Something funky going on here... (sensor artifacts on P65+ ?)

[Christoph B.]

So I just noticed something weird. Something that's not really visible under normal conditions and has never shown up until I 'tortured' my raw files in CaptureOne.

Those strange pentagonal shapes show up on my P65+ sensor (always on the same spot) but the sensor itself shows no signs of damage and works without any problems what so ever.

They are not related to the lenses I use, they are the same every time, at every aperture setting and exposure.

Does anyone know what's going on here? Do I need to be worried?

[Christoph B.]

Could it be reflections from inside the camera body? Has nobody else ever had anything like that appear on his/her images?

[TonyW]

A complete stab in the dark.  I can see you used a 120mm lens @ f/16 from the information at the bottom of the image, does this lens have a 5 bladed aperture? 

[Paul2660]

They look like crystals, possibly on the sensor or between sensor and IR cover.  I would consider sending to P1 to have the unit cleaned if the problem gets serious or to the point where you can't shoot without them being in the image. 

Pentagon shape, common to many crystals. 

Fluid or moisture dried and left the shapes.  Just a thought.

Paul C

[Christoph B.]

A complete stab in the dark.  I can see you used a 120mm lens @ f/16 from the information at the bottom of the image, does this lens have a 5 bladed aperture?

I wish - it appears with every lens (80mm, 120mm, 210mm) in every kind of light situation. Studio flashes, location, short and long exposure, ISO50, ISO400 - doesn't make any difference.

Crystals? Hum....well the image I posted is the whole photo, not a crop but the whole frame. So that would have to be a friggin huge crystal... ^^

[Paul2660]

Probably not a crystal but a stain of some sort.  Or it be a big old crystal.

Have you cleaned the sensor with the Phase One A solution followed by B? 

A is more of a soapy (blue) color then you follow it with the B which will remove streaks.

Paul C

[TonyW]

I sincerely hope it is something as simple as a clean or eliminating a light leak

After cleaning if the problem still exists and is repeatable then I would wrap the camera up completely in black cloth just leaving the lens opening and do a couple of shots to see if it is light penetration through the body gaps and being reflected onto the sensor.

Good luck with this fingers crossed 

[ErikKaffehr]

Hi,

Perhaps you shouldn't torture your images in Capture One. CCD stuff is tricky, much dependent on calbration. if you don't see the stuff in your images just don't care.


Or, you can find an explanation, great! Or you can send your back to Phase One for calibration. Or it is something like Paul's suggestions.

Testing a dark shot seems like a great idea.

Best regards
Erik

So I just noticed something weird. Something that's not really visible under normal conditions and has never shown up until I 'tortured' my raw files in CaptureOne.

Those strange pentagonal shapes show up on my P65+ sensor (always on the same spot) but the sensor itself shows no signs of damage and works without any problems what so ever.

They are not related to the lenses I use, they are the same every time, at every aperture setting and exposure.

Does anyone know what's going on here? Do I need to be worried?

[Jeffery Salter]

Hi C + B

I have seen this before.  It is not your sensor.  If the digital back was splashed by any liquid or even tap water which has mineral content in it and not cleaned or wiped off of the glass protection - if left to dry the result will be a tiny doughnut ring.

I concur with Paul.  Clean the digital sensor.

Hope this helps.  Have a great weekend.

Jeffery

[ErikKaffehr]

Hi,

Fingers crossed!

Best regards
Erik

Hi C + B

I have seen this before.  It is not your sensor.  If the digital back was splashed by any liquid or even tap water which a mineral content in it and not cleaned or wiped off of the glass protection if left to dry the result will be a tiny doughnut ring.

I concur with Paul.  Clean the digital sensor.

Hope this helps.  Have a great weekend.

Jeffery

[Christoph B.]

Phew okay... I have already cleaned it before but it's been a month or so - even if I have to send it to P1 for a cleaning because the user before me got some liquid between the sensor and the IR glass it's not the end of the world...

Does anyone know how much P1 charges for a CLA?


edit: I only have the "B" solution (bought a new one and they don't have the "A" any more). I'll ask again the Mamiya/PhaseOne/Leaf forum - maybe they'll know for sure what's up.


@Jeffrey: that would make sense if it was just a small spot, right? But this is pretty big, it has to be at least 5mm and the sensor is absolutely clean as far as i can tell. I'll try cleaning it right now and tomorrow I'll be able to see if there's any change.

edit2: just cleaned the sensor and - no luck, the spots are still visible.

[Jeffery Salter]

@C + B. When I saw something similar it was on the front surface of the sensor glass.  Perhaps it's best to sent it in for evaluation.   

In the meantime perhaps you could shoot an LCC while working / shooting and apply it to your take in Capture One to see if that would clear it up from your photographs?

[Christoph B.]

Sadly the LCC does nothing to improve the image, the photo I posted already has LCC applied to it.

Does anyone know how much it costs to have the back cleaned / the glass replaced?

[torger]

It's strange. I've seen similar patterns and then it's some dirt on the lens ahead of the aperture, and the shape projected on the sensor is in the shape of the aperture. But as you claim it's the same regardless of lens and shoooting aperture it can't be that. But I would double-check, try shoot wide-open (when the aperture should be 100% round) and see if the shape changes.

If it's the full shot we see it looks totally unlike a cover glass problem, and totally alike some lens dirt problem. I'm no camera repair man though so I'm sure there are people that can figure this out.

[Christoph B.]

As I said it appears on all of my lenses, the 50mm, 80mm, 120mm and 210mm - and at all aperture settings.

I just contacted PhaseOne, they also suspect it's some kind of residue/dirt between the sensor and the glass

[ced]

Are you able to shoot without the calibration file embedded or redo the calibration but starting from scratch, this is possible with a Leaf back not sure how this is done with a Phase.
Good luck with the problem.

[Christoph B.]

Calibration file?
I guess you don't mean the LCC file?

I doubt I'm able to redo the sensor calibration data, that's not something I would feel comfortable to do and I wouldn't even know how to.

[Ken R]

Calibration file?
I guess you don't mean the LCC file?

I doubt I'm able to redo the sensor calibration data, that's not something I would feel comfortable to do and I wouldn't even know how to.

Are you located in the USA? If so I am sure Digital Transitions in NY can help you out.

[Christoph B.]

Sadly no - I'm in Austria, so no DT for me. But my local dealer is very helpful and nice so we'll see!

[torger]

There's calibration data embedded in the back to compensate for various sensor issues. I'm a bit rusty on this, but I think it's basically just flat-field, dead-pixels and ADC linearity. Bad calibration can show up as tiling on the P65+, but I think this is something different.