Uneven aperture blades on FA 50 1.4

RiverKayaker · 09-06-2018, 07:01 AM

Hi, I noticed that the aperture blades on my FA 50 1.4 look uneven beginning around f4-f2.8. Photo attached. Can anyone with experience confirm if this is a problem? I am going to be selling the lens and never noticed this before. I want to determine if there's a simple way to correct this or not. If there's no easy method of fixing it, please let me know what would be the most honest and accurate way to describe the impact that this issue has so that I can fully disclose this information when I sell it. Thank you kindly.

**BigMackCam** · 09-06-2018, 07:30 AM - **1 Like**

There's nothing wrong with it. Many lenses will have slightly uneven closing of the blades due to manufacturing tolerances and a certain amount of free "play" in the mechanism. It typically varies copy to copy, and can even vary shot to shot. Yours is extremely minor compared to some. Nothing to worry about

Ronald Oakes · 09-06-2018, 10:34 AM

Just because its not 1000% symmetrical doesn't mean there is a problem.
I had a Pentax-F 50mm 1.7 that isn't even either. It was bought NEW in the box.
I returned it to the store I bought it in Tucson and they agreed to replace it.....the replacement wasn't perfect either so I kept it.
Its aggravating , but I just learned to ignore it as its a great lens.

RiverKayaker · 09-06-2018, 11:44 AM

Great. Thanks for the responses, guys! So would it be truthful to state that this is characteristic of the lens and does not cause any noticeable affect to image rendering? I personally don't see any affect to image quality.

**BigMackCam** · 09-06-2018, 12:53 PM

Originally posted by RiverKayaker

Great. Thanks for the responses, guys! So would it be truthful to state that this is characteristic of the lens and does not cause any noticeable affect to image rendering? I personally don't see any affect to image quality.

It's not even characteristic of that specific model. It's simply common across a wide range of lenses. I'm a stickler for honest advertising, but I wouldn't even point this out to the potential buyer... As I said, compared to many lenses, it's extremely minor - really, it's negligible.

RiverKayaker · 09-07-2018, 12:14 PM - **1 Like**

Originally posted by BigMackCam

It's not even characteristic of that specific model. It's simply common across a wide range of lenses. I'm a stickler for honest advertising, but I wouldn't even point this out to the potential buyer... As I said, compared to many lenses, it's extremely minor - really, it's negligible.

Thank you for the perspective sir. I much appreciate your comments. Have a nice weekend.

**BigMackCam** · 09-07-2018, 12:16 PM

Originally posted by RiverKayaker

Thank you for the perspective sir. I much appreciate your comments. Have a nice weekend.

You're most welcome, and the same to you

Cabessius · 09-07-2018, 04:24 PM

See how they close in the Volna-9

And the interesting effect that it causes in the background highlights

**BigMackCam** · 09-07-2018, 04:27 PM

Originally posted by Cabessius

See how they close in the Volna-9

That's a great effect, but not really what the OP was talking about

There are numerous lenses (including several Soviet models, but others too) with unusually-shaped apertures when stopped down a bit, but it's the uneven shape the OP was concerned about (however, as I stated, unnecessarily so)...

09-06-2018, 07:01 AM	#1
RiverKayaker New Member Join Date: Apr 2014 Posts: 6	Uneven aperture blades on FA 50 1.4 Hi, I noticed that the aperture blades on my FA 50 1.4 look uneven beginning around f4-f2.8. Photo attached. Can anyone with experience confirm if this is a problem? I am going to be selling the lens and never noticed this before. I want to determine if there's a simple way to correct this or not. If there's no easy method of fixing it, please let me know what would be the most honest and accurate way to describe the impact that this issue has so that I can fully disclose this information when I sell it. Thank you kindly.

09-06-2018, 07:30 AM - 1 Like	#2
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,686	There's nothing wrong with it. Many lenses will have slightly uneven closing of the blades due to manufacturing tolerances and a certain amount of free "play" in the mechanism. It typically varies copy to copy, and can even vary shot to shot. Yours is extremely minor compared to some. Nothing to worry about Last edited by BigMackCam; 09-06-2018 at 07:47 AM.

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09-06-2018, 10:34 AM	#3
Ronald Oakes Pentaxian Join Date: Jul 2017 Location: Virginia Posts: 1,585	Just because its not 1000% symmetrical doesn't mean there is a problem. I had a Pentax-F 50mm 1.7 that isn't even either. It was bought NEW in the box. I returned it to the store I bought it in Tucson and they agreed to replace it.....the replacement wasn't perfect either so I kept it. Its aggravating , but I just learned to ignore it as its a great lens.

09-06-2018, 11:44 AM	#4
RiverKayaker New Member Join Date: Apr 2014 Posts: 6 Original Poster	Great. Thanks for the responses, guys! So would it be truthful to state that this is characteristic of the lens and does not cause any noticeable affect to image rendering? I personally don't see any affect to image quality.

09-06-2018, 12:53 PM	#5
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,686	Originally posted by RiverKayaker Great. Thanks for the responses, guys! So would it be truthful to state that this is characteristic of the lens and does not cause any noticeable affect to image rendering? I personally don't see any affect to image quality. It's not even characteristic of that specific model. It's simply common across a wide range of lenses. I'm a stickler for honest advertising, but I wouldn't even point this out to the potential buyer... As I said, compared to many lenses, it's extremely minor - really, it's negligible.

09-07-2018, 12:14 PM - 1 Like	#6
RiverKayaker New Member Join Date: Apr 2014 Posts: 6 Original Poster	Originally posted by BigMackCam It's not even characteristic of that specific model. It's simply common across a wide range of lenses. I'm a stickler for honest advertising, but I wouldn't even point this out to the potential buyer... As I said, compared to many lenses, it's extremely minor - really, it's negligible. Thank you for the perspective sir. I much appreciate your comments. Have a nice weekend.

09-07-2018, 12:16 PM	#7
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,686	Originally posted by RiverKayaker Thank you for the perspective sir. I much appreciate your comments. Have a nice weekend. You're most welcome, and the same to you

09-07-2018, 04:24 PM	#8
Cabessius Veteran Member Join Date: Jun 2013 Location: Ibiza, Spain Posts: 471	See how they close in the Volna-9 And the interesting effect that it causes in the background highlights

09-07-2018, 04:27 PM	#9
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,686	Originally posted by Cabessius See how they close in the Volna-9 That's a great effect, but not really what the OP was talking about There are numerous lenses (including several Soviet models, but others too) with unusually-shaped apertures when stopped down a bit, but it's the uneven shape the OP was concerned about (however, as I stated, unnecessarily so)...