[inferno10]

My K-5 sensor is spotless; no dust or stains whatsoever all the way down to f/22.
Serial number starts with 3889.

View the full-size image of my sensor at f/22: http://img.skitch.com/20101205-8c1dmhep8xfc6qnrcb914d44fs.jpg

- Jason

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Last edited by inferno10; 12-05-2010 at 12:47 PM.

[imtheguy]

My K-5 sensor is spotless; no dust or stains whatsoever all the way down to f/32.
Serial number starts with 3889.

View the full-size image of my sensor at f/32: http://img.skitch.com/20101205-8mnsspt4hhx9qpm99tcgi278nx.jpg

- Jason

Yep, thats one beautiful looking sensor.
Nice to know all the good ones did not go to the canikon factories. Ok, we got ONE so far...lets hear it for Pentax!

[Kunzite]

imtheguy: Please, it's not like all the units are affected! Even thinking about this is ridiculous, and about is stopping the production - why would they do that? The problem must be identified and fixed "on the run", if it wasn't already; that's all.
And yes, my K-5 is stain-less

[Rense]

stainless steel?

[Urkeldaedalus]

I looked again and I couldn't find the spot I saw earlier. So my sensor may be in the clear, too. (And I'm not going to go out of my way looking for it again.)

[telfish]

Terry -
Assuming you had the same motivation I now have, I will skip Amazon bending the policy since you already tried. Like you, next stop is Pentax support where I expect to be told its either dust or "they have no reports of defective sensors". In the end I expect they will have enough stock of good sensors that suddenly it will be admitted and sensors replaced. It may be awhile before they stop making new K-5's just so they can fix all the first ones though. In the meantime...really no affect on me. I can use the k20d for f/22 macro shots.

My question to the group is; are there any GOOD sensors that came out in the first 6 weeks so far? Trying to get a handle on if this is a 5% QC/production problem or 100% problem.

My wife bought one last week from Newegg. Serial No 3865797 mine is 3223991. I tested hers and it looks clean as a whistle. Maybe she got one from a second batch or it has not shown up yet, or she has not used it enough to show up. I am a bit lost on this for the moment.

Terry

[Class A]

Aperture and focus affects the image coming through the lens. (Maybe I’m dumb but...) How/why does it makes a difference if those stains are on the sensor itself?

As Falk wrote, changing the focus, changes the effective aperture. The aperture makes a difference for the following reason:

Imagine a particle on the sensor that is lit with light rays that are perpendicular to the sensor. The particle would then create a sharply defined shadow on the sensor. This case, where no light rays can hit the sensor area hidden by the particle from the side is approximated by a very small aperture; the light rays almost come from the same point and there are few light rays that can illuminate the sensor area under the particle.

When you open up the aperture (lower the f-ratio), more light rays become available. The additional rays come from the outer part of the aperture opening and hit the sensor at angles which are suited to "shine around" the particle, i.e., illuminate the sensor area under the particle. The place on the sensor under and around the particle then sees a mix of hard shadows and some light rays hitting it, in other words, a soft shadow will be created.

If you think of the particle as a model then small aperture means "harsh light" -> harsh shadows and wide aperture means "soft light (big light source)" -> soft shadows.

This is why by looking at the difference in shadow shapes depending on the f-stop (size of the light source) Falk has a chance of calculating the distance of the particle to the image forming part of the sensor (which in practice are the micro lenses).

[dadipentak]

Blame me Dave, I got you pumped up to buy before they had the good sensors ready.

OK

I emailed my retailer (also linking to this thread) asking how we should proceed. I'm guessing he'll be in touch with Pentax right quick. I sure hope it turns out that wet-cleaning fixes the problem.

[robbiec]

I was doing some testing on metering K and M lenses and found out that my lovely K-5 is also affected. Only shows at f/16 and f/22 so i'm not too bothered, don't think I've ever used these in real life. Strange that only 3 of us have put that detail up on the serial db, the amount of noise this is generating sounds like 100s, so much for disclosure !

[Michaelina2]

My K-5 sensor is spotless; no dust or stains whatsoever all the way down to f/22.
Serial number starts with 3889.

Like inferno10's K-5, mine is a 3889x unit. It shows no issues per the OP's description that I can see.

Also, like my K-7, it has a minor dust spot or two scattered about. I've used it outdoors everyday since mid-November with a variety of lenses so I would be very surprised, if it was spotless. Checking for dust spots is part of my normal pp work-flow and they are easy to remove, so no big deal to me.

Cheers...

[imtheguy]

imtheguy: Please, it's not like all the units are affected! Even thinking about this is ridiculous, and about is stopping the production - why would they do that? The problem must be identified and fixed "on the run", if it wasn't already; that's all.
And yes, my K-5 is stain-less

Absolutely its ridiculous,
but without making an inflammatory statement I couldn't flush out more folks who have no problems since only the unhappy complain. I expect Pentax/Sony knew about it long ago and its fixed now but they made a decision to sell the bad units instead of accepting a delay. Just a business decision. Now when I discuss it with Pentax I want to have as much info as possible. Thats all the drama was about. I am happy that you won't have to deal with the problem.

[BobRad]

I got mine from Amazon the same week. I tried to do a return but they only accept up to 30 days. I looked but there is no contact info to write too.

I lodged a claim on the Pentax website using their customer service contact form and will call them tomorrow.

Let us know how you get on with Amazon assuming you can get to speak to a human being.

Terry

Two things:

You can speak to a customer rep at Amazon USA. On their main page click on "Help" from the list at the bottom. Then click on "Returns and Refunds". The site will ask you to sign in and you will get a page with 3 tabs, including one that is "Phone". Click that and provide the requested info. They will then call you at the phone number you give them. I have done it and they do call.

Second, when I bought my K-7 from Amazon, it had AF issues. I followed the directions on the pink sheet on the box and contacted Pentax instead of Amazon. They told me to send it to them for repairs. They sent it back with the issues not fixed and by the time I got it back, the 30 period for Amazon return had expired. I called Amazon and explained the situation and they agreed to take the camera back for a replacement. They even paid the shipping cost. So give that a try.

Good luck,
Bob

[Wiker]

Aperture and focus affects the image coming through the lens. (Maybe I’m dumb but...) How/why does it makes a difference if those stains are on the sensor itself?

As Falk wrote, changing the focus, changes the effective aperture. The aperture makes a difference for the following reason:

Imagine a particle on the sensor that is lit with light rays that are perpendicular to the sensor. The particle would then create a sharply defined shadow on the sensor. This case, where no light rays can hit the sensor area hidden by the particle from the side is approximated by a very small aperture; the light rays almost come from the same point and there are few light rays that can illuminate the sensor area under the particle.
. . .

Aha... quite logical really. Thanks.

[deadpixelx]

I live in Spain, and on top of that I had a to change my K-5 6 time for Hot Pixels reason,
one time was because of an oil drop like that I cleaned with an Eclipse kit.
The oil has been removed but under, a permanent mark, like corrosive damage, was still there. The location seems to be the same as most of you...
Here I let you a JPG map rendered by my K-5 of this dot.

[dexmus]

On dpreview, in the part-2 of the same titled post (part-1 is closed), a user called Dcuk has posted very clear image of this issue using his Raynox M-250. The marks are on the underside of the AA filter.