Digital Still Photography

[Tenolian Bell]

I’ve recently learned quite a bit about digital photography workflow. What I’ve learned is not very encouraging.

 

A computer based web site has published a test between RAW image conversion and managing software. An earlier test by this same site conducted an evaluation of Apple Aperture 1.0 and Adobe Lightroom beta.

 

Aperture 1.0 was found to have a bad RAW image converter. Apple quickly went back and fixed Aperture and recently released the update to 1.1.

 

This latest test was of Aperture 1.0, Aperture 1.1, Capture One Pro, and Adobe Lightroom. Their were several tests of pictures rendered by each converter.

 

As I looked at the same picture rendered by all four RAW converters I aked myself what is the common thread between these that makes this evaluation valid. There has to be some neutral benchmark that they started from.

 

In one picture of a cat. The cat has black fur. The Aperture 1.0 picture is low contrast and you can see noise in the dark areas. In Aperture 1.1, Capture One Pro, and Adobe Lightroom there is more contrast and the darker areas have less detail which does not show the noise of the Aperture 1.0 render.

 

Another picture of a high school football game at night. The background of the picture is extremely underexposed. The Aperture 1.0 picture has lots of noise. The other three renders have noise but not nearly as much as 1.0. Its clear that some type of noise reduction or sharpening was applied to smooth over the noise.

 

Another picture is an extreme close up of a dog. On the dogs nose near the middle of its eyes you can see some type of digital artifacting. The artifacting is very noticeable on the Aperture 1.0 render. The artifacting is less noticeable in the 3 other renders but you can see that it is there. Some type of algorithm had been applied to smooth it out.

 

The conclusion of the test was that Aperture 1.1 performed much better than Aperture 1.0. In some pictures Captures One Pro or Adobe Lightroom performed best.

 

In the open forum discussion of the test my first question I asked about the test is what exactly is it evaluating? Its pretty clear that Aperture 1.1, Capture One Pro, and Adobe Lightroom are increasing contrast, sharpening, and smoothing out defects from the RAW Bayer data. While Aperture 1.0 wasn’t making any of these corrections so the image did not look as good. Its clear that these are interpretations of the Bayer data and not necessarily the true picture.

 

Is the point RAW conversion to show you what the picture looks like or to make your picture look better than what the camera captured?

 

The response I got back assentially said the RAW conversion is basically an interpretation. And is too complex a topic to determine the truest rendering.

 

So I explained that I work in film/video. When we make evaluations of our imaging equipment we start with a neutral benchmark. Generally we want the default image to have accurate skin tone, neutral color, and neutral gray scale. I thought this would be important in still photography also.

 

Some people responded that accuracy is not very important in still photography, and that a photographer of photo editor with a good eye will create a nice looking picture.

 

Some people said accuracy is important in still photography and it is possible. But of more importance is to get as much information as possible.

 

 

My next point is to them is that making an objective evaluation of different RAW converters you need to start at a common point of reference. In this test you have 3 converters using sharpening and noise reduction skews the results even further.

 

Someone points out that these RAW converters are using 3 to 4 different color space gamuts. Adobe RGB, sRGB, Pro Photo RGB, and Lightroom is using Adobe Camera Raw. Then I respond if all of these converters aren’t even using the same color space how can anyone possibly give a useful evaluation of their performance. With different color space the histograms of all of the pictures will be entirely different.

 

If all of the converters were using the same color space such as Adobe Camera Raw, would the numerical values for luminance and chrominance even be the same?

 

Someone else says that color accuracy for photography isn’t as important as it may be for motion film. Because a photo shoot only last a few hours. Versus a film shoot over weeks or months.

 

I respond that I understand that. But color consistency and accuracy are ways that we in motion picture judge all of our equipment. I don’t understand how you can make a clear judgment between film stocks, digital sensors, lenses, or color converting software if you cannot start at a neutral place. Too many variable will cloud the results.

 

 

The whole thing sounds like a mess to me and I pray that digital cinema does not follow the same path.

[Michael Nash]

The whole thing sounds like a mess to me and I pray that digital cinema does not follow the same path.

