To PP or not to PP ...

[GaryDeM]

you stated- "Digital sensors are notorious for not having the same dynamic range as film."

not entirely true. SLIDE film has virtually the same dydnamic range as a digital sensor. and, unlike digital, it cannot be pp or enhanced after the shot. itis literally -what you shoot is what you get-.

i shot slides for 32yrs, and going to digital was very easy for me. i simply applied my slide shooting techniques to digital. iot worked. i currently crop almost zero(you cannot crop at all in slides) and postprocess about 5% of all i shoot. when i do pp i kick myself because that is not as good as i was doing with slides. with slides i was at about 100% correct on the exposures.

i believe that shooting with digital and being correct has an enormous amout to do with your photgraphic film(slides) background. there are now a great many people who staarted with digital and have no real(or very little) prior experience with photos.

 

[GaryDeM]

i am not interested in trying to restore it.

the question is: why would you take a messed up pic like that in the first place? the camera operator is responsible for taking the photo. he should be doing the job right. no excuses.

 

[Ferenc MOGOR]

Wait a minute- you messed it up on purpose (wasn't the original
suppose the be the "final", best version?), then you want us to
un-mess it up?

What are you trying to prove here?

Peace, Goopup, ...peace, ...let there be peace!

Why don't you comment on GCam's attempt on restoring the WB of the sample pic? You've got something to say, I'm sure! )))

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'

 

[Myer]

Not knowing what the true colors should be I did a Curves adjustment in LAB to reduce the blue in the vertical panels on the building on the left-hand side. I assumed they should be white. I let everything else fall into place as it may.

 

[rdutto01]

Doing the PP on my monitor at work so it my be worse instead of better.

Here's my try, levels, hue/saturation, channel mixer and some sharpening:



I hope Peano comes back and does his magic. His PP is always first rate!

Thank you,

--
Randy Dutton

 

[Ferenc MOGOR]

i am not interested in trying to restore it.

Accepted. A bit sorry, but really accepted. ;-)

the question is: why would you take a messed up pic like that in
the first place? the camera operator is responsible for taking the
photo. he should be doing the job right. no excuses.

Fully agree with you!

But why take such a messed up picture? Because this is a game, a game to see how we can recover our own mistakes. Of course, this is much far from what we do in general, but it's just a game to let us all try what we can do in such extreme cases with an 8 bit jpg image in our editing software. That's all! Let's look at the fun side!

If we are really able to save such an extremely bad shot we are able to do anything we wish! ;-)

Did you serve in the Army? I did! Sometimes we had to do extremely blunt things we would never think of doing in our civil lives. But now we have a reference point, the least to say, eh? Nothing will ever surprise us anymore!! LOL

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'

 

[Myer]

Why did he mess it up?

Well, I can tell you that the first time I took my digital SLR on a trip, I left it on all day and had it bouncing off my hip. Late that day I noticed some of the setting had changed due to the bouncing. One of them was WB.

I could either retrace my steps the next day or decide i had some PP to do.

I chose the latter.

 

[Pat]

Speaking of JPEG, be aware that this file format doesn’t support
high-bit data, only 8-bit. Many users recognize that Photoshop can
convert an 8-bit file to 16-bit and wonder if that provides any
advantages. Unfortunately, no.

I have read otherwise and can find various sources to support my position, but not yours. While it is true that you won't gain any information by converting to 16-bit, you will lose less information when making corrections.

To see for yourself, take a jpeg, open it up and make drastic tonal corrections then save it. Do the exact same thing with the source file using the same settings only convert it to 16-bit before you do your corrections. Now compare the histograms, and the one edited in 16-bit mode will have less combing than the one edited in 8-bit mode.

Here's just one source that supports this view:

http://theonlinephotographer.blogspot.com/2007/02/demythologizing-photoshoppingsix.html

The author writes:

"Tonal editing done in 16-bit mode almost never loses data or information, no matter how extreme. (Spatial editing is another matter.) I recommend people with enough computer muscle always work in 16-bit mode, even if their starting point is an 8-bit file. Makes for less worrying about such losses."

Can you find a source that takes the opposite view?

If you started with a high-bit file and converted to 8-bit, the
additional data is thrown away; you can’t get it back. The reason
Photoshop allows such conversions are situations where you might
build a composite and paste an 8-bit image into a 16-bit image.

....and to allow for less data destruction when editing any image whether originally a jpeg or raw.

So, I'd appreciate it if you can find a source that will agree with you on this exact point.

--Pat

 

[Ferenc MOGOR]

Pat,

Thanks for your kind reply, it definitely contains a lot of interesting stuff to consider and re-consider.

Since it's already past mid-night on my part of the world I have to get some sleep, but will surely get back to you tomorrow.

See Ya and thanks as always.

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'

 

[GaryDeM]

using your example i would fix the shots the best way i could. it is either that or go back and reshoot them, which some times is impossible for many reasons.

i was speaking of taking a shot or shots knowing they could be wrong in the first place. THEN it is either carelessness or incompentance or just don't care. pp will fix all. hogwash. do it right in the camera-then if pp it(you) will at least start with the best image(jpeg or raw) possible.

 

[GaryDeM]

ferec-

what i did was to test each of the major settings(contrast/sharpening/saturation/IQsettings

to see what they did, what i liked, what gave the best images for me; then shoot my pics. that way no suprises. i haven't changed my settings since. now i have the look i want in my pics and i leave the settings alone.

