Proper histograms for image printing.
Landscape photographers frequently have to deal with extremes in light intensities within a single image. A situation that is typically found in landscape images is when the light intensity in the sky is much greater than the light intensity in the foreground as is the case in our sample photograph below. Take a look at the histogram for this image. Looks a little like the profile of a Bactrain Camel’s back (a two hump camel.) If we try to print this image we will end up with an image that is muddy and flat looking in the foreground and washed out in the sky. In this instance we need a histogram that has data well distributed throughout; or a histogram that looks like a Dromedary Camel (a one hump camel.)
There are three approaches to this problem:
Graduated Neutral Density Filters
When making the image we could have used a “graduated split neutral density filter”. This rectangular filter fits on the front of your lens and you simply move it up or down depending upon where the horizon lies in your photo. My favorite filter is made by Tiffen, it is a .06 graduated neutral density filter (or 2 stop density.) I like Tiffen because their filters are made of glass which gives the best color quality. Resin filters tend to render off colors in the density area. You will notice that this image’s histogram is closer together or moving towards a one-hump look but the image still requires some post processing to print well.
High Dynamic Range
The next method is to make this image as a HDR (High Dynamic Range) photograph. This requires making a series of exposures of the same scene; bracketing from a proper exposure for the foreground to a proper exposure for the sky. The image was then post processed using special software (available in Photoshop or Photomatix) to combine the various exposures into one resulting image. This popular process results in an image that combines the best of all exposures and results in an image that has a one hump camel’s back histogram and a full range of data across the histogram that will result in a pleasing print with good color and tonality throughout the image. In the Photomatix software, which is my preferred method of making HDR images, there are several controls that allow the photographer to adjust contrast, saturation, intensity of the HDR blend, and special effects. This image is a pretty straightforward rendition.
Post Processing and the History Brush
My favorite technique is to post process the image in Camera Raw and Photoshop to obtain a proper one-hump histogram and an image that will print with dynamic color and tonality. The image below was exposed in camera with the post processing in mind to achieve the look and feel I envisioned when I photographed the scene. This method offers me the highest degree of control while still maintaining a natural look and feel.
I use a careful selection of post processing in Camera Raw: typically I add a little Fill Light, a small amount of Recovery and a careful selection of overall Exposure which is usually a slight movement of the Exposure slider to the left.
These adjustments result in a good starting point for the image in Photoshop. Once the image is in Photoshop I burn and dodge (lighten and darken) selective areas to bring the image into a one-hump histogram (although not a true one hump it is well within the tolerances for printing.) With this method I have the greatest control over exactly how much lightness, darkness or saturation I want to add to a given area of the photograph. My technique for burning, dodging, and saturation adjustments is with the “history brush”. If you need a tutorial on the “history brush” look for it on the next newsletter.
November 30, 2011 | Categories: Digital Workflow | Leave A Comment »
The Digital Dilemma
Good Camera Techniques:
Shoot, download, save, back-up, reformat.
Your camera’s disc is not a long term storage device!
They can and will fail at any time. 
Always reformat the camera disc after you have removed it from the camera and downloaded images.
Good Storage Techniques:
Your computer’s hard-drive is the best and most stable storage device.
All digital media can and will fail with time, even your computer’s hard-drive, therefore it is imperative that you have a back-up plan.
Back-up your digital files frequently on a separate hard-drive. I recommend external hard-drives like the “Free Agent Desk” drive by Seagate-1Terrabyte drive is about $170. Store off-site if possible.
The Industry buzz word for “archiving” digital media is “Migration” what that means is that no digital device or storage media can be trusted for long-term storage. You must continuously up-grade your storage media and devices to keep abreast of technological change, in short KEEP UP WITH THE TIMES.
Digital Media
CD discs-Short term storage, approximately 3-7 years.
DVD discs– Short term storage, approximately 3-7 years.
Sata II Hard-drives (Standard hard-drive found in most computers today.) A great for medium term storage-approximately 7 year average lifespan. Storage on hard-drives requires redundancy and back-up of file storage. RAID systems or Drobo type device for large volume users.
