Undeniable Truths of Life (including jpgs)
Written by: Phoenix Wedding Photographer and Pictage Member Jared Platt
There are certain things I hold as undeniable truths in life, among these are:
1. God exists.
2. All humans are endowed by God with certain unalienable rights and among these are life, liberty and the pursuit of happiness.
3. Hot liquid magma is not a toy.
4. JPGs are a very bad filetype!
I know that most of you reading this entry will say, “well I shoot RAW, so I’m cool!” But you may only be half right about that. So let me fill you in and then you take stock of your image pipeline and decide weather or not what you feel good about what you are doing. I am not passing any judgement on you, I will leave that between you and God. (See truth #1).
It is a foregone conclusion that shooting a JPG as a filetype is a bad idea. For those of you who are not up to speed on this issue, it is as simple as this: when shooting a JPG, you are asking a camera that contains a very small and not very powerful computer with no user intervention to make critical decisions about the colors, contrast, dynamic range, etc of your file, then compress that file down to a fraction of the size by throwing away what it sees as non-essential pixel data, and save it to a disk. You certainly save space on your CF Card, but what do you do when the camera makes the wrong decisions? What do you do when the compression does not allow for the subtle gradients in the sky and creates ugly banding? There is no going back to the original data, the RAW image, because you threw it away as you shot the photograph. So now you are left running noise filters, grain actions and gaussian blurs to try and soften the offending tonal stair-steps in the sky.
You see a JPG can only have 8 bits worth of information even when it is not severely compressed, so a JPG has a very difficult time describing very subtle gradients, like the sky, or a white backdrop, or a smooth skin tone and it transitions from light to shadow. The problem of the JPG’s 8 bit depth is only compounded by the fact that an onboard camera computer is making the compression, rather than a super computer Mac Pro with the most advance photo editing software in the world (Photoshop) making the calculation. A camera computer is good at recording data, not interpreting it. Your camera’s computer should also not be used as a heart monitor or a dialysis machine. Your camera’s computer is very good however, at recording the RAW data on its chip, logging the shooting decisions and saving it to a disk. By shooting in a RAW format, you are giving yourself access to the full capabilities of the file your camera is able to produce. And that 16 bit file makes all the difference in the world.
So, most of you read through that, still saying to yourselves, “I already shoot RAW, so let’s move on.” Thanks for sticking with me, I just had to get the others over to our side on that concept. Now for those of you who are shooting RAW. Check yourselves on the next issue.
The advantage of shooting a RAW image in the first place is that you have a full 16 bit file available to you to edit in Lightroom, Aperture, Capture One, Photoshop RAW or some other RAW editor. This means that you have the ability to recover blown highlights, adjust the original shooting decisions, like the color balance, etc. All of this is very clear to all of us who shoot RAW. And further more, I think everyone can understand why it is best to make as many adjustments as you can in the original RAW before exporting the image as a new file for printing or further Photoshop work. So the question is this: why, do so many people shoot RAW for the 16 bit advantage, adjust it in a RAW editor for the same advantage, but then when they go to do their Photoshop work, they make an 8 bit JPG file and start editing the images, burning and dodging, and making curves, etc?
The common excuse is that the JPG is smaller, so it takes up less space. When people are making an album, they don’t want to make 60 to 100 16 bit PSD files, that takes up a lot of space on their disk drive. Funny, that is the same argument they were using for shooting JPGs in the camera. Disk space is plentiful and cheep. I was in the computer store yesterday and saw a Western Digital Green Drive 2 TB for $160. With that kind of space at that price, space is not an issue. Some people excuse this JPG fetish with computer speeds. Yes, a larger file requires a bit more processor and RAM, but that too is easy to come by, especially if you live in the PC world.
I choose not to compromise the quality of my work and take full advantage of the 16 bit advantage of RAW image capture even when I am retouching in Photoshop. All of my files leave Lightroom as 16 bit PSD files in a Pro Photo RGB Color Space. The combination 16 bit and the Pro Photo color space allow me the ability to adjust and edit my images to a much greater degree without introducing banding in the gradients and noise in the shadows. If you are one who shoots in RAW, then you obviously agree that the 16 bit advantage is worth the extra effort, but you loose that advantage when in Photoshop if you are editing a JPG. Exporting your images as a 16 bit PSD or TIF will maintain that data bit depth advantage you enjoyed in RAW.
Some of you are now on board with the bit depth, but what about this color space? Let me briefly explain color space. There are three basic color spaces that you use while editing and working with digital images. Pro Photo RGB, Adobe RGB (1998) and sRGB. Everything you are printing at Pictage or any other photo lab are being printed in sRGB because that is the color space that the printer understand and use to make the prints. It is basically their total range of color recognition. sRGB is a very limited color space, like using an 8 crayon box. There are less total colors available, but enough colors for the human eye to see much as it does in nature. This is also the color space used on the world wide web and on digital display units of all kinds. Adobe RGB (1998) is a much more broad and deep color pallet that contains arguably more colors that the human eye is capable of seeing. This has been the standard for many years for profession image editing. The latest and greatest color space then is the Pro Photo RGB which contains even more color depth than the RGB (1998) and contains more colors than either your eye or your monitor can even detect. So why then would someone not want to work on their photo in sRGB which is where it will end up if it is going to be printed or displayed on a monitor? Simple, for editing purposes, you want to have the most information possible in your image file. Each time you make an adjustment, a burn, a dodge are curve, a level, a hue adjustment, etc, you are drawing on the additional information in the file that you are not able to see. That bit depth and color depth become extremely important as you make destructive edits inside of Photoshop. Remember, you have left the RAW arena where non-destructive is the rule. Now, everything you do is destructive to your image. But the more bit and color depth you have, the more you can edit your image without seeing the image pixels break down.
Only after you have done everything you intend to do with a given image should it be converted into an 8bit sRGB JPG. At that point, your JPG is a “print only” document. Your computer can take your 16 bit Pro Photo RGB image and convert it into an 8 bit sRGB JPG that will look, to your eyes and to the printer, exactly like it’s more perfect parent file, but, like a shallow sand drawing, it will only contain the needed color and depth to show itself as you have exported it. Start trying to change that shallow sand drawing and you will quickly reveal the gaps between the sand crystals and the table below the patterns.
If you are anything like me, you will not use Photoshop all that often because I can do most of what I want to do inside of Adobe’s Lightroom. If I have no editing to do to an image, I will send it directly out as a JPG and post it to web sites, to my printing service (Pictage) and use it in my album designs. But when I have something additional to be done to an image in Photoshop, I will always export that image as a 16 bit Pro Photo RGB PSD. My greatest concern as a photographer is to maintain the brilliance of the message in my photos with an unsurpassed quality at all stages of production. A JPG is a necessary part of that production pipeline, but it is always and only at the very end.
Mon, Nov 2, 2009
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