digitaldog

Your answers here:

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http://www.digitalphotopro.com/articles/2007/janfeb/bitdepth.php

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Couple points. LR does have cloning functionality although it's not anywhere on par with

Photoshop.

There's nothing unique with respect to the overused marking term 'non destructive' in

terms of Photoshop or LR, they just do it differently. No editing is non destructive! The

original is untouched but that's easy to do in Photoshop too (use a copy, save as etc). An

adjustment layer is non destructive UNTIL you flatten the file or print it. The term is rather

silly. I wish it would go away.

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The main problem is you're using Adobe Gamma, an unsupported product that was never

designed to work on LCD displays (and even with CRTs uses an almost useless process called

eyeball calibration). Trash it and move onto a 21 century product for this important task.

-->Lightroom will globally edit a large amount of images (I have no actual experience).

--> I cannot imagine sitting down to 400 digital images and each one needs a little tweak

in levels but lightroom will do it all while you paint the bathroom...

Well you should look it over before saying more. As for speed, you can tweak 400

individual images differently far faster in LR than Photoshop any day of the week. LR is a

metadata image editor. You don't have to wait to open 400 individual files, all at full rez to

edit a file and the edits are simple instructions to the tweaks you want. Photoshop is a

pixel editor! That means you need to deal with each pixel in the file (after you even open

it), save it, then you're stuck with the edit unless you apply the edit to something like an

Adjustment layer (net result, a bigger raster file).

If speed in editing with unlimited possibilities in undo'ing them is useful, you're going to

be looking seriously into instruction (metadata) based editing. Photoshop is a pixel

polisher.

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It's nothing like Photoshop. Its like asking why they would release GoLive. This is a product

designed from the ground up for a digital photographer to do certain tasks quickly and

easily. Download the demo and look it over.

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Sounds like your display profile is hosed. Try something like say Generic RGB. If that clears

up, trash and rebuild your display profile.

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Here are a few PDFs:

http://www.ppmag.com/reviews/200409_rodneycm.pdf

http://www.ppmag.com/reviews/200411_rodneycm.pdf

http://www.ppmag.com/reviews/200410_rodneycm.pdf

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I have a rendered image that is captured linearly. Without an associated profile to describe

this, it looks quite dark but fine when you Assign the profile (as you'd expect).

The Histogram IS all shoved to one side in Photoshop. When you convert to a gamma

correcte space (like a working space), you see the Histogram redistributed and the color

appearance appears the same. I guess I could pop a lower rez version with the correct

profile on my iDisk if anyone cares to see it.

There are a few Raw converters that will allow you to get to the scene refereed linear

encoded data if you wish (Raw Developer comes to mind). You can kind of, sort of do it in

Photoshop Camera Raw plug-in and LR.

PhotoKit Color II provides these (and more). There's a fully functional demo (7 days) at

www.pixelgenius.com.

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No, you're correct that the camera histogram represents a gamma corrected image, your JPEG

based on the camera settings, NOT the Raw file (which would look odd, all pushed to the

left).

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You want RGB targets. Find out how many patches they plan to measure (900-4000 is about

right).

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There's a free Yahoo group (Color Theory) that Dan hosts so you can get an idea first if this is

a good fit (note, if you're a photographer, he's coming from a very different slant).

Martin Evening's books along with Katrin's are super IMHO.

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Its not supposed to be a damning indictment of sRGB. It's the actual facts based on the

designer and goes against much of Dan's advise with respect to sRGB and pro work,

specifically to a rather low gamut output device: the press. Imagine how inappropriate it is

for someone shooting raw and printing to say Canon or Epson inks that exceed Adobe RGB

(1998)!

Interestingly, Dan never followed up on this post, nor did any of his fellow sRGB Kookaid

drinkers when Michael specifically stated way back in 1998 that sRGB wasn't designed nor

in his opinion appropriate for press work. That's fairly typical of this list to turn a blind eye

to what is actual color theory. Rather, say that working space like ProPhoto RGB are 'ultra

wide gamut' and I quote:

> However, I've

>always pointed out that I have *not* extensively tested exotic alternatives, such

>as 1.0 gamma files, or ultra-wide gamut RGBs such as ProPhoto. The reasons

>they are not tested are 1) they have limited market presence and 2) I strongly

>recommend against their use in color correction.

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-->I've read that you should calibrate your monitor gamma to the color space that you

use for photo editing.

Absolutely not! The working space and the profile that defines the display conditions have

nothing to do with each other. You can have a working space gamma that is totally

different than the gamma (actually TRC) of the display (which should ideally be native for

calibration).