Printing your digital image files:
The only current way to insure that your images will be around for generations after you have made them is to convert the images into prints. You must be careful about this process as different print processes differ widely in their longevity.
Photographic Prints and Ink Jet Prints
Photographic prints: average lifespan of photographic prints ranges from 22 years to approximately 45 years. They can be quick and easy to obtain because your local photo service provider does the work. 4×6 sized prints are relatively inexpensive.
Ink-Jet Prints: average lifespan can range from 6 months to over 250 years depending upon the printer, ink, and paper used. It is important to know what the life expectancy is for the particular combination of printer, ink, and paper is that you use (see Wilhelm Institute resource listing below.) DO NOT skimp on cost of materials, most after-market inks and papers designed for the home user fade in a very short period of time.
Pigment inks last longest, dye based inks fade quickly.
Online Resources:
Library of Congress: Website on Digital Preservation:
http://www.digitalpreservation.gov/
Wilhelm Institute: Website with comprehensive list on longevity of print materials:
http://www.wilhelm-research.com/
Drobo data storage systems:
http://www.drobo.com/Products/Index.html Seagate External Hard-drives:
http://www.seagate.com
September 1, 2011 | Categories: Digital Workflow | Leave A Comment »
Creating Image Clarity using Photographic Technique
Some thoughts on image clarity and perceived image sharpness in relation to; Subject Sharpness, Color Value, Image Contrast, and Localized Image Contrast.
Subject Sharpnessis the result of several factors including the camera focus, depth of field, camera support, and proper shutter speed relative to subject motion.
Subject Sharpness cannot be altered by any post processing tool or fix. The image sharpening tools found in Camera RAW or Lightroom should not be considered an acceptable manner of “fixing” subject sharpness. Subject Sharpness is a result of the decisions made at the time of capture. Get it right in the camera!
Color Valueis the amount of detail or separation of color values within an image. It is primarily dependent upon the bit-depth of the image capture. A j-peg format image is 8 bit color, this means that each color has 256 distinct color values. An image captured by a Canon 40d in RAW image format is 14 bit color and has 16,384 distinct color values.
If properly processed a 16 bit image will always be perceived to be sharper than its 8 bit counterpart. My good friend and excellent digital photographer, Jeff Morgan, disagrees with me on this point, but if you (or he) were to visit my studio I can show you results of image tests that prove this. Capture your images in Camera RAW format and learn to use a conversion software, your images will have greater clarity.
Image Contrast is the overall contrast or range of density values from highlight to shadow detail. Images of high contrast have dark blacks with little or no detail and bright highlights with little or no detail.
Image Contrast is best controlled in the “Basic” module of Camera RAW or Lightroom. The sliders that control overall image contrast are: Exposure, Recovery, Fill Light, Blacks, Brightness, and of course Contrast. Adjustments here are as individual as the photographer’s vision and subject. There is no absolute right or wrong with respect to proper image post processing. Generally speaking, however, large corrections usually leave some kind of tell-tale defect in the image, which if you print the image larger than 5×7, becomes immediately apparent. A philosophy of “Less is More” will serve you well when using these tools.Localized Image Contrast is the separation of color values in the image. Images with greater Localized Contrast have a more pronounced separation of color or density values within a given color or density range, Localized Contrast can be increased without changing the detail in the shadows or highlights.
Localized Image Contrast is also controlled within the “Basic” module by the Clarity, and to a lesser degree the Vibrance and Saturation sliders. The Clarity adjustment will increase or decrease the tonal separation of color within your image. The Vibrance adjustment will increase or decrease the intensity of neutral or mid-tone colors before increasing more vibrant colors like bright reds, yellows, or oranges. Therefore the Vibrance adjustment can be perceived to increase Localized Image Contrast . The Saturation adjustment can increase or decrease overall color saturation-it effects all colors equally regardless of their brightness or hue. Again-the “Less is More” philosophy will help you keep your clarity of vision.
