rb61 Loc: Maple Grove, MN

Coming from 40+ years of film, should I still be obsessed with fast lenses? I liked them for easy focusing (MF). Fast lenses became more important as I aged.

Do current autofocus lenses gain any advantage from faster lenses?

Thanks

TriX Loc: Raleigh, NC

Yes - Lower ISO, shallower DOF to isolate subjects, faster auto focusing....

RichardTaylor Loc: Sydney, Australia

CHG_CANON Loc: the Windy City

You can still be obsessed with f/1.2 to f/2.8 lenses. You can also spend a lot less for f/4 zoom lenses, universally supported by image stabilization technology. Yes, AF works better with lenses that pass more light onto the AF sensors. In the lowest light, AF for an f/2.8 lens is going to be better than an f/4 lens and both better than an f/5.6 lens. But outside uniquely demanding situations, you're not going to find / notice a different in AF performance between f/1.2 lenses and f/5.6. It's not the max aperture of the lens as much as the quality / pro-grade aspect of the AF motor in the lens.

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

And they are much sharper and lower in CA and other flaws at F4 or F5.6 than a slower lens. Also, faster lenses cost more, are usually better built and offer superior overall image quality. Usually, but not always.

LWW Loc: Banana Republic of America

Also, a fast zoom would be a slow prime ... so blazing fast 1.8 prime glass is lighter and less expensive than a 2.8 zoom.

bleirer

There are so many variables to the question and so many tradeoffs, it's hard to answer. In general sure, but it depends on the lenses, in a side by side comparison in good light on a camera that handles noise well and you are not desiring narrow depth of field, maybe worth the extra weight and size and money or maybe not.

leicajah Loc: Texas, grew up in Louisiana

I have more problems focusing a faster lens when it is wide open

LFingar Loc: Claverack, NY

I was always of the opinion that with the low-light capabilities and image stabilization of today's bodies and lenses that fast lenses weren't all that important anymore, except for DOF. Over the past ten months, after buying a Canon EOS R, I sold my last DSLR, a 5DIV, and most of my EF lenses. I now have 4 RF lenses, two of which are fast primes. An RF 50mm f/1.2 L and a RF 85mm f/1.2 L. They are quickly becoming my favorite lenses. They focus incredibly quickly, even in conditions where an f/4 would hunt and sometimes not focus, plus IQ and color rendition are the best I have seen. Plus, they can really make a subject pop when shot wide open. The RF 15-35mm f/2.8 L that replaced my EF 16-35mm f/4 L is also impressive for its quick focus and low-light ability. I'm beginning to understand why some people are obsessed with fast lenses. If you still are then I would guess that you have plenty of company!

TriX Loc: Raleigh, NC

👍👍

JD750 Loc: SoCal

Yes and no. Photography is about optics. It still is. But digital sensors have a much greater ISO range than film had. And modern sensors are relative free of noise easily up to ISO 800 and above. So that can make up for a stop or two on the lens.

However, lower ISO is still lower noise and fast lenses still provide the same advantages, in dim lighting.

And fast lenses provide the option for shallow DOF as well.

TriX Loc: Raleigh, NC

Indeed! It’s easy to think that modern sensors with high ISO capability obviate the need for fast lenses - they don’t. When I moved from ASA 400 (pushed to 800-1200) film, I thought that too, but after awhile, I learned better.

Jeffcs Loc: Myrtle Beach South Carolina

Not sure if it would be posible but! For those of aging wonder if manufacturers could incorporate a split image focusing screen
That said
I prefer as fast glass as possible for several reasons
Generally the quality of a fast lens better built
Better lens coatings
Generally sharper edge to edge
Better boca wide open
And yes faster more light equals
Lower ISO
Easer focusing
Just to point out a couple things

LWW Loc: Banana Republic of America

Another thing is that a prime has fewer elements and fewer moving parts which allows them to not only lock onto focus quicker but also to maintain that focus alignment over time.

larryepage Loc: North Texas area

Many years ago, when I was using Olympus OM 35mm film equivalent, I progressed through three 50mm Zuiko lenses...f1.8, f1.4, and finally, f1.2. The total journey was just about one f-stop, but it was really much, much more than that.

The f1.8 was clearly and unarguably a consumer grade lens. Lightweight and not real sturdy. Serviceable, but not great. Reasonably sharp, but never in the corners. My first real hint of trouble was during my first photography course, when our photographs were judged and graded all the way out to the edges and I got tired of taking hits for my entire image not being good and not being able to do anything about it. (We had to print the whole frame in that class, including at least a little bit of the negative border.)

I eventually found a slightly used 50mm f1.4, which made quite a big difference. In addition to the extra half stop, it had the advantage of being an intermediate grade lens. Not perfect, but much better than the 1.8, and quite a bit better over the entire frame.

When KEH had their retail store in Dallas during the 1990s, it becamea place that I liked to visit. King Grant was there pretty often, and his wife, who was the store manager was also. On one of my visits, they had a Zuiko 50mm f1.2. I didn't really think I needed it, but bought it anyway, and wow... That was a real, professional lens. Yes...it had an extra half stop of aperture, but that wasn't the main point. It was a true, professional grade lens of the absolute best design and construction. It was a joy to use, and it was sharp all the way to the corners. (And yes, it did look really cool taking pictures through that big "windshield."

The prices and weight of those lenses progressed along with their exposure capability. But I guarantee it wasn't just the difference in maximum f-stop among those lenses.

Bokeh wasn't a thing then, by the way, and was never a consideration among those lenses.