Defying conventional wisdom, we printed a wall-sized picture of the Golden Gate Bridge.

When Boris contacted me 3 months ago, he sounded desperate.  He had a special request and not much hope of getting it met. Boris wanted to have a wall-sized print of one of my pictures. He wanted to print one of the pictures he found on this website at 128x100 inches. At first, I was puzzled and I asked him to confirm his request. I guessed that he was German, so I translated his request into metric units for confirmation.

After confirmation, I suggested some of my large-scale stitched images as an alternative solution, but Boris knew exactly what he wanted and stayed firm in his request. I therefore discussed the potential outcome of resizing the desired image with him. We quickly dismissed the possibility of re-taking the shot, due to the cost and the unknown outcome. Atmospheric conditions in San Francisco are not predictable.

We focused on the more predictable issue of upsizing the original image and on print quality. After explaining that even an 8.2MP file of the Canon 20D is several times larger than the highest HDTV resolution, we concluded that it has to look better at those giant dimensions too. You need to see a 72” HDTV at full resolution to know how good these look at 2 Megapixels (1080p).

A good-looking result was also our goal. Boris had already found a specialist in large-scale printing and left it to them and me to figure out the potential of success. I suggested working with CCS Digital on a test print, a slice of the upsized image at full resolution.

After experimenting a bit with different upsizing methods, we settled on a result that Boris ordered from CCS for review. One week later, I had the order filled. Gaining a better understanding of the limits of printing, satisfying a customer and my own curiosity made it a worthwhile effort.

I asked Boris for a picture of the result and permission to write this article.

 

Someone sitting on the curb

Learn how to optimize pictures for websites without sacrificing quality.

The benefit of small pictures is immediately obvious. Requiring less bandwidth will reduce your cost and the cost to your visitors (time or volume charges). People will not remember your site as being slow and come back again (although slowness might happen for other reasons).
I also reduce the size of personal images I send via email to friends and family.
It is thoughtful not to waste other people's time and mailbox space.
The image on the left is only 13.8kB and can be loaded, even through a dialup connection, in a fraction of a second (the text on this page is bigger). Further optimization could reduce the size of this image to about 10kB without too much loss of quality. To save time, I have automated my workflow (including the final compression), leaving some room for further improvements.
I will demonstrate how to optimize your images with Photoshop, but you should be able to reproduce these steps with just about any Photo Editor

Preserve the Colors of your Images Recently Ron sent me an email and hinted me towards the fact that I missed the last mile on my workflow tutorials.
I was asked to give some more insight into the process of preparing images for web viewing and/or printing.
In this tutorial I am going to cover some of the basics of color profiling and in the next tutorial I am going to talk a bit about resizing and compression of images. After all you want your images to look good without annoying your viewers (and your wallet) by large data transfers. As you can see this site has a reasonable amount of graphics, but (hopefully) still loads fairly quickly. Part of the reason (besides a good host) is that I optimize my images for online viewing. Since I have automated the process, I forgot to cover this subject. You can use the same technique to send your pictures via email.

Color Profiles and Management

I am by no means an expert in color profiling, nor do I understand all of it. But I can give you some tips on what worked for me without drifting too much into technical jargon.
Color Management should be part of your digital workflow and it is tightly interwoven with all the applications.
Since different devices use different technology (an LCD uses light and color filters to render pixels while an inkjet puts ink onto a paper), you need color management to make the picture look the same on either of them. You want the picture to be printed the same way it looks on your screen. Today's consumer grade LCD screens are often too bright and too cold (blue/green tint). I guess the reason behind this is that manufacturers want them to look brighter in the show room. Unfortunately, this really messes up your color management, so if you are serious about getting the best quality from your pictures, check out my short article on LCD Color Calibration.

