[ScooterMaxi Jim]

Back in the film days, we were pretty happy with most f/2.8 zooms. Then we wanted them for crop sensors because you need to get greater separation - less DoF. Really good zooms that around f/4 or f/3.5 aren't all the common, but when find them and can get good image quality out of them (the 16-45 and the a-series 35-105 for example) - those have a real advantage over all but the best f/2.8 zooms which are big, often heavy - and usually not decent until f/3.5 or 4 anyways. Not all, of course, but most often that's the case.

Then you have variable aperture zooms that tend not to give great results overall, but the 16-85 certainly dispels that notion.

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Last edited by ScooterMaxi Jim; 04-14-2015 at 09:10 PM.

[Des]

So the "f4 vs f2.8" zooms debate can translate to "f2.8 vs faster" for primes

Except when we are talking about telephoto primes.

By 300mm it's probably f4 v f2.8. And here we are talking completely different animals:
- Pentax DA*300 f4 - about 1070g, $1500
- Nikkor 300mm f2.8 - about 2900g, $5800.

Or if you prefer a legacy lens comparison:
- Pentax FA*300mm f4.5 - about 935g, $800
- Pentax FA*300mm f2.8 - about 2500g, $3,500+

This is a much starker choice than between say a DA40 f2.8 and FA 43 f1.9, or the much-debated DA 35 Ltd v FA 31 or DA 70 v FA 77.

[redrockcoulee]

FWIW, both Canon and Nikon offer a 70-200 f4, and Canon (not sure about Nikon) offers a 16-35mm f4 and a 24-70mm f4 too. So it's not like they are taking money from their coffers.

And it is the F4 lenses that Art Wolfe uses. His photos seem to Come out OK ☺

[Tony Belding]

When I got my Olympus OM-D E-M5, it was the first camera I'd bought in several years, and it seemed like an amazing low-lighter performer. Then I took it to an alpaca show, which was all indoors under yellowish (sodium?) lights, and I discovered the *only* lens I had that I could use was the 20mm f/1.8. My longer zooms weren't going to cut it.

Afterwards I looked wistfully at the Olympus 75mm f/1.8, but I never have sprung for it yet.

I've gazed wistfully at the Sony A7s as well. Why must they be so costly?

And then as others have mentioned, there's the whole bokeh issue.

I do love my new Samyang 35mm f/1.4. Yes, it's big and heavy. It's still wonderful, and autofocus is only a passing fad anyhow. I can use it on my old 35mm SLRs with the split prism and microprism focusing screen. That kind of focusing screen almost goes black when you put a f/4 lens on it; it's not usable. I'd love to get the new Pentax FF and put in a Katzeye and use with lenses like that Samyang.

But maybe I'm just not hip to the new ways of doing things.

[SpecialK]

Canon and Nikon offer a 70-200 f4

I'm mostly a daylight shooter, so I chose the 26-ounce f4 over the 50-something-ounce f2.8. It was also about $800 cheaper, which paid for 2 more used lenses.

[sterretje]

From an available light perspective I think we keep on raising the bar with our expectations. What we can do today with f/2.8 and ISO1600 can be done next year with f/4 and ISO3200. But then we start using f/2.8 and ISO3200 in even worse light conditions and have to wait a year (or two or) and f/4 at IS6400 is feasible. And we can go on

So I don't think that f/4 is the new f/2.8.

[stevebrot]

To me, there is not that much of a difference between f4 and 2.8

Yep...only one stop.


Steve

[stevebrot]

Back in the film days, we were pretty happy with most f/2.8 zooms.

I don't remember too many f/2.8 zooms back in the day (Pentax FA and back). Those who could afford them were likely very happy.


Steve

[normhead]

When I'm sitting out there in my blind in the falling light, trying to squeeze just a couple more frames out of the session, ƒ4 is not the new ƒ2.8. At the magic moment when I can no longer use 1/100/sec. with my ƒ4 lens, I'm pretty much done. Improving ISO puts off that moment a bit longer for a few more images, but the moment always comes, when you would have had 5 more minutes of shooting if you had ƒ2.8.

