[PTGui] Losing image quality

[Slap Happy]

Hi - apologies, I'm sure the question of workflow has been done to
death but I can't find a thread.
My workflow is:- Raw file from Canon 5Dii / 16bit tiffs exported from
Lightroom into PTgui / output of full size 16bit tiff (single layer)
re-imported into Lightroom for final touching up, cropping, etc.

My main question is -- when first exporting the tiff files from LR is
it best to have applied sharpening and contrast to the converted raw
file, or will better image quality be obtained by feeding PTgui tiff
files that are just 'basic' raw conversions with nothing extra like
sharpening or contrast applied?? (I assume chromatic aberration is
best addressed as early as possible in the flow).

Are there any other tips/issues for maintaining maximum image quality
in a simple workflow like this one?

Thanks

--
You received this message because you are subscribed to the Google Groups "PTGui" group.
To post to this group, send email to pt...@googlegroups.com
To unsubscribe from this group, send email to ptgui+un...@googlegroups.com
Please do not add attachments to your posts; instead you may upload files at
http://groups.google.com/group/ptgui/files
For more options, visit this group at http://groups.google.com/group/ptgui

[Kevin Wilton]

The last thing you do to any image, regardless of whatever you are doing to
it is apply sharpening. If you do anything to a sharpened picky in
Photoshop, it looks awful.

[Joergen Geerds]

As Kevon already said, CA and chroma/luma noise are the things to fix
in the first step (ACR to tiff), no sharpening, no cropping, all color/
exposure/recovery settings the same, and generally flatter than
normal.

all those other things can/should be fixed in LR/PS later, with
sharpening as the very very last step after resizing to the final
output size.

joergen

[l_d_allan]

My understanding is that more and more Photoshop book authors are
recommending to apply some sharpening early in the workflow. This is
based on writings by Bruce Fraser (now deceased) and others. He called
this "creative sharpening", which tended to be a relatively low to
moderate amount of sharpening. Subsequent sharpening would be done at
or near the very end, based on output considerations.

It seems like this might be an emerging concensus ... to have light to
moderate sharpening early in the work-flow, but this is controversial,
and by no means agreed to by everyone (obviously, based on other
replies to this thread).

I consider myself too inexperienced to have a valid opinion.

********** a semi-related issue *********

is that the noise reduction (NR) of LR and ACR is much less effective
than plug-ins like Noise Ninja, NeatImage, etc. imo. Every book I've
read about Photoshop has described Photoshop/LR noise reduction as
less than effective. LR3 and ACR6 are supposed to be better, but that
wasn't my experience, based on the LR betas. My experience is that the
NeatImage NR plug-in is much better than ACR/LR's NR. My evaluation of
commercial NR plug-in trials was that they were all much better than
ACR/LR.

I think it is pretty much universally recommended to do NR before
sharpening, but the work-flow is less than optimal to do some
sharpening in ACR/LR, and then use a NR plug-in. This would seem to
argue against having any sharpening in ACR/LR.

If I didn't have a NR plug-in, I think my work-flow would be NR in ACR/
LR, and also light-to-moderate sharpening in ACR/LR. Then final
sharpening based on output.

However, pretty much everything I've read about CS4 is that ACR/LR
sharpening has gotten much better than previous releases. I've only
used CS4, so I have no valid opinion on that either.

Ideally, it would be better for ACR/LR to allow integration of NR plug-
ins, so higher quality NR was done earlier in the processing pipeline.

This is (yet another) aside, but NR plug-ins can be harder to use with
PTGui because they like to have EXIF info, especially ISO, which PTGui
doesn't seem to keep in the generated pano. Drat, but perhaps I'm
doing something wrong. I'll ask in a separate thread.

[Joergen Geerds]

Hi Lynn,

I think there are some controversies below that I would like to
address:

On May 24, 11:27 am, l_d_allan <lynn.d.al...@gmail.com> wrote:
> My understanding is that more and more Photoshop book authors are
> recommending to apply some sharpening early in the workflow. This is
> based on writings by Bruce Fraser (now deceased) and others. He called
> this "creative sharpening", which tended to be a relatively low to
> moderate amount of sharpening. Subsequent sharpening would be done at
> or near the very end, based on output considerations.
> It seems like this might be an emerging concensus ...

Most photoshop book authors don't do panoramas, and don't take the
very special environment of stitching not into consideration. while
their suggestions might work fine in a classical environment (I love
sharpening in ACR for my normal photos), they are counter-productive
for panos:
I for example do not sharpen my RAW->tiff files because they go into a
exposure blending process, where initial sharpening would create nasty
color fringes. in addition, the individual tiles get a lot of warping
with various kinds of interpolations, and since sharpening is a lossy
process (information gets lost in this process), giving the
interpolators the maximum amount of information rather than less info
is beneficial (see all the lengthy discussions about jpg vs. tiff as
input files). but if you like it, go for it, but please don't call it
"emerging consensus".