 

 

I think it's already there. As my brother the rocket scientist says, "that's the wonderful thing about standards -- there are so many to choose from."

 

But I don't worry as much about mismatching standards at the origination end. As we know in motion picture there is already a color correction pass where SOMEONE puts their eye and discretion to the image and finalizes the look. My concern is more about the mismatching DISPLAY standards (film, HD, SD, internet, iPod, cell phone, etc.). There's almost no way to ensure a proper calibration for all of those release formats, even if you do separate mastering for each one.

[Francis Kuhn]

Is the point RAW conversion to show you what the picture looks like or to make your picture look better than what the camera captured?

 

 

Some people said accuracy is important in still photography and it is possible. But of more importance is to get as much information as possible.

Hi Tenolian,

 

I’m still learning the digital capture process, but it reminds me a lot of the choices we make in the analog photography world. Depending on the subject matter, I’ll choose Velvia over Proivia or E100VS. Or use Tri-X instead of Plus-X or Tmax 400 or 5245 instead of 5246. It also reminds me of telecine: Different machines and operators will invariably yield different results, but they may all may also look great in their own way.

 

And, aside from recording maximum, uncompressed data, the main reason for shooting camera RAW files actually is to allow personal interpretation the raw data captured by the camera’s sensor (as opposed to letting the camera’s built-in processor to do the work and rendering its interpretation as a jpeg.). It is your digital negative, and you are free to process it as color, B&W, cross-processed, saturated or desaturated. And, I might point out, this is all before it gets opened in PhotoShop, which is where the real magic happens.

 

As for standards, it's not perfect, but shooting a gray card or color chart at the beginning of each setup lets you (at least in theory) white-balance and start with a neutral rendition.

 

As for stills vs. motion, I’ve never quite understood the debate over which requires more attention to detail or accuracy. Typically, a client will want to see an accurate (or pleasing) skin tone, or to see their product’s all-new Metallic Cobalt Black paint rendered correctly, whether your camera is shooting one frame-per-second or twenty-four. They’re both challenging in their own way.

[Tenolian Bell]

I think it's already there. But I don't worry as much about mismatching standards at the origination end.

 

I actually think we are doing pretty good in respect to digital cinema. SD,HD,2K,4K all have fairly set and agreed upon resolution and color space. Even if all the cameras do not create their images the same way or shoot the same format or record the same medium, the end result is pretty much the same. Moving from one to the other isn't too difficult because you are moving from one set standard to another set standard.

 

Digital post color correction is about the last place that needs some type of standard measurement. The ASC Technology committee is working with the leading color correction vendors to come up with a consistent numerical system for digital RGB color. That should be in use sometime in the near future.

 

And, aside from recording maximum, uncompressed data, the main reason for shooting camera RAW files actually is to allow personal interpretation the raw data captured by the camera?s sensor (as opposed to letting the camera?s built-in processor to do the work and rendering its interpretation as a jpeg.). It is your digital negative, and you are free to process it as color, B&W, cross-processed, saturated or desaturated.

 

This is all true. But the test I describe was to be a definitive judgment on which RAW converter is better and which is worse. This test was conducted with no consistency or image neutrality.

 

A RAW converter is going to have to place the image inside of a color space container and give it limited color gamut. If each RAW converter is using entirely different color space tables then the comparison is apples and oranges.

 

Three of the RAW converters are applying sharpening and noise reduction which renders any real objective observation useless.

 

Depending on the subject matter, I?ll choose Velvia over Proivia or E100VS. Or use Tri-X instead of Plus-X or Tmax 400 or 5245 instead of 5246.

 

Choice is fine. But choice is based on subjective opinion which there is no true measurement of right or wrong.

 

 

It also reminds me of telecine: Different machines and operators will invariably yield different results, but they may all may also look great in their own way.

 

Before a professional cinematographer goes out on a big shoot he/she will need intimately know the characteristics of their chosen film stock.

 

This involves shooting tests. For example if judging between shooting Fuji 8552 250T or Kodak 5217 200T you shoot a scene with a model, grey chart, and color chart. You are looking to see how both stocks respond to underexposure, proper exposure, and over exposure. You need to know at what exposure and negative density will both stocks record accurate skin tones, neutral colors, and neutral gray.

