[ve2vfd]

The filter assembly is glued on top of the chip after it is soldiered onto its PCB, thereby making a seal. Most probably by hand.

Could this contamination problem be an artifact from the gluing process?

Pat

[blende8]

I remembered my body cap pinhole which has an effective aperture of f190.

I tested my K20 and my K5.
Both show basically the same kind of spots. But the K5 has more.
K20: ca. 22, K5: ca. 36
At the K5 there is one area where I have some kind of cluster.

Sample areas: ISO 100, 20 s


These spots are not recognized by the dust alert and cannot be removed with Isopropanol.

Best possible resolution of the K5 cluster:



keywords: stars, galaxy, light years, nebula, supernova, black hole, pulsar, curved spacetime

[Douglas_of_Sweden]

I remembered my body cap pinhole which has an effective aperture of f190.

I tested my K20 and my K5.
Both show basically the same kind of spots. But the K5 has more.
K20: ca. 22, K5: ca. 36
At the K5 there is one area where I have some kind of cluster.

Sample areas: ISO 100, 20 s


These spots are not recognized by the dust alert and cannot be removed with Isopropanol.

Best possible resolution of the K5 cluster:



keywords: stars, galaxy, light years, nebula, supernova, black hole, pulsar, curved spacetime

Good thinking with the pinhole!

I kind of suspected something like this, that it would not be unique to K-5, but that we somehow inspect every new camera model more and more critically.
We cannot from just one comparison say if K-5 generally have more "spots" than K20D.

One conclusion though: this is not unique to Sony sensors, Samsung has it too. Whatever it is.
Will try to get time to check my *istDS, K20D, K-7 and K-5, but it won't happen before weekend.

Have you guys checked if your spots stay in the same place from day to day??? It may sound stupid, but it is sort of basic test one should do.

[dgaies]

Have you guys checked if your spots stay in the same place from day to day??? It may sound stupid, but it is sort of basic test one should do.

My spots stay in the same place (at least over the past 4 days).

[ve2vfd]

Great idea blende8!!!

I checked my K20d and other than a few dust spots (which I blew away) it's clean as a whistle.

Douglas, my K5 spots are not moving.

Pat

[Douglas_of_Sweden]

My spots stay in the same place (at least over the past 4 days).

Great idea blende8!!!

I checked my K20d and other than a few dust spots (which I blew away) it's clean as a whistle.

Douglas, my K5 spots are not moving.

Pat

Didn't think they would, but better not assume too much considering we don't know what it is. After all, they could have been some sort of secret nano-robots Pentax employ to crawl around on the sensor and repair hot pixels

[falconeye]

I remembered my body cap pinhole which has an effective aperture of f190.

I tested my K20 and my K5.
Both show basically the same kind of spots. But the K5 has more.
K20: ca. 22, K5: ca. 36

As great as the idea sounds, it has one caveat: a pinhole creates a large depth of field for the effect. I.e., the method becomes sensitive for all kinds of dust, higher up in the optical chain as well. That's not very relevant as invisible with existing apertures.

If a particle is, e.g., 40µm. Then at f/32 you can basically see it up to 1 mm. At f/190, you basically see it up to 7.6mm which makes removable dust indistinguishable.

IMHO, the string of pearls is the fingerprint to search for.

[secateurs]

id think these sensors are put together by machine not hand....

Urban Dictionary: tool

[RichardS]

Does anybody here have an electron microscope? i think we can see the problem more clearly.

Can't help, I'm afraid. I used to electronics supervisions at UNI with someone who could have helped with a SEM (Charles Oatley - Wikipedia, the free encyclopedia), but that was a long time ago and he's no longer with us. How a lowly undergraduate ended up doing one-on-one supervisions (aka "tutorials") with someone like him is another story

Richard.

[blende8]

As great as the idea sounds, it has one caveat: a pinhole creates a large depth of field for the effect. I.e., the method becomes sensitive for all kinds of dust, higher up in the optical chain as well. That's not very relevant as invisible with existing apertures.

If a particle is, e.g., 40µm. Then at f/32 you can basically see it up to 1 mm. At f/190, you basically see it up to 7.6mm which makes removable dust indistinguishable.

IMHO, the string of pearls is the fingerprint to search for.

I agree, I just wanted to get a better resolution of the area in question on my K5.
Btw. is it normal that all these spots have about the same size?

[hs57]

I got Stains on my K-5 Sensor in different sizes...
The big one is visible from F-Stop 7.1...
The quality control of Pentax's just a shame.









LG
hs57

[falconeye]

I got Stains on my K-5 Sensor in different sizes...
The big one is visible from F-Stop 7.1...

The big one is probably dirt.

At least, I managed to get rid of stains like your big one by some repeated cleaning. If they look soft and big, they probably aren't the kind of stains we're talking about.

[falconeye]

I found the root cause of the string of pearls and cluster of pearls defect.

She's a 22 year old

[imtheguy]

I found the root cause of the string of pearls and cluster of pearls defect.

She's a 22 year old

Falconeye, not are are the premier stainologist, among other technical talents, but also a gifted comedian in this time of world-wide crisis. Thank you for your contributions.
+1

[Class A]

She's a 22 year old

Someone tell her that while we appreciate the intention, we'd prefer if she'd no longer "beautify" the sensors.

EDIT: The pink foundation also explains the "propensity of the K-5 for showing PF"! Two puzzles solved!!