[bobphoenix]

A few years ago, I asked about image banding on my K-20D. There was no resolution that, although as helpful as you all were, and I thank you for that... No one could figure out what was up with that...?!?
I finally resigned myself to using the K20D as a parts camera to resolve a Red K30 with the dreaded aperture solenoid failure issue...

Well, sad to say, here I am back again... with my K7 and it is doing the same thing and... ironically... in nearly the same pattern.

Mind you this is the first time I noticed this in this camera and it is the first time in more than six months that I have even picked up this camera... (Just in case that may be part of the problem...)

So any and all help and suggestions would be greatly appreciated...

So, here are a couple of images to show what is going on...

Automatic Exposure


Exposure with enhanced brightness and lowered contrast to bring out the patter.


Oh yeah... And for reference... Here's an image from my K-20D

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Last edited by bobphoenix; 08-20-2022 at 10:51 AM. Reason: add third image...

[jlstrawman]

So any and all help and suggestions would be greatly appreciated...

I checked....the K-7 was first introduced in 2009, so is +/- 12-13 years old.
It might be time to treat yourself to a new(er) body. The dark areas in your
attached photos, appear noisy to me. A newer body should improve on that.

[bobphoenix]

I checked....the K-7 was first introduced in 2009, so is +/- 12-13 years old.
It might be time to treat yourself to a new(er) body. The dark areas in your
attached photos, appear noisy to me. A newer body should improve on that.

Yeah, Thanks for that... This is my backup, at this point... I'm currently running a K1 (alpha).
It's just getting annoying having a shelf full of digital cameras that can only collect dust... As opposed to my collection of 35mm's (which are also collecting the rest of the dust...)

So, are you thinking it's just an age thing?

[AfterPentax Mark II]

A few years ago, I asked about image banding on my K-20D. There was no resolution that, although as helpful as you all were, and I thank you for that... No one could figure out what was up with that...?!?
I finally resigned myself to using the K20D as a parts camera to resolve a Red K30 with the dreaded aperture solenoid failure issue...

Well, sad to say, here I am back again... with my K7 and it is doing the same thing and... ironically... in nearly the same pattern.

Mind you this is the first time I noticed this in this camera and it is the first time in more than six months that I have even picked up this camera... (Just in case that may be part of the problem...)

So any and all help and suggestions would be greatly appreciated...

So, here are a couple of images to show what is going on...

Automatic Exposure


Exposure with enhanced brightness and lowered contrast to bring out the patter.


Oh yeah... And for reference... Here's an image from my K-20D

Well, after all it is the same sensor and the only thing I can detect is it is very noisy. The automatic exposure looks just like a picture taken with a K-7, by which I mean it is more or less identical to what my K-7 produces...

[ChristianRock]

I see the banding and no, that's not normal but it might be a "feature" (a downside, in other words). It's been a long time since I had my K20D (also a Samsung sensor) so I couldn't tell if I raised shadows if something like this happened, but I do know that I always avoided raising shadows on that thing. Only DSLR I couldn't use the shadows at all. Even my K10D and K200D have a somewhat useable dynamic range in the shadows. The K20D had none.

I personally avoid that 14.6MP Samsung sensor, otherwise I would have gotten another K20D, because the feel of that body was incredible. If you get a K-5 or K-5II/K-5IIs, you'll get basically the exact same body as the K-7 with a better sensor. The K-3 is slightly bigger/heavier. I personally have a K-S2 as my "newer" body for kids sports/events, and keep the K200D as my main "leisure" shooter.- that is the one that gets most of our vacation pictures. I feel the K-S2 and K200D are the best implementations of two eras of sensors, the CCD (K200D) and CMOS (K-S2) are my favorite APS-C sensors. Not that the others aren't good, this is just a personal preference.

[AfterPentax Mark II]

I see the banding and no, that's not normal but it might be a "feature" (a downside, in other words). It's been a long time since I had my K20D (also a Samsung sensor) so I couldn't tell if I raised shadows if something like this happened, but I do know that I always avoided raising shadows on that thing. Only DSLR I couldn't use the shadows at all. Even my K10D and K200D have a somewhat useable dynamic range in the shadows. The K20D had none.

I personally avoid that 14.6MP Samsung sensor, otherwise I would have gotten another K20D, because the feel of that body was incredible. If you get a K-5 or K-5II/K-5IIs, you'll get basically the exact same body as the K-7 with a better sensor. The K-3 is slightly bigger/heavier. I personally have a K-S2 as my "newer" body for kids sports/events, and keep the K200D as my main "leisure" shooter.- that is the one that gets most of our vacation pictures. I feel the K-S2 and K200D are the best implementations of two eras of sensors, the CCD (K200D) and CMOS (K-S2) are my favorite APS-C sensors. Not that the others aren't good, this is just a personal preference.

Samsung used that sensor in mirrorless camera and I was amazed that this happened in a Pentax but not in the Samsung mirrorless. At that time I could not get my hands on a GX-20 to upgrade from my GX-10. So I bought an NX with the same sensor later on and was pleasantly surprised. I would certainly avoid that 14,6MP sensor in a Pentax, but Samsung showed me what the sensor can (still) do!

[GUB]

What iso are these images at?

