Holy C&^$ there is a lot to learn-- questions about color space and image quality.

[expat42451]

In being on the learning curve on my D7000 and new to digital.....after having questions about color space settings and whether or not to use Adobe RGB I did a web search and was led to an excellent thread here

http://www.thephotoforum.com/forum/...prophoto-colour-management-general-worth.html

from 2008 started by Garbz...... I had no idea about what all is involved with digital photography.

OK. So lets say that I use Adobe RGB--then the color space on any given photo will be Adobe RGB which from what I read ViewNX2 and most of the Photo Shop stuff will recognize and act accordingly. So I am assuming for example that if I use Adobe RGB whether I save a shot in RAW or JPEG fine the color space will still be either sRGB or Adobe RGB depending on how I have the camera set, right?

Next question NEF--from reading what I see I assume that to truly take advantage of AdobeRGB I want to save the NEF image in 14 bit to take more advantage of color depth rather than 12 bit ? I am assuming that in NEF (and JPEG?) sRGB and AdobeRGB are 2 independent ways to map color space (depth?) from the sensor to the stored image and--either color space "format"--- is theoretically independent of whether I save in 12 or 14 bit? Trying to understand here....

A final question--I again am assuming that the color space selection is theoretically independent of the image quality setting. I also am assuming that I would be able to take much more advantage in what I am able to do in post processing--and to a lesser extent actually see--for example saving in NEF 14 bit then a little less in NEF 12, then less in JPEG fine and less still in JPEG Normal and JPEG Basic....is this a valid assumption?



This past weekend I was shooting a concert in one of the parks here, a Blues band (the Traveler graciously took one of my Fllickr photos of the event and critiqued it on another thread here in "beginners' forum). In trying to shoot that type of venue I find I shoot a lot more rapidly --and take a lot more shots than I would in a landscape or portrait or wildlife setting..... so this past weekend I saved everything in JPEG fine rather than NEF due to file size and buffer restrictions..... part of this is probably due to inexperience but I am trying to learn and understand as I go along.

Since I am running Windows 7 here --but only using ViewNX2 I can see right now that I am going to have to do better than I am doing with post processing software....my laptop is problematic in that I run SUSe Linux there and am going to explore how GIMP will handle AdobeRGB (among other things).....of course then there is the idea of buying Photoshop and since I would be doing that (dont go there!!!) maybe an Alienware I7 laptop with 6 GB of RAM for use in the field (I am running an I 7 LGA 1366 desktop with 6 GB RAM right now, another hobby is building computers) plus of course a couple more pieces of glass to add to my inventory and maybe another body as well.....what?? NO!! WAIT!! DONT GET CARRIED AWAY!!!

Seriously I do want to thank everyone here because I am continually amazed at the depth of knowledge that exists...and even moreso at the depth of my ignorance in digital photography- why I am here is to try to understand how to be able to learn good composition and make great photos. Getting carried away with the hardware is something I have to continually fight. Learning the science is something I am passionate about.

Thanks to all of you for being tolerant, kind and helpful for all of us newbies.

Expat

 

[SunnyHours]

Basically Adobe RGB is supported by most PP software...but sRGB will be the predominant one on the web. For appropriate color representation make sure to save the color space with your file.
Your color space is what the computer will read to make sure the right amount of black, white...etc is present in your picture...

 

[expat42451]

SunnyHours

Thanks very much for the read and explanation. I find on searching GIMP that it seems that it will load Adobe RGB. Seems that GIMP may do a lot more than will ViewNX2 as well but I dont know this yet. Tomorrow I plan to shoot some AdobeRGB and play with it and compare it to same shots in sRGB to see if I can see much difference.

Expat

 

[ronda]

Great questions. It's been awhile since I've been able to put my color science to use. I hope these answers are useful.

1. Whatever profile you select when shooting will be the profile embedded in the image. By default, Photoshop's Color Management Policies (under Edit/Preferences) is set to PRESERVE EMBEDDED PROFILES. So, if you capture with AdobeRGB, Photoshop respects that. GIMP on the other hand is set to ASK WHAT TO DO, which can be changed to KEEP EMBEDDED PROFILE. (If you make changes to the color management policies, launch the application first, make the change, then open your image).