> ********** a semi-related issue *********
> is that the noise reduction (NR) of LR and ACR is much less effective
> than plug-ins like Noise Ninja, NeatImage, etc. imo. Every book I've
> read about Photoshop has described Photoshop/LR noise reduction as
> less than effective. LR3 and ACR6 are supposed to be better, but that
> wasn't my experience, based on the LR betas. My experience is that the
> NeatImage NR plug-in is much better than ACR/LR's NR. My evaluation of
> commercial NR plug-in trials was that they were all much better than
> ACR/LR.

this is unfortunately very wrong, for various reasons:
- the NR in ACR6 is spectacular (yes, i am an adobe fanboy), and beats
about any other NR (IMO). it is so good in fact, that I can afford to
shoot panos at ISO5000 now. but whatever you use, you want to remove
the noise before warping.

- noise is a regional statistical phenomenon, in other words, the
noise is more or less equally spaced. every NR application is relying
on this fact. if you apply your NR AFTER warping, the noise is not
equally spaced anymore, and NR apps can't remove the noise anymore,
because they can't detect it properly (especially in areas of really
large distortions near the Z/N). in addition, noise can appear in
patterns (i.e. vertical streaks), which after warping can be very
visible, and almost impossible to blend nicely (at least in cases with
heavy noise).

> Ideally, it would be better for ACR/LR to allow integration of NR plug-
> ins, so higher quality NR was done earlier in the processing pipeline.

there is no need for it at all. first, CS4 is outdated, and adobe will
not work on the code ever again (besides minor security fixes).
second, adobe has already really good NR in ACR6, and they are
tremendously proud of it (rightfully so), that they don't see a reason
why to offer third-party NR in ACR... if you still don't like the
results of ACR6, you can use plugins in the app environment (LR/PS),
or use a different RAW developer.

> This is (yet another) aside, but NR plug-ins can be harder to use with
> PTGui because they like to have EXIF info, especially ISO, which PTGui
> doesn't seem to keep in the generated pano.

I don't see this a mayor flaw of ptgui not to include the ISO... if
you really need it, use exiftool to add that piece of info to your
file.

joergen

[Slap Happy]

Thank you for your thoughts Joergen. I was especially interested to
hear why NR should definitely be applied prior to processing in
PTgui. And in my ignorance of how PTgui actually works, I had
wondered if a little sharpening might not help it align the images!

1). To be completely clear then:-

In LR initially, set:
a) White balance chosen and synchronised across images.
b) Tone and presence controls (including blacks) all set to zero, with
possible exception of:
c) Brightness and contrast -- LR defaults are 50 and 25 respectively;
when you say the image should be "flatter" I take you to mean that
these should be reduced somewhat, if not actually set to zero.
d) No sharpening to be applied.
e) Corrections for CA, and any noise reduction, to be applied at this
stage (I must admit I forgot NR but I very rarely see the need to
apply it).

2). You obviously like the NR in ACR6 - do you think we'll see the
same technology in Lightroom 3?

3). Just out of interest I'll say what I mean by losing image
quality. Generally I cannot see any difference between a re-imported
tiff and the rendering of the original raw file in LR prior to
export. However, when a panoramic file is re-imported I see two
things. A loss of natural vibrancy - boosting the contrast and so on
can of course offset this loss, but I am unable to recreate a wholly
natural looking vibrancy. Second, fine detail takes on a slightly
'spongy', very 'digital looking' quality, as though micro-contrast has
been unduly amplified, or the clarity control in LR has been abused.
I should admit though that this is looking at the files in LR only -
it may well be that once printed the effects become more negligible.

And thanks to everyone else for their replies.

On May 24, 2:40 pm, Joergen Geerds <jgee...@gmail.com> wrote:
> As Kevon already said, CA and chroma/luma noise are the things to fix
> in the first step (ACR to tiff), no sharpening, no cropping, all color/
> exposure/recovery settings the same, and generally flatter than
> normal.
>
> all those other things can/should be fixed in LR/PS later, with
> sharpening as the very very last step after resizing to the final
> output size.
>
> joergen
>
> --
> You received this message because you are subscribed to the Google Groups "PTGui" group.
> To post to this group, send email to pt...@googlegroups.com
> To unsubscribe from this group, send email to ptgui+un...@googlegroups.com

> Please do not add attachments to your posts; instead you may upload files athttp://groups.google.com/group/ptgui/files

[l_d_allan]

> Most photoshop book authors don't do panoramas, and don't take the
> very special environment of stitching not into consideration. while
> their suggestions might work fine in a classical environment (I love
> sharpening in ACR for my normal photos), they are counter-productive
> for panos:

Ok. Makes sense that different rules would apply for panos vs non-
panos. My practice prior to my interest in panos was to try to do as
much as possible in ACR, and as little as possible in CS4. Some of
that appears to be bad habits to carry forward to panos. Thanks for
the clarification.

