[jeverettfine]

Yes, modern DSLR's are more difficult to focus manually, the screens just are not as good (thus us Pentax Users love hearing and seeing that little red bleep). Back with manual cameras, a 1.4 lens in a low light situation made precise focusing much easier and yes, they were generally sharper stopped down. The f/1.0 lenses were optimized to be used wide open. Why else would you want one.

As far a Bokeh is concerned, shoot wide open and it is guaranteed to be round.

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Last edited by jeverettfine; 03-14-2016 at 08:56 AM.

[LensBeginner]

the jagginess isn't caused by stopping down. It's due to the shape of the aperture blade. has got nothing to do with lens speed.

Jaggines is caused by stopping down, because when you stop down you move the aperture blades (or you move a stop on the lens and the camera moves the blades for you when you shoot, which ultimately leads to the same outcome)...

It is also related to lens speed, since they both impact the end result, and since old 6-blades lenses like the one I mentioned will generally have a round bokeh wide open, so you actually choose the speed at which rhe bokeh is round when you choose a lens of a given speed.

For instance, speaking of SMC-M, a 50/2 will produce a round bokeh wide open, just like the 1.7, but of course at a different f-stop
Knowing at which aperture one is likely to shoot, one can make the tradeoff between sharpness, bokeh shape, f-stop (speed and DoF) etc. in a conscious way.

...next time I'll probably write two or three time the text, since as soon as someone makes the mistake of leaving some basic thing implied on a forum, he's immediately "corrected"... jeez!

@Na Horuk
I brought up that example because, as I said, it's a lens I use all the time, and it is a phenomenon worth considering. I also have a DA 40mm XS, but I don't think I like it as much as the 50mm.

If one uses a lens with many and/or rounded blades, the phenomenon can be less apparent, but I'm starting to think that having rounded aperture blades (or lenses which are well corrected for various CAs) isn't necessarily something you would want... it's merely another of the many tradeoffs that you are forced to make in photography (see the interesting blog entries by Yannick Khong someone linked here in PentaxForums)

[Winder]

Why does it seem to have become the Holy Grail of lens and/or camera performance? As most cameras and photographers struggle focusing with it and the extreme narrow DOF is a minority taste its importance seems overrated.

Good AF systems don't really struggle with it. AF accuracy of the new mirrorless systems make it pretty easy. DSLRs with a mirror need to be calibrated to the lens, but with a good AF it should AF just fine. The AF in the K-5 was just not accurate enough for my F/1.4 85mm. The K-3 does a much better job. The Sony A7II with Eye AF lock gives you dead on AF at any aperture 99% of the time.

Event shooters often don't have the luxury of controlling the light or the background. In studio you don't need F/1.4 most of the time. Working a venue that doesn't allow flash makes fast glass a must have. Being able to shoot wide open and have the busy background melt away and separate from your subject is what make you work look different than something taken with an iPhone. Yes, it is a pain in the @$$ to work with, but when you nail the right shot with it you will love the results. Is it overblown? Yes, but for many professional photographers the fast prime is a must have.

Its not something all photographers need.

[WPRESTO]

Do you think if we'd had electronic flash sooner (hypothetically the magic flash fairy comes along and grants it to us), things might have taken a different path? With light on tap whenever we needed it, would the onus of the candid photographers then have been placed more on the film companies to improve the grain of their faster films?

The electronic versus flashbulb debate is had in my edition of Keppler's "The Pentax Way" (1972, incorporating the Spotmatic ES but not the F), when both were still very much contemporary; even then, with the expense of the electronic units being admitted, the practical concerns were leaning away from flashbulbs because of their one-shot nature and the need to change them to continue shooting.

I had a copy of Kepler's book. He was always sympathetic to Pentax when Canon & Nikon were establishing their dominance (and brands such as Topcon, Exacta, Praktica, Petri, Miranda, Konica, etc. etc. were still around). The bulb/strobe debate went on so long as both required guide number calculation to determine exposure, but bulbs were really doomed when the first auto-exposure strobes were introduced (when was that?). However, 1972 is LATE in the pursuit of a f1.4 normal lens. I'm thinking about the 1950's and early 60's as the period when "natural light candid photography" was the thing to do and that meant: 1) natural light; and 2) being unnoticed so that the subject would never realize a picture had been taken. Granted there were photographers who used bulbs for street photography when the light was low, but at least some of them were using 4X5's equipped with f4.5 lenses and were using screw-base flash bulbs the size of a 40W incandescent. (WeeGee comes to mind).