Color Proofing

Even after you calibrated your monitor, you still need an application like Photoshop that supports color management. As far as I understand the process, the monitor profile consists of two parts. One part is loaded in the operating system (the one that converts a standard color space to the color space of your monitor) and another part is used by the application.
All you need to worry about is that your application supports color management. On some LCDs (like my laptop screen) I can see a visible difference between an image that I open in Photoshop on the calibrated monitor and one I open with the Windows picture viewer.
In order to color proof your image for your printing service, you need an ICC Profile. Since EZPrints offers good prices and a color profile (EZPrints Profile), I am going to use them as an example. Simply download the profile and right click on the file. Select "Install Profile" and start (or restart) Photoshop.
In Photoshop open the picture you wish to color proof.
Go to View -> Proof Setup -> Custom
Under Device to Simulate select ezprints.icc (or whatever printer you want to use) and leave the rendering intent on Relative Colorimetric.
Now you can do two things:
1) You can go to View -> Gamut Warning and let Photoshop highlight the areas in your picture that are out of Gamut (that have levels of saturation your printer cannot reproduce). If you have a lot of those areas and if the color range is wide, you will see posterization effects. That usually happens when you try to boost the saturation too much.
2) Or you can go to View -> Proof Colors. Provided your Monitor is calibrated and able to reproduce the entire color range (that's usually the case, as a monitor has a wider color space than prints), you will be able to preview exactly how the final print colors will look like. Don't even try this with an uncalibrated screen.
I have also set up Photoshop to use ProPhoto RGB as my working color space (Edit -> Color Settings). For some reason, Photoshop only lets you select ProPhoto RGB after clicking the "More Options Tab" (which cost me quite some time to find out).

Color Spaces

Ron asked: "The instructors for Photoshop at the UC ext. courses there in Cupertino always said to use Adobe RGB color space. Now I see that people say sRGB might be better."

Point Reyes Farm and Fog

Often I get questions via email and I think the answer to many of them could benefit others as well, so I decided to introduce my new series From the Mailbox where I will publish a few of the questions and answers. Don't worry, I won't reveal any contact information, so your emails will be safe.

Hello Andre, Thanks for so much information. Couple questions: 1. Equipment: For your stitching I see you use a 50 prime. Have you tried say 180mm Telephoto lens? 2. I use a mac... What Stitching SW would be good? I've tried PTGui ...seems ok bu the final file is always a smaller than what i get from CS3. 3. The instructors for Photoshop at the UC ext. courses there in Cupertino always said to use Adobe RGB color space. Now I see that people say sRGB might be better. I upload photos to the web and did A-B comparisons and they look very close to me. I've heard said that Adobe RGB web photos have dull washed out reds. Any thoughts? Maybe a tutorial on uploading photos to websites. Keep up the good work.

Reply: I just returned from my weekend trip, so I will try to be brief. Don't hesitate to send me some more questions if things aren't clear yet. For the Machu Picchu Image (222 Megapixel Mosaic) I have used a focal length of 200mm. It's really just about how much resolution you want to get. I don't limit myself to 50mm. It was just an example. Stiching: I use PTAssembler on PC. I think PTGui is good. The size you get is probably related to how the control points are calculated and how things are warped (I know thats a poor explanation, but check this link ) About the color space: I use ProphotoRGB for editing and sRGB for output. ALWAYS use sRGB for display and printing, but use something with more Gamut (Adobe or Prophoto) for editing. Convert using the Adobe Perceptual Engine. Most people's monitors and browsers are not calibrated and sRGB will defenitely look better. AdobeRGB contains too much gamut and will result in out of gamut colors on many peoples screens (posterization effects).

In my hasty response I forgot to mention my article on color calibration, that might be a good source of information. LCD monitors that you buy these days at Electronic Outlet stores are not very good and are over saturated and usually have a cold tint (blue / green). They need to be calibrated in order to render color correctly. Otherwise your prints will not match your monitor output.

The tutorial sounds like a good idea too, maybe spiced up with some general color recaps.

The picture on the left is a quick B/W conversion with some curves adjustments (mainly contrast boosting) of one of the photographs I took this weekend at Point Reyes. During the summer months Point Reyes sees more fog then any other time of the year. Fortunately thats not bad news for us. While most tourists chose not to get out of their cars, I used the chance for soft light.

