[axl]

Hi all,

to all of you lot who own FA50/1.4 I have one simple favor to ask.

Could you please post some 100% crops of in focus areas shot at f1.4?
Curiosity is getting better of me and the fact that FA series has faaaaaaaaaaaaaaaaaast AF....

Regards
P

[Danny Delcambre]

Not f1.4. Over f2.0 better. I have my own FA 50mm f1.4. I use over f2.0-f22.
F1.4 is very thin. Not good.

[RickyFromVegas]

Maybe I'm doing something wrong, but at 1.4, its images aren't very usable for a lot of things.
It's soft, fuzzy and not sharp at all.

But above 2.8, it's amazing (pretty good).

Anyways, auto-focus at "how Starbucks saved.." book on a tripod @1.4
100% crop

[RioRico]

Maybe I'm doing something wrong, but at 1.4, its images aren't very usable for a lot of things.
It's soft, fuzzy and not sharp at all.

Actually it IS quite sharp. It's just sharp in a very very thin field, especially when the lens-subject distance is close. Plug some numbers into this DOF calculator and you'll see how little margin there is. And I'm not sure how flat its subject field is. So yes, getting wide-open sharpness is tricky.

But (as I've mentioned before) we don't use superfast f/1 or f/1.2 or f/1.4 lenses for edge-to-edge flatfield sharpness wide-open -- we use them to GRAB LIGHT, to capture otherwise-impossible images, for low-light or fast-action, and for DOF control. Just like we don't use macro or enlarger lenses (which ARE edge-to-edge flatfield sharp) for soft dreamy portraiture. Different tool for different tasks.

[SpecialK]

If you click on it a couple times it will be about 50%. Best I can do.

[SylBer]

IMHO, the FA 50mm f1.4 is very sharp at f1.4 WHEN the focus is perfect. The problem is it is very diffucult to focus because of the super thin depth of field.

[axl]

thanks goes to posters above,
anyone else willing to chime in?

[Rondec]

thanks goes to posters above,
anyone else willing to chime in?

My copy of the FA 50 always seemed pretty soft below f2.8. Thats one of the reasons I sold it and bought the DA 55. Unfortunately I don't have any comparison shots.

[RickyFromVegas]

Similar shot @ 2.8

[RickyFromVegas]

Another at 4.0

[Class A]

Curiosity is getting better of me and the fact that FA series has faaaaaaaaaaaaaaaaaast AF....

I can confirm that the FA 50/1.4 AF is very fast.

Regarding its performance below f/2.8 it is no secret that it produces soft images. Have you seen the Dpreview test of the FA 50/1.4? It features crops of f/1.4 shots compared to other aperture settings.

Blende8 has argued that the softness is mainly a loss of contrast and that resolution is retained to a large extent. I'm not sure what to make of that. The FA 50/1.4's optical design is rather straightforward and spherical aberrations just go out of hand close to wide open. The 50/1.7 has better performance in the f/1.7-f/2.8 region but its bokeh isn't as nice. The DA* 55/1.4, as you know, improves much on the FA 50/1.4 when it comes to sharpness wide open, in the centre and in particular in the corners.

I'd still prefer the FA 50/1.4 over the DA* 55/1.4 because in my experience FA 50/1.4 images shot at f/2.8 or stopped down further look excellent and have more of an FA Ltd touch than the DA* 55/1.4. This is my subjective opinion which a) everyone is welcome to differ from and b) may be based on too few comparisons (however, I'm quite certain I've seen enough shots from both lenses).

I don't shoot the FA 50/1.4 much below f/2.8 because then it does not only loses "bite" in the in-focus areas, its bokeh also becomes less appealing. Every time I try to exploit f/1.4 the resulting bokeh becomes distracting, IMHO. I'm sure one can exploit that for clever and cool bokeh effects, but below f/2.8 the FA 50/1.4's bokeh becomes less and less useful to create a non-distracting background.

Actually it IS quite sharp. It's just sharp in a very very thin field, especially when the lens-subject distance is close.

Getting the focus right is a challenge, but that's not the main issue with the FA 50/1.4 wide open. It simply isn't that sharp even if the focus is bang on. Several professional tests have confirmed it and it becomes apparent in comparison to more modern lenses that are sharper at f/1.4 like the DA* 55/1.4 or the Sigma 50/1.4.

Anyways, auto-focus at "how Starbucks saved.." book on a tripod @1.4

Please note that AF "points" are not points but rather large areas. It is impossible to unambiguously focus at exactly "how Starbucks saved..". You'll have to be prepared that the camera will settle on something adjacent to lock focus. As a matter of fact, in your latter shots, the books in front of the one you intended to focus on are in sharper focus. It could obviously be an FF issue but, again, with such a target you cannot be sure what exactly the camera went for.