[ChristianRock]

Samsung used that sensor in mirrorless camera and I was amazed that this happened in a Pentax but not in the Samsung mirrorless. At that time I could not get my hands on a GX-20 to upgrade from my GX-10. So I bought an NX with the same sensor later on and was pleasantly surprised. I would certainly avoid that 14,6MP sensor in a Pentax, but Samsung showed me what the sensor can (still) do!

I avoided it due to the lack of dynamic range and because the noise was so ugly. I don't remember seeing the banding issues that you are seeing.

I'm sure they fixed that 14.6MP sensor with time. Also, their 20MP and 28MP sensors were super nice.

[kypfer]

Are these problems noticeable on JPGs straight from the camera or are they possibly artifacts introduced by Photoshop?

[PDL]

To answer a few issues.
First and second K7 image ISO 400, 1/4000, f/16
K20D image ISO 200, 1/180, f/6.8

My question - why use ISO 400 at 1/4000 of a second when you could have used a lower ISO on the K-7 shot and ISO 200 on a really dark shot on the K20D?
Why take the images into photoshop and push the exposure/contrast to find banding? Seems a bit of overreach to me. I am not in the least surprised that the only way banding is detected is through pushing the sliders way too much.

If you take any image from any digital camera and boost exposure and contrast to high limits, you will get what you call "banding". This sensor, I have a K20D, does have DR issues and it prone to noise when pushed in post processing. I shot many images during concerts and events in difficult lighting situations. You learn to live or accept the limitations of the device but understanding the behavior of the device is very important.

Rule of thumb:
Use the minimum ISO for the situation, ISO 400 and a shutter speed of 1/4000 is a clue. ISO 400 is way too high for the situation. As for the K20D image shown, that is where you need to push the ISO and drop the shutter speed to compensate. You need to be careful when raising the shadows on the K20D as it does increase noise.

[GUB]

First and second K7 image ISO 400, 1/4000, f/16

Well if that is indeed the settings then the image was underexposed by at least another 3.5 stops. It doesn't look like flash is used - there is shadow thrown so thanks to the sunny sixteen rule at f16 iso 400 then 1/400 would be needed.
f16 1/4000 would need iso 4000 for a sunny day.
If those settings are correct then it has been pushed at least EV 3.5 in post. ("at least" because it doesn't look quite like a full sunny 16 day.)

[mikesbike]

A few years ago, I asked about image banding on my K-20D. There was no resolution that, although as helpful as you all were, and I thank you for that... No one could figure out what was up with that...?!?
I finally resigned myself to using the K20D as a parts camera to resolve a Red K30 with the dreaded aperture solenoid failure issue...

Well, sad to say, here I am back again... with my K7 and it is doing the same thing and... ironically... in nearly the same pattern.

Mind you this is the first time I noticed this in this camera and it is the first time in more than six months that I have even picked up this camera... (Just in case that may be part of the problem...)

So any and all help and suggestions would be greatly appreciated...

So, here are a couple of images to show what is going on...

Automatic Exposure


Exposure with enhanced brightness and lowered contrast to bring out the patter.


Oh yeah... And for reference... Here's an image from my K-20D

Yeah, that's something to carp about, all right.

Aside from making light of the way you stated your situation (chuckle)- I think others here are right in that a K-7 is far from the best backup for a K-1 in terms of quality imaging. Not terrible, by any means, just not close to the same league. A KP is a huge jump forward and is a good compact APS-C complement to your K-1. It was designed, it seems, with this in mind, even having a similar set of controls, which are quite different than those of the K-7. But you'd notice a major upgrade in IQ over the K-7, and in dealing with low light/higher ISO. It is especially great when wanting or needing to avoid having to deal wth the bulk and weight of the K-1.

A k-3 III is an even greater step up, especially in higher IS performance, or if you are interested in fast action shooting or in burst shooting. But it is not a lightweight camera or as compact, and is minus some of the extra features of the KP, plus is much more expensive.

[StiffLegged]

I use a K-7 too, it’s my only DSLR, and read the exposure figures given here with incredulity - 1/4000s at f/16 and ISO set to 400. You’re hugely underexposing and the banding in the shadows might be expected with most DSLRs. Been there, done that; problem wasn’t the camera, but a couple of inches behind the viewfinder.

[bobphoenix]

What iso are these images at?

The ISO on this was 400...
Which I don't normally shoot in daylight...

[GUB]

The ISO on this was 400...
Which I don't normally shoot in daylight...

We are are responding to this data from a download of your image.
The aperture setting is a bit ambiguous ( f16 or f8) so we would love to see a screenshot of your original exif.
Presumably it was a sunny day without flash. That implements the "sunny 16 rule" (f16 , sensitivity iso X , shutter speed 1/X)
This exif shows shutter speed 1/4000 which if correct (and if f16 is correct) would mean the shot is underexposed 3.5 stops. So to achieve your first natural looking image this would have had to been done in your editor as an EV adjustment of 3.5 stops.
Now I don't know if your K7 is iso-invariant but if it is then the finalised natural image would have noise of an image taken with iso 4000 - quite a challenge for a K7
If the K7 is not iso-invariant then the outcome of brightening in post processing would be even worse noise.