 

With this method you have a fairly objective view of how the film stock performs and are able to make you choice on whether to use it or not.

 

One stock may tend to record more saturated colors and reddish skin tones at a proper exposure. You go into your production knowing this. You may want this look or you may compensate for it.

 

A shoot may be days, weeks, or months and it is the responsibility of the DP to maintain consistency. After you shoot the film will go to the lab and post production where the DP no longer has direct control of it. So its important to know what you want and how the film will respond.

 

The nature of the telecine room really makes this even more important. Because much the time the DP will not be there and if you don't understand how to communicate what you need, you have no idea what you will get back.

 

As for standards, it's not perfect, but shooting a gray card or color chart at the beginning of each setup lets you (at least in theory) white-balance and start with a neutral rendition.

 

If the various RAW converters are using different color space tables and apply sharpening or noise reduction there is nothing neutral about that at all. As all of the results will be entirely different.

 

Without the ability to have some objective or neutral test there would no way to usefully gain empirical differences between imaging tools. We would be left with emotional opinion and manufacturers marketing spin to tell us what performs better than what. Which seems to be the state of digital photography.

[Greg Gross]

ISO/ASA in relation to digital photography is quite different. Using film you are concerned about

sensitivity but shooting digitally you are dealing with amplification. Shooting raw does not excuse

you from using a proper exposure. In the football photo was your foreground brighter or darker

than your background? Did you expose for the foreground,the background? What mode was the

camera in? Center weighted,balanced would probably have been better than a program mode. In

raw your sensor will capture the entirety of your scene,frame. A high quality jpeg setting may have

been better than a raw setting. In the real world raw is not all its cracked up to be. The group of pro-

fessional photographers that I am associated with have learned the merits of raw and high jpeg. I

use CS2 with absolutely no problems professionally. Color space is a choice you have to make cre-

atively. If you start comparing every digital program(software) for conversion and the color spaces

associated with them you are not going to be happy. The digital labs I use here for my special pro-

jects are all based on CS2 and associated color spaces. In my own film/digital darkroom I use CS2

and its associated color spaces. Absolutely no problems. I'm using Windows.

 

Greg Gross

[Francis Kuhn]

Dear Tenolian,

 

I agree. It sounds like the RAW comparison test you read was flawed on many levels. I used to work for a large consumer magazine publishing company, so this doesn’t surprise me. Most of the editors’ testing procedures were utterly subjective and un-scientific. I’m not saying they’re completely invalid, but consider who's doing the testing (and advertising) the next time you purchase a RAW processor (or an automobile) based on what you read in a magazine test.

 

 

Before a professional cinematographer goes out on a big shoot he/she will need intimately know the characteristics of their chosen film stock.

 

This involves shooting tests. For example if judging between shooting Fuji 8552 250T or Kodak 5217 200T you shoot a scene with a model, grey chart, and color chart. You are looking to see how both stocks respond to underexposure, proper exposure, and over exposure. You need to know at what exposure and negative density will both stocks record accurate skin tones, neutral colors, and neutral gray.

 

Of course testing is essential. But even among the professional cinematographers testing and shooting procedures will vary, sometimes wildly.

 

A while back I took a UCLA cinematography class led by a highly respected instructor dedicated to using the somewhat technical LAD (Lab Aim Density) procedures for exposing and processing film. He developed LAB because he believed there was no existing procedure based on scientific principles. He is convinced that LAB is the gold standard and the only way to consistently get the “perfect” negative as intended by the people who designed the film. So the class spent a lot of time shooting gray cards and color charts and comparing various technical data.

 

One week, another very respected cinematographer came in as a substitute instructor. Her approach was much less technical and based mostly on practical experience. She knew nothing about this LAB approach except to say that it was far too technical and she didn’t feel it was entirely necessary, though she encouraged those who found it helpful to continue using it. She did the normal camera and lens testing during prep (which, I should add, is done by many still photographers as well). Her standard shooting procedure is to take a meter reading and shoot a gray card under a properly color-balanced light, take a color meter reading (yet another variable standard as no two meters are exactly alike), filter accordingly and shoot. I found this all very interesting because both instructors use very different procedures make films that look exactly as they intend. So much for standards.

