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butangmucat · 03-27-2018, 11:12 AM

Hello,

I just read in a forum thread (1.4/50 vs. 1.7/50 vs. 1.8/55 - PentaxForums.com) that the aperture ring on A50/1.7 is prone to being stuck, I wonder does the same issue apply to A50/1.4?

Sincerely

通过我的 moto x4 上的 Tapatalk发言

Adam · 03-27-2018, 11:28 AM - **1 Like**

I wouldn't say "prone" is the right word. But because these lenses are so common, there are lots of defective (damaged) copies out there. The good news is that oftentimes, it's an easy fix since the parts are rather simple.

timw4mail · 03-27-2018, 11:34 AM

I want to say no, as the 50/1.4 has generally been (one of) the higher end lenses through the series (Takumar/K/M/A/F/FA).

That said, I haven't actually used one, so I could be wrong.

**jatrax** · 03-27-2018, 11:35 AM - **1 Like**

Generally (from my experience and reading here), no. The A 1.7 has a plastic thingy that comes loose. The A 1.4 is a different design. The A 1.7 is an easy fix even if it breaks. And as Adam says they produced a lot of these lenses so seeing some that break is not unusual.

I have both the A 1.4 and 1.7 and my 1.7 did have the aperture ring issue. Took me 45 minutes to disassemble, repair and put back together.

Not a Number · 03-27-2018, 12:20 PM - **1 Like**

Short answer, no.

Just look at the number of posts about the aperture ring problem with f/1.4 - none that I can find.

I have both the f/1.4 and f/1.7. The 1.4 was bought new by my sister in the 80s with a Program Plus body. The 1.7 I bought from Goodwill as with a beat up K1000 as rear cap. The builds are different, the 1.4 feels much more robust with a smoother moving aperture ring. The f/1.7 needed repair which took me several hours. I must not be as dexterous as Jatrax - the A pin assembly keep falling apart on me and the tiny parts take a little juggling to get them back together. To top it off I had to take remove and clean the assembly a few months later as I had gotten some grease in it which make the electrical connection unreliable.

The f/1.7 and f/2.0 were pretty much the kit lenses of the time, with the f/2.0 being the low budget lens.

**monochrome** · 03-27-2018, 02:00 PM - **2 Likes**

To put a fine point on it, on the A50/1.7 the detent for the ball that clicks the aperture ring at the stops is a plastic strip that is spot heat welded inside the barrel. In a small but reportable number of cases the welds break, locking the aperture ring out of the A position. A detailed repair article with many images was posted to the Forum articles section here: A50/1.7 Aperture Ring Repair

The condition seems limited to the A50/1.7 specifically (the A50/1.4 seems not to suffer from this malady, nor do any of the other 50/1.4’s).

**gofour3** · 03-27-2018, 02:43 PM - **1 Like**

Add one more to the "plastic aperture assembly" list, the A50/2.

Phil.

**jatrax** · 03-27-2018, 04:53 PM - **2 Likes**

Originally posted by monochrome

detent for the ball that clicks the aperture ring at the stops is a plastic strip that is spot heat welded inside the barrel.

Like I said, a plastic thingy.

swanlefitte · 03-27-2018, 05:09 PM

My 1.7 aperture ring seems pretty brittle from age but works, just a little finicky. The 1.4 doesn't suffer at all.

**pepperberry farm** · 03-27-2018, 05:36 PM

there is a distinct difference in feel and movement between my 1.4 and 1.7 - it doesn't matter much for me, as I tend to leave them both in the 'A' position...

**boriscleto** · 03-27-2018, 05:44 PM - **1 Like**

Originally posted by pepperberry farm

it doesn't matter much for me, as I tend to leave them both in the 'A' position...

It doesn't matter for me because I own the K & M as well as the A and 2 Super Takumars, so why use the A when I need to use an aperture ring

**pepperberry farm** · 03-27-2018, 05:45 PM

Originally posted by boriscleto

It doesn't matter for me because I own the K & M as well as the A and 2 Super Takumars, so why use the A when I need to use an aperture ring

bingo!

butangmucat · 03-27-2018, 09:25 PM

So the M 50/2 is not affected by this issue?

Sincerely

**gofour3** · 03-27-2018, 09:58 PM - **1 Like**

Originally posted by butangmucat

So the M 50/2 is not affected by this issue?

Sincerely

Correct, all the "M" series lenses are fine.

Phil.

Jonathan Mac · 03-27-2018, 10:07 PM

Something inside the A 50/1.7 that is made of plastic becomes brittle and breaks with age and use. Most of the A 50/1.7s I've come across have suffered from this problem, which starts off as the aperture ring just not moving smoothly. I've never owned the 1.4 but on the occasion I met up with a seller to potentially buy one I backed out because of the low quality feel of the lens, which didn't seem any better in general than the 1.7.

Other A lenses which I've used (and still have and enjoy) - the 28/2.8 and 50/2.8 macro - are built much better and the aperture rings move smoothly with no sign of any problems.