If you are unsure about the Color Management policies of an application, you can usually check the Preferences or Color Settings menus

2. Yes, 14-bit gives your more color depth than 12-bit. The benefits to high-bit depth images pay off during image editing - the subject of another post perhaps. And yes, the color space and color bit-depths are independent. Forgive me if I'm repeating what you may already know, but any JPEG captured image undergoes some additional processing in-camera. JPEG is first and foremost a compression scheme. (Whether this is good or bad depends on how you're going to use your images, what your workflow is, etc. It's just good to know off the bat.)

3. Not having a Nikon in hand I can't answer the last question definitively (some cameras use the same terminology but may refer to different things). That said, Image Quality usually refers to varying compression schemes (whether digital data is thrown out or not) and varying pixel dimensions. Color space is independent.

Let me know if this helps.

 

[expat42451]

Ronda

Yes extremely helpful !

1. Whatever profile you select when shooting will be the profile embedded in the image. By default, Photoshop's Color Management Policies (under Edit/Preferences) is set to PRESERVE EMBEDDED PROFILES. So, if you capture with AdobeRGB, Photoshop respects that. GIMP on the other hand is set to ASK WHAT TO DO, which can be changed to KEEP EMBEDDED PROFILE. (If you make changes to the color management policies, launch the application first, make the change, then open your image).


Thats what GIMP appears to do--spot on. So to preserve the color integrity of the image in GIMP one would "keep the embedded profile". (of course now this means that I am going to have to calibrate the monitors here so what I see is accurate )


2. Yes, 14-bit gives your more color depth than 12-bit. The benefits to high-bit depth images pay off during image editing - the subject of another post perhaps. And yes, the color space and color bit-depths are independent. Forgive me if I'm repeating what you may already know, but any JPEG captured image undergoes some additional processing in-camera. JPEG is first and foremost a compression scheme. (Whether this is good or bad depends on how you're going to use your images, what your workflow is, etc. It's just good to know off the bat.)



You arent repeating anything I know--this is what I was looking for. I do understand that JPEG is of course a compression scheme but from what I understand with repeated editing and reclosing the image, a lossy one where NEF--RAW is not. I am at the point where I have no idea what my workflow is even going to be--still trying to figure out what PP stuff to use (since I originally posted this thread earlier this evening Ive been buried in GIMP--<whew>). I also am at a point where I still dont realize what I dont know but am working on that.

3. Color space is independent.

Yes quality and size settings are independent from color space on the D 7000.

And yes this did help a great deal in my understanding of the beginnings of how some of this works.

Among my wanderings since I first posted this thread have been mainly in GIMP and trying to find an EXIF plugin for the program. One of the things I like about ViewNX2 is that along with the image I can look at pretty detailed camera lens and exposure settings when it was taken-- something fascinating and that I think will help me out a lot in learning as I do this. A lot different from my film days!

Thanks very much for the kind and clear explanation

Expat

 

[ronda]

Glad to help.

 

[expat42451]

Ronda--Thank you very much --I need it

 

[Bitter Jeweler]

Keep in mind, when you work in a colorspace other than sRGB, and post them on the web, not all browsers are color space aware. IE is not, Safari is, firefox is, I believe. This means an image save as AdobeRGB will be read as sRGB by Internet Explorer, an your image will appear slightly darker and duller.

 

[expat42451]

Bitter Jewel

Interesting. Thanks very much for pointing this out. I encountered the question of browser color space awareness in the thread I linked in my first post. After reading that and out of curiosity I did a search --I currently use Firefox 4.0.1-- for a color space plugin. There is one which I downloaded and installed. It may be found here

https://addons.mozilla.org/en-US/firefox/addon/color-management/

So one could then possibly convert an Adobe RGB image to sRGB before posting to the web to try to avoid the propensity for many browsers to render it inaccurately. Although browser color awareness is addressed in the article I had not thought much beyond achieving a higher color definition in the image file created on the camera and what would be possible in PP. So this yields another question. In addition to the possible problems with a non color aware browser, then what happens when say someone uploads a photo to Flickr? Would this type of web hosting site accept anything other than sRGB? Further consideration- when attaching a photo to an e mail, the rendered image on the other end would be subject to whatever image rendering software was on the recipients computer and its capabilities (and inherent limitations). Plus of course their monitor calibration.....plus their eyes. I have whats known as typical male pattern color blindness, not severe, but have always had problems with this when messing about with colors. Color histograms (which I have never used before this) seem to want to show up things that I dont think that I see.

