Raw Versus JPEG – What They’re Not Telling You

by with 6 Comments Geek SpeakLatest Articles

In the ever-present quest for perfection, photographers from around the country call me weekly with questions about shooting raw versus jpeg. The debate over this topic has been waging strong on the internet since the advent of digital still-image capture. Creating confusion, every photo blogger and “expert” in the forums has their opinions. Each of them expressing “this is the right choice”.  Well today’s post is here to proclaim that it’s mostly bunk. There is no perfect answer that fits every photographer all of the time. The Holy Grail of file type is a myth and it’s time to stop looking for it and get on with the business of taking great images. The two camps in the JPEG versus RAW debate have strong emotional bonds to their “rightness” and are willing to go to great lengths – even as far as to embarrass themselves online while attempting to change the unchangeable minds of the opposing camp. They cling to the strategy of looking for evidence to support their case while ignoring the evidence of the other. In the end it just adds up to more confusion for the reader – who continues to be un-prepared to make their decision. If you are hoping this post will give you the right and perfect set-it-and-forget-it-forever options, you won’t find them, because I don’t think they exist – though you may find one that works for you most of the time. What you will find is unbiased data to help you make educated decisions before you enter a shooting scenario. You will also find enough data to see clearly why I made my bold statements against the “This is always the right way” mentalities.

Let’s get down to business
If you are a professional shooter, regardless of market you will likely have some of the following example criteria to consider as part of your decision making process:

    • On what standards do your customersdetermine quality of service?
      • How important is color accuracy?
      • How critical is the pixel depth (megapixels)?
      • Is dynamic range an issue?
      • What are your expected turn times from capture to delivery?
    • Technical issues
      • Are you shooting under controlled lighting and can control scene dynamic range?
      • What is the expected use of the image?  Web, press, photographic, pigment, all of them?
      • How large will the file be expected to print?
      • Do you have time for custom white balance?
      • Do you have time to verify exposure settings with a quality hand-held meter?
    • Business related
      • Do you see time as money?
      • Are you paying assistants or digital artists to post-process?
      • Are you paying your lab to color correct for you?
      • What is your present customer satisfaction rate and is there room for improvement?
      • Are you willing to spend some time, effort, and resources to impact product quality?
      • Do you expect your workflow to minimize the post-process impact on margins?

If you are a hobbyist, what are you looking to gain?

  • The best possible print.
  • To spend more time with family and less time with post-processing
  • To gain more control over the final image
  • To fit more images on the limited space of a card
  • Technical questions:
    • What is the subject matter?
    • Under what conditions am I shooting?
    • How will the image be used?
    • What is your personal criteria for quality?

Perspectives – it’s all a point of view
Before choosing your shooting format I recommend you first determine your priorities and make a list. When you know what is important to you, then the best choices can be made and most often with higher levels of confidence. For these examples, we’ll look at the typical requirements of each shooter type. Knowing the requirements will lead to understanding why a certain thing might be a priority. Photographers and business models vary, so results and opinions may differ. For the pro, they have to satisfy an end user in order to make a living. Often working with pro level tools to maximize image quality and speed the process. For some of the professional markets such as studios, time is an expense against the profit margin and customer experience may have the largest impact. For other business models such as fine art, it’s often maximum image quality that is the primary target. Studios are the business model most likely operating in some type of assembly-line type of workflow. They have dozens of images from each person or product shot and each of these files needs some kind of attention. Usually starting with elimination of the unusable, then selection of the prime images followed by editing. The artists that are paid to handle this process are usually compensated by the hour. The longer it takes to move a job through the work-flow, the deeper the cut into the bottom line. Quality needs to be maintained to meet or exceed the customer’s minimum expectations. The average consumer’s expectations are often that the professional print should exceed the quality of a drug-store print. As long as they can see a higher level print, that particular expectation is met (photographic skills such as composition aside for the intent of this discussion).  Skin-tones and most all other colors related to people photography fit will inside the sRGB colorspace. Studios have a great deal of control over their lighting, and thus the required dynamic range for the shoot. A good setup can usually hold within a 6 stop limitation of a JPEG work-flow. Interior location photography has additional challenges resulting from ambient conditions that might not be controllable. Office lighting, large windows, etc. can contribute to the overall lighting of a scene and may result in lighting ratios that exceed the 6 stop limit. In profit-centric people photography, merging brackets for HDR is rarely an ideal solution.