 

 

 

The nature of the telecine room really makes this even more important. Because much the time the DP will not be there and if you don't understand how to communicate what you need, you have no idea what you will get back.

 

Now, I’m certainly no expert and maybe I’m oversimplifying things, but isn’t color correction in telecine (or on a computer) guided by the numbers (eg: 245/245/245 = white) and not simply by what you see on a studio display or monitor?

 

Even film gets scanned (or telecined) most of the time, at which point it falls into the same allegedly standard-less realm as digital stills. Aren't the numbers are there to guide and verify that what you see on the screen is what you're really getting?

 

 

Three of the RAW converters are applying sharpening and noise reduction which renders any real objective observation useless.

Choice is fine. But choice is based on subjective opinion which there is no true measurement of right or wrong.

 

But here's where I believe you're missing the real point: RAW processors are not meant to perform to any standard. Choosing a RAW processor is like choosing a film lab--you work with the one that you feel makes your film look best. (and that's how the RAW designers try to sell you: Ours is better than Theirs). :)

 

By the way, I noticed you just reached the magic 666 number with this post. :ph34r:

[Filip Plesha]

Well is there a color standard with negative film? Not really

 

Different papers bring out different images out of the same piece of film. That's the beauty of it. Same is with digital.

[Tenolian Bell]

Well is there a color standard with negative film? Not really

 

Negative is limited by its physical properties. All color negative films are made essentially of the same basic chemicals and they all contain Cyan, Magenta, and Yellow dyes that record basically the same limited spectrum of light.

 

In the digital world without a working standard any manufacturer can make a sensor that records any resolution, at any bit rate and sample rate, in any color space. Which will not work with any other digital format.

 

He developed LAB because he believed there was no existing procedure based on scientific principles. LAB is the gold standard and the only way to consistently get the ?perfect? negative as intended by the people who designed the film.

 

She did the normal camera and lens testing during prep (which, I should add, is done by many still photographers as well). Her standard shooting procedure is to take a meter reading and shoot a gray card under a properly color-balanced light, take a color meter reading (yet another variable standard as no two meters are exactly alike), filter accordingly and shoot. I found this all very interesting because both instructors use very different procedures make films that look exactly as they intend. So much for standards.

 

What you have described doesn't really have any thing to do with any standard, it is a workflow. Workflows can be different from project to project depending on its needs.

 

The method of the substitute instructor's basic way of preparation is fine under certain circumstances. Without having done tests and actually shot film with the equipment the DP is trusting that it will provide the look they want. They trust that the rental house is giving them color matching lenses, they trust the film stock will give consistent color and contrast at given exposures, they trust the lab will print the look they intend, or the telecine colorist will provide the look they have intended. In situations such as episodic television where the production and post production have already established a workflow and can maintain a consistent look minimal preparation is fine. But this way would not work well under every production situation.

 

The real importance of the lab test is the ability to see an unbiased performance of the equipment. The DP may see a film stock does not give them the look they want under certain exposures, or one lens is softer than another lens, or the chocolate filter gives a better warming effect than the tobacco filter.

 

A DP shooting a much more complex production. Such as a film that travels to several different countries, or has extreme photochemical or digital manipulation, or two to three camera units. Under these condition it is necessary for the DP to test everything. Establish negative densities and printer lights with the lab. As well as establish a final look with the telecine or DI colorist. This workflow is to insure color remains consistent and the DP's original look is maintained through the production chain.

 

maybe I?m oversimplifying things, but isn?t color correction in telecine (or on a computer) guided by the numbers (eg: 245/245/245 = white) and not simply by what you see on a studio display or monitor?

 

No, I've never heard of those numbers.

 

Even film gets scanned (or telecined) most of the time, at which point it falls into the same allegedly standard-less realm as digital stills. Aren't the numbers are there to guide and verify that what you see on the screen is what you're really getting?

