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Wim Vanmaele

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As usual I always test my camera's in special conditions. So I tested the X-T2.

Camera without an objective, cap on camera. ISO 12800 5 sec.
As expected I got a black picture.

But, if we put the lightlevel upwards (LR, PS, ...) the image changes and becomes purple with a lighter square in the middle.

Anyone an idea ? What if we should stack a huge amount of images just as with astronomical photography. Will this influence the image ?

treated image

d639fcfd6c634a1b872279a80ca6e2de.jpg




Original image: (full size, RAF on request)



bce71ece223c481d83553ec6b21c0fe9.jpg
 
Looks like Phase Detect focus point area.
 
OK, Phase detection area. But why is this visible in the image when we take a picture with long exposure. It is visible with 12800 ISO and 5 sec, but it is even visible with a lower ISO but higher exposure.

When we push the exposure-level to higher values, the square appears, thus this behavior resides in any image ... What is the influence of this on the picture.

When I stack a hundred of images just like for Astronomical photography, what will be the impact on the result ?

Another question I have: Is this a result of the firmware FujiFilm developed for the X-T2 and X-Pro2 (same sensor) or this it mean that the sensor is made that way ? In the first case, upgrading the firmware may give solutions (for at last, FujiFilm creates a upgrade for this if it is necessary), in the worst case (hardware with influences on the image) a solutions will be hard to find ...
 
Wim Vanmaele said:
OK, Phase detection area. But why is this visible in the image when we take a picture with long exposure. It is visible with 12800 ISO and 5 sec, but it is even visible with a lower ISO but higher exposure.

When we push the exposure-level to higher values, the square appears, thus this behavior resides in any image ... What is the influence of this on the picture.

When I stack a hundred of images just like for Astronomical photography, what will be the impact on the result ?

Another question I have: Is this a result of the firmware FujiFilm developed for the X-T2 and X-Pro2 (same sensor) or this it mean that the sensor is made that way ? In the first case, upgrading the firmware may give solutions (for at last, FujiFilm creates a upgrade for this if it is necessary), in the worst case (hardware with influences on the image) a solutions will be hard to find ...
Click to expand...
I've processed thousands of pics from my X-T2 and never seen this, or any evidence of it in any of my images. I've also seen many stacked long exposure astro images, once again, with no evidence of this visible in any image. Overprocessing and pushing an image to the point where this comes out would have to render most any image as all but useless.

To be honest, I think you are concerned about a complete non issue.
 
That you have too much time on your hands?
 
Jerry-astro said:
Wim Vanmaele said:
OK, Phase detection area. But why is this visible in the image when we take a picture with long exposure. It is visible with 12800 ISO and 5 sec, but it is even visible with a lower ISO but higher exposure.

When we push the exposure-level to higher values, the square appears, thus this behavior resides in any image ... What is the influence of this on the picture.

When I stack a hundred of images just like for Astronomical photography, what will be the impact on the result ?

Another question I have: Is this a result of the firmware FujiFilm developed for the X-T2 and X-Pro2 (same sensor) or this it mean that the sensor is made that way ? In the first case, upgrading the firmware may give solutions (for at last, FujiFilm creates a upgrade for this if it is necessary), in the worst case (hardware with influences on the image) a solutions will be hard to find ...
Click to expand...
I've processed thousands of pics from my X-T2 and never seen this, or any evidence of it in any of my images. I've also seen many stacked long exposure astro images, once again, with no evidence of this visible in any image. Overprocessing and pushing an image to the point where this comes out would have to render most any image as all but useless.

To be honest, I think you are concerned about a complete non issue.
Click to expand...
.. unless you are into taking photos at ISO12800 of your lens cap?? And silly me, taking photos of ... what??

Valid suspicions though, but I am with you on this one, a non-issue me thinks. Or else, show me the one photo ever taken after dark where this is visible. A night sky is remarkably busy and light even when it is seemingly dark as ...
 
Jerry-astro said:
I've processed thousands of pics from my X-T2 and never seen this, or any evidence of it in any of my images. I've also seen many stacked long exposure astro images, once again, with no evidence of this visible in any image. Overprocessing and pushing an image to the point where this comes out would have to render most any image as all but useless.

To be honest, I think you are concerned about a complete non issue.
Click to expand...
Many thanks with this reply.

I was wondering if it had an effect and with your answer I see it is a non issue.

But I find it strange. Do I have to much time as someone pretends ? Not at all, but I like knowing, testing some items so I could understand more and better the function of my camera.

Rest the question if this is due to firmware or if it is due the sensor-construction. Ok, it will not change or have an effect on the images, but the knowing-how can be nice and is not forbidden.
 
