What the Duck! D-FA* 50/1.4

**ffking** · 08-04-2018, 12:55 PM - **1 Like**

Originally posted by normhead

The big question is, is it good enough users will stop converting Leica and Zeiss 50s.

Not just that, IMHO - it will make users of other systems keen to keep Pentax alive

ZeljkoS · 08-05-2018, 07:22 AM

Originally posted by normhead

It's KAF4, and only works on a K-5 at ƒ1.4 and green mode or AV as far as I know. I know KAF4 doesn't work on my wife's K-5. (We have a55-300 PLM, the other KAF4 lens.)

that's not good. I see in in the lens database that it has KAF4 with electromagnetically actuated aperture, so K-5IIs cannot control it. Of course, K-50 is supported via firmware upgrade, but K-5IIs is just too old

Also, the lens compatibility check says "Compatible with limitations"? I would say incompatible, if the only aperture you can use is wide open...

phoebus · 08-05-2018, 07:33 AM

Originally posted by ZeljkoS

that's not good. I see in in the lens database that it has KAF4 with electromagnetically actuated aperture, so K-5IIs cannot control it. Of course, K-50 is supported via firmware upgrade, but K-5IIs is just too old

Also, the lens compatibility check says "Compatible with limitations"? I would say incompatible, if the only aperture you can use is wide open...

Works quite nicely at F1.4 ....

;-)

Would probably feel a bit front heavy on the K5 though.

MikeyBugs95 · 08-08-2018, 09:21 AM

I figured it was going to be something about ducks... Nice pictures.

MJKoski · 08-09-2018, 02:11 AM

Image center is somewhat like Zeiss Milvus 50mm f/1.4 shot wide open. Acceptable. But then again, what was the point of the test photo? Duck's eye? Kind of same issue of having very sharp human eye and the rest of the face blurred. Waiting for someone to plan a dramatic landscape shoot in really nasty weather and punish the lens properly.

davidsladek · 08-09-2018, 06:08 AM

Originally posted by MJKoski

Image center is somewhat like Zeiss Milvus 50mm f/1.4 shot wide open. Acceptable. But then again, what was the point of the test photo? Duck's eye? Kind of same issue of having very sharp human eye and the rest of the face blurred. Waiting for someone to plan a dramatic landscape shoot in really nasty weather and punish the lens properly.

You are obviously not a fan of shallow DOF and bokeh so this picture clearly wasn't for you. And I am not going to start calling for nasty weather just to please you

MJKoski · 08-09-2018, 06:13 AM

AW spec! Come on

Just a little bit water, waves and sand.

davidsladek · 08-09-2018, 06:20 AM

Originally posted by MJKoski

AW spec! Come on

Just a little bit water, waves and sand.

I can tell you that I've never been so nervous about seeing specs of dust on the front element... it is so big and beautiful almost makes people stare into it like in a mirror

MJKoski · 08-09-2018, 06:37 AM

Slap a polarizer there permanently. Good one not to spoil the IQ too much.

normhead · 08-09-2018, 08:02 AM - **1 Like**

Originally posted by Paul the Sunman

I don't drink alcohol, so does that mean I can buy the lens?

Only if you start a fund called "beer money" and put $60 a week into it.

stevebrot · 08-24-2018, 04:18 PM

Originally posted by Pikselisiirto

Why out of focus areas are especially prone to chromatic aberrations?

That is typical of longitudinal CA (sometimes referred to as "bokeh CA"). That being said, I don't see any CA (Lo or La) in the duck shot, though there is birefringence typical of bird feathers and perhaps some moiré. The main concern is that the subject is for the most part out of focus.

Steve

davidsladek · 08-28-2018, 01:31 AM

Originally posted by stevebrot

That is typical of longitudinal CA (sometimes referred to as "bokeh CA"). That being said, I don't see any CA (Lo or La) in the duck shot, though there is birefringence typical of bird feathers and perhaps some moiré. The main concern is that the subject is for the most part out of focus.

Steve

which is exactly as expected when one is trying to show the sharpness and bokeh of a 1.4 aperture

I certainly didn't shoot the pictures to get the whole bird in focus, apologies

stevebrot · 08-28-2018, 09:01 AM

Originally posted by davidsladek

which is exactly as expected when one is trying to show the sharpness and bokeh of a 1.4 aperture

I certainly didn't shoot the pictures to get the whole bird in focus, apologies

Indeed, depth of field is quite precious at f/1.4, particularly if pixel peeping. My comment was in response to the claim that there are pervasive optical aberrations in the photos. There is none. The last statement was in regard to the comment's suggestion that the lens is soft at f/1.4. I did not feel there was evidence to judge one way or another.

Your lens shows lovely bokeh and very pleasing transitions. It is an impressive tool.

Steve

08-28-2018, 09:01 AM	#43
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by davidsladek which is exactly as expected when one is trying to show the sharpness and bokeh of a 1.4 aperture I certainly didn't shoot the pictures to get the whole bird in focus, apologies Indeed, depth of field is quite precious at f/1.4, particularly if pixel peeping. My comment was in response to the claim that there are pervasive optical aberrations in the photos. There is none. The last statement was in regard to the comment's suggestion that the lens is soft at f/1.4. I did not feel there was evidence to judge one way or another. Your lens shows lovely bokeh and very pleasing transitions. It is an impressive tool. Steve Last edited by stevebrot; 08-28-2018 at 10:29 AM.

