D60 pixellated blue sky

RichW · Dec 30, 2002

No problem with that. As long as you don't save back into jpeg you should not have any problem. Other programs such as WinXP image viewer will damage your pics! Never do any rotation or editing there. Sounds like you have it figured out. Good luck,

Rich

Diane B said:
Okay, here's another question. I thought I understood this pretty
well, but now--not sure. I've used graphics apps for good long
while and knew to never resave a jpeg. I normally shoot in RAW,
convert, etc. However, sometimes I do shoot in jpeg--large/fine.
I open in PS, rotate if need be, do all my processing--THEN save as
tiff. Should I save as tiff--THEN post process? I didn't realize
that PS would do a lossy rotation--have not seen that spelled out
anywhere, but any extra bit of knowledge I can pick up concerning
PS is greatly appreciated.

Mike Fulton · Dec 30, 2002

Simon Tate said:
Camera settings are confirmed by Exif info. Large/fine setting at
100 ISO. Standard parameters. Absolutely no changes made in PS -
this image is straight from camera. I took 5 others at around the
same time & all show same effect. Took images of sunset later in
day & no sign whatsoever of pixellation with camera settings
unaltered apart from exposure. Have e-mailed image to Canon & await
their reply.
--
Simon Tate (UK)

Contrary to popular (?) opinion, using "Large/Fine" settings doesn't mean you'll never see JPEG artifacts. And in fact, a large gradient area where only the brightness is changing is precisely where you ARE more likely to see them.

JPEG works largely by taking small differences between adjacent pixels and making them just a little bit bigger. This results in areas where there were two or three adjacent pixels with slightly different values becoming an area with 3 pixels of the same value.

The higher the quality setting, the less it does this. But even in "Fine" mode, it's going to do it occasionally. If you really want to avoid this, use RAW mode.

Mike

Jason Hutchinson · Dec 30, 2002

Diane B said:
Okay, here's another question. I thought I understood this pretty
well, but now--not sure. I've used graphics apps for good long
while and knew to never resave a jpeg. I normally shoot in RAW,
convert, etc. However, sometimes I do shoot in jpeg--large/fine.
I open in PS, rotate if need be, do all my processing--THEN save as
tiff. Should I save as tiff--THEN post process? I didn't realize
that PS would do a lossy rotation--have not seen that spelled out
anywhere, but any extra bit of knowledge I can pick up concerning
PS is greatly appreciated.

This might get confusing, but the short answer is your current workflow of post processing then saving as TIFF is fine. There is no need to save as a tif then post process (although this doesn't hurt).

What's meant my lossy rotation is this. You have a compressed JPG, and you open it up in Photoshop. Now, you rotate. Now, if you re-save the JPG, you're applying lossy compression to your image in order to save it as a JPG again. That is to say, you're throwing away information to re-save the image as a JPG. This is in addition to the camera throwing away information when it created the original JPG.

Breezebrowser on the other hand, merely re-arranges the structure of the JPG to rotate it. The drawback is Breezebrowser can't rotate in anything but 90 degree steps, which Photoshop can rotate any amount. The reason has to do with the fact that a JPG image is made up of small square blocks of pixels.

Jason

Mike Fulton · Dec 30, 2002

Mike Fulton said:
Simon Tate said:

Camera settings are confirmed by Exif info. Large/fine setting at
100 ISO. Standard parameters. Absolutely no changes made in PS -
this image is straight from camera. I took 5 others at around the
same time & all show same effect. Took images of sunset later in
day & no sign whatsoever of pixellation with camera settings
unaltered apart from exposure. Have e-mailed image to Canon & await
their reply.
--
Simon Tate (UK)

Click to expand...

Contrary to popular (?) opinion, using "Large/Fine" settings
doesn't mean you'll never see JPEG artifacts. And in fact, a large
gradient area where only the brightness is changing is precisely
where you ARE more likely to see them.

JPEG works largely by taking small differences between adjacent
pixels and making them just a little bit bigger. This results in
areas where there were two or three adjacent pixels with slightly
different values becoming an area with 3 pixels of the same value.

The higher the quality setting, the less it does this. But even in
"Fine" mode, it's going to do it occasionally. If you really want
to avoid this, use RAW mode.

Mike

Oh by the way, are you sure this was done in "Fine" mode? The image is only a little over 500kb, which is WAY too small for that mode. If you didn't shoot in FINE mode, then the chances of JPEG artifacts are that much greater.