Thanks ! Food for thought. So if sRGB and JPEG are common (I inadvertently tried to send a RAW image to a friend in Canada, know how that worked out, his mail server rejected it because of the size) then part of a work flow might be to convert a NEF(RAW) AdobeRGB image to JPEG/sRGB for anything outside of your own computer. Will be interesting to try that to see what the results of the conversion are.

Regards
Expat

 

[clanthar]

"So one could then possibly convert an Adobe RGB image to sRGB before posting to the web to try to avoid the propensity for many browsers to render it inaccurately."

Yes, but it's a little more complicated. sRGB is the better fit which is NOT to say that non-color-aware software is sRGB by default. sRGB was created to be a "best-fit" match to typical consumer market display hardware. And since it's adoption that "best-fit" relationship has strengthened since many of the hardware manufacturers have embraced it as a standard. It's common now to find a consumer-grade LCD display with a hardware switch labeled sRGB. Which doesn't mean the display is actually capable of physically rendering all of the colors in the sRGB space as many, if not most of them, are not.

However, software that is non-color-aware is just that. Micros**k's IE or Google's Picasa don't have sRGB compliance built it. They're just not compliant at all. They ignore the fact that no accepted standard exists for mapping RGB image values.

"In addition to the possible problems with a non color aware browser, then what happens when say someone uploads a photo to Flickr?" Yep, that's another problem. Most image hosting sites will leave your uploaded file alone as long as it complies with their posting requirements. So if you upload a photo with an embedded ICC profile your photo will display correctly for anyone using appropriate viewing software. The big BUT here is if you upload a photo that's for example larger than the site's limits. If the site is going to re-size your photo to match their requirements then (depends on the site) they may strip out your embedded profile without an appropriate conversion.

Best bet is to assume that when you turn a photo loose it will be viewed by people with non-color-aware software on uncalibrated systems and as such will be trashed. Make the photo sRGB for best possible results and don't expect too much.

Joe

 

[clanthar]

More to add on this topic:

(Glad I'm retired!) I was talking last night to one of my students who's just breaking into the wedding/portrait business. I recommend in this case a whole-hearted adoption of sRB because of the expectation now that digital files (the DVD) be turned over to the client.

Aside: I think you should all track down and punish the bleep bleep fool who started this idiocy of shooting 1000+ photos at a wedding and burning them all onto a DVD.

Anyway -- your client (wedding/senior portrait/baby pics/etc.) is going to look at those photos on their hardware and with each passing month that array of hardware keeps expanding to include every kind of computer, HD-TV, iCr*p, phone, you name it. I've seen my students looking at photos on some really gosh-awful devices. Some of these netbook screens are insanely bad. One of my students hauled in this Acer netbook the other day and was going through their recent photos. I'm looking at this thing with my chin on the floor!

So, what do you do?

I've proposed in class that we add a new feature to the ICC standard so that a photographer can throw a flag that identifies the image as a pro-photo. Then if someone tries to view the image on their iCr*p or netbook a message pops up informing the user that they should view photos on "photo-compliant" hardware and they have to click a release button to proceed. I get a laugh out it, but I'm serious!

Joe

 

[ronda]

So, what do you do?

I've proposed in class that we add a new feature to the ICC standard so that a photographer can throw a flag that identifies the image as a pro-photo. Then if someone tries to view the image on their iCr*p or netbook a message pops up informing the user that they should view photos on "photo-compliant" hardware and they have to click a release button to proceed. I get a laugh out it, but I'm serious!

Joe

Where's the petition! I'm first in line to sign it. I will add this one thing ... I don't shoot sRGB unless I absolutely have to. I shoot AdobeRGB (from my 5D) so that I can have my originals archived in a wider/broader space. Then I can work on and export my images with sRGB profiles - and a sigh. (I use Adobe Lightroom for 95% of my workflow, but still do final tweaking in Photoshop).

By the way, if you've shot in a space other than sRGB, you can get a preview in Photoshop of your image dressed up in sRGB: [this is CS5] View > Proof Setup > Internet Standard sRGB. Then, View > Proof Colors. In the title bar of the image it will display [file title/color space/bit-depth/proof] or, for example picture/rgb/8/windows. (Of course, this is assuming you've left the other color management settings alone).

I haven't checked yet (still new here) but is there a forum set aside for Color Management issues. Expat's questions are good, the comments have been excellent.

