Sony A7Riii Stripes

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Geopressure
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Sony A7Riii Stripes

Post by Geopressure »

I have been encountering a diffuse waffle pattern, visible in JPEG stacks as light colored noise over a dark background. I assume this is the same basic "PDAF" (phase detection auto focus) issue discussed elsewhere. Admittedly this is not a complete show stopper as it can largely be edited out, however it is annoying. It seems to me that an expensive camera should not display such issues. I am debating whether it warrants returning the camera and looking for a better option.

Anyone have any thoughts on this?

Lou Jost
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Post by Lou Jost »

It is interesting that someone from our community has noticed this. It was one of the reasons I avoided that camera. I had read about some software that removed much of the pattern...can't remember the name though, sorry.

Geopressure
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Post by Geopressure »

Yes, I saw there is some software that works on RAW files, but the thought of another processing step doesn't appeal to me. If anything, Sony should fix this in-camera.

Lou Jost
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Post by Lou Jost »

They've known about it for a very long time and show no signs of fixing the problem. Their attitude towards problems is disturbing. Look at the way they treated the "star-eater" problem for example.

ray_parkhurst
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Post by ray_parkhurst »

Hmm, I never got so far with the camera that I noticed this problem. Perhaps another good reason I would have sent it back!

BTW, I think I read that the A7RII has only the multi-port for tethering, and no USB port for triggering, but the A7RIII has the additional USB port. Is this true, or do both cameras have both ports? I'm considering getting an A7RII, but if I have to dance at midnight in a full moon to get it to trigger and tether same time, I will pass.

Geopressure
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Post by Geopressure »

I believe you are correct about the ports. The A7Riii does indeed have both a USB C port for tethering, and a Sony USB "multiport" for shutter triggering. It works well with the Wemacro rail as long as you have a Sony connector cable.

In my previous post Beatsy explained that he uses an Infrared remote shutter trigger on the A7Rii and has had good luck with that.

Macro_Cosmos
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Post by Macro_Cosmos »

It is speculated that the concentric waffle pattern is due to Sony's sharpening algorithms. This is visible in many stacks posted on our community. It can be seen in some of Beatsy's stacks too, as well as a friend of mine who uses an a7r2.

May I ask for these?
1. Attach lens cap to lens
2. Take 2 dark field exposures, 5 minutes and 10 minutes. MAKE SURE long exposure noise reduction is OFF

Send the uncompressed raws to my email: macrocosmos1949@gmail.com

This will allow me to pinpoint the issue.
I will post the a7m3 raws when I get home. They look truly... gross. It's Sony's firmware issue for sure.

I didn't really want to make such things public due to fear of getting attacked by people. Luckily things like this isn't present in our community.

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Post by Macro_Cosmos »

Above is the original ARW file, below is the converted DNG using lightroom.
Software is Maxim DL.

Image
Image

I do not understand why the ARW shows up as these stripes. Maybe Maxim DL cannot read it properly?

On the converted DNG, one can clearly see a huge cluster of pixels on the left. This is due to either shuttercurtain lightleaks or sensor luminescence. It's not an isolated case. Nikon D750's lightleak got sensationalised, and it's a rare occurrence; I do not understand why the mainstream isn't pointing this problem out, which is a definite occurrence for extended exposures.

Details:
Camera: a7m3
Exposure time is 606 seconds.
Lowest native ISO possible
Dark field exposure
25 degrees room temperature

Here's 2 converted JPEGs,
Top: +100 highlights
Bottom: +100 highlights +3EV exposure (to exaggerate the issue mentioned above)

Image

Image

View full size here:
https://farm2.staticflickr.com/1875/304 ... 4695_o.jpg
https://farm2.staticflickr.com/1860/304 ... bd8e_o.jpg

To those asking why does a 10-minute exposure matter, think of it this way:
A 10-minute exposure is equivalent to 120 5-second ones.
For people who do not use strobes/speedlights, the exposure time is anywhere from 1 second to 5 seconds or above. For example, my stacks are a sequence of 5-second exposures. Usually 150+ raws per stack.

What happens? Hot pixels really do become an issue, and stacking may or may not help, or worst case, exaggerate the problem. Then comes software sharpening, treating these pixels as actual information, which are sharpened. This cause a lot of issues.

It will help if the OP or anyone is willing to send me dark field raws. An example of this "diffuse waffle pattern" would be greatly appreciated too. I've seen some of these actually, but I do not know if it is exactly what the OP is referring to or not. We all have our own ways to describe such oddities.

~ MC

mawyatt
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Post by mawyatt »

Macro_Cosmos,

Interesting stuff about the Sony and the strips (seems the Sony Fanfolks always bashing Nikon, but you don't much in the reverse).

Is this caused by the phase detect focus sensors on the chip?

Will be interesting to see if the new Nikon Z6 and Z7 Mirrorless cameras have any of these types of issues.

BTW don't think you can say that one long exposure Tlong is "exactly" like N shorter exposures Tshort, where Tshort is Tlong/N. The reason being the readout noise when a pixel is digitized (readout) happens every readout. So Tshort would have the result accumulation of N readout noise effects (if non-correlated should follow rootN), where Tlong only has only one read noise effect. Depending on how much noise the sensor produces this may or may not have an effect of the final resultant image noise level.

Anyway just a thought and thanks for showing the Sony image artifacts,

Best,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

mjkzz
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Post by mjkzz »

wow, but I can not do 10 minutes exposure, only up to 30 sec . . . well maybe it is disabled in silent mode.

Exposure for my stack usually is less than 0.5 second and interval is about 4 seconds, so the sensor should have enough time to cool down.

mjkzz
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Post by mjkzz »

OK, converted ARW to TIFF, I can see the left and right border are slightly grayish vs pure black.

Exposure 10+ minutes, lens mount cap (the one you put on the camera, not on lens) on, ARW, Sony A7M3

Image

Lou Jost
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Post by Lou Jost »

The classic stripe problem is different from this, and depends critically on how a scene is lit, and also on the lens; it would not show up in long-exposure dark frames. It is almost certainly due to the PDAF pixels. It occurs in normal short exposures. As entry points to the literature on this subject, see:
http://blog.kasson.com/a9/pdaf-striping-on-the-a9/
https://blog.kasson.com/a7riii/sony-a7i ... ping-faqs/
https://www.dpreview.com/forums/post/61073358
Note that Nikon cameras also can show this (Edit:: IF I RECALL CORRECTLY).
Last edited by Lou Jost on Tue Aug 28, 2018 7:11 am, edited 1 time in total.

mjkzz
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Post by mjkzz »

I see stripes when I am using flickering continuous light and shutter speed is higher than 1/50 and in silent shutter mode.

mjkzz
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Post by mjkzz »

the new Nikon Z camera has banding (stripes) issue, too.

Lou Jost
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Post by Lou Jost »

The stripes with flickering light and fully electronic shutter are a third problem, and that is due to the light source rather than the camera. Nothing to do with either the PDAF problem or hotspot problems.

When you say the Nikon Z has a problem, do you mean banding with certain light sources, or PDAF ghosting?

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