Mike

Mike Fulton · Dec 30, 2002

Simon Tate said:
Jason Hutchinson said:

The edited EXIF and messed up thumbnail give it away!

Click to expand...

Hey...I may be new to DPReview but I am not a complete digital
virgin. THE IMAGE IS STRAIGHT FROM THE CAMERA!!!! That's it!! No
plot to deceive Canon ....just an aberarrant set of pics for which
I am trying to find an answer. The EXIF info is not with the pic
because of the way it was upoladed to the web site. IT HAS NOT BEEN
IN ANYWAY ALTERED....PERIOD!!!

How exactly would the uploading method remove EXIF info? Unless it's manipulating the image file in general, that doesn't make sense.

What exactly is this uploading method you are referring to?

Mike

Mike Fulton · Dec 30, 2002

Simon Tate said:
Jason I apologize. The image has been rotated using Photoshop. But
that is all. Seriously, no other alterations. Plus no other image
rotated in this way has ever shown this problem, even images taken
the same day.

That's enough to do it. You're recompressing data that was already compressed once before, which is definitely going to emphasize something like artifacts in a gradient area.

To avoid this, you'll need to use something that does lossless JPEG transformations. Something like ACDSee or ThumbsPlus can do basic transformations like image rotation on a JPEG image without having to completely decompress and then recompress the whole thing.

Mike

Julius · Dec 30, 2002

I have the same pixellated “blotchy” banded skies many times and I never shoot JPG, only RAW files converted into TIF and these files are not rotated. I had the same problem with my old Canon EOS D30 and now on the D60. A friend of mine has a D60 and he has the same problem as well. I also have a Fuji S2 Pro and I never had this problem on any of the pictures taken with this camera. So when I shoot landscapes with blue skies I use my Fuji S2 Pro which has a lot better resolution than the D60 anyway. I just hope that with the 1Ds (whenever I get it) I will not have this problem.
Julius

Simon Tate said:
Greetings all!

New user here with a D60 & a curious problem.

Took about 6 images last week & all show a strangely pixellated
sky. Sun was behind me & shots were taken at 100 ISO with Canon
28-80 L lens (1/90 at f8). Have not seen the problem either before
or after...though admittedly clear blue skies are something of a
rarity in the UK at this time of year!! Any ideas? Pixellation is
odd as it is uneven - clumps or blocks of pixels which produces a
sort of tide mark effect when printed.

Yours thoughts would be appreciated.

Images can be found at:

http://web.onetel.net.uk/~thetates/

& will need to be opened in Photoshop at 100% to see the effect

Simon Tate (UK)

TerryAhBo · Dec 30, 2002

Simon Tate said:
Greetings all!

New user here with a D60 & a curious problem.

Took about 6 images last week & all show a strangely pixellated
sky. Sun was behind me & shots were taken at 100 ISO with Canon
28-80 L lens (1/90 at f8). Have not seen the problem either before
or after...though admittedly clear blue skies are something of a
rarity in the UK at this time of year!! Any ideas? Pixellation is
odd as it is uneven - clumps or blocks of pixels which produces a
sort of tide mark effect when printed.

Yours thoughts would be appreciated.

Images can be found at:

http://web.onetel.net.uk/~thetates/

& will need to be opened in Photoshop at 100% to see the effect

Simon Tate (UK)

The file found at the above site is a bmp file, you have convert the file, right? better to conver the raw to tif instead of bmp. or simplfy convert directly to jpeg.

--
AhBo

Thomas Kachadurian · Dec 30, 2002

James Long said:
Jim

Jason Hutchinson said:

You did a lossy rotate, which caused this compressed mess.

Click to expand...

Hey Jim:

Jason isn't fully explaining what he means. The fact is ANY action you take in photoshop is lossless, except conversions like RGB to CMYK. You can rotate, and rotate again with no loss of data. You only lose data if you save your work again in the JPG format. Each time you save it recompresses. The thing to do is work without saving in JPG until you're done and then make a final JPG to transmit. If you want to save your work as you go use the photoshop or compressed TIF format.

Tom
--
http://www.kachadurian.com

Greg Matty · Dec 30, 2002

Jason Hutchinson said:
This might get confusing, but the short answer is your current
workflow of post processing then saving as TIFF is fine. There is
no need to save as a tif then post process (although this doesn't
hurt).