If you capture your images in j-peg format you have surrendered all of the above (with the exception of Subject Sharpness) aspects of image clarity to the default settings of your camera’s image processor. By taking this route you have predetermined most of the thoughtful decisions that are available to you to in the post processing phase of image making.
Localized Image Contrast is also controlled in the “Detail” module by the sharpening tools, however, I will leave that discussion to next month’s newsletter.
September 1, 2011 | Categories: Digital Workflow | Leave A Comment »
Using The “Detail” Module In Adobe Camera Raw
While these instructions are for use with Photoshop CS3 or CS4, they may also be applied to Lightroom 1.4 or 2.0.
The Detail Module controls one of the most important post-processing features available to the digital photographer.
Sharpening:
The first adjustment is to set the “Radius” to .9. This will apply the sharpen filters to only one pixel at a time. If this is set to something greater than 1 the sharpen filters will sharpen and re-sharpen the same pixel resulting in sub-standard results. Next enlarge the preview to 100%(lower left corner of the preview) to view the effects of the sharpen filters on the individual pixels. Select an area of the image that has critical information, like tree branches against the sky or a subjects face.
Hold the Alt key (or Option key) down and move the “Amount” slider. The preview will convert to a B&W image. This is to help delineate how much sharpen is being applied. My partner , Val, doesn’t like the B&W conversion so she simply adjusts the slider to her likely while viewing color preview.The next slider is the “Detail” control. This determines how the edges within the image are sharpened. If you hold the Alt key (or Option key) down while activating this slider you will see an embossed preview showing how much of the edges are being affected. Experimentation and personal preference will determine how you need to adjust your images. Typically I find that setting is correct if I adjust the detail slider to the point where I can just begin to see a white subject outline on the embossed preview. Too much detail can result in hard edges that look digital and fake, it is most noticeable in landscape images with trees against a sky.
The next slider is the “Masking” control. This determines how much sharpening is applied to the middle-tones of the image. Holding the Alt key (or Option key) will show a bunch of squiggles on the preview. The squiggles should just begin to form in the mid-tones of the image. This can be tricky as the mid-tones in one area of the image begin to form before the mid-tones of another area. Compromise and practice are the keys here.
Images sharpened for print by ink jet printers should be sharpened to a slightly greater degree than images for projection or web use. Ink jet printers spray ink, hence the ink will soften slightly when it hits the paper.
Noise Reduction:
There are two sliders in the Noise Reduction area; Luminance and Color.
The Luminance slider controls grayscale noise, which can make an image appear grainy. The Color slider controls chroma noise which is seen as speckles of color contamination.
Noise is a function one or more of the following:
Improper exposure
High ISO settings
Poor quality optics
Poor quality image sensor
The higher you set the noise reduction settings the softer the image becomes. Therefore I do not adjust the noise reduction settings. The defaults settings are: Luminance at zero, and Color at 25. You should properly adjust the image sharpness as noted above, if noise is an issue consider setting your ISO at a lower setting, getting a new lens or camera, or avoid under or over exposure.
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September 1, 2011 | Categories: Digital Workflow | Leave A Comment »
To Profile or Not To Profile; that is the question.
Most Photoshop guru’s will tell you that the only way to get good consistent print results is to profile your images in Photoshop and then choose “Photoshop Manages Color” in the printer dialog box. Ever ready to serve as the contrarian I say; “Bunk! And More Bunk!”
Many times profiling in Photoshop will work wonderfully, and while the results coming off your printer will never (EVER) look exactly like your computer’s monitor, they are reasonably close. Close enough that you are able to get a general idea of what the image will look like prior to printing it.
My color management workflow is as follows:
Shoot in Camera Raw format.
Convert in Adobe Camera Raw–use ProPhoto RGB Color Space
Open in Adobe Photoshop-Selectively edit in Photoshop to create look and feel of image.
Convert to Printer/Paper Profile prior to sending the image file to printer.
