[toni-a]

Shallow depth of field, subject isolation, all those are interesting in portraits but how muchof it do we really need ?

when using my 50f1.4 I rarely use it at f1.4 why ? DOF is too shallow, I want the whole face i focus, with my 100mm macro on full frame, I never felt I needed more DOF, for some shots it is good to have a lot of blur but not for all of them.

it is worth carrying the extra weight and often using ND filters for that extra blurr ? I am in the middle of a decision of getting an ultra fast portrait lens, so help me decide before I end up with a dust collecting expensive item

[Klaus]

Well, it all depends on the shooting distance ...

[JJ_SO]

If you need to decide between f/1.4 or f/1.8, I'd say the aperture alone should not be the decision to make, but mostly it's a useless discussion. Wide open lenses need more accuracy for focusing, but also deliver more light for the focusing unit. Even if you don't take pictures with a wide open lens, you benefit for the more simple definition of sharp areas.


And in turns of DoF, yet another useless discussion. DoF gives you no room of sharpness, it's room of increasing less blur, but maximum sharpness exists still only in a shallow area.


If you have a wide open lens, you can use more bokeh, if you have no wide open lens, forget nicely blurred background. That doesn't mean you don't get great portraits.

[Rover]

Shallow depth of field, subject isolation, all those are interesting in portraits but how muchof it do we really need ?

when using my 50f1.4 I rarely use it at f1.4 why ? DOF is too shallow, I want the whole face i focus, with my 100mm macro on full frame, I never felt I needed more DOF, for some shots it is good to have a lot of blur but not for all of them.

it is worth carrying the extra weight and often using ND filters for that extra blurr ? I am in the middle of a decision of getting an ultra fast portrait lens, so help me decide before I end up with a dust collecting expensive item

I had the same problem with the 70-200/2.8L IS that I have, very often I was forced to shoot at wider apertures due to poor light, and ended up with not enough DOF for real life shots (especially theatre - thankfully I don't do that one anymore). Say, I had to use f/3.5-4 to eke out decent shutter speed, where f/6.3-8 would be a minimum requirement for getting more than a part of one actor's face in focus. And no, it was not always possible to get closer and use the 16-35 instead (apart from the fact that I'd be getting a very different perspective - disjointed, for a lack of a better word).

I have one f/1.4 lens but I'm mostly using it in very lousy light. Ironically enough, it's the least accurate of my lenses AF-wise in such conditions - it incurs a noticeably higher degree of OOF shots (including completely blurred ones) where the 16-35/4 just gets there (albeit with some struggle at times). The lens in question... 24/1.4 L II. By the way, if anyone has had the same experience as me, please tell me - I'm eager to know if something is wrong with my copy, or it's a common trait of this model... (but no, I'm not ready to put it on the chopping block - when it is in the right mood, it's making wonderful shots).

[davidmanze]

I like wide apertures for portraits and blurring backgrounds that would otherwise be distracting!

 

 My Nikor MF  55 F1.2 is great if you can nail the eyes, it's not easy but it can look very classy if you get it right.

 

  Away from 50mm,  F1.4 gets expensive, only you can say

[Studor13]

An f2.8 lens may not be great unless stopped down to say f3.2 or f4. But an f1.4 lens is almost certainly going at its best at f2.8.


So, there are other good reasons to get a faster lens, other than better bokeh/shallow dof.


You are not getting a worse lens by going faster. On the contrary!


And this is why they are more expensive.

[toni-a]

Yes but price difference and weight and bulk go along with it.

Also regarding sharpness which 85-100 mm prime is significantly sharper than 100mm macro at f2.8 ?

I am just in the decision phase get a fast 85mm prime or don't

[Klaus]

Again, you may not need an ultra-fast aperture for head portraits but you do "require" it for full body portraits.

[obican]

I prefer ultrafast lenses for full body shots, like this:

 



 

Ok it's not a person but you get the idea.

 

 

An f2.8 lens may not be great unless stopped down to say f3.2 or f4. But an f1.4 lens is almost certainly going at its best at f2.8.


So, there are other good reasons to get a faster lens, other than better bokeh/shallow dof.


You are not getting a worse lens by going faster. On the contrary!


And this is why they are more expensive.

 

Sony 85/2.8 is a little piece of gem that is probably as sharp as any fast 85/[email protected] at f/2.8 so there are exceptions and this one is quite a cheap exception too.

[wojtt]

Might be too late to join the discussion already, but I guess I can share my story. As for portrait lenses, I'm really a fan of the fast glass even if I don't use it at f1.2 or 1.4 all that often. I tried different lenses starting from the "reasonable" 1.8 primes,  then eventually going for the pro f2.8 zooms, some macro 100mm in between, then  migrating finally to fast primes ...and selling the other lenses to finance it   A rather expensive way to find out what I really like, granted, but it's just that with the fast lenses, usually at the top of the ladder, I found better drawing, colour, contrast. The wider aperture, wide-open bokeh and limited DOF was a bonus.

 

However, that is a subjective choice and yours might be different. It's not always a rule that a (new ) fast  lens has to be better than the old - it all depends on your needs.  For me the Canon 85L 1.2  is so much better then either the f1.8  or the macro 100L (slow AF), that I had to take the plunge   

 

Back in my Nikon days I enjoyed a lot the 85mm 1.4D, a much nicer rendition at wide open till f4 then the newer 85 1.4G lens - but that is my own preference, for a classic look where the "center" is reasonably sharp and the outer part of the frame goes away in a nice blur   Then maybe that's also why I'm so tempted to try the Fuji X, despite it's limitations, but drawn into it becouse of the colour and overall rendering of the image with the Fuji primes (35mm and 56mm). Well just my 2c