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Here's the tread (full in context) from Dan's so called Color Theory list:

Re: MacbookPro & Cinema Display Color Syncronization

On 1/25/07 4:32 AM, "Laurentiu Todie" wrote:>

> 2) sRGB WAS the compromise color space of old CRTs, isn't anymore

> (LCDs can have twice the brightness of CRTs, therefore more light

> colors)

With respect to sRGB, its useful to look at the origins and design. This is

a synthetic color space like all the RGB working spaces Adobe installs. Its

all pure math. Define the RGB chromaticity values, a white point and a tone

response curve which is often called (incorrectly depending on the design of

the space) gamma. Such synthetic spaces are built because its they are based

on a theoretical, predictable device behavior. The behavior defined can as

specific as the ambient light under which this theoretical device exists. In

the case of sRGB, the chromaticity is based on a pretty darn old technology

(P22 phosphors), the so called gamma is really two TRC's (there's a tweak in

the shadows), the white point is OK but the reference media (the conditions

this CRT display reside, the contrast ratio etc) isn't anything like an LCD.

There?s only one true sRGB output device, its an emissive CRT display in a

very fixed condition and environment.

Now, for some useful info about sRGB, from the man who designed it. I have a

post from the Colorsync list dated November of 1998 which may clarify some

interesting debates about sRGB, notably its usefulness to pro?s:

On 11/30/98 8:56 AM, "Stokes, Michael" wrote:

Jeff and Andrew,

I just ran across a couple of threads you wrote in response to a query about

sRGB. Being the color scientist behind this effort at HP, I would like to

clear up some apparent misconceptions.

1. sRGB is not base on "standard" "typical" or any other type of PC monitor,

but is directly derived from the HDTV standard ITU-R BT.709/2

2. sRGB does represent not only average PC monitors, but is within the

factory tolerances of almost all CRTs on the market today, including Barco

professional CRTs. This is due to the shared family set of P22 phosphors

which almost all CRTs use today. While this "family" of P22 phosphors has

some differences between manufacturers, these differences fall within each

manufacturer's factory tolerances. Saying that sRGB chromaticities are

"quite small" is simply saying that CRT phosphors in general are quite

small.

3. While the 2.2 gamma was directly derived from HTDV, it has been

independently verified by Sony, Barco and others to represent the native

physical state of CRTs today. It is also very close to the native human

perceptual lightness scale when viewing CRTs. This combination makes this

gamma the optimal for CRTs to physically operate at. This also goes a long

way in explaining the compatibility with Windows and PCs in general since

these systems have not imposed any arbitary or proprietary system

adjustments.

4. The white point again is derived directly from the television industry

and is the standard is televisions and also in many aspects of photography.

Achieving a bright enough D50 white point to comfortably adapt to continues

to be a technical challenge for CRT vendors.

5. I agree that there is a different in gamut shapes between sRGB and press

CMYKs. This is due the the difference in gamut shapes of CRTs in general and

press CMYKs in general. Since sRGB represents the native physical condition

of CRTs, this is an obvious outcome. I also note that the sRGB gamut in

general is significantly larger than press CMYK gamuts an most areas other

than cyan.

6. I agree that if I am in a high-end graphic arts D50 only workflow, that

sRGB is not the optimal solution and neither HP nor Microsoft claims it to

be so. On the other hand, it is the optimal solution for any display-centric

workflow such as desktop publishing in the office or home, the world wide

web or any assortment of workflows where a display plays an integral part.

7. Claiming that pure cyan in sRGB converts to 78% cyan in press CMYK is

completely dependent upon which gamut mapping technique you are using. I am

assuming you are using whatever is in Photoshop. I can tell you that this is

not the case for the gamut mapping in our own printers.

8. We've worked very hard with Pantone to provide a solid physical and

scientific foundation for their RGB representations. I am at a loss to

explain your criticims on this front and your implicit request that Pantone

base their CRT RGB palettes on something other than established standards,

physics and science. I would appreciate some input on this one.

9. Your statements that "However, I've been told that the original color

scientist from HP that

proposed this colorspace has stated that it has gone too far, that this was

a proposal ONLY for the web. . .not for printing or cameras or scanners.

I've also heard the even Microsoft is kinda backing away from sRGB for

ANYTHING other than the web." are simply untrue and I would appreciate

knowing where to go to straighten this out. I have never said that sRGB is

not for printing or cameras or scanners. I believe sRGB provides an

excellent, robust and fundamentally sound solutions for these mass markets.

HP has a lot of evidence both internally and with real customers to support

this. We also have many partners in the camera, scanner and desktop printer

businesses that have independenty confirmed this. I also believe that

Microsoft has not backed off from sRGB in any way.

10. A better web site for sRGB information is at www.srgb.com

11. I would very much like to have a discussion on the difference between

display spaces and editing spaces. I agree that a larger editing space would

be helpful, but am skeptical from my own scientific research if this can be

done in a 24bit encoding by simply changing the chromaticities without

resulting in other problems. Would you and Rodney be interested in such a

discussion?

12. Characterizing our efforts as hoodwinking seems a bit stretched since

we've gone out of our way to conform to existing international standards,

sound physics, and state of art research results.