Commercial product photography has unique demands, especially when the product or person being photographed requires special staging and effects.
And yet the images themselves usually end up being used in the lowest of gamut conditions: 4-color press and the internet. In a complex shoot, where lighting, effects such as smoke or movement are in play, bracketing is not an option so maximum dynamic range is beneficial.  In table top product photography – think catalog photos – there is no movement, lighting is completely controllable and product colors rarely exceed the basic gamuts of Adobe1998 or sRGB. Since the subject does not move, bracketing can be used to maximize dynamic range.. Food photography brings the potential for highly saturated colors that would do well with a larger gamut and maximum control.  A commercial photo session often includes a day or more of styling, prep and active capture, followed by a similar amount of time in post. There are thousands if not ten’s of thousands of dollars at stake and final image quality can be critical to the customer’s end sales. Such diversity creates situations where JPEG would be most profitable and other times where a RAW work-flow is mandated.   The fine-art photographer is often most concerned with image quality. They seek an integrity in the image that jpeg does not deliver. Maximum dynamic range, sharpness, color fidelity and detail are all sought in the persute of the ideal print that meets the artist’s vision and the expectations of the descriminating print buyer. Fine art images are often heavily manipulated to create the mood sought by the artist and to bring out maximum detail. Through manipulation, detail along with any compression artifacts will also be brought to greater light. Artists will often use improper white balance to enhance mood and emotional response. The artist will often spend countless hours laboring over pre-planning of a shoot, and many financial resources are spent on models and assistants. The final editing is usually performed by the photographer rather than an assistant.

Pick a card, any card…
Prepared with the insights you now have into the requirements of a few professional photographer types, these charts should help clarify why one format type won’t properly cover every photographer’s needs, and how some photographer’s might benefit from both types during their day.

Jpeg Versus Raw, Capabilities by File Format Type

Basic Pros and Cons
Pros Cons
Raw
  • Can be any working space you have a profile for.
  • WB can be tuned post-capture.
  • Greater exposure latitude – though precise exposure is recommended.
  • Highest level of adjustment flexibility before causing gaps in histogram.
  • Best option if over-sampling is required.
  • Supported by Pro-level software
  • Non-lossy raw formats contain highest levels of color-fidelity
  • Takes the more time and resources to post process.
  • Larger in-camera and offline storage space requirements.
  • Must be processed before online sharing/distribution can occur.
  • Must be processed prior to printing
  • Additional software required.
  • Not supported by all editing software
Jpeg
  • Smaller file sizes maximize in-camera and offline storage space.
  • Proper WB and exposure can often go directly to print.
  • Easily shared via email and web with no additional work.
  • Lower time investments.
  • No additional software required.
  • Maximum software support both pro and consumer level.
  • Usually limited to sRGB or Adobe1998 at time of capture.
  • Any settings applied in camera i.e. WB, sharpening, noise reduction, etc. are “fixed” into the image – changes require post-capture retouching/editing.
  • Minimal exposure latitude of 1/8 stop.
  • Lossy format means you paid for resolution that you are sacrificing.
  • Typically does not over-sample well due to in-camera sharpening and compression related artifacts.

 Jpeg Versus Raw, Considerations by Photo Type

A successful photographer will learn the needs and expectations of their client, then support those needs through technical and artistic know-how, all the while minding the needs of the bottom line.

You can help our readers by sharing tidbits you have discovered regarding JPEG and Raw workflows in the comments below. And as always, we are here to answer your questions.

Learn about Tiff versus jpeg. Does Size Really Matter?

by with 4 Comments Business Trends and TechnologyGeek Speak

Is Bigger Always Better?

men on a very large bicycleYou are probably frustrated with the Tiff vs Jpeg debate. The truthful answer is not one of always use this, or never use that.  Like cars versus trucks, they each have attributes that make them well suited for certain tasks and not others. Often we are asked to describe the difference between tiff and jpeg files. While they share a few similarities, there are a few differences and particularly some characteristics in the Jpeg format that any individual looking to get the very best image quality should know.

A Tiff file (Tagged Image File Format) and a JPEG file (Joint Expert Photographic Group) are both raster file types. A raster is a grid, and raster images have their pixels (picture elements) arranged in a grid pattern – like a chess board with a large number of squares, with each square being assigned a color and density value. When the squares get small enough that our eyes cannot see them individually, they blend together to create the image.