What's meant my lossy rotation is this. You have a compressed JPG,
and you open it up in Photoshop. Now, you rotate. Now, if you
re-save the JPG, you're applying lossy compression to your image in
order to save it as a JPG again. That is to say, you're throwing
away information to re-save the image as a JPG. This is in
addition to the camera throwing away information when it created
the original JPG.

Breezebrowser on the other hand, merely re-arranges the structure
of the JPG to rotate it. The drawback is Breezebrowser can't
rotate in anything but 90 degree steps, which Photoshop can rotate
any amount. The reason has to do with the fact that a JPG image is
made up of small square blocks of pixels.

Jason

Jason,

As a Photoshop newbie, I want to make sure I understand this. The rotation itself did nothing to hurt the quality of the image, it was the re-save as a JPG that did it. This makes perfect sense. As another person mentioned, you can process the original JPG all you want as long as you then save it as a TIFF. The other options are to save the JPG as a TIFF before any processing or shoot RAW and extract an uncompressed image right from the start.

Is that about right?

Greg Matty

James Long · Dec 30, 2002

Julius,

I also believe I have a similar problem. It is inconsistent in that I have never put together enough information to find a pattern to the occurrence. It only appears when there is very little graduation in a virtually featureless area of a shot and not regularly even then.

I never resave a jpeg. I work from "virgin" files and save only in Photoshop or TIFF format. I thought maybe it could be a rotation-related phenomenum, but from what I see in this thread, I don't think so since I do not save as jpeg.

I had the problem rarely with my KOdak DCS-520 (EOS-2000). I have it more frequently with my EOS-D30. If it is my workflow, i would like to isolate it and get rid of the problem.

Any ideas?

titus20025504773 · Dec 30, 2002

Photoshop can't... I used IrfanView... this freeware has a thumb viewer and a full viewer, with slide show, etc... I am currently using it to sort through (delete or rotate) my folders.

Regards
Titus

dogbyte said:
Fascinating discussion.

Is it possible to do a lossless rotation on a JPEG image in Photoshop?

I always shoot in RAW and convert to 16 bit TIFF, plus I rotate in
Breezebrowser straight away so for those two reasons it doesn't
affect me. But to loose that amount of data on a simple rotation
seems mad. I'd be interesrted to know for future reference. Cheers.

Mike Fulton · Dec 30, 2002

TerryAhBo said:
The file found at the above site is a bmp file, you have convert
the file, right? better to conver the raw to tif instead of bmp. or
simplfy convert directly to jpeg.

--
AhBo

No, the file is not a BMP file. It's just that Internet Explorer is only giving you the option to save it as a BMP file for a number of various reasons.

It's entirely stupid that Microsoft hasn't fixed this problem.

Mike

Jason Hutchinson · Dec 30, 2002

Greg Matty said:
Jason,

As a Photoshop newbie, I want to make sure I understand this. The
rotation itself did nothing to hurt the quality of the image, it
was the re-save as a JPG that did it. This makes perfect sense.
As another person mentioned, you can process the original JPG all
you want as long as you then save it as a TIFF.
The other options
are to save the JPG as a TIFF before any processing or shoot RAW
and extract an uncompressed image right from the start.

Is that about right?

Yes, that's all correct.

For all but the most selective people, one generation of JPG isn't a horrible thing. The main thing, is to make sure to use something like TIFF if you're going to be doing saves over and over again.

Jason

Dan Brown · Dec 30, 2002

although it is interpolated resolution
Fuji S2 Pro which has a

Julius said:
lot better resolution than the D60 anyway. > Julius

--
Dan Brown
http://www.pbase.com/wheatenman

'If nothing changes, nothing changes'

Jason Hutchinson · Dec 30, 2002

Thomas Kachadurian said:
Hey Jim:

Jason isn't fully explaining what he means.

I think we're saying the same thing in two ways, and each way corresponds to how some people are processing the info.

Thomas Kachadurian said:
The fact is ANY action
you take in photoshop is lossless, except conversions like RGB to
CMYK. You can rotate, and rotate again with no loss of data. You
only lose data if you save your work again in the JPG format.

While technically correct, it's important for some people to be clear that you can't do a lossless rotation of a JPG in photoshop. You can rotate a JPG and save it as a tif and not lose any quality, but you really have lost something. You're lost the perfect compression of the JPG. You now are storing 1MB of info in say an 8MB file. You've lost hard drive space. If you're doing other manipulations to the data however, there really is no loss.