03-27-2018, 11:12 AM	#1
butangmucat Veteran Member Join Date: Jul 2016 Posts: 709	A50/1.4 Aperture Ring Hello, I just read in a forum thread (1.4/50 vs. 1.7/50 vs. 1.8/55 - PentaxForums.com) that the aperture ring on A50/1.7 is prone to being stuck, I wonder does the same issue apply to A50/1.4? Sincerely 通过我的 moto x4 上的 Tapatalk发言

03-27-2018, 11:28 AM - 1 Like	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,608	I wouldn't say "prone" is the right word. But because these lenses are so common, there are lots of defective (damaged) copies out there. The good news is that oftentimes, it's an easy fix since the parts are rather simple. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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03-27-2018, 11:34 AM	#3
timw4mail Pentaxian Join Date: Apr 2017 Location: Driving a Mirage Photos: Gallery \| Albums Posts: 1,670	I want to say no, as the 50/1.4 has generally been (one of) the higher end lenses through the series (Takumar/K/M/A/F/FA). That said, I haven't actually used one, so I could be wrong.

03-27-2018, 11:35 AM - 1 Like	#4
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Generally (from my experience and reading here), no. The A 1.7 has a plastic thingy that comes loose. The A 1.4 is a different design. The A 1.7 is an easy fix even if it breaks. And as Adam says they produced a lot of these lenses so seeing some that break is not unusual. I have both the A 1.4 and 1.7 and my 1.7 did have the aperture ring issue. Took me 45 minutes to disassemble, repair and put back together.

03-27-2018, 12:20 PM - 1 Like	#5
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Short answer, no. Just look at the number of posts about the aperture ring problem with f/1.4 - none that I can find. I have both the f/1.4 and f/1.7. The 1.4 was bought new by my sister in the 80s with a Program Plus body. The 1.7 I bought from Goodwill as with a beat up K1000 as rear cap. The builds are different, the 1.4 feels much more robust with a smoother moving aperture ring. The f/1.7 needed repair which took me several hours. I must not be as dexterous as Jatrax - the A pin assembly keep falling apart on me and the tiny parts take a little juggling to get them back together. To top it off I had to take remove and clean the assembly a few months later as I had gotten some grease in it which make the electrical connection unreliable. The f/1.7 and f/2.0 were pretty much the kit lenses of the time, with the f/2.0 being the low budget lens.

03-27-2018, 02:00 PM - 2 Likes	#6
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	To put a fine point on it, on the A50/1.7 the detent for the ball that clicks the aperture ring at the stops is a plastic strip that is spot heat welded inside the barrel. In a small but reportable number of cases the welds break, locking the aperture ring out of the A position. A detailed repair article with many images was posted to the Forum articles section here: A50/1.7 Aperture Ring Repair The condition seems limited to the A50/1.7 specifically (the A50/1.4 seems not to suffer from this malady, nor do any of the other 50/1.4’s).

03-27-2018, 02:43 PM - 1 Like	#7
gofour3 Site Supporter Join Date: Oct 2008 Location: Vancouver, Canada Posts: 8,093	Add one more to the "plastic aperture assembly" list, the A50/2. Phil.

03-27-2018, 04:53 PM - 2 Likes	#8
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by monochrome detent for the ball that clicks the aperture ring at the stops is a plastic strip that is spot heat welded inside the barrel. Like I said, a plastic thingy.

03-27-2018, 05:09 PM	#9
swanlefitte Pentaxian Join Date: May 2015 Location: Minneapolis Photos: Gallery Posts: 4,068	My 1.7 aperture ring seems pretty brittle from age but works, just a little finicky. The 1.4 doesn't suffer at all.

03-27-2018, 05:36 PM	#10
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,780	there is a distinct difference in feel and movement between my 1.4 and 1.7 - it doesn't matter much for me, as I tend to leave them both in the 'A' position...

03-27-2018, 05:44 PM - 1 Like	#11
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,477	Originally posted by pepperberry farm it doesn't matter much for me, as I tend to leave them both in the 'A' position... It doesn't matter for me because I own the K & M as well as the A and 2 Super Takumars, so why use the A when I need to use an aperture ring

03-27-2018, 05:45 PM	#12
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,780	Originally posted by boriscleto It doesn't matter for me because I own the K & M as well as the A and 2 Super Takumars, so why use the A when I need to use an aperture ring bingo!

03-27-2018, 09:25 PM	#13
butangmucat Veteran Member Join Date: Jul 2016 Posts: 709 Original Poster	So the M 50/2 is not affected by this issue? Sincerely

03-27-2018, 09:58 PM - 1 Like	#14
gofour3 Site Supporter Join Date: Oct 2008 Location: Vancouver, Canada Posts: 8,093	Originally posted by butangmucat So the M 50/2 is not affected by this issue? Sincerely Correct, all the "M" series lenses are fine. Phil.

03-27-2018, 10:07 PM	#15
Jonathan Mac Pentaxian Join Date: Apr 2009 Location: Madrid, Spain Posts: 10,911	Something inside the A 50/1.7 that is made of plastic becomes brittle and breaks with age and use. Most of the A 50/1.7s I've come across have suffered from this problem, which starts off as the aperture ring just not moving smoothly. I've never owned the 1.4 but on the occasion I met up with a seller to potentially buy one I backed out because of the low quality feel of the lens, which didn't seem any better in general than the 1.7. Other A lenses which I've used (and still have and enjoy) - the 28/2.8 and 50/2.8 macro - are built much better and the aperture rings move smoothly with no sign of any problems.

A50/1.4 Aperture Ring

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