Both file types contain what is called “Meta Data”. Meta originates with the Greek language and means beyond or above. So meta data is information that is above or beyond the “normal” data in the file. In this case, the data that forms the image. This meta data may contain image relevant information such as what color space the file is in, what embedded or assigned color profiles are of note, the actual file type – tiff or jpeg, image dimensions in pixels and inches/cm, a thumbnail preview and some pertinent info that software uses to rebuild our image file from the raw data. This meta data may also contain additional extended information that is not used to display the file, such as the type of device used to capture the image, i.e. what camera or scanner, exposure settings, flash settings, date, time and even GPS co-ordinates and copyright information if available. This list is not intended to be a complete technical description, but just enough info to give you a general idea.

JPEG files use a variable compression scheme to throw information away, thereby allowing the stored image file to require less file size. Jpeg compression is fairly intelligent. The software throws data away to save space, then the application that opens the file uses information embedded in the file to “rebuild” what the lost data might have looked like. The more data that gets discarded, the less there is for the software to base it’s rebuild on and we begin to see anomalies, or what are called “artifacts”. The authors of the JPEG standard knew that the human eye is far more sensitive to density information than it is to color. So color information sees the most loss of detail. Maintaining as much density information as possible here is key to keeping as much quality as possible. While this does effect color-detail, this process is nicer to look at than throwing out the density detail. Our eyes are less likely to see a smearing of the color than smearing of the detail. At higher levels of compression, more information is discarded, including more of the density detail, resulting in an image that looks blurry, or grainy. Some applications such as The GIMP – http://www.gimp.org/ – allow the user flexibility to increase compression in the color only, and leave the detail alone, thus allowing for a bigger bang for the compression buck. One of many nice GIMP features that Adobe could learn from.

Mid Level CompressionLow Quality-Maximum Compression

Max quality - Minimum Compression

 

 

 

Jpeg likes to work in 8 pixel by 8 pixel blocks and any one block has no idea what the next block contains. This can result in the borders of neighboring blocks failing to match for color and density. As levels of compression increase, these blocks become increasingly apparent to the viewer because the “rebuild engine” in the software has less original information to work with and therefor errors will be greater.

The tiff standard had it’s birth in the desktop publishing world as a proposed standard amongst desktop scanning devices. It is widely accepted as one of the image format defacto standards for printing and publishing. The other being EPS. Many consider tiff to by synonymous with uncompressed or lossless compression. This is a false assumption. While the baseline (basic level) of tiff is either uncompressed or uses a lossless line level compression, a tiff file can also be a “container” for a jpeg compressed file. This jpeg-in-a-tiff scenario is subject to all the loss and limitations of any other jpeg file. So be aware that a file with a .tiff extension may not have all the integrity you are expecting.

Tiff’s early days were very limiting. The format supported only 1 bit of data per pixel – meaning black or white. No gray and no color. Over the years the tiff standard has expanded to support ever increasing bit depths and files up to 4 gigs in size. Files over that size use a format called Big-Tiff.

Just in case this whole file comparison thing is not quite “geeky” enough for you, here is a fun fact; The third and fourth bytes in a tiff file alway represent the number 42, which is a nod to “The Ultimate Answer to the Ultimate Question” in “The Hitchhikers Guide To The Galaxy” http://en.wikipedia.org/wiki/Phrases_from_The_Hitchhiker%27s_Guide_to_the_Galaxy#Answer_to_the_Ultimate_Question_of_Life.2C_the_Universe.2C_and_Everything_.2842.29

And they say programmers don’t have any fun.

The tiff standard has been expanded to include support for multiple “pages”. Just like a layered photoshop file. Adobe, who owns the rights to the tiff format, have taken advantage of this flexibility and allow layered photoshop files to be saved in the tiff container, alongside a “flattened” version of the file so that standard tiff reading applications can provide you with a usable composite image.

So I hear you asking: “Which one is best?” This of course depends on your needs. For general photographic and fine art pigment printing, file quality is a majority factor in the final print. Lossy compression means less than stellar printing. So use jpeg if you must, but compress it as little as possible. If you are using tiff, if you must compress, avoid using jpeg compression and go with line level compression. LZW for example.

Now if maximum quality is your biggest concern. Stop shooting JPEG in your camera, unless your raw files are compressed too. Many manufacturers only provide compressed raw.  Check your camera specs. If you aren’t gaining anything by shooting raw, then go for JPEG and save the space. If you have an uncompressed raw or a tiff option, these will yield the best file integrity but take the most room in storage.

