• Hot pixels in "all" shots, normal for the X1D?

[Dimitric]

Hello -


I start with the positive news: overall I am very happy with my X1D.   :-)



I just have a concern regarding "hot pixels" (dead pixels).

I just recently have been noticing that I have quite a few of these appearing in my pictures. 
No matter if I am working in a dark environment or in a place where there is a lot of light, or if  I am shooting a 2 seconds or 7 minutes pause these hot pixels are always present.

I know the obvious answer is to Photoshop them out but I can have as many as 50 of these in one image! This would be rather cumbersome. Moreover, I can have a mix of red, blue or white pixels appearing in one shot.

And you can see in shot "3B" seems to be more of an artefact rather than a dead pixel.


The following images were all taken with a XCD 21 lens and I zoomed in at 50%; image "3B" is zoomed at 200%.

NB. I probably miss some, but the most obvious one have been encircled in pink.
 
 
My question is now should I be worried?
Could it be that this is happening because the camera does not derawtize the images?
Should I sent back the X1D to Hasselblad?


Thank you.




- Dimitri

[Dimitric]

 
Pictures "3A and "3B":
 
 
 

[tavisbohlinger]

Definitely send it to Sweden.

[Dimitric]

Thank you Thavis..

Anyone else, same advice?


Thank you...

[BillW]

I always thought that hot pixels occurred in the same place. FWIW, I had an issue with my 21. I was getting all kinds of artifacts on my shots and it was not the sensor, it was the back lens element. Not sure if this is your issue but just a thought.

[Vieri]

Hello Dimitri,

I might be wrong, but I don't think they are sensor-caused hot pixels, I think they are software artefacts. Can I ask you which converter you use for your RAWs?

Best regards,

Vieri

[hvk]

I had a very similar problem with my old CFH-22 (CCD back). That was solved with a CCD recalibration which required a trip to Hasselblad. The best way forward is probably to send a raw file to Hasselblad for analysis.

/Henrik

[jwillson]

Lots of possibilities, and you may need to do some experimentation to narrow it down a bit.

First, you mentioned this happens both with "lots of light" and in dark situations, but you also mentioned 2a to multi-minute exposures.  I would hardly consider 2s exposures to be "lots of light".  Do you see this in much shorter exposures as well?  Like 1/60s?  Even a 2s exposure is long enough for thermal noise to be relevant.

Next, is this with or without electronic shutter?  I don't remember the details, but there are definitely some differences in noise patterns with the X1D depending on whether ES is enabled.  Basically, don't use ES on the X1D unless you need it because of adapted lenses or because you want to minimize sound.  The image quality—specifically the noise characteristics in shadows—are better with the mechanical shutter.  There was a thread on this a couple years ago you could likely dig up.

Next, is this fixed pattern noise or not?  Is it always the same pixels involved?  And is it the same at all ISO's?  No chips are perfect, and most camera manufacturers make a bad pixel map for each camera and interpolate values on those hot pixels automatically from surrounding pixels.  This is normal.  But chips do age.  They gain additional bad pixels over time due to gamma ray strikes on the chip and other causes.  It is possible that your chip has aged, that it has an incorrect bad pixel map loaded or that it has no bad pixel map loaded at all.  If it's always the same pixel involved I would call Hasselblad and see if they would recalibrate the chip.  If it's different pixels in different photos this isn't the cause, though. 

Do you see this at all ISO's or only at higher ISO's? Shooting Raw or JPG?  If shooting raw, what raw converter?  Most raw converters try to identify and remove hot pixels if they aren't too numerous.  How many pixels are involved in the typical photo?  Ten?  A hundred?  A thousand or more? 

[Dimitric]

Hello friends -


Thank you for your answers...

@ BillW  ->   OK, what should I do, send back the lens?  Can I check that by myself?
@ Vieri  ->   I open the 3FR files in Phocus® with some settings I apply by default and directly after I open them (as DNG) with Adobe Camera Raw® (By the way, it's really sad that Phocus® doesn't not export the settings within the exported DNG file)
@ jwillson  ->   
•  I always shot minimum 1s (required by my subjects).
•  NO it's without the "electronic shutter" active (I rarely use it, only with none native lenses).
•  My camera is 1year 1/2 old.
•  All shots were taken at 100ISOs, except for a few of them at 400ISOs (and the hot pixels were there too).
•  Hot pixels always at the same "place", hmmmm... I have to check.
•  I exclusively shoot in "RAW" mode.

...

From what I understand, I should sent back the X1D to Sweden? 
How many time will I be without camera?

Thank you, regards,
 
 
 
- Dimitri
 

[hvk]

From what I understand, I should sent back the X1D to Sweden? 
How many time will I be without camera?

Thank you, regards,



- Dimitri

Have you tried contacting Hasselblad support? What was their response?
They are pretty competent at solving problems with their own products and I usually get a response within a few hours.

[BillW]

Dimitri,
My lens only needed to have the back element cleaned by me. No need to go to Hasselblad.

[Dimitric]

Hello again...

@BillW  ->   Thank you for your answer :-)

I checked again some files selected on the fly, and it seems that when they are open with Phocus®
there is no "dead/hot pixels and/or artefacts", but since they are exported has DNG files and opened via Adobe® Camera Raw... well the hot pixels/artefacts appear 

Does anyone else has also noticed this?
Thank you.




- Dimitri
 

[Vieri]

Hello again...

@BillW  ->   Thank you for your answer :-)

I checked again some files selected on the fly, and it seems that when they are open with Phocus®
there is no "dead/hot pixels and/or artefacts", but since they are exported has DNG files and opened via Adobe® Camera Raw... well the hot pixels/artefacts appear 

Does anyone else has also noticed this?
Thank you.

- Dimitri

As I suspected At least, you won't probably need to send your X1D to Sweden. Try exporting as TIFF, not as DNG, and see if this helps. Best regards,

Vieri

[SrMi]

Hello friends -


Thank you for your answers...

@ BillW  ->   OK, what should I do, send back the lens?  Can I check that by myself?
@ Vieri  ->   I open the 3FR files in Phocus® with some settings I apply by default and directly after I open them (as DNG) with Adobe Camera Raw® (By the way, it's really sad that Phocus® doesn't not export the settings within the exported DNG file)
<snip>

Why do you go via Phocus if you use it only for converting from 3FR to DNG (settings are not applied to DNG)?
I recommend either exporting from Phocus as TIFF or using Adobe's DNG Converter to convert the image to DNG or opening 3FR file directly with Adobe Camera Raw.

[Dimitric]

Hello -

OK, I finally found some time to make some experiments.
I opened again an exported DNG file (exported via Phocus®) with ACR (Camera Raw) ->  left side of the below screenshot.
and I opened the 3FR file (of this picture) directly with ACR...  —>   right side of the below screenshot.

Well, the result is interesting, blue and red colourful "hot pixels" are not coloured anymore.
BUT if you look carefully, you may still see them (this time much less present and they are white!).

Is the result acceptable for you?
Or is that still abnormal, and I should send back the X1D?


Thank you,




- Dimitri