I just wanted to clarify a few things and hope this helps,

Michael Stokes

HP

In a following post (answer to Jeff Schewe):

> sRGB reflects the characteristics of the average PC monitor. If you are

> producing graphics to be viewed on the Web, sRGB will reflect what most

> viewers see. The downside to sRGB is that it has a limited color gamut

> and cannot represent as many colors as other color spaces. It is NOT a

> good choice for Professional prepress users since too much CMYK gamut

> lies outside of it".

I have told Adobe and their quote is factually accurate, but possibly not as

informative as it could be. I do agree that when using a purely prepress D50

CMYK workflow, sRGB is not the optimal solution.

I think we're in agreement that sRGB is mainly or primarily targeted at the

mass market and not the high end professional market (for all of the many

sound reasons you gave above).

Any questions? I think it puts sRGB in the historic perspective it deserves.

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Keep reading and you'll toss your Tivo and auto and go back to the life of the Amish.

Seriously, he's way off base with the sRGB stuff and I'm blue in the fact arguing with him

despite showing him clearly that there are all kinds of capture and output devices that

exceed sRGB and that sRGB was NEVER built for Pro use. I even submitted a message dated

way back in 1998 by Michael Stokes of HP who in writing a number of times states this

clearly (I'd be happy to copy and paste if anyone wants to read this public thread from the

ColorSync list).

When it comes to color management, you're best to ignore Dan big time!

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-->I think rendering intents refer to printing output, rather than colour space

conversions. -->At least I have never encountered this issue in discussions of spaces.

Simple matrix profiles like all those used to define RGB working spaces only have one

table, the Colorimetric table so the only rendering intents are Relative and Absolute

Colorimetric when doing such conversions. That's one reason the profiles are so small in

file size. If you pick Perceptual in Photoshop, it provides RelCol.

Printer profiles use look up tables or LUTs and are larger in size and contain all three

tables. This is a much more complex profile.

->it's nice to see that Scott's fingers and keyboard are still working. I often wonder if

being the Windows tech support guy for a major retail chain has something to do with his

testiness on this subject.

He must be out trying to score the new iPhone. Its been over a month for him. I hate to

point out this "bad" news:

Apple on Wednesday posted a record-breaking $1 billion profit on record revenue of $7.1

billion for the first fiscal quarter of 2007 ended December 30, 2006. Earnings per share

for the quarter were $1.14.

Apple said it shipped 1,606,000 Macintosh computers and 21,066,000 iPods during the

quarter, representing 28 percent growth in Macs and 50 percent growth in iPods over the

year-ago quarter.

-->i appreciate the responses guys. the windows image viewers seems to be ICC aware bc

the way the images look dramatically changed after profiling (in a good way).

They may look better due to the calibration and resulting LUT but there are absolutely no

Windows broswers (and a handful of Mac browsers) that are ICC aware.

An ICC aware application uses the display and the tag in images to produce a preview. The

Windows browser is simply sending the RGB numbers to the display.

Do they look identical in Photoshop and the browser?

A LUT is loaded on start up however, the actual display profile isn't used outside of ICC aware

applications. You have to be viewing images in such applications for the full color

management system to be working. That's why for example on Windows, an image will

appear different in Photoshop versus in a browser as the later simply doesn't know squat

about the profile.

The display profile is only used in ICC aware applications like Photoshop. So you have to

evaluate the effects there, NOT on the desktop or outside such applications.

Not sure it's fair to call him an idiot but in respect to this discussion, he's wrong! I think

he's doing this more for attention and to be controversial since he's take on which to use

is technically BS.

Might I suggest another article?

The Role of Working Spaces in Adobe Applications:

http://www.adobe.com/digitalimag/pdfs/phscs2ip_colspace.pdf

Send him the link too. Ask him if he wants to argue with me and all the color guys at

Adobe based on the above piece.

The K3 Epson inks as well as the new Canon stuff absolutely has a color gamut that in some

areas exceeds the gamut of Adobe RGB (1998).

What do you mean by compatible? The color space of such diverse output devices simply

can't match. We've got ink jet printers that exceed Adobe RGB gamut. So we can reduce

that gamut (no please) or wait for even wider gamut displays.

Also, we need a wide gamut display that actually produces a close sRGB behavior as there

are all kinds of imagery where a wide gamut display is not the best solution. Ain't no free

lunch here.

Actually the Epson isn't really a CMYK printer IF you want to get picky here.

Maybe I wasn't clear. First, you can't send CMYK to the Quickdraw or GDI drivers supplied

by Epson, they expect RGB data so they can do a proprietary conversion to CcMmYKKK or

whatever number of inks used. If you want to simulate CMYK proofing on the desktop (you

want to have your Epson match a Kodak Matchprint for example), you must bypass the

driver and use what is often called a Rip although it doesn't have to rasterize anything.

ColorBurst's Rip (and it is a true RIP) will do this and will accept CMYK data in the print

stream. So will ImagePrint but the product is designed more for productivity, B&W

conversions etc.

The printer isn't simulating RGB, that's not a subtractive color model.