Expert: Scott Valentine - 2/12/2009

Question
I am a new photographer and photoshop user (CS4) and am working toward a career as a professional portrait photographer.  I noticed that my photos are appearing more heavily pixilated and grainier than I would like.  I shoot with a Canon 50D in RAW and would expect the image quality to turn out much better.  My images are typically saved w/ a resolution of 240 ppi.  Should I be resizing the pictures?  I'm just not getting that sharp look that I'm after. What can I do to sharpen the image and make it look not - so - pixilated?

Answer
Hi Angie,

This is an excellent question, and one that sparks a lot of debate. I'm very happy to hear you are shooting in raw format. Using CS4, I recommend you convert immediately to Adobe's DNG format when you import your images, and choose to preserve the original file. This gives you some protection for archiving your images into the future.

Now, back to the sharpness issue. I'm not familiar with the 50D specifically, so what I'll discuss here is a general approach to sharpening your images. Since you are shooting raw, you will be able to take advantage of Adobe Camera Raw (ACR) processor. Open your images in ACR and check out the adjustments you can make there. For straight photographs, try to do as much as you possibly can in ACR before opening the images in Photoshop.

Sharpening should be near the end of your adjustment process, and usually has to be tweaked specifically for your rendering 'intent' or output method. A typical work flow goes something like this:

Exposure
Contrast
Color
Sharpen

There are lots of details in each of these, but they are for another discussion. There is a sharpen tab in ACR that you need to read up on and fiddle with so you get comfortable with how it works. Don't worry, though - since you are working in ACR, the changes are not actually committed to the image itself, so you can go back later and undo any changes you make here. However, when you open up the image in Photoshop, *that* copy of the image starts from whatever you send it from ACR.

Once you have something you like in ACR, and are ready to sharpen in Photoshop, you should be looking at how you want to use the image. For standard print, use Unsharp Mask's advance control features, but use them carefully. Each image will take individual work, and it can be easy to overdo it. I'll presume you know what you want the image to look like, and will spend some time fine-tuning your approach.

On the print, it may be that your print engine (whether from Photoshop or other image processors) is resizing the image to fit your paper. The ppi you mention has to do with the information the printer receives from the print engine - 240 should be adequate for most print jobs, with 300 being a little overkill unless you are printing very large images with a lot of detail, intended to be viewed closer than normal.

If the pixelization occurs in specific areas, say shadows for example, it may be that you are clipping the colors in that range. Check your Photoshop help files for gamut correction and previews. This will help you figure out if your image contains information that the printer can't print. Alternatively, if you are saving as a JPG and then printing, the issue probably has to do with JPG compression - don't print from JPG when you have a PSD available =)

However, if the pixelization is all over, it could either be the printer itself, or the file information from the 50D. Both situations require some investigation. For example, I've had trouble with older Nikon cameras shooting in NEF (Nikon's raw format) above ISO400 - the images come out very noisy and grainy on my D100. Lowering the ISO to 200 solves the issue. On the printer side of things, there may be some settings that cause the printer to misinterpret the image data, but that usually goes along with some slight color problems, so you'd probably notice that, too.

If this isn't the information you are looking for, please provide a link to an example so I can better understand the problem.

I hope this helps! Let me know if you have further questions.

-Scott