I have obtained my printer profiles from downloading them free from Epson, or the paper manufacturers of the paper/canvas types that I use. These free profiles can range in quality from excellent to poor.
“Well,” says the Photoshop guru “you need to purchase custom profiles that will solve your problem.”
Custom profiles are specific printer profiles that are written for specific printers and paper types. Custom profiles typically run about $100 per profile. I own and use three different Epson Printers; I select from approximately 8-10 different media types (I like to experiment so my paper stocks are in constant flux.) The only problem that custom profiling will solve is the bank account balance of the service bureaus providing me the custom profiles!
Here is what I have found after several years of working with printer profiles and dozens of different photographers who have taken print making or digital imaging workshops from me.
Generic profiles work pretty well when you are working with the latest generation of printers, and camera files. If your camera or the printer is older than about 3 years the profiles may or may not work well. If your paper profile is coming from a smaller paper company it may not work well. Most of Epson’s and Hahnemuhle’s profiles are pretty good-I have not had much luck with Moab’s profiles.
What to do when a paper profile does not result in a good looking image:
Don’t freak out it’s not the end of the world. Go back to the ProPhoto RGB color space image file. Convert to Adobe 1998 RGB Color space. Edit the image as you normally would in Photoshop. When you are ready to send it to the printer select “Printer Manages Color” in the printer dialog box. With Epson Printers you should select the “Color Controls” under “Media Settings/Mode.” This means that in essence you are allowing the printer to profile the image prior to output.
Is this a bad thing? Epson is a multi-billion dollar world-wide corporation. They employ over 72,000 people (by comparison Adobe employees a little over 7,000, and most paper manufacturers are considerably smaller yet) don’t you think that the Epson Corporation has the resources to hire people who can figure out how to make an image file look pretty good when it comes off of their printers? Try it you might be surprised. I suspect that the results are the same when working with HP or Canon printers.
Using this method will mean that you may have to print a test print and then adjust the color and or density/contrast before making the final image.
Something that I usually need to do even with the best of printer profiles.
In particular I have found that Moab Entrada paper profiles render an image that is contrasty and wholly un-appealing. However, when I send an Adobe 1998 RGB image to the printer (with some extra magenta added to the file) it comes out of the printer looking very nice. The colors are soft and pastel like, a very acceptable print.
Don’t be afraid to experiment. This is the only way that you will find a color management workflow that will work for you.
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September 1, 2011 | Categories: Digital Workflow | Leave A Comment »
Understanding Color; the key to fine art printing.
While I can teach most people the computer fundamentals of digital fine art printing in about 3 or 4 days the nuances of understanding color can take years to develop.Photography captures the world in a RGB color Palette (Red, Green, Blue), but most digital print devices output in a CMYK color palette (Cyan, Magenta, Yellow, and Black.) This difference can cause some misunderstanding and confusion. I don’t have the space here to write a full dissertation about color theory, however, I can give you a few tips that hopefully will further your understanding of the relationship between the image captured by your camera and the image reproduced by your printer.
Look at the above illustration, this is what I call the Color Circle. This illustration should hang next to your printer. It is the key to understanding how to make proper color corrections on your test print images. Look at this illustration everytime before you make a color correction. If you would like a pdf file of this illustration just email me at the email address listed below and I will send you a free pdf file so you can print it.
Here are some common color printing mistakes:
Blue–Cyan, these are two of most commonly mistaken colors. Most novice printers will look at an image that is too “warm” and add blue thinking that they need to “cool” the image down. Blue has red in it, if the image is too “warm” because it already has too much red in it this will only make it worse. If adding blue makes the “warm” image muddy looking try adding cyan instead.
 Red -Magenta, and Green-Yellow, are frequently mistaken as well. A proper color correction to an image will result in the colors being distinct and vibrant. A misdiagnosed color correction frequently results in mudding colors or cross curves of color that show up in the shadows or highlights.
