Rangefinder Magazine
January 2006

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Digital Photography John Rettie
Quality Needed for a Giant 12x16 Print

SEVERAL WEEKS AGO, I received a phone call from an art director at a promotions agency working for Volkswagen of America. They needed a photo “at least 100MB in size” so they could produce a 12x16 print for use at an exhibition. I wondered why they needed such a large file until they pointed out they were talking about feet, not inches.

Apparently they had tried using an image taken on a 6-megapixel camera, but it was breaking up when blown up to this size. I felt confident that an image I had shot on the new Canon EOS 5D camera with its 12.8-megapixel sensor would be fine, even though the file size was “only” 36.4MB.

I emailed them a link to several images posted on my website, and they chose one, which I duly emailed to them. It was a 4.2MB JPEG file, unaltered since I captured it on the camera. I had not shot in RAW, since I was more interested in a speedy workflow than ultimate quality, and never expected a request for a 12x16-foot print.

I didn’t hear anything more, so at first I was not sure if they had successfully made a print. A few weeks later, while attending the SEMA automotive aftermarket show in Las Vegas, I saw the print on display behind the Volkswagen Touareg that won the $2 million prize in the DARPA Grand Challenge race for autonomous vehicles. The print was fine. Even on close examination there was no pixelization, and from a few feet away it was full of detail. I was impressed.

The giant photo was printed by KSK Digital Printing Solutions in Troy, MI, on Trevira 600-gram canvas using a Vutek 5300 printer. The latest version of this giant wide-format inkjet printer is the Vutek 5330 and according to tech specs, it can print images up to 16.4 feet wide by 150 feet long. It tips the scales at 6100 lbs. and costs almost $600,000—certainly not an everyday printer for a photography studio.

One of the most impressive aspects of this print is that the lab cropped the image and only half the full-size frame was used. I checked the dimensions in Photoshop and discovered that the part of the image used was only 1810x2544 pixels, which is less than five megapixels. The image therefore had to be quadrupled in size to reach the final dimensions of 7200x9600 pixels, printed at 50dpi. (The printer actually prints at 300dpi but only requires a file set to 50dpi.)

Ironically this ended up being a smaller file than a non-cropped image from a 6- megapixel camera. I shot the original on a 28–300 Tamron zoom at 300mm, as I was some distance away from the race vehicle. I would have been just as well off using my old Canon 10D to get the shot. I suspect though that the agency would have rejected the file as being too small.

I have run some quick side-by-side comparisons of shots taken on the 5D and the 10D; there is surprisingly little difference in image quality when cropping to the same size and using the same lens settings.

A few months ago in this column I described how I think reduced-size sensors are the wave of the future, as they will produce image quality sufficient for the majority of uses. I am still convinced of this, despite mixed experience. There are two ways of looking at this scenario. One point of view suggests I was fortunate to have shot using a full-frame camera because I got an image of sufficient resolution that it could be cropped. On the other hand, if I’d been using the new Nikon D200 with its 1.5X crop factor, I’d have ended up with an image “pre-cropped” in the camera containing almost twice as many usable pixels.

I suggested that in the future full-frame 35mm-based cameras will replace mediumformat cameras and medium-format digital cameras will replace 4x5 film cameras. I received several emails from readers disagreeing with my perspective.

One says “I read your article ‘Three New Cameras Create Waves’ (Nov. 2005) and was taken aback by the subhead for the new Hasselblad 22-megapixel camera… ‘undoubtedly good enough as a replacement for 4x5 film cameras.’ No offense John, but that’s nonsense. Most people use 4x5 for perspective control, not just for its amazing image quality. Now, if you want to say ‘undoubtedly good enough to replace a 645 or 6x7 medium-format film camera,’ that’s another story. I’m not sure if you use a 4x5 on a regular basis, but I use my medium and large/panoramic formats all the time, and the medium-format images can’t even compare with the detail in the largeformat exposures… and never will. Not that I wouldn’t salivate to own one of these Hasselblads— but not as a replacement for a 4x5 camera. Just my two cents. Thanks!”

Another says: “We professionals need shallow depth of field. We’ve already lost so much from large to medium to 35mm format. In my opinion, APS-sized sensor images look more ‘amateurish’ than a fullframe sensor.”