[cali92rs]

When I'm sitting out there in my blind in the falling light, trying to squeeze just a couple more frames out of the session, ƒ4 is not the new ƒ2.8. At the magic moment when I can no longer use 1/100/sec. with my ƒ4 lens, I'm pretty much done. Improving ISO puts off that moment a bit longer for a few more images, but the moment always comes, when you would have had 5 more minutes of shooting if you had ƒ2.8.

Thats the compromise of not only photography but life
Is the extra weight and cost worth it for the extra 5 minutes of shooting (or any other edge of the envelope situation ).
For the majority of folks, probably not. For some, they wish they would release an f2.0 zoom and wouldnt mind lugging around a 25 pound lens that cost $20k.

As long as there are billionaires, and people willing to drive insane speeds around hairpin curves, there will be Formula 1 cars They just will be expensive as hell and rare.

[jsherman999]

An f/4 constant zoom that is very sharp and contrasty wide-open is a godsend. My Sigma 100-300 f4 probably spends most of it's time at f/4, and I never lack sharpness.

On aps-c, it was a nice long telephoto option, but it sometimes lacked the low-light capability I wanted - on FF, it's perhaps better, more useful, for me.

So... f/4 is not the new f/2.8 - more total light makes for better images - but f4 is certainly a nice option some of the time when sacrificing light or subject isolation a little doesn't harm the image in a significant way.

[ScooterMaxi Jim]

I don't remember too many f/2.8 zooms back in the day (Pentax FA and back). Those who could afford them were likely very happy.


Steve

Actually, I had two of them. The Tokina 24-40 which is a great lens now for video - especially for interviews - was considerably better than the Tokina primes; damped focus and zoom mechanisms feel just as good as the best m-series lenses. Still, you wouldn't want to use that one wide open. The Tamron 28-75 (shot on Canon) is a totally different lens at f/4 vs. 2.8 - unrecognizable going from moderately soft at all lengths to very sharp in one stop. These were relatively small, fairly inexpensive lenses. Its a shame that Pentax didn't take f/4 zooms seriously until the 16-45 came along.

[D1N0]

There actually was a 24-50mm F4 (F) and I have a nice litte 28-70mm F4 (FA very plasticky).

[ScooterMaxi Jim]

There actually was a 24-50mm F4 (F) and I have a nice litte 28-70mm F4 (FA very plasticky).

I think Pentax was somewhat serious about the 24-50 and the FA 24-35 - which is an especially odd lens (I didn't think anyone would try a 24-40 again after that went over poorly due to limited range). However, I am colored by the 28-70 which is an interesting lens only in that it is so small - but the optical quality is not better than the current-day 18-55s, and build is far worse.

[northcoastgreg]

My primes consisted of the DA21, F50 f1,7 and DFA 100 macro WR. I found that 50mm was too tight for me, and went with the DA40 instead. I can confess that I do not, at any time, miss having something faster than f2.8.

I've gone even more extreme with slow primes. I have the DA 15 f4, the M 20 f4, K 28 f3.5 and the K 35 f3.5. And not only don't I miss anything faster, I rarely shoot any of these lenses wide open. I just don't need fast apertures at those focal lengths.

Really good zooms that around f/4 or f/3.5 aren't all the common

This is the main problem with the slower glass: there's a perception, which is often justified, that the slower glass is not as good, even at lower apertures, than the f2.8 zooms. I would guess there's considerably more than twice as many f2.8 professional grade standard zooms as there are f4 pro standard zooms. Indeed, the only pro grade f4 standard zooms I can think of are the Canon 24-105, the Canon 24-70, the Nikon 24-120, the Sigma 24-105, and the Sony FE 24-70.

It doesn't look like f4 will be the new f2.8 in Pentax's upcoming FF system. Pentax is making the obligatory trio of f2.8 zooms, with what looks to be a variable aperture standard kit zoom thrown in to win over cash strapped FF-ophiles. Nonetheless, I'm hoping at some point to see a DFA* 24-105 f4 enter Pentax's FF lineup.