[GeneV]

As many have noted, it was very important with manual focus film cameras. However, I could probably count on my fingers and toes the number of good photos I have taken on film at f/1.4 over the last 40 years. For some journalistic situations I suppose it was useful, but the times you really want DOF that shallow are few and far between.

[gmans]

This is interesting and explains some fascination with the fast lens.

You Tube

You Tube

[WPRESTO]

V-A-V high speed lenses. Just out of curiosity I went on EBAY to see what the asking is for a 0.95 Leitz Noctilux. Goes from about $4500 to just shy of $9000 (for a new one). Apparently the real collector's item is a 50mm f1.2 Noctilux for which you'll have to anti-up between $17,000 and $19,000 USD. One should expect some pretty decent IQ and bokeh for that price, certainly better than what you'd get from a 50mm f3.5 collapsible Elmar.

[normhead]

To, me it's not important at all. I've never owned an ƒ1.4 lens. I've never felt the urge to buy one. For me, I'm going to be carrying 7 lenses for up to two weeks on canoe trips, and I carry them all at the same time. Ounces count. Fast lenses get left home. My old reliable FA 50 1.7 is rarely used, though it always comes. If you use your 50 1.7 for less than 2% of your photos, you definitely don't need 1.4.

But I do see lenses like the FA 50 1.4 and the DA*55 1.4 and think " I should try one of those out." But, I think the same thing about the K-1, the d FA 150-450, the DA 560, the D FA 70-200, the DA*200, the 15 ltd, and the D FA 100 macro, the FA*250-600. I see 1.4 as something I might get to, but, usually when I look at the sample image, I don't see the type of image, I'm likely to ever take. Others are completely fascinated by that type of image, to the point of being obsessed.

So in answer to "Why is f1.4 so important?"
It's all about you. Is it important to you, or isn't it?

It's Ok to make narrow DoF a signature or your style.
It's Ok to ignore it completely.

[pathdoc]

Apparently the real collector's item is a 50mm f1.2 Noctilux for which you'll have to anti-up between $17,000 and $19,000 USD.

I'll pass, thanks. At that price, I could have the K-1 and just about all the D-FA zooms with change left over. Or even a 645Z and at least one lens for it. Next to that, the SMC-A 50/1.2 is just a drop in the bucket (and probably not much worse in IQ terms).

[todd]

It's often said that FA50/1.4 needs to be well stopped down to be 'acceptably' sharp... I understand why this is said, but it doesn't get said often enough that there are some scenarios where it can be used, like when one may actually want less sharpness for creative purposes. When I have most often used it is in low light, when the sharpness it provides is usually acceptable to me... This shot was K3 + FA50 at 1.4, hand-held at 1/5s, ISO1250...



I have the luxury of being an unprofessional, so I don't know how much better this could get with some other lens or rig by someone more skilled. I just know it's 'acceptably' sharp - for me - for that low light level. Had I used my FA43 or FA77 wide open I'm not sure how much better the result could have been in that low of light. Of course the ISO would have needed to be higher too, and couldn't have gotten the same angle with FA77 without grabbing a chair, or doing the shot over when my K1 arrives (and puppy is much bigger now though haha)...

Another use I've made out of F1.4 with this lens is low-light Brenizers, and it works well with - for me - acceptable sharpness.

[WPRESTO]

The lovely picture above is a good example of the some-things-sharp, everything-else-soft use of a very wide aperture. The fact that the woman's face is out of focus, whereas the dog's muzzle and her hand are sharp is what creates a sort of dreamy atmosphere in the image. "Happiness is a warm puppy."

[normhead]

When I do my own images with the Sigma 70 2.8 macro, I always shoot a different ƒ-stops and select the one I like. So, what I'd like to see is, what does this image look like at 1.7 or 2 or 2.4 or 2.8? While the above is a very nice picture, I have nothing to compare it with. SO as a non-1.4 owner, it leaves me with more questions than it answers. My first question would be, how would it have looked with my 70 2.8, which is my favourite portrait lens among the ones I own. But then, I tend to look for reasons not to buy lenses, and buy the least I can get away with, unless they are under $80, in which case I'll buy them just to play with them.

[WPRESTO]

Confession: I also look for reasons, and logic, and common sense to avoid buying another lens, but I fail.

[normhead]

Confession: I also look for reasons, and logic, and common sense to avoid buying another lens, but I fail.

The good thing is, when you fail, you have a new lens to play with to distract you from your grief.

[WPRESTO]

The good thing is, when you fail, you have a new lens to play with to distract you from your grief.

New lens encourages me to take pictures, just to see what it will do. Not a total cure for inertia, but close.