at f2.0 most of my lenses hold up well. Making the purchase of ultra-fast lenses kind of....stupid. 

Photographers are being regaled this month by a torrent of "news" about a new 50mm f1.2 lens from Sony. It's supposed to be really good, and maybe it is. But it's too expensive and it's not going to deliver a better photographic experience for most users compared to good lenses in the same focal length with which they already use. It might be better at f1.4 but by the time it gets to the optimum picture taking apertures of f2.8-f8.0 most of the benefits essentially are limited by the resolution and imaging potential of the camera sensors and the techniques of the users. But they will have splashed out big cash to mostly end up with performance that's a near even match with lenses with smaller maximum apertures. 

I'm also seeing an endless parade of 50mm lenses from Chinese makers that boast f.095, f1.0 and f1.1 apertures. Interest seems to be running high among the faithful. 

I've tested a couple of these and find them to be very difficult to focus well, wide open, and not very high performers when used that way. When stopped down they become....adequate. That's a pretty sorry review for modern lens. 

I'm more interested in lenses like the Sigma 45mm f2.8 which I've written about here from time to time. It's not great performer wide open but in the middle ranges it out performs just about any zoom lens and is better than similar focal lengths from Sony and several other makers when stopped down just one stop. Soundly outperforming them at two stops down (f5.6). It's built like a tank, is fun to use and still compact enough and light enough to be a 24/7 carry lens.

I think the reasons to own fast lenses are diminishing and as our hobby and industry continue to change I'm betting we'll see more and more lenses done in a traditional way = a fast enough aperture for any real use. A small enough footprint for comfort, convenience and handling, and a price that is affordable to many more users. I count all that as a win. 

Interested to know how you feel about this. Am I once again totally off base and wrong? What benefits (if any) do you get from using ultra-fast aperture lenses? Share?

Program note; written a few hours later:  Matti Sulanto is a Finnish photographer and a Lumix Ambassador. He has a nice and informative YouTube channel where he discusses nuts and bolts, reviews cameras and goes out for photo walks in all kinds of crazy weather. Today I wrote this blog post and ten minutes later I was on YouTube at Matti's channel only to find that his post today was also about the same subject. We posted almost simultaneously!!!

Here is Matti's take: https://www.youtube.com/watch?v=04InY8cyuEY

He's got a very slightly different take on it than I do.... but mostly we're in agreement. check it out.