If storage space is your primary concern, then jpeg is your friend, at least until camera makers are willing to include lossless compression in their firmware, and it is unlikely they will until there is a demand for it. So if you think it’s a good idea, write your manufacturer and request it.

Want more on shooting Raw vs Jpeg?  Check out my blog post on that topic here

Have a question? Put it in the comments below!

 

What “they” might not be telling you about the flaws in ICC profiled workflows.

by with No Comment Artists Trends And Technology

Profiles are typically generated using less than .016% (yes that is less than 16/1000 of one percent!) or 16/100,000 of the 16.4 million colors available in 8bit RGB. Talk about a shot in the dark. There is a tremendous amount of mathematical software based “guessing” that occurs in the ICC color management process.

Profiles are 100% dependent on consistency. They only work if you have consistent input and consistent output. Lenses used in capture, accuracy of camera white-balance calibration, scanner calibration, conditions in process, paper, chemistry, ink, equipment condition, light sources, supply voltages, time of day, humidity, blah blah blah can all have an impact on product output or digital input. These conditions are all subject to change, and do change. Thus, profiles are at their most “accurate” for the moment the profile was created. As these conditions drift and change over time, they effect the “accuracy” of the profile. Many individuals in our industry have touted that profiles have an expectation of consistency. One that unfortunately just does not exist in real world conditions. Through equipment care and high levels of professional level calibrations we attempt to keep our input/output equipment “calibrated” to the same standards on which the profile is based. In theory, this causes the final output to float around the bull’s eye and stay close to the expected, rather than take a direct bee-line away from it and continually get further off-target.
A good lab will calibrate their devices back to factory standards several times during a production day.  This is done to compensate for process variables that occur over time, and changes in paper from batch to batch.
My goal here is to help you become aware that though profiles are often elevated to a high stature as an end all solution,  they really fit more into a false-god category.

Now this is not to say that profiles are useless. Far from it in fact. They can have a dramatic impact on overall color approximation across multiple devices. Such as getting your ink jet to approximate your file and to get our LightJets to approximate that very same file. In fact we use profiles in-house to get our LightJets to approximate the smaller sRGB color space of the Fuji Frontier prints. Due to the larger available gamut of the LightJet, it is more likely to get the LightJet to approximate the Frontier than the other way-round. And we use them in some profile dependent work flows such as our professional digital press, and our Durst Sigma scans. The software that drives these devices, will not function correctly without profiles in place. The truth is, most digital capture and print sotware have some sort of embedded profiling built in. Your digital camera for instance, needs to know the characteristics of the dyes used to filter the image sensor in order to deliver a density and color accurate file.
I believe that any NON-DESTRUCTIVE method of producing better color has the potential to be a good idea. I’ll again stress “NON-DESTRUCTIVE”.  I am a big proponent on avoiding color channel damage whenever possible.  The caveat to forcing a profile on an image is it’s potential for color channel damage. I have seen many files where the colors were pushed too close to 100% saturation prior to a profile conversion. The resulting breaks/banding is inevitably and incorrectly blamed on the profile.

The great thing about ICC profiles in your work flow is their potential to get you closer to your target. They are by no means any guarantee of a bull’s eye, an exact match, perfect color, or any other false promise you have heard or at this point still believe. I often use this analogy: “Profiles are like a ticket to a baseball game. They get us in the gate, and might just get us a good seat, but that ticket will never allow us to sit on home plate while the batter hits a homer. BUT, that good seat is still much better than listening to the game on the AM radio while sitting in the parking lot.”

So, better. It’s just not a guarantee.
Profiles, in a nutshell, describe the devices available boundary or gamut as well as the limitations or inaccuracies and should not ever be confused with or used as working color spaces. They are far too small for use as a working space and should be thought of something to move colors <to> not <within>. Banding/breaking/clipping will likely result if you should choose to ignore this. It is best practice to use a working space that is larger than the output space, then allow your profile conversion to remap to hold detail.

If you remember my remarks regarding consistency, these constant changes diminish profile accuracy.  So why do we make a profile available for our printers? Well, quite frankly, because in most cases, an perceived improvement in print quality will result from a proper color-managed workflow.

One exception to this is our Fuji Frontier. This device is specifically calibrated to work within the sRGB colorspace. It’s output gamut is limited of course by the capabilities of Fuji Crystal Archive paper, but this design will allow a photographer who is color-calibrated and working in sRGB to be free of output profiles. One less layer of potential damage to the file.
So how should you be using your profiles?