I agree that many photographers need the versatility of perspective control in a 4x5 camera. But what’s to stop one from being made with a smaller size digital sensor? As far as depth of field is concerned, that is an issue raised by many photographers. On the other hand, I have also read of photographers who enjoy the greater depth of field offered by a camera with a smaller sensor.

I hope that all these varying opinions and needs will eventually result in the introduction of all-new cameras and lenses that can meet photographers’ needs, perhaps in ways not yet dreamed of.

For example, in the past few weeks there have been discussions on a new sensor that performs focusing after an image has been captured. The photographer can then work on a RAW file and give an image as much depth of field as desired. Another experiment is a “living” sensor where microbes react to light—who knows where that might lead.

However fixated we are on what we are comfortable with, we need to have an open mind as to what may or may not come in the future.

Sometime in the future our grandkids might take this well written humor piece seriously: “Scientists have announced that they have managed to create a gigapixelper- square-inch ‘light sensor’ using only silver halide molecules coated onto a transparent plastic substrate. On exposure to light, some molecules change state by dissociating into pure silver. Exposure times of just a few milliseconds were all that were needed. This image is not visible to the naked eye, but can be ‘developed’ using chemical processing to amplify the image to make it visible. The final image can be then fixed and rendered no longer light sensitive by bleaching out the remaining halides. The image is then rendered permanent. With its vastly higher-resolution-than-ordinary digital CCD sensors, scientists are hailing the discovery as a breakthrough for creating ultra-high resolution images. They have also speculated that by creating a sandwich of light sensitive layers and color filters, color images could be recorded by the same process. The only question is: Is the usual digital imaging that we have all grown used to doomed by this new process?” (posted by Graham Cox on technology website, Slashdot.com)

CompactFlash Card Update

During the past few months I have been doing a lot of shooting with different cameras. I have been fortunate enough to have at my disposal a variety of different CompactFlash cards. The most impressive cards, size-wise, are the 8GB SanDisk ultra II and the 4GB Lexar Professional 80X cards; however, I’m a little concerned at having all my eggs in one basket. Nevertheless, it is great to be able to shoot several assignments and still have the counter report 999 or 1999 shots remaining. It seems that most cameras can’t count past 999 or 1999.

I have changed my workflow with these large-capacity cards; I no longer reformat cards after downloading images to my PowerBook. Instead, I leave the images until the cards are full or I have finished editing, and then make DVD backups.

Kingston Technology is a well known company that has marketed storage cards for some time, but it is not as well known as Lexar or SanDisk in this part of the market. Its latest card, the Ultimate, brags of a 100X speed rating. I’ll be honest—on the whole I have not noticed much difference in speed on newer cameras; most have a large enough buffer that I rarely have to wait for images to be written to the card while shooting. Likewise, when transferring images from cards to my PowerBook, most transfers are fast enough with USB 2.0 card readers.

Kingston has also introduced a new reader that supports 12 different card formats. Like most readers, it uses a cable to hook up to a computer. Personally I prefer to carry a Crucial Technology Flash Card reader at all times, which does not require a cable, takes up less space, and is easy to use. I’ve even used it (along with the 8GB SanDisk card) to transfer files from one computer to another when I didn’t have time to burn a CD or use a network to transfer the files. It’s sort of like having a really large USB flash drive.

Quick Book Review:

Hacking Digital Cameras

Chieh Cheng, author of this intriguing book, says it is unfortunate that the term “hacking” has become a negative word that refers to criminal activities. He points out that hackers were originally people who skillfully modified computers and programs to improve them. In a dictionary the word enjoys numerous definitions.

Cheng has a myriad of “hacks” in this book (520 pages, $24.99, one of several Hacking titles published by Wiley) that can help improve a user’s photographic experience. The title is a bit misleading, as only a quarter of the book is concerned with electronic modifications to digital cameras. Much of the book covers mechanical items, such as making your own monopod or a camera holder for a car. There are also plenty of tips for creating and modifying unique filters, adaptors and lenses.

Chapters on electronics include hacking the firmware in a Canon Digital Rebel to activate some of the features that appear in the more expensive 20D camera, but were disabled in the consumer camera. Other items include making a remote control device, turning a digital camera into an infrared camera, and even accessing RAW data on some cameras that don’t include it as an option. It’s an interesting book for anyone who enjoys tinkering with cameras and accessories.