Wim Vanmaele said:
Jerry-astro said:
I've processed thousands of pics from my X-T2 and never seen this, or any evidence of it in any of my images. I've also seen many stacked long exposure astro images, once again, with no evidence of this visible in any image. Overprocessing and pushing an image to the point where this comes out would have to render most any image as all but useless.

To be honest, I think you are concerned about a complete non issue.
Click to expand...
Many thanks with this reply.

I was wondering if it had an effect and with your answer I see it is a non issue.

But I find it strange. Do I have to much time as someone pretends ? Not at all, but I like knowing, testing some items so I could understand more and better the function of my camera.

Rest the question if this is due to firmware or if it is due the sensor-construction. Ok, it will not change or have an effect on the images, but the knowing-how can be nice and is not forbidden.
Click to expand...
Photography is all about seeing. If you can not see it in any photograph of a photographic subject, then it is not there. The same applies to the visions that appear to the pixel peepers who examine RAW conversions at 200%! What matters is what you see on a print or an on-line image of a real photographic subject.
 
lnbolch said:
Wim Vanmaele said:
Jerry-astro said:
I've processed thousands of pics from my X-T2 and never seen this, or any evidence of it in any of my images. I've also seen many stacked long exposure astro images, once again, with no evidence of this visible in any image. Overprocessing and pushing an image to the point where this comes out would have to render most any image as all but useless.

To be honest, I think you are concerned about a complete non issue.
Click to expand...
Many thanks with this reply.

I was wondering if it had an effect and with your answer I see it is a non issue.

But I find it strange. Do I have to much time as someone pretends ? Not at all, but I like knowing, testing some items so I could understand more and better the function of my camera.

Rest the question if this is due to firmware or if it is due the sensor-construction. Ok, it will not change or have an effect on the images, but the knowing-how can be nice and is not forbidden.
Click to expand...
Photography is all about seeing. If you can not see it in any photograph of a photographic subject, then it is not there. The same applies to the visions that appear to the pixel peepers who examine RAW conversions at 200%! What matters is what you see on a print or an on-line image of a real photographic subject.
Click to expand...
Hm, I don't think photography is about seeing (to some extent it is, of course), but it is about making us see something. If the tools cannot produce what one wants to show, or not with the necessary quality, then there is a problem.
 
Wim Vanmaele said:
OK, Phase detection area. But why is this visible in the image when we take a picture with long exposure. It is visible with 12800 ISO and 5 sec, but it is even visible with a lower ISO but higher exposure.

When we push the exposure-level to higher values, the square appears, thus this behavior resides in any image ... What is the influence of this on the picture.
Click to expand...
You increased the brightness of the image, not the exposure. When doing so, any small differences in pixel intensities will at some point show up.

The PDAF areas show up because they collect a bit less light than normal pixels. However, for the vast majority of applications, the minimally reduced sensitivity is of no consequence.
Wim Vanmaele said:
When I stack a hundred of images just like for Astronomical photography, what will be the impact on the result ?
Click to expand...
You may want to ask in the astrophotography forum if cameras with PDAF areas are generally considered less useful for low-light photography. It's an interesting question. I think the answer would be 'yes', but only for primarily technical or scientific applications where every photon counts. Even for advanced amateur applications (e.g., stacking thousands of images of the night sky, even when taken through consumer-grade telescopes), I would not really expect any tangible issues. The point of stacking is to build up SNR beyond where anything like the PDAF areas would be visible. So, perhaps, one would just need a few more images in the stack to alleviate any issues.
Wim Vanmaele said:
Another question I have: Is this a result of the firmware FujiFilm developed for the X-T2 and X-Pro2 (same sensor) or this it mean that the sensor is made that way ? In the first case, upgrading the firmware may give solutions (for at last, FujiFilm creates a upgrade for this if it is necessary), in the worst case (hardware with influences on the image) a solutions will be hard to find ...
Click to expand...
As said, the hardware is different. Nothing to be done here.
 
From the responses here, clearly nobody knows. I don't know either but I shall not be sarcastic. I hope you find the answer, in the meantime enjoy the new camera.
 
afm said:
From the responses here, clearly nobody knows. I don't know either but I shall not be sarcastic. I hope you find the answer, in the meantime enjoy the new camera.
Click to expand...
I think the answer is quite straightforward. Since the OP showed a zero-exposure image, what is seen is noise. PDAF areas have electronics that are different from normal pixel clusters, and they have different properties regarding thermal noise, read noise, etc. When amplified enough, these different noise characteristics become visible.
 
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