Let’s start with what NOT to do.

If I use profiles in an attempt to get one device to approximate the characteristics of another device, I am in essence, attempting to get device A to look like device B, and both devices inaccuracies will be included! This is a great example of Square Peg I A Round Hole. If the gamut (outside edges of the pegs) of device A do not match the gamut (profile outliers) of device B, loss will occur. Much like using a hammer to get that peg in – you’ll shave off some of the peg, and what is left does not completely fill the hole.

In fig.1 above, the LightJet Fuji Matte has the larger gamut.The darker looking cube inside that area is the gamut of the Epson Enhanced matte. The bit of gray peeking out at the bottom is the zone where the Epson’s gamut is a bit larger than the LightJet. The area labeled Profile Overlap represents the available colors that both devices share. So this would be the available gamut when trying to match one of the devices to the other. In other words, all of the areas outside the overlap would be lost. In my opinion, that is a pretty large chunk of color to toss away just for the gratification of getting two prints to look as close as possible to one-another.  In essence, we would be “dumbing-down” the quality of our final print.

Good profile methods will attempt to “re-map” or squeeze those outside colors to fit within the range of output (the square hole), but the missing colors (the corners) aren’t properly restored. This results in a sacrifice of color fidelity from the original file.

So if you still want to profile, this is how I approach ICC profiling for Maximum Color Fidelity. At least within the limits resulting from profiling.

Let’s assume that we have:

– A source file: test.jpg
– Ink jet printer A that lets say: prints Blues with too much Green,
– and I have printer B that prints Reds with too much Yellow.

So:
A) +Green cast in Blues = Damaged Color
B) +Yellow cast in Reds = Damaged Color
ICC Profiles = Attempted Damage Reversal (at least in theory anyway)

Example 1: Try to get Printer B to look like printer A with one profile – bad Idea

If I print test.jpg on B, trying to approximate A via A’s ICC Profile, I have a print that has the native issues of too much Yellow in the Reds, and because we told B to look like A, I also have too much Green in the Blues. Why would I want a print with both sets of issues?
Damaged Color + Damaged Color = MORE Damaged Color.

Example 2:  Try to get Printer B to look like printer A with two profiles – best idea for closest approximation between printers 

I print test.jpg using profiles for both printers. I tell my software to make B look like A, but use B’s profile too.
So now the output attempts to remove B’s issues, the Yellow cast from the Reds.
BUT, because I am still approximating printer A, I am still introducing the Green cast in the Blues. So now I have at least one printers issues in full glory.
Damaged Color + (Damaged Color + Attempted Damage Reversal) = Damaged Color. Still some loss, but I should have two prints that are fairly close.

Example 3:  Try to get Printers A and B to look like the source file – best idea for maximum fidelity to source file.

Rather than attempting to get A to approximate B, We print the file to each printer, avoiding an approximation between the printers.
Instead, we want to allow each printer to get as close to test.jpg as possible. So we print test.jpg to A with it’s profile and to B with it’s profile.
A) Damaged Color + Attempted Damage Reversal = Less Damage.
B) Damaged Color + Attempted Damage Reversal = Less Damage.

So rather than compounding issues or keeping some and removing some, in theory, both prints are now as close as they independently can be to the original contents of the test.jpg file.

 

 

TIP!

Nothing in nature is saturated to 100% of any given color. There will always be some absorption of wavelengths of all colors. So don’t push your files thinking the final product will still be believable or still hold detail. The closer to 100% you push the saturation, the closer to zero you push the detail. And please don’t blame your profiles for damaging a file that was pushed too far.  Perceptual profiling is just not designed to work with a lack of color fidelity and you just might be wasting your hard earned cash to get a print you don’t like.

If your preference is hyper-saturation, make sure to match image type to printer type. For example, if you like saturated yellows, you could be printing to a device that can actually reproduce the brilliance you are seeking. Giclee printers are a great example of this. Being an ink-jet, they are quite capable of reproducing intense yellow as this is one of the native ink colors on the device.The same holds true for the other two colors, Cyan and Magenta. When you add any two or more inks together to create a new color, you are adding density and reducing saturation. With the advent of the intermediate “photo” colors, some of the subtler in-between colors are now improved. On the LightJet, the Kodak Metallic paper holds more saturation than Fuji Crystal Archive, but the blacks are not as rich nor as neutral.