Every travel photographer knows the scenario. While most photographers advise not to shoot during the harsh light of the day, we often have little choice. Often I find myself at a place and I know I will have to move on, either because I have a travel schedule or because I am on a weekend trip and have to get back to my daily routine. Believe me, if I could afford it, I would follow the good advice and spent a lot of time on each location waiting for perfect conditions to make my photos shine.
In situations such as this, the best would be to put your camera on a tripod and bracket your exposure. You can then combine the pictures on your computer. However you cannot take your tripod everywhere (it may not be allowed) and it is very cumbersome.
In the past I have often written about RAW processing and I have stated that you can make good use of the dynamic range captured by your camera. Almost every Digital SLR camera and many of the better Point and Shoot models alow you to record RAW files. A RAW file is the data captured by your Camera's sensor that is not processed yet. It does not contain color information (yet), which is very useful to adjust white balance at the computer and apply sharpening and other enhancements the way you like it (check my other Worklfow Tutorials for more information). A 12-bit file contains 16 times more levels then a 8-bit JPG file. This is the main reason why I only shoot RAW.

I love taking night time photographs of city skylines. Nightshots present a challenge to just about any camera, due to the enourmous dynamic range of the picture. While most of the image will be dark, the image should be exposed for a long time. However strong lightsources will be overexposed by a large amount. These bright spots are exposed so much, that they "leak" into adjacent pixel sites. Without going into too much detail, here is what happens:
Photons (light particles) that enter the sensor knock loose charge carriers (electrons). Those are stored and read out after the exposure, thus getting a count of Photons that entered the sensor during a period of time (exposure time). Imagine each pixel being a water bucket. When one is full, and no special drainage is supplied (vertical and lateral overflow drains) they will flow into adjacent buckets.
With most cameras the result is a blue and red halo around a strong light source. Viewed from a distance, this will make the lights look unnatural.
As with all my Photoshop tweaks, I am trying to improve the overall look of the picture without changing too much.
In this tutorial I am going to show a simple technique I came up with quite a while ago.

Today we are finally going to take the RAW images that we converted during the last 3 tutorials and do some Photoshop work on them. I know this is probably starting to get more interesting then RAW conversion for most of you, but I urge you to read my last blog entry with the title Photoshop it Later.
The digital workflow is just as important as taking the photos. I have refined my workflow over and over again. Each photographer uses his/her own techniques and I urge you to develop your own. This tutorial will help you to get started on this. In this tutorial I will introduce you to some basic techniques to digitally enhance your photos. Until I write the next tutorial, I recommend you download the Photoshop Action (below) that combines everything in this tutorial into one clickable action (for automation) and modify it to your liking. It is just a rough framework.
One of the most important things is automation. Photos shown on this website area all run through automation scripts. I simply convert all RAW files to tiff (automatically) and then run an action on those to generate JPG files (no need to spend all this time on each image).
Often forgotten but one of the most crucial and important steps in this process is color proofing. Many people are not even aware of the process. It is a way to guarantee that the output from the photo lab really matches what you see on your screen. I will end this tutorial with an introduction to color proofing. (The picture is from my resent deserts trip that I will upload tomorrow).

In my last tutorial I gave a quick overview over the user interface of Adobe Camera RAW and I mentioned a couple of the really nice things you can do with it. Today I am going a little deeper. I will be explaining some of the more important functions of Camera RAW, without going into too much detail. I will use the same example of a rather difficult image that requires some curve tweaking to demonstrate some of the capabilities of Camera RAW.
The picture I will be tweaking is not exactly my most glorious photographic example but it serves the purpose nicely.
Often the question arises why I make these adjustments during the RAW conversion process when they are often easier in Photoshop. As I said I don't want to bore the hell out of you with technical details. In short: RAW files represent the data in linear form while a bitmap is a nonlinear processed image that matches our perception of reality better (light levels as seen by the eye). The during the nonlinear processing dynamic range and color information is lost (another reason why I use 16-bit and ProPhoto RGB as indicated in the last tutorial).