> this is unfortunately very wrong, for various reasons:
> - the NR in ACR6 is spectacular (yes, i am an adobe fanboy), and beats
> about any other NR (IMO). it is so good in fact, that I can afford to
> shoot panos at ISO5000 now. but whatever you use, you want to remove
> the noise before warping.

Glad to hear the release ACR 6.x in CS5 is much better. I had high
hopes for the NR in the first LR3-Beta, since the Adobe announcement
indicated it was much better. I saw little or no difference from
ACR-5.x, so was disappointed. I installed the second beta of LR-3, but
got busy on other things, and barely tried the NR.

My understanding of the ACR 6.x that comes with CS5 is that it is
essentially the same "engine" as LR3. The user interface is different,
but the NR should be equivalent.

I'm also close to being an Adobe "fan-boy". I anticipate updating
Photoshop every other release to conserve budget. I'll probably
install the trial, and check the release NR, and also the improved
"content aware fill".

Unrelated question ... has you found CS5 to have better capabilities
for masking?

> I don't see this a mayor flaw of ptgui not to include the ISO... if
> you really need it, use exiftool to add that piece of info to your
> file.

I didn't mean to convey it was a major flaw ... more of an
inconvenience. It makes batch processing that includes after-the-fact
NR of PTGui generated panos more difficult, but that isn't my typical
work-flow anyway.

[Kevin Wilton]

I can't agree with this at all, so count me out of the consensus, any work
done on sharpened images just looks awful. Which is why it is also annoying,
to me anyway, that there is a small amount of sharpening as default in ACR.

However, if you want to clean up edge contrast a little, use the clarity
slider, just above Vibrance in LR/ACR.

Kev

-----Original Message-----
From: pt...@googlegroups.com [mailto:pt...@googlegroups.com] On Behalf Of
l_d_allan
Sent: Tuesday, 25 May 2010 1:28 AM
To: PTGui Support

[Joergen Geerds]

On May 24, 3:44 pm, Slap Happy <pdm33...@yahoo.co.uk> wrote:
> In LR initially, set:
> a) White balance chosen and synchronised across images.
> b) Tone and presence controls (including blacks) all set to zero, with
> possible exception of:
> c) Brightness and contrast -- LR defaults are 50 and 25 respectively;
> when you say the image should be "flatter" I take you to mean that
> these should be reduced somewhat, if not actually set to zero.
> d) No sharpening to be applied.
> e) Corrections for CA, and any noise reduction, to be applied at this
> stage (I must admit I forgot NR but I very rarely see the need to apply it).

That is all absolutely correct, and since I use relatively wide
brackets, I prefer each individual tiff as flat (linear?) as possible
(brightness/contrast set to 0). I add contrast etc later in photoshop.
also, a higher brightness increases noise in dark aras, and no/little
noise is mission-critical in my night panoramas... day panos might not
suffer so much from it. besides, ACR/LR always apply a default setting
of NR, which is why you mostly see no noise anyway.

> 2).  You obviously like the NR in ACR6 - do you think we'll see the same technology in Lightroom 3?

Yes, LR3 will have the same engine as ACR6.1 or newer. I am quite
surprised that the latest LR3 beta doesn't have all the bells and
whistles that ACR6.1 has yet?

> 3).  Just out of interest I'll say what I mean by losing image
> quality.  Generally I cannot see any difference between a re-imported
> tiff and the rendering of the original raw file in LR prior to export.

that is correct, since you are looking at exactly the same data... you
never really see the RAW data, you always just see an interpretation
of the data.

> However, when a panoramic file is re-imported I see two
> things.  A loss of natural vibrancy - boosting the contrast and so on
> can of course offset this loss, but I am unable to recreate a wholly
> natural looking vibrancy.  Second, fine detail takes on a slightly
> 'spongy', very 'digital looking' quality, as though micro-contrast has
> been unduly amplified, or the clarity control in LR has been abused.

Keep in mind that those poor image pixels had just gone through math
hell, and have been mangled and interpolated in unimaginable ways. I
assume you are seeing the results of the various interpolators... try
another one, maybe the results become better... also, additional
errors (negative clarity) might come upscaling the images... but there
are too many factors, and too much math that I don't know, so I can't
tell.

> I should admit though that this is looking at the files in LR only -
> it may well be that once printed the effects become more negligible.

It doesn't matter where you see your files... and rarely anybody
prints anyway.

joergen

--
You received this message because you are subscribed to the Google Groups "PTGui" group.
To post to this group, send email to pt...@googlegroups.com
To unsubscribe from this group, send email to ptgui+un...@googlegroups.com

[l_d_allan]

On May 24, 11:20 am, Joergen Geerds <jgee...@gmail.com> wrote:
> CS4is outdated, and adobe will

> not work on the code ever again (besides minor security fixes).

Interesting .... Adobe released 11.0.2 update for CS4 within the last
week or so. As you note, mostly related to security, but also:
> The Photoshop 11.0.2 update also addresses a number of problems with
> brushes, styles and gradient preset files discovered after
> Photoshop CS4 was released.