[Colorado CJ]

Well I sent the lens back to be replaced. I bought this lens from Adorama. They were very helpful when I called and emailed me a return label within 5 minutes of calling them. This was my first time using Adorama, and so far, it seems like they are a great company to deal with. I should be getting a new DA40 in a few days.

I can't wait though! I really loved using the DA40 for the few days I had it. My next closest prime, an A 50 F2 seems so much narrower in comparison, but it will have to do for a few days.

[alexeyga]

On mine there's a similar "problem".... thing is, it's only apparent fully closed... but besides testing K5's sensor for spots, how often does one shoot the DA40 at f22? Knowing that diffractions kick in at f8, I'm rarely closing down over f11... so does it really matter if fully closed it's not a perfect circle?

Get real guys... Pointless worries... Reminds me of a lot about AF durring video in D7000... everybody know that AF is useless for any serious video work, especially on large sensors... yet there are big debates going on about how bad video AF is on D7000...

[Colorado CJ]

On mine there was definitely a problem. When nearly fully open, a few of the blades were still obstructing the aperture while the rest were already fully opened. There was also the matter of about ten dust particles/dirt on the inside lens elements. The whole diaphragm seemed very sloppy and not nearly as precise as even my cheap lenses. If I'm going to spend $330 on a lens it better be in perfect condition, no if ands or buts, I'm not rich so I won't accept faulty parts for my money. This one lens will probably be my only "good" lens for a long time to come.

[sjwaldron]

Well I sent the lens back to be replaced. I bought this lens from Adorama. They were very helpful when I called and emailed me a return label within 5 minutes of calling them. This was my first time using Adorama, and so far, it seems like they are a great company to deal with. I should be getting a new DA40 in a few days.

I can't wait though! I really loved using the DA40 for the few days I had it. My next closest prime, an A 50 F2 seems so much narrower in comparison, but it will have to do for a few days.

I checked my lenses. None were like that, so it's probably a good idea to get it replaced like you did. Oddly enough the lens that has the most oblong hole at f22 is my new 31mm, but it's no where like that 40mm you had.

[Banjo]

I often browse through secondhand lenses on offer and sometimes notice lenses that have irregular diaphragm openings. I would normally reject such lenses as requiring a CLA.

However, it is interesting to note the range of different diaphragm designs: some have 15 or more blades while others have only two (Olympus Trip 35), yet they all give excellent results.

[wlachan]

On mine there was definitely a problem. When nearly fully open, a few of the blades were still obstructing the aperture while the rest were already fully opened. There was also the matter of about ten dust particles/dirt on the inside lens elements. The whole diaphragm seemed very sloppy and not nearly as precise as even my cheap lenses. If I'm going to spend $330 on a lens it better be in perfect condition, no if ands or buts, I'm not rich so I won't accept faulty parts for my money. This one lens will probably be my only "good" lens for a long time to come.

Not uncommon with Pentax lenses since the FA series. The cause is that the blades are loosely guided so if you rotate the lens with the aperture slightly closed, you can actually see the shape changes due to gravity. In your case, the blades were poorly adjusted in the factory too. My FA43 & 77 had the same issue and I had to rearrange the blades for more even shape. It's a time consuming process but can be done. Good luck on having yours fixed.

[Helen Oster]

Well I sent the lens back to be replaced. I bought this lens from Adorama. They were very helpful when I called and emailed me a return label within 5 minutes of calling them. This was my first time using Adorama, and so far, it seems like they are a great company to deal with.....

That's really good to hear; thanks so much for the feedback!

[Colorado CJ]

No problem Helen.

I called Adorama today and found out that they shipped my lens 3 day UPS instead of regular ground so I'll be getting my new lens on Christmas Eve just in time for the holidays!

They didn't have to send it via expedited shipping but they did, even without me asking. I really appreciate it.

Great company to deal with.

[Colorado CJ]

Well, looks like I got another dud! I saw that this one was bad within 1 second of opening the package.

I'm now wondering if Adorama is buying seconds, or if the Pentax quality control is REALLY THIS BAD!

This is absolutely not acceptable. One of the diaphragm blades is actually BENT! How this could possibly pass inspection is beyond me.

I'll be returning this one and asking for a refund. Two in a row is enough for me. Looks like Limited's are only limited on getting a good one.

Here is a picture. I have no idea how this was looked over. I'm now wondering if I'm getting seconds. See the bend in the blade (the white part on the edge of the bad blade)? That is making friction against the other blade, not allowing that blade to open fully at any aperture. Unbelievable.

[greymda]

well, kinda stupid question, but how can you close the aperture, since this lens has no aperture control on it?

i would like to inspect my lens. just received it from B&H

[macTak]

well, kinda stupid question, but how can you close the aperture, since this lens has no aperture control on it?

i would like to inspect my lens. just received it from B&H

Just actuate the aperture control lever with your finger.

[Vasheek]

Hi, I've noticed exactly the same problem. But even more. When i do an optical preview, at for example F4, the aperture isn't fixed and is spilling from side to side in dependence on position of the lens. This is my second defective DA40. The first one had somehow dirty blades and every picture was overexposed.

[scorpioh]

Pentax's quality control these days are really bad - big specks of dusts or spots and poorly aligned aperture blades are common place. I had bad experience from my FA43 to DA70. Simply unacceptable! They were still ok some 2 years ago.

[Colorado CJ]

Yeah, I'll probably just start buying some older glass like A's and M's and just forget about my dream of a line of limiteds.

Pentax never should have moved their lens manufacturing to Vietnam, really bad move on their part.

Really disappointed.

[wlachan]

To be honest, all my FA lenses were MIJ and I saw some defective FA/FA* samples too along the way, and some were hard to believe. Poor QC started way b4 AIV. Fortunately, I was able to correct most of the physical issues which 4 out of 9 lenses I have suffered. Forget features, Pentax DO need to check their QC. Period.