 

[expat42451]

Clanthar and Ronda

Isnt it amazing how we take all that we do online for granted!! I started in college days on an IBM punch card machine to be able to write Fortran cards to take across campus to the computer center to run the program. I knew the IP address of a buddy at a college a couple hundred miles away and we would use a really crude program called IRC (not todays version) to talk to each other via text. No one dreamed of sending photos. I for one never even --since photos "evolved" more or less as a part of the internet evolution I was not involved with-- even considered what was involved with digitizing images to transmit digitally and render back in analog with them having any semblance of what was either taken or transmitted. Jesus !!

So I have not attempted to calibrate any of this system, something it seems that I will be doing as this progresses. I did try the ICC version 4 test on it and it of course failed--but what part? Its a custom I 7 that I built a year ago using NVidia graphics cards and 4 22" Samsung monitors....but one must ask what part is not compliant? Monitors? Graphics cards? Something in the CPU or motherboard? It could be anywhere. I have seen these little calibration widgets (that I assume measure color temperature) that one plugs in to a USB port and holds up to look at a portion of ones' monitor and sets color from its readings.....one could I suppose use that for a calibration run on ones' printer but I can see where that could be fraught with a whole load of other inaccuracies --from type of paper used to equipment temperature to phase of the moon and alignment of Sagittarius with something else......

I agree with and would sign a petition to support you professionals on the "click to release" when viewing a carefully crafted professional photo on some of the equipment now. After all someone has spent a good amount of time and money in equipment and moreover the time and talent to create something beautiful--with no guarantee that it would be rendered as intended......

So why not adopt an ICC standard? Theoretically it might be not that hard to do from an engineering standpoint. From an equipment mfgrs standpoint, well that would different. The video drivers and image control software would default to the correct color temperatures &c to comply with the ICC standard. If the user wanted to dither anything then they would have a small message "you are leaving an industry color rendering standard. Some images may not be rendered as they were intended". Then if an ICC standard image was rendered on their system the small pop up click on would be there to remind them......


"Aside: I think you should all track down and punish the bleep bleep fool who started this idiocy of shooting 1000+ photos at a wedding and burning them all onto a DVD." LOLOL. 1000 seems a bit much....however I did a week ago shoot a blues band at a concert and event at one of the parks here and came away with almost 600 photos !! A band by nature is more dynamic subject matter --although a number of weddings I attended at friends' homes in Mexico when I lived there a few years ago certainly came close to qualifying....but in my 35 MM days I NEVER shot that many photos. I was bulk loading my own film and developing transparencies using E4 processing in a little light tight device one loaded the exposed film into and poured the chemicals through.....as I learn this totally new medium that is digital photography....one of the things I am concerned about and mentioned it earlier is---the ability to take really beautiful photos, something that will reach out and strike a resonance in someones' heart. To me that is art and that is what I want to learn to do one day.....in my ignorance of this new hobby, one of the things that I perceive that might be a pitfall is reliance on the machine and the methodology too much to make up for deficiencies in technique and composition....I can see for me the pitfall of shooting way too much and then using post processing as a way to salvage something that might be worthwhile.....on the other hand (and I am NOT wishing for the film days-- if I wanted that I would buy another film camera and shoot that again) I can also see the breathtaking possibilities with post processing software and new cameras and imaging technology in the hands of an artist. The idea of being able to shoot low light high ISO images and have them meaningful in any way in the film days (remember how horrible 1000ISO film was?) was--well forget it. With my D 7000 and my 50 MM prime I can shoot at 1000 ISO and to my untrained eye the result is amazing.

"Some of these netbook screens are insanely bad." Agreed. Not only that Ipods/pads/Kindles/laptops &c. I have a nokia semi-smart phone with a camera in it and internet capability and can not stand to even use it. Friends with all of the latest appliances....passing phones around to look at pictures its well....can be pretty horrifying cant it.

Next week I am visiting Canada for a month or so, to see friends, do some sailing and wander around Toronto with my kit. My friends there are photographers, have done wildlife and people photography all over the world. I am looking forward to having someone to work with on my composition. The problem of course is storage and editing. The D 7000 will supposedly do a fair amount of in camera editing on its small LCD display-- but I can not imagine trying to use it for that. My laptop is a 2 year old Toshiba I ve modified a bit to make it faster....and it runs SUSe Linux. After considering what it might be like to try to do what little editing I am capable of on that laptop what I may do is buy a large USB drive and simply use the laptop as a means of passing photos to the USB drive for the final save back here where I have a lot of monitor real estate and something other than a touchpad mouse to work with.......

