K7 busted sensor strikes production body

bentax · 07-08-2009, 03:13 PM

Made a discovery last night that bums me out.

Ive managed to get a body with the line through the middle of the sensor like that pre-production K7 was exhibiting.

Spotted it shooting high ISO but its re-producable at every ISO. Heres a couple examples.

ISO 200

Shows the area the crops from... although in this one you can clearly see the line without the crop.

bentax · 07-08-2009, 03:26 PM

Just quickly having a play before work and i cant get the line to show this morning whereas it was in every shot last night.
Last night i had just been messing with Liveview for a bit (5mins?) before i noticed this line start showing up.
Could Liveview cause this?

jeffkrol · 07-08-2009, 03:51 PM

Originally Posted by bentax

Just quickly having a play before work and i cant get the line to show this morning whereas it was in every shot last night.
Last night i had just been messing with Liveview for a bit (5mins?) before i noticed this line start showing up.
Could Liveview cause this?

Increase gamma and drop the end points so as to spread out the contrast. Split channels and look at the green channel... Line is very evident. As a guess I suspect (w/ absolutely no proof) that Samsung is stitching some sensors together. Nikon's FF's can exhibit a similar thing (As far as I know most FF sensors are stitched).
Send it in and let Pentax sort it out.....
Blame Samsung.........

roof_top · 07-08-2009, 03:52 PM

ooohh...that doesn't sound good. If you look closely there's also a repeating pattern/banding (I think falkconeye pointed it out).

jeffkrol · 07-08-2009, 03:58 PM

Originally Posted by roof_top

ooohh...that doesn't sound good. If you look closely there's also a repeating pattern/banding (I think falkconeye pointed it out).

You got a better eye then me.. I torture tested the image and any pattern (I do see very mild patterning in the blackest patches but really amounts to very little)is weak at best (except for the glaring green line in the almost center), besides most sensors will band when underexposed this much...

jeffkrol · 07-08-2009, 04:00 PM

Originally Posted by bentax

Just quickly having a play before work and i cant get the line to show this morning whereas it was in every shot last night.
Last night i had just been messing with Liveview for a bit (5mins?) before i noticed this line start showing up.
Could Liveview cause this?

One possibility would be auto hot pixel removal has "eliminated" your line... This all will be interesting...

*falconeye* · 07-08-2009, 06:20 PM

Originally Posted by roof_top

ooohh...that doesn't sound good. If you look closely there's also a repeating pattern/banding (I think falkconeye pointed it out).

Yes, it was me.

But the repeating pattern every 256px (or was it 128?) isn't there here. I had a VERY careful look for them

Might require a hotter sensor and uniform/defocussed background to make them visible, I guess. I don't think that the sensor is stitched.

Yes, it looks like the middle vertical noise line I got with the preproduction camera after heating the sensor with extensive use of LV / movie capture. Jim (another tester, called sixstring here) saw it first. It needs about 10-30 minutes to develop and disappears after 2 minutes, or so. I only saw it with a 40°C temperature reading in the EXIFs (which could be the max. reading anyway). The manual says that extensive use of LV can produce additional noise. So, this must be it.

Somewhat disappointing that this isn't confined to preproduction.

Anybody else seeing this?

-> Record movie for ~30 min (until you get the red thermometer) and shoot a uniform, defocussed surface at ISO 1600 right afterwards.

The attached image from my preproduction camera shows how difficult it is to spot the secondary lines (this sample is boosted EXTREMELY in contrast!!)
The two secondary lines are at exactly 256px distance from the middle line (image was supersampled to 1 px height!). I couldn't identify ternary lines (at 512px distance). There are no secondary lines in the sample posted by the OP.

raider · 07-08-2009, 07:09 PM

Bentax, does this vertical line appear if you don't use liveview but with high ISO and slow shutter speed (like say 5 sec or something)?

I am interested to know how this turns up. Thanks

bentax · 07-08-2009, 08:00 PM

Originally Posted by raider

Bentax, does this vertical line appear if you don't use liveview but with high ISO and slow shutter speed (like say 5 sec or something)?

I am interested to know how this turns up. Thanks

The photo shown was shot without liveview. EXIF intact.
I first noticed the line on a 'liveviewed' shot (after about 5-10 mins liveview/video) but all shots after that were non liveview and still showing the line.

Would be great if others could test this out using steps similar to what falconeye outlined above.
Then we can see if this is a K7 'feature' early in the piece, or just a one off flaw.

Will do some more testing after work and also try that for you raider

*KungPOW* · 07-08-2009, 08:06 PM

Jeffkrol,

Is a green line like that a symptom of a stitched sensor that has a problem?

If they are stitching APS-C sensors, then Samsung must have the tech to make full frame sensors. Am I reading too much into this?

K-9 · 07-08-2009, 08:14 PM

Just like a car, you never want to buy the first production year model. Anyway, if this is affects more than just your body, Pentax may have seen it's last days. Camera stores like Ritz in the US and Jessops in the UK seem to stop carrying them, and this may well secure that anyone who still is, doesn't anymore.

*nulla* · 07-08-2009, 08:44 PM

Originally Posted by K-9

Just like a car, you never want to buy the first production year model. Anyway, if this is affects more than just your body, Pentax may have seen it's last days. Camera stores like Ritz in the US and Jessops in the UK seem to stop carrying them, and this may well secure that anyone who still is, doesn't anymore.

Happy with both my new ford and my K-7

Going by my satisfaction and the majority of happy users I have spoken to so far regarding my ford and my camera brands and models I can see a very bright future for both.

GaryM · 07-08-2009, 09:14 PM

Originally Posted by K-9

Just like a car, you never want to buy the first production year model. Anyway, if this is affects more than just your body, Pentax may have seen it's last days. Camera stores like Ritz in the US and Jessops in the UK seem to stop carrying them, and this may well secure that anyone who still is, doesn't anymore.

Here's a prediction for you: Pentax will outlast Ritz.

jeffkrol · 07-08-2009, 09:21 PM

Originally Posted by KungPOW

Jeffkrol,

Is a green line like that a symptom of a stitched sensor that has a problem?

If they are stitching APS-C sensors, then Samsung must have the tech to make full frame sensors. Am I reading too much into this?

not sure. I briefly looked at an article by Illya Borg showing the artifacts in a photo due to the stitching of the sensor.
Here is a brief desc. of the technique and a bit on sensor costs:
Chipworks
Anyways I believe the orig samples from Mr. Borg were examned after desaturating the image.. I'll see if I can find it.
The stitching thing is a long shot but it's still a vague possibility. I threw it out here more for discussion then anything real.

raider · 07-08-2009, 09:30 PM

Originally Posted by bentax

The photo shown was shot without liveview. EXIF intact.
I first noticed the line on a 'liveviewed' shot (after about 5-10 mins liveview/video) but all shots after that were non liveview and still showing the line.

Would be great if others could test this out using steps similar to what falconeye outlined above.
Then we can see if this is a K7 'feature' early in the piece, or just a one off flaw.

Will do some more testing after work and also try that for you raider

Okay. So is it fair to assume that if liveview is not used at all (before the shots) then the stripe will not appear in any ISO and any shutter speeds combination?