Reading mode: Light Dark

What is this pattern

Go to last post
kitsios_spyros

kitsios_spyros

Senior Member
Messages
2,849
Reaction score
727
Location
Thessaloniki, GR
I was shooting in raw and I noticed the pattern on the sky on the camera's LCD.

I have seen this pattern only in highly compressed jpegs. But the raw files as viewed in FastStone Image Viewer have the same pattern too. Same goes for the raw-to-jpeg files through the same programm.





































Can you see it too? And if so, what could be the cause?

Other files with uniform sky color do not show the same pattern









Thanks in advance.
Spyros
 
Very good explanation of the problem, I learn something new every time I get on this site, even after, fifty years in photography. It proves your never to old to learn.
 
When you review RAW files on the camera lcd screen you are looking at the embedded low quality jpeg. The same is likely to be true for FastStone - check your settings and make sure you are using the "Actual size" option on the RAW tab.

--
Steve

http://www.pbase.com/steephill
 
Thank you for the responses.

I know that posterization is ease to show up if one overprocess or simply compress an image too much.

But these are (16-bit) raw files with no processing at all (other than jpeg convertion with 100% quality for the ones I uploaded) and the histogram of the raw file is full of picks along the curve. Also, the effect is visible in actual size too.

So, why did this happen in a raw file?? Should I worry about the sensor?

Kind Regards,
Spyros
 
Notice how the stripes (for want of a more technical word) go side to side in the landscape orientation shot?

And how they still go side to side in the portrait orientation shot? (They even change the radius of curvature.)

If it had been a fault in the sensor, I wouldn't expect the problem to rotate according to the orientation of the camera or the shape of the aberration to change.

I don't know what is causing it, but maybe there is something causing multiple reflections. Do you have a filter on the lens? Are you using a lens hood?

--
Duncan
 
I would suggest you post a raw file somewhere for people to look at.

Looking at the images they look like the low resolution jpeg sidekick files from the raw, not a jpeg created from the raw.

Looking at the exif there is no mention of any RAW processor which again is indicative these are not quality jpeg conversions but just extractions of the thumbnail jpeg.

I don't know your converter to say how or if this is the case but posting a RAW for others to convert will prove it one way or another.

or try Raw Therapee a free converter.

Given these are 16Mp files compress into less than 1.5 Mbs I'm impressed they look as good as they do.

--
My PPG
http://www.pentaxphotogallery.com/artists/andrewwaldram
My Photo Stream
http://www.flickr.com/photos/awaldram/
1x.com
http://1x.com/artist/awaldram/wall
 
kitsios_spyros said:
But these are (16-bit) raw files with no processing at all (other than jpeg convertion with 100% quality for the ones I uploaded) and the histogram of the raw file is full of picks along the curve. Also, the effect is visible in actual size too.

So, why did this happen in a raw file?? Should I worry about the sensor?
Click to expand...
It didn't happen the RAW file. You never 'see' a RAW file; the image you see in any viewer or on your camera's LCD is a jpeg produced after the demosaicing process which converts the RAW data in to a viewable image. These artefacts are almost certainly not present in the RAW file - and as someone else pointed out they cannot be associated with the sensor as they orientation and curvature changes from picture to picture (as the sky changes). Both the camera LCD screen and your viewer and doing quick-and-dirty jpeg conversions which is what you are seeing. note that the histogram on the back of the camera also belongs to the jpeg conversion, not the original RAW file.

Try opening one in a different RAW convertor like Adobe Camera Raw and processing it conventionally using minimum compression and see if the posterisation is still there... I bet it disappears.

Best wishes
--
Mike
http://www.pentaxphotogallery.com/artists/mikeward
 
I Changed SD card, no difference.

But, I tried
RAW
RAW+
jpeg and
jpeg + raw rertieved from the memory of the camera (AE-L button)

I viewed them first on the camera's LCD. In every case jpegs have very normal histogramms. Raw files have the typical posterization-type histograms.

So, both K5 and FastStone present polarization with polarization type histograms for raw files only, while jpegs look fine with normal histagrams too.

I was totally lost by now.

And then, I imported the raw files in LR3 and everything is perfect there, with smooth colour degradation. RGB and luminance histograms are as expected for a K5 raw file (that is great) and same happened with Bridge.

So, for some reason the version of FastStone I use seems that can not co-operate with K5 raw files. I'll download a newr version if there is one available. The only issue for me is if I can trust the histogram of a raw file right after each shoot if I use RAW only. For RAW+ everything seems fine, but for RAW only I see the above described problem.

Thank you all for the feedback

Kind Regards,
Spyros
 
You just won a bet...

Kind Regards,
Spyros
mike703 said:
kitsios_spyros said:
But these are (16-bit) raw files with no processing at all (other than jpeg convertion with 100% quality for the ones I uploaded) and the histogram of the raw file is full of picks along the curve. Also, the effect is visible in actual size too.

So, why did this happen in a raw file?? Should I worry about the sensor?
Click to expand...
It didn't happen the RAW file. You never 'see' a RAW file; the image you see in any viewer or on your camera's LCD is a jpeg produced after the demosaicing process which converts the RAW data in to a viewable image. These artefacts are almost certainly not present in the RAW file - and as someone else pointed out they cannot be associated with the sensor as they orientation and curvature changes from picture to picture (as the sky changes). Both the camera LCD screen and your viewer and doing quick-and-dirty jpeg conversions which is what you are seeing. note that the histogram on the back of the camera also belongs to the jpeg conversion, not the original RAW file.