 

At this point digital grading does not have standard numerical values of color such as the printer light system for film. The only real limiting factor is color space. The machine can tell when a color is within or outside of a given video formats color space. A numerical system for digital grading is currently in development and should be in use in the near future.

 

What makes the film scanning process different from digital photography is that at the end of the process the data will go into a set format that will have a consistent resolution and color space. 4K is always 4K, HDCam is always HDCam.

 

But here's where I believe you're missing the real point: RAW processors are not meant to perform to any standard. Choosing a RAW processor is like choosing a film lab--you work with the one that you feel makes your film look best. (and that's how the RAW designers try to sell you: Ours is better than Theirs).

 

That's fine, but that leaves no way to take a basic picture and through unbiased observation see which system delivers the best performance based on similar variables.

 

Because neutral skin tone, neutral color, and neutral gray scale are a pretty universal concept it is possible to tell which lab you like better based on which one can deliver them accurately and consistently.

 

In the football photo was your foreground brighter or darker than your background? Did you expose for the foreground,the background? What mode was the camera in? Center weighted,balanced would probably have been better than a program mode.

 

I did not take the football picture it was on the website doing the test between the four RAW converters. The entire picture was noisy. It was probably taken at 1000 ISO or higher, but I think that was the point to see how the RAW converters could deal with noise.

 

Color space is a choice you have to make creatively. If you start comparing every digital program(software) for conversion and the color spaces associated with them you are not going to be happy.

 

That's what I'm saying and there is no real way to say which is better.

[Tenolian Bell]

Just spoke with a photographer friend of mine who gave me a lot of in-site into what is going on in the digital photography realm. Now all of this makes a lot more sense to me.

 

First he told me most RAW files are proprietary. Canon, Nikon, and Sony lock their RAW images files. Software developers have to reverse engineer the proprietary file to be able to process it. That seems a bit crazy and unproductive to me.

 

I asked why has the photography industry gone along with this. He says most people don?t really care because they are already financially or emotionally invested in Canon or Nikon. If people have spent thousands of dollars on Canon EOS lenses they will stay with Canon digital cameras to continue using their lenses. The same with Nikon F mount lenses. So it doesn?t so much matter if the RAW format is proprietary.

 

He tells me Adobe has attempted to develop a common RAW format for everyone to use but Canon, Nikon, nor Sony will adopt it.

 

Next he tells me that all of those different RGB color space tables have been created to be used for specific reasons.

 

sRGB was created in 1996 by Microsoft and HP as a way of dealing with computer and internet pictures on cheap un-calibrated 8 bit computer screens that 90% of the worlds PC?s use. sRGB has a low sample rate and a smaller color gamut. So that a picture will appear fine on the lowest common denominator screen running at 800x600 at 256 colors. sRGB has too small a color gamut to be used effectively for CMYK print. He tells me it should only be used for computer display.

 

He tells me that sRGB has become popular for consumer digital cameras because it is easy to process. At the most consumers generally are going to make 4x3 prints from a 3 megapixel JPEG. At that small of a picture accurate color reproduction doesn?t matter.

 

He tells me Adobe RGB has been the standard color space for professional digital CMYK print. Adobe RGB has a much larger color gamut and can accurately reproduce CMYK prints. He tells me all pro photographers making prints from RAW images should at least be using Adobe RGB color space.

 

Adobe has a newer color space called Adobe Wide Gamut RGB which is larger than Adobe RGB. He says Wide Gamut RGB is made to work with 16 bit files anything less could produce severe digital artifacts from lack of information. The downside to using Wide Gamut RGB as the color space becomes larger the file becomes larger and the longer it takes to render and process.

 

He says there is another color space called ProPhoto developed by Kodak. But its such a large color space that only those shooting extremely high resolution digital need to deal with it.

 

I asked him about using different color space tables for aesthetic reasons. He tells me in his opinion that color space serves more a technical function than an artistic function. If you shoot RAW and use sRGB all you have done is significantly decreased the amount of color you can use.

 

He tells me amatuer photographers or a photographer new to digital who hasn?t learned about digital photography probably would not know these differences. And not know how to use correctly use color space.

 

We also had a whole conversation about megapixels and how its a marketing gimmick and fairly useless for actually determining the quality of a camera.