Look at the neutral tones or whites in your image, they should be color neutral. A quick and easy way to tell if they are color neutral is to hold a blank piece of the printer paper next to the test print or screen image. Do the neutral tones or whites still look white, or do you perceive a color cast.Get the colors right before you move on to the next step in your digital workflow. There is a reason why the Adobe Software Engineers put the color balance tools at the top in the Camera Raw workflow. If the image looks muddy, flat, or soft there is a good chance that the “color temperature” and “tint” are not set correctly and no amount of “clarity”, “vibrance”, or “saturation” will fix the problem.
Your computer monitor will never-ever– match your prints. Get over it and move on. Judge your prints on the basis of the print. Unless you hang your computer monitor on the wall next to your framed artwork the final viewer will only see and judge your work based upon the finished print.
Always judge your test prints under the same light conditions. The light conditions that you view your test prints under should be the same light conditions that you typically view your images in. Variances in light sources can dramatically alter the perceived color of a print. This effect is called mesmerism, a fancy term for chronic and frustrating problem for fine art color printers everywhere.
Always consider the first print to be a test print. While a test print can be smaller than the finished print to conserve paper and ink costs, the test print should be large enough to adequately see all aspects of the image. Most of my test prints are made on 8.5×11 inch paper.
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September 1, 2011 | Categories: Digital Workflow | Leave A Comment »
Geotagging Your Photographs
Originally Posted May 2010
When I was hired by the MN Department of Natural Resources and the Nature Conservancy, both of these organizations requested that I provide GPS (Global Positioning System) information in the metadata of all submitted photographs. After an initial round of research I discovered that my Canon 5d was one generation too old to accept GPS input into the metadata. The solution would require me to purchase a new camera the Canon 5d Mark II ($2700) a wireless transfer unit to attach to the camera ($800) and a hand-held GPS unit ($200-500) for a total cost approaching $4000. Needless to say this approach was not in the budget for these projects.After some more research I found a device called PhotoTrackr Mini DPL900. This unit is about the size of an overgrown thumb drive, on one end of the unit is a USB male-port just like a thumb drive. The device retails for about $69, along with an upgrade to read Raw format images, charging unit, and shipping my total cash outlay was about $120. It will work with any digital camera.I received the unit in a timely fashion and downloaded the software. The software set-up is not for the technically challenged, but if you have anything more than basic computer skills it should go fairly smoothly. Within about 30 minutes I was ready to test the unit. The first step was to sync my camera with the GPS device, this is a relatively simple process of going to the PhotoTrackr's software clock and setting my camera clock to the same date, hour, and minute. Then I went outside and turned on the PhotoTrackr unit. The unit is a passive GPS locating device, it records a GPS position every 5 seconds. It initially took the unit about 10 minutes to locate the GPS satellites for positioning; subsequent start-ups take a lot less time usually under a minute. I made several test exposures, walking and sometimes running between locations. I came back into the office and downloaded the images in my normal fashion, I also downloaded the GPS data from the PhotoTrackr unit.
Once the data was downloaded I opened the PhotoTrackr software and went through the step by step wizard to attach the GPS coordinates to all of the images. This process will take anywhere from a few seconds to several minutes depending upon the number of images, the largest batch I have processed at one time was about 200 images and it took about 5 minutes to sync the data. The PhotoTrackr software looks for images that have the same date and time stamp as the GPS data that was downloaded from the device. Once you have your images tagged the software allows you to go to a Google Map where the photograph locations are displayed, the software even displayed the rate of speed of travel required between the images.
As time goes by the additional GPS information will be extremely valuable for the MN DNR and Nature Conservancy land stewards and biologists. I have used this unit on a couple of photo-shoots. The process is pretty simple and doesn't take too much effort once the initial set-up is in place on your computer. Of course there are the additional steps of making sure the unit is charged and goes with you on the photo-shoot, as well as downloading the data after each trip, however, if you have ever wondered where you took that mysterious great image this process will insure that you always have the exact location.
August 27, 2011 | Categories: Digital Workflow | Leave A Comment »