Try opening one in a different RAW convertor like Adobe Camera Raw and processing it conventionally using minimum compression and see if the posterisation is still there... I bet it disappears.

Best wishes
--
Mike
http://www.pentaxphotogallery.com/artists/mikeward
Click to expand...
 
So, after the explanations, some photos.
first K5 with Tamron 28-75
FastStone jpeg conversion... what I have available at the moment
C&C appreciated



























































 
and now K10d with 18-55wr

All from Ioannina. Lake and castle

























































Thanks for looking
Spyros
 
Lovley images far to many to provide any coherent C&C

But a couple of thoughts

on the image with the monolith and OOF Bride , Lose the Photographer clone him out he ruins what would be a very powerful image.

The abstract images I don't get , why an OOf padlock and sharp hasp bolt.?

To me every image has to tell a story convey an emotion these don't , Might be just me being a heathen :)

And last

fIMGP7639 b&w seems to have a lot of pale green for a Black and white shot it looks just a desaturated version of the one above.

It either needed shooting in BW or truly being converted to BW probably with rendering intent to a known film type until your comfortable with the process.

Most processor have plugin or inbuilt tools to do this.

If your wish I can bung the colour one through Aftershot\bibble to show you what I mean.?

--
My PPG
http://www.pentaxphotogallery.com/artists/andrewwaldram
My Photo Stream
http://www.flickr.com/photos/awaldram/
1x.com
http://1x.com/artist/awaldram/wall
 
Thank you awaldram,

Valid and usefull comments, all of them, and most my thoughts too, especially the oof bride + photographer, who stepped in the frame 3 times in a raw (...) or the sharp bolt vs lock (my mistake, no BF here).

But since I mostly comment or ask questions I just posted some pictures, even if the K5 ones gould be greatly improved with a better program and proper time for PP.

The 7639b&w was on purpose desaturated that much and not true B&W. Again, a quick and dirty desaturation on my worst monitor, where it looks very pleasant.

I hope I will soon find some time to upload last month's shoots from the ballet and theatre shows of my daughters. Again K5+28-75 and K10d+kit lens+Flash

K5 is a great improvement over K10d in many ways. But I still enjoy my K10d, although I have to do a couple of tricks to make it work in certain situations due to a couple of mechanical problems. The two cameras are a great combination in good light. In lower light K10d demands flash in many situations, more static subjects and/or other technics (prefocus/manual metering/ AE-lock) more often than K5. But I still enjoy it. K5 is in a different league in many ways, but not every way.

Thanks for the comments and fill free to PP with any of these!

Kind Regards,
Spyros
awaldram said:
Lovley images far to many to provide any coherent C&C

But a couple of thoughts

on the image with the monolith and OOF Bride , Lose the Photographer clone him out he ruins what would be a very powerful image.

The abstract images I don't get , why an OOf padlock and sharp hasp bolt.?

To me every image has to tell a story convey an emotion these don't , Might be just me being a heathen :)

And last

fIMGP7639 b&w seems to have a lot of pale green for a Black and white shot it looks just a desaturated version of the one above.

It either needed shooting in BW or truly being converted to BW probably with rendering intent to a known film type until your comfortable with the process.

Most processor have plugin or inbuilt tools to do this.

If your wish I can bung the colour one through Aftershot\bibble to show you what I mean.?

--
My PPG
http://www.pentaxphotogallery.com/artists/andrewwaldram
My Photo Stream
http://www.flickr.com/photos/awaldram/
1x.com
http://1x.com/artist/awaldram/wall
Click to expand...
 
For anyone who uses FastStone and read this thread please note that the problem was solved when I swithced the settings for RAW from
Actual size
to Embedded Preview Image
and then back to
Actual size

For some reason the K5 files defaulted to Embedded Preview Image while at the same time the K10d raw files worked in Actual size. Maybe due to the low cost processor I use on this PC (Pentium dual core 2.5GHz) it defaulted to this mode (much faster this way!)

The embedded preview image is a 16MP file of HEAVY quality compression, so it is difficult to see right away since the pixel numbers are unchanged.

Kind Regards,
Spyros
 
Thanks for the little photographic excursuion to the mainland! ;)

(Glad you sorted out the banding thing!)

--
-----------------------------------------------
Miles Green
Pentaxian with chronic LBA
Corfu, Greece
 
Ioannina is a place I would visit any time of the year. It happens to be where my father was born and raised, so there is some emotional stuFF into this sentence. But no mattter how many times I've been there, I enjoy each and every single time I visit this place. The castle, the lake and the place with the restaurants and cafeterias that open every summer (Nautakia) is just wonderfull.

And Corfu is only a couple hours away. I'd just love to visit your wonderfull island again.

Kind Regards,
Spyros
 
You must log in or register to reply here.

Keyboard shortcuts

f
Forum
m
My threads
Mobile site
About
Editorial content
Cameras & Lenses
Community
All content, design, and layout are Copyright © 1998–2025 Digital Photography Review All Rights Reserved.
Reproduction in whole or part in any form or medium without specific written permission is prohibited.
When you use DPReview links to buy products, the site may earn a commission.
©GPS Media - Guides, Products, Services.
Back
Top