The other side of all of this for me is that I am a bit of a geek, I love technology. What is possible here is so far past what I thought was possible that its pretty enthralling. I am reasonable computer fluent in some areas but not imaging. This new and wonderful hobby for me has posed many more questions than it has answered.....I see a lot of people that use Photoshop and Lightroom. To do that on any sort of a portable in the field type of setting of course means a lot of storage space and running one of the Microflaccid....oops Microsoft OS'es to run such software. I have GIMP running on this machine under Windoze 7 but dont yet know how to use it. On the other hand I ve never owned an Apple but for a next laptop that might be a consideration....but not right now.....

Expat

 

[clanthar]

Clanthar and Ronda
So I have not attempted to calibrate any of this system, something it seems that I will be doing as this progresses. I did try the ICC version 4 test on it and it of course failed--but what part? Its a custom I 7 that I built a year ago using NVidia graphics cards and 4 22" Samsung monitors....but one must ask what part is not compliant? Monitors? Graphics cards? Something in the CPU or motherboard? It could be anywhere. I have seen these little calibration widgets (that I assume measure color temperature) that one plugs in to a USB port and holds up to look at a portion of ones' monitor and sets color from its readings.....one could I suppose use that for a calibration run on ones' printer but I can see where that could be fraught with a whole load of other inaccuracies --from type of paper used to equipment temperature to phase of the moon and alignment of Sagittarius with something else......
Expat

The first step in setting up a color managed work environment is to make sure that your hardware is physically capable. You can still benefit from calibrating any system and there are real advantages to applying display calibration to a laptop for example, but you've got to know the parameters of what you're doing. If you take a laptop screen that can only physically display 60% of the content in the sRGB color space and calibrate and profile that screen you'll get a display that does a better job showing you 60% of the sRGB color space....duh. I have a Toshiba laptop that is very handy and I've calibrated and profiled the display with an X-Rite i1. I'm not deceiving myself about what it is and what it's for. I do not use it to edit photos! It has a better than average display for a laptop and the calibration helps a lot. IT IS NOT an editing workstation.

So the first question about display calibration is; what are the hardware's physical limitations. Laptop displays can't physically handle sRGB. Most consumer market LCD panels only handle 70-80% of sRGB. There are some higher end consumer market displays that are physically capable of sRGB. Then you jump to the larger gamut Adobe RGB color space and you need one of these: EIZO ColorEdge CG243W

Here's a fun question: What's the advantage/disadvantage to using Adobe RGB if you're working on a display that can't physically render 25% of the content in that color space? Wouldn't you be better off actually seeing what you've got rather than hoping it's there and looks OK? I run into "photographers" all the time that shoot in the wider-still Pro-photo color space and do all their editing on a MACbook. When I ask them what they do about all the color they're not seeing they give me that funny look.

So, those calibration widgets are very useful, but in the hands of the ignorant they often just shift the confusion around. I'm very happy with the X-Rite I mentioned which will calibrate and profile my displays (within physical limits) and allow me to create custom profiles for printer/paper combinations. When I introduce this technology into my classes my students at first expect miraculous results. This is supposed to make prints look just like the computer screen -- right? Well, it's a little more complicated than that. What if there's a color on the computer display that can't be created from any combination of the inks in that printer? Oh?! Does that happen?

Joe

 

[expat42451]

The EIZO Color Edge is pretty fantastic ditto the XRite i1..... I can see getting an i1 pretty soon. The EIZO well....... maybe in a few months.

"Here's a fun question: What's the advantage/disadvantage to using Adobe RGB if you're working on a display that can't physically render 25% of the content in that color space?"

That is an excellent question--- I just got back from about an 8 mile cycle ride downtown with the kit. I shot some comparisons using both RGB and Adobe in both MPEG fine and the same two color spaces in NEF (RAW) 14 bit. While I was gone I stopped by Office Depot and picked up a 1 TB USB drive and backed up all 1800 of the shots that I have so far made with the new camera to the drive. I still have 874 GB free. THe drive will go in my data pack along with my laptop to Canada. Now I have more than enough room to save anything I might shoot.

I could not agree more about only using a laptop as a transfer means. I cant imagine doing any sort of editing on one in the field.

So next is uploading the camera photos and doing comparisons to see if there is much difference between the different shots.
More as it happens

Expat