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12-19-2010, 06:43 AM   #166
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Just trying to understand, what does aperture has to do with visibility of stain? Why stain is more visible at lower apertures?

12-19-2010, 07:28 AM   #167
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QuoteOriginally posted by yusuf Quote
Just trying to understand, what does aperture has to do with visibility of stain? Why stain is more visible at lower apertures?
Perhaps someone will chime in with a more techincaly explaination, but from what I understand in order to see the strains you need the incoming light to be as close to a point source as possible. At large apertures, light would be able to hit the sensor behind the stain from slightly different angles and it would be difficult to actually detect the stain since the pixels under the stain would still recieve a fair amount of illumination. However, at very small apertures, the light is closer to coming from a single point source and the light that would normally hit the pixels on the sensor (under the stain) is blocked from hitting the sensor by the stain.

Not sure if that made sense or not. Hopefully if I'm wrong someone can correct me
12-19-2010, 08:07 AM   #168
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I also found stains on the K5 sensor. Fortunately I managed to get rid of them by using SensorSwab with its Eclips fluid after I was not successful with the blower and the dry swab.
12-24-2010, 03:46 PM   #169
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I got my replacement K-5 from Adorama...I charged up the battery and installed my 43mm prime and performed the test using ISO 80 and F22 and infinite focus...Sensor is clean....

Plus I returned the original K-5 and today I got an email saying they've credited my credit card for the original purchase..

Happened to read the attached *PDF file and it said the reason for the return was because 'SPOTS HAVE A SENSOR ON IT' I am not making this up...

12-25-2010, 06:44 AM   #170
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Hi guys, from what I could read so far, it seems that the most affected ones are serials starting with 382~384. Mine is a 387 ... I see a small stain, but will need to clean it first before saying it's a sensor default.

Are there many users experiencing the same issue with serials outside that 382~384 range ?
12-26-2010, 02:07 AM   #171
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QuoteOriginally posted by Sprags Quote
Happened to read the attached *PDF file and it said the reason for the return was because 'SPOTS HAVE A SENSOR ON IT' I am not making this up...
Does that mean that your new camera has spots without a sensor?
Cool!
12-26-2010, 02:18 AM   #172
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QuoteOriginally posted by Sprags Quote
Happened to read the attached *PDF file and it said the reason for the return was because 'SPOTS HAVE A SENSOR ON IT' I am not making this up...
Lol, that must have been a REALLY bad case.
12-27-2010, 03:46 PM   #173
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Hi there just found this thread and checked my K5 serial 383 it's got the spots! What are Pentax saying ? Will contact the camera supplier this week and will post feedback here. I'm uk based purchased from Clifton Cameras pro dealer.


12-27-2010, 07:11 PM   #174
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QuoteOriginally posted by myeates Quote
Hi there just found this thread and checked my K5 serial 383 it's got the spots! What are Pentax saying ? Will contact the camera supplier this week and will post feedback here. I'm uk based purchased from Clifton Cameras pro dealer.
These types of spots are normal...it's called dust...I am sure this spot theory is going to make lots of folks with just dust on there sensor to think it's a "fault".

I just checked mine for the second time and there are quite a few dust spots, but none of them are cliustered together or I don't see a halo either...I am going to clean my sensor tomorrow and confirm it.
12-27-2010, 08:34 PM   #175
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All people have to do it check there Dust Alert feature and if the spot dosen't show up in there and it dose on your photos I'd say you have a problem with the lens or the Sensor. Mine only showed up at f11 or smaller in my photos.
B&H replaced mine with no problem.
12-28-2010, 04:06 AM - 1 Like   #176
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sensor marks

Just performed the sensor clean and marks are still there, checked at full size the other marks are like donuts, attached image of full frame. Given the previous posts I am quite confident this is not dust, but the staining.
12-28-2010, 04:07 AM   #177
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12-28-2010, 06:50 AM   #178
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QuoteOriginally posted by Fl_Gulfer Quote
All people have to do it check there Dust Alert feature and if the spot dosen't show up in there and it dose on your photos I'd say you have a problem with the lens or the Sensor. Mine only showed up at f11 or smaller in my photos.
B&H replaced mine with no problem.
This is not correct...The dust alert is not even close to 100% accurate. I've had my K-7 sensor with numerous dust spots that never shwoed up on Dust alert.
12-28-2010, 06:52 AM   #179
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QuoteOriginally posted by myeates Quote
Just performed the sensor clean and marks are still there, checked at full size the other marks are like donuts, attached image of full frame. Given the previous posts I am quite confident this is not dust, but the staining.
The image is still too small to tell...what do you mean by sensor clean (Did you physically clean the sensor with a swab ?) as I hope you are not talking about the in-camera sensor cleaner as that doesn't work all the time either.
12-28-2010, 08:08 AM   #180
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I don't know how to get the image loaded to show it properly, I haven't touched the sensor I don't see the point given the previous posts, I have looked at the marks and then checked the previous images and mine are very similar. They appear to be mini donuts aside from the one in the centre of the frame which resembles a single sperm sorry but it does!

My previous cameras have all been Olympus and I have to say the dust reduction was outstanding, in all the time I used them I never had occasion to notice dust. Am I to assume that the Pentax system is not as good as the Olympus at this?

I will contact the dealer I purchased from when they open for business again, I would also like to point out that I'm not anal about the camera I just feel that given its price and the likelihood of this affecting it's resale value it does need to be sorted. As I mentioned my Olympus gear never had an issue with this, I have owned four starting with the E1.
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