Thomas Kachadurian said:
The thing to do is work without
saving in JPG until you're done and then make a final JPG to
transmit. If you want to save your work as you go use the photoshop
or compressed TIF format.

Agreed.

Julius · Dec 30, 2002

The Fuji S2 Pro in the 12.1MP RAW file mode resolves 1750H x 1710V x 1550 diagonal lines while the D60 resolves 1500H x 1550V x 1450 diagonal lines. The difference in detailed resolution of the same landscape scene printed out on a 13x19" print is so obvious that the D60 does not even come close with any of my best L lenses.
Julius

Dan Brown said:
Dan Brown said:

lot better resolution than the D60 anyway. > Julius

Click to expand...

--
Dan Brown
http://www.pbase.com/wheatenman

'If nothing changes, nothing changes'

Simon Tate · Dec 31, 2002

But....as I mentioned earlier...I also saved one image after initial rotation in PS (& no other changes) as a PDF file. This image is also corrupted in the same way. I still think the problem precedes PS. I understand what u are driving at & it makes sense. What doesn't make sense is why I have no other images which exhibit even a hint of the the same problem....& I have shot a LOT of skies with the D60.

Jason Hutchinson said:
Greg Matty said:

Jason,

As a Photoshop newbie, I want to make sure I understand this. The
rotation itself did nothing to hurt the quality of the image, it
was the re-save as a JPG that did it. This makes perfect sense.
As another person mentioned, you can process the original JPG all
you want as long as you then save it as a TIFF.
The other options
are to save the JPG as a TIFF before any processing or shoot RAW
and extract an uncompressed image right from the start.

Is that about right?

Click to expand...

Yes, that's all correct.

For all but the most selective people, one generation of JPG isn't
a horrible thing. The main thing, is to make sure to use something
like TIFF if you're going to be doing saves over and over again.

Jason

--
Simon Tate (UK)

Simon Tate · Dec 31, 2002

Thanks Julius!

Thought I was going crazy or something. Pleased that I am not the only one on the planet to have experienced this problem. PLEASE e-mail me if u find an answer....& likewise if Canon come back with an inspired response I will let u (& everyone else) know. Cheers!

Julius said:
Simon Tate said:

Greetings all!

New user here with a D60 & a curious problem.

Took about 6 images last week & all show a strangely pixellated
sky. Sun was behind me & shots were taken at 100 ISO with Canon
28-80 L lens (1/90 at f8). Have not seen the problem either before
or after...though admittedly clear blue skies are something of a
rarity in the UK at this time of year!! Any ideas? Pixellation is
odd as it is uneven - clumps or blocks of pixels which produces a
sort of tide mark effect when printed.

Yours thoughts would be appreciated.

Images can be found at:

http://web.onetel.net.uk/~thetates/

& will need to be opened in Photoshop at 100% to see the effect

Simon Tate (UK)

Click to expand...

--
Simon Tate (UK)

Jason Hutchinson · Dec 31, 2002

Collectively, people in these forums have wasted thousands of hours helping people with problems that they themselves created. So, if you want any real help, get an unedited image showing this problem. I looked over that image again, and with the amount of detail and the f/stop, that image should have been 3-4MB. That's 3MB of data you dumped, and that image quality left proves it. It doesn't take much of your time if this is a real problem to get an unedited image showing it, at least compared to the time of everyone responding.

Jason

P.S. Depending on your PDF settings, it just uses JPG to store the image, and you have the same problem. If you haven't noticed, not many people are actually considering your ways of explaining why this can't be a PS problem. You've lost a lot of credibility posting an edited image, and if you want to prove you're right, post an unedited image with these problems.

Simon Tate said:
But....as I mentioned earlier...I also saved one image after
initial rotation in PS (& no other changes) as a PDF file. This
image is also corrupted in the same way. I still think the problem
precedes PS. I understand what u are driving at & it makes sense.
What doesn't make sense is why I have no other images which exhibit
even a hint of the the same problem....& I have shot a LOT of skies
with the D60.

D60 pixellated blue sky

Forum Pro

Senior Member

Forum Pro

Senior Member

Senior Member

Senior Member

Leading Member

Member

Veteran Member

Senior Member

Forum Enthusiast

Active member

Senior Member

Forum Pro

Senior Member

Forum Pro

Leading Member

Member

Member

Forum Pro

Keyboard shortcuts