Peter, I have f/1.4 shots from my FA 50/1.4 but have a look at the Dpreview review I linked to and let us know if you need to know more. As you probably know, Dpreview also tested the DA* 55/1.4 (requiring multiple attempts to get a good copy and even the last one they used wasn't a 100% OK) and you may use that test to compare against the FA 50/1.4 test. Since you know the performance of the DA* 55/1.4, this should give you a good feel for the FA 50/1.4.

[axl]

I can confirm that the FA 50/1.4 AF is very fast.

Regarding its performance below f/2.8 it is no secret that it produces soft images. Have you seen the Dpreview test of the FA 50/1.4? It features crops of f/1.4 shots compared to other aperture settings.

Blende8 has argued that the softness is mainly a loss of contrast and that resolution is retained to a large extent. I'm not sure what to make of that. The FA 50/1.4's optical design is rather straightforward and spherical aberrations just go out of hand close to wide open. The 50/1.7 has better performance in the f/1.7-f/2.8 region but its bokeh isn't as nice. The DA* 55/1.4, as you know, improves much on the FA 50/1.4 when it comes to sharpness wide open, in the centre and in particular in the corners.

I'd still prefer the FA 50/1.4 over the DA* 55/1.4 because in my experience FA 50/1.4 images shot at f/2.8 or stopped down further look excellent and have more of an FA Ltd touch than the DA* 55/1.4. This is my subjective opinion which a) everyone is welcome to differ from and b) may be based on too few comparisons (however, I'm quite certain I've seen enough shots from both lenses).

I don't shoot the FA 50/1.4 much below f/2.8 because then it does not only loses "bite" in the in-focus areas, its bokeh also becomes less appealing. Every time I try to exploit f/1.4 the resulting bokeh becomes distracting, IMHO. I'm sure one can exploit that for clever and cool bokeh effects, but below f/2.8 the FA 50/1.4's bokeh becomes less and less useful to create a non-distracting background.


Getting the focus right is a challenge, but that's not the main issue with the FA 50/1.4 wide open. It simply isn't that sharp even if the focus is bang on. Several professional tests have confirmed it and it becomes apparent in comparison to more modern lenses that are sharper at f/1.4 like the DA* 55/1.4 or the Sigma 50/1.4.


Please note that AF "points" are not points but rather large areas. It is impossible to unambiguously focus at exactly "how Starbucks saved..". You'll have to be prepared that the camera will settle on something adjacent to lock focus. As a matter of fact, in your latter shots, the books in front of the one you intended to focus on are in sharper focus. It could obviously be an FF issue but, again, with such a target you cannot be sure what exactly the camera went for.

Peter, I have f/1.4 shots from my FA 50/1.4 but have a look at the Dpreview review I linked to and let us know if you need to know more. As you probably know, Dpreview also tested the DA* 55/1.4 (requiring multiple attempts to get a good copy and even the last one they used wasn't a 100% OK) and you may use that test to compare against the FA 50/1.4 test. Since you know the performance of the DA* 55/1.4, this should give you a good feel for the FA 50/1.4.

thanks for that, I did have a quick look at dpreview review of both FA50 and DA*55 but I can't really tell much from the crops and in samples section there is very few pictures shot at f1.4. Also I think the DA*55 is flawed...

anyways, I do like DA*55 but have 2 issues with it:
a) AF - is not as slow as many say (maybe touch slower than 77ltd) but compared to my FA*24 and FA100/2.8 it's a slouch and by mile! These two lenses are superfast by Pentax standards and I'd love to have short tele that would rival them!
b) colours and overall rendering. By all means the DA*55 is not bad in any of these two but for me FA lenses have the best colours, followed by K series, M, A+DA. I really like the warm glow the FAs emit, which is very obvious in comparison of my line up.

I know about F/FA50/1.7 being sharp from wide open as I used to have F50/1.7.
Problem with those two is that they only sport 6 blades which makes for really fugly OOF by my standards
Sigma? No thanks, it's a brick of a lens and I'm really not fond of the onions in OOF highlights....

[dgaies]

I know about F/FA50/1.7 being sharp from wide open as I used to have F50/1.7.
Problem with those two is that they only sport 6 blades which makes for really fugly OOF by my standards

Somewhat off-topic, and certainly not a practical solution, but could one swap the apertures of the FA50/1.7 and FA50/1.4 if they wanted?

[farfisa]

Here are some shots I took the day I got mine. I don't have it any more or I could do more tests.

All shots at ISO 100 with the K-7; no processing except changing the WB

1/3200 100% crop:


1/5000 100% crop: detail isn't perfect, but not bad either; there's other stuff going on here too though, like in the white petals


..and no post of mine is complete without a kid shot!
1/200 Full image:


100% crop. The detail isn't bad for f/1.4, but you really notice the loss of contrast. At 1/200 on a K-7 there might have been a little shutter blur here too. A little work in post though and this shot is printable.

[dgaies]

..and no post of mine is complete without a kid shot!

True

Peter, this was the only one I could find online taken at f/1.4. I can check at home tonight for the full-sized version so you can see a 100% crop.

K-7 + FA50/1.4 @ f/1.4, 1/60s, iso1600