 

[joe604]

Pat,

Speaking of JPEG, be aware that this file format doesn’t support
high-bit data, only 8-bit. Many users recognize that Photoshop can
convert an 8-bit file to 16-bit and wonder if that provides any
advantages. Unfortunately, no.

If you started with a high-bit file and converted to 8-bit, the
additional data is thrown away; you can’t get it back. The reason
Photoshop allows such conversions are situations where you might
build a composite and paste an 8-bit image into a 16-bit image.

This can’t be accomplished unless all the documents have the same
bit-depth (and for that matter, the same color space). So while you
can convert from a lower bit-depth to a higher bit-depth, unless
you’re doing this kind of composite work, there’s no real benefit
in doing so. Much like starting with a high-resolution file, if you
interpolate it down and then interpolate it up to the original
size, you don’t have the same original data.

--
Cheers, Feri

I hope that those who are perusing through this thread understand that some of Feri's opinions are simply wrong, so beware. The above comment is such a case about an important issue. and I don't think it should be left uncorrected.

Editing in 16-bit mode produces fewer artifacts than in 8-bit mode. This is in part because the new values calculated for a pixel as a result of an edit must be rounded to the nearest 8-bit value, and there are only 256 of them. If one is going to do several editing steps, then the rounding errors that occur with each edit can add up to significant artifacts. With 16 bits, the rounding error of each new value is much, much less significant, and one can do many edits without the rounding errors adding up to a problem.

This principle is true regardless of whether the original was 8-bit or 16-bit. Therefore, if one is going to do many editing steps on an original 8-bit file, then there can be a perceptible benefit in converting to 16-bit mode prior to doing the PP. Then do a single rounding of the values to 8 bits as the final step.

--
Regards,
Joe

My fancy equipment does a great job of capturing reality. Fortunately, I can fix that with Photoshop.

 

[Ferenc MOGOR]

Hi Joe,

I do appreciate all of your in-depth explatations on a somewhat misunderstood myth,...whle in the meantime I would really appreciate your proof on restoring the white balance of this shot, ...all based on your explanations set forth in your previous post.

http://forums.dpreview.com/forums/read.asp?forum=1006&message=23225654

Should you be able to do it, ...I'll stand corrected.

Otherwise, well, ...we will need to find the time and place to have a beer or two for further discussions! )

Lookin' forward!

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'

 

[andrewD2]

I clicked the mouse and slid a few sliders. ACR4 is a revolution for jpgs.



Andrew

 

[joe604]

Feri did not make clear whether he adjusted the WB in the camera or in post processing. Based on the histograms, I guess that he did it in PP because I don't think having the wrong WB in the camera will skew the blacks like we see here.

In either case, the error can be partially corrected with a levels adjustment as shown below. I simply realigned the black point and white points for the three channels. This is not a complete fix because the skewed WB lost some of the red data in the shadows and some of the blue data in the highlights, which cannot be recovered. However, the midtones look fairly well balanced after the correction.



--
Regards,
Joe

My fancy equipment does a great job of capturing reality. Fortunately, I can fix that with Photoshop.

 

[andrewD2]

Feri did not make clear whether he adjusted the WB in the camera or
in post processing. Based on the histograms, I guess that he did it
in PP because I don't think having the wrong WB in the camera will
skew the blacks like we see here.

Very astute. The camera WB was on auto according to the exif.

Andrew

 

[Ferenc MOGOR]

Hi to All,

Thanks for coming along to this thread.

But first of all to Joe,...so here are the original WB correct pictures of that beautiful building I captured recently in the old town of Prague in The Czech Republic:









And also thanks to those who participated in this game of white balance correction on an 8 bit jpg image. ;-)

Finally thanks to those who squeezed me to do a lot more thinking about the captioned subject, especially I learned something new on how to look at histograms in regards of the so-called combing effect.

And thanks to the poster who finally stopped sending "weirdo" messages to my private e-mail account. No message in the last few hours! ))

The thread is now officially closed by the original poster (that's me), but please feel free to follow up at your own discretion. Still far from the allowed 150 limit!!

I only owe a reply to Pat which is to come soon tomorrow.

Happy shooting and pp'ing to All!

Honorable mention goes to : Stan Schutze. You've got talent there that I did enjoy to the brim!!

Bye now!

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'

 

[Bernd Taeger]

Workflow: (PS7)

Sample sky
new layer
fill with sampled color
invert layer
set to color
set fill to 43%
S-curve layer to up contrast
Hue/Sat layer for yellow & blue
convert to 16 bit
Reverse USM 15, 40?
Downsample
USM 500, 0.2, 0
convert to 8 bit

--
Bernd Taeger

 

[Ferenc MOGOR]

Hi Pat,

Thanks for that article which I read with great interest.

While it does have valid points, it still doesn't really cover my topic.

OK, so as a summary, we can basically do the followings:

• Shoot in jpg mode. This means we rely on the editing capabilities of our camera, we are fully aware ofthe fact that there has been an intermediate jpg compression (file size and bit rate down) and accept it and will continue editing on our PCs on an already compressed file.

• Shoot TIFF. This means we rely on the editing capabilities of our camera, but we know there was no compression in the middle, so we can continue editing on a lossless/uncompressed file with it's original bit rate.

• Shoot RAW. This means we don't want the camera to do the editing, instead we wanna have the raw material and do the tweakings by our own hands with the original bit rate intact.

That's all!

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'