[Greg Gross]

Gentlemen,

Don't forget the latitude of film. Your scene will show up in different reflectance values

on film. What your sensor sees(so to say) with digital is amplified to give you an image.

Amplification is involved and is not the same as 1000 ASA with film. This is why a lot of

people with consumer digital cameras complain about noise when they shoot at high ASA's

with their digital cameras. The trick is to expose,shoot to eliminate the noise or keep it to

a low minimum. If I'm going to provide b&w photos for Washington D.C.,Baltimore, Phila-

delphia,Harrisburg(film) newspapers, Then I print different prints for each newspaper so

that they look good in whatever paper. I have not had any difficulty will digital newspaper

photos. Film ASA and Digital ASA are not equal and cannot be compared but only a figure

of speech. When I shoot digital- I expose much as I would if I was shooting slide film. If

I shoot digital for the shadows then I do have to look out for noise more and I tend to carry

a Sharp 15" monitor with me. I can see the image better on the Sharp versus the camera

screen. Sometimes also use a laptop. I have never seen a sofware program where noise re-

duction worked well. Sometimes creative white balance that I desire enters in to the final im-

age also. I shoot digital with a Canon EOS-1D Mark II N and Canon primes,rarely a zoom. I

do prefer the slightly cool look as compared to the Nikon warmer look. I cannot emphasize

enough that when shooting digitally you have to selectively make a choice to shoot raw or

shoot high quality jpeg. Raw is not always good and High Jpeg is not always good. You need

to make a proper choice between the two.

 

Greg Gross

[Greg Gross]

One thing I hope that never happens is for people to lower their heads when they admit

to shooting High Jpeg Vs. Raw. Both files have their merits and times for use. Remember

for one thing just the sheer size of the files. If I'm shooting stills for the Harrisburg Cele-

bration Of The Arts on the waterfront, I'll shoot in High Jpeg and not raw. I'll shoot the same

for Harrisburg Magazine. If I'm shooting the Harrisburg skyline for my on personal stock im-

ages then I'll shoot in raw. I use raw for all my personal fine art stills and consider the raw

file to be my personal digital negatve(if there is one). Often times you will see color casts in

the shadows and when removed you'll have an improved image. You will be more happy if

you develop a personal digital work-flow and stick with it. Remember also to communicate

with your local digital lab and find out what color space they are using or spaces. RGB,sRGB

etc. ? Yesterday I was at a Borders Cafe in Camp Hill,PA, I stopped for a cafe aut lait and one

of my film student friends was there. She's a stunning blonde and I'm old enough to be her gr-

and pa. I like to tell the joke that I'm too old for girls and too young for medicare. My friend is

fascinated with my Canon EOS -1D Mark II N and she had her Nikon D-50 with her(a fine camera

even if it is a little warm). I gave her my camera and I took hers. I said okay Meagan lets pick an

available light subject here and see which camera can do its stuff(camera?). We each framed a

window with beautiful trees out side of it and in the distance a Toys R Us sign with red,green,blue,

yellow. It was a cloudy day with blue punching through the clouds at times and direct sun at times.

I set my white balance between tungsten(inside light) and daylight. Inside I had beautiful black top-

ped tables trimmed with tan and black and tan trimmed chairs. The walls were a beautiful burnt or-

ange and the reflection of the word borders was under the window on the wall. I watched and waited

for the light to change and added a "golden" polarizer to the lens(a nikon prime). Meagan said I was

taking too long and I told her to go talk to her boyfriend for a while. I made one exposure with "gold-

en" polarizer and one without it. We asked the Border's manager f he would please print them on his

printer(I gave him some Kodak photo paper). The print with the "golden" polarizer won out. Meagan

said, "you made a fine art photo with my camera"? I said, "yes I sure did". The joy of visualization

and then creating is awesome. By the way, I was shooting in High Jpeg.

 

Greg Gross

[Greg Gross]

American Association of Media photographers- www.amp.org

Supports organizations who represent standardization of color.

A PDF file can be found there for work flow and for proven tech-

niques in standardization of color.

 

Greg Gross