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08-04-2018, 12:55 PM - 1 Like	#31
ffking Site Supporter Join Date: Nov 2015 Location: Old South Wales Posts: 6,038	Originally posted by normhead The big question is, is it good enough users will stop converting Leica and Zeiss 50s. Not just that, IMHO - it will make users of other systems keen to keep Pentax alive

08-05-2018, 07:22 AM	#32
ZeljkoS Veteran Member Join Date: Feb 2014 Photos: Gallery \| Albums Posts: 421	Originally posted by normhead It's KAF4, and only works on a K-5 at ƒ1.4 and green mode or AV as far as I know. I know KAF4 doesn't work on my wife's K-5. (We have a55-300 PLM, the other KAF4 lens.) that's not good. I see in in the lens database that it has KAF4 with electromagnetically actuated aperture, so K-5IIs cannot control it. Of course, K-50 is supported via firmware upgrade, but K-5IIs is just too old Also, the lens compatibility check says "Compatible with limitations"? I would say incompatible, if the only aperture you can use is wide open...

08-05-2018, 07:33 AM	#33
phoebus Pentaxian Join Date: Jun 2013 Location: Buckinghamshire (UK) / Morbihan (FR) Photos: Gallery Posts: 470	Originally posted by ZeljkoS that's not good. I see in in the lens database that it has KAF4 with electromagnetically actuated aperture, so K-5IIs cannot control it. Of course, K-50 is supported via firmware upgrade, but K-5IIs is just too old Also, the lens compatibility check says "Compatible with limitations"? I would say incompatible, if the only aperture you can use is wide open... Works quite nicely at F1.4 .... ;-) Would probably feel a bit front heavy on the K5 though.

08-08-2018, 09:21 AM	#34
MikeyBugs95 Pentaxian Join Date: Sep 2017 Location: New York Photos: Gallery \| Albums Posts: 1,206	I figured it was going to be something about ducks... Nice pictures.

08-09-2018, 02:11 AM	#35
MJKoski Veteran Member Join Date: Aug 2016 Posts: 1,784	Image center is somewhat like Zeiss Milvus 50mm f/1.4 shot wide open. Acceptable. But then again, what was the point of the test photo? Duck's eye? Kind of same issue of having very sharp human eye and the rest of the face blurred. Waiting for someone to plan a dramatic landscape shoot in really nasty weather and punish the lens properly.

08-09-2018, 06:08 AM	#36
davidsladek Veteran Member Join Date: Sep 2006 Location: Surrey Photos: Gallery \| Albums Posts: 346 Original Poster	Originally posted by MJKoski Image center is somewhat like Zeiss Milvus 50mm f/1.4 shot wide open. Acceptable. But then again, what was the point of the test photo? Duck's eye? Kind of same issue of having very sharp human eye and the rest of the face blurred. Waiting for someone to plan a dramatic landscape shoot in really nasty weather and punish the lens properly. You are obviously not a fan of shallow DOF and bokeh so this picture clearly wasn't for you. And I am not going to start calling for nasty weather just to please you

08-09-2018, 06:13 AM	#37
MJKoski Veteran Member Join Date: Aug 2016 Posts: 1,784	AW spec! Come on Just a little bit water, waves and sand.

08-09-2018, 06:20 AM	#38
davidsladek Veteran Member Join Date: Sep 2006 Location: Surrey Photos: Gallery \| Albums Posts: 346 Original Poster	Originally posted by MJKoski AW spec! Come on Just a little bit water, waves and sand. I can tell you that I've never been so nervous about seeing specs of dust on the front element... it is so big and beautiful almost makes people stare into it like in a mirror

08-09-2018, 06:37 AM	#39
MJKoski Veteran Member Join Date: Aug 2016 Posts: 1,784	Slap a polarizer there permanently. Good one not to spoil the IQ too much.

08-09-2018, 08:02 AM - 1 Like	#40
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Originally posted by Paul the Sunman I don't drink alcohol, so does that mean I can buy the lens? Only if you start a fund called "beer money" and put $60 a week into it.

08-24-2018, 04:18 PM	#41
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Pikselisiirto Why out of focus areas are especially prone to chromatic aberrations? That is typical of longitudinal CA (sometimes referred to as "bokeh CA"). That being said, I don't see any CA (Lo or La) in the duck shot, though there is birefringence typical of bird feathers and perhaps some moiré. The main concern is that the subject is for the most part out of focus. Steve

08-28-2018, 01:31 AM	#42
davidsladek Veteran Member Join Date: Sep 2006 Location: Surrey Photos: Gallery \| Albums Posts: 346 Original Poster	Originally posted by stevebrot That is typical of longitudinal CA (sometimes referred to as "bokeh CA"). That being said, I don't see any CA (Lo or La) in the duck shot, though there is birefringence typical of bird feathers and perhaps some moiré. The main concern is that the subject is for the most part out of focus. Steve which is exactly as expected when one is trying to show the sharpness and bokeh of a 1.4 aperture I certainly didn't shoot the pictures to get the whole bird in focus, apologies