Thursday, June 30, 2011

Digitally Editing Photographs of Paintings

In my previous article, I explained how I photograph my paintings, recording high enough quality jpg's to reproduce well to at least 7 inches square in high-resolution print. In this article, I explain the digital editing process I use in Adobe Photoshop 7.0, once I have downloaded the images to my computer. The aim is to have a final high-resolution file ready for print, and also some lower resolution files suitable for use on a website. Whether or not freeware is as good as Photoshop, I wouldn't know, but if you don't have Photoshop already, I would research this before buying a copy.

This article is not a Photoshop or computer tutorial. It lists what I do, but doesn't give instructions. This article is for readers that already have a reasonable knowledge of Photoshop, and other computer skills. I only have basic skills myself, so nothing too advanced is needed. Before you do anything, you will need to ensure your computer screen is properly calibrated. If you type "PC monitor calibration" into your internet search, there are plenty of websites that will take you through this.

Let's assume I've just finished photographing my latest painting, and have just downloaded the images into my "Source Images" folder on my computer. I keep all my source files in this folder, and keep a regular backup of this, and all my other images folders, safely hidden in another location. I back-up to CD or DVD, as it's non-volatile memory. You might want to consider backing up to an external hard drive too. Any editing I do to the source file is saved as a different file, in a different folder.

Firstly, you may remember from my previous article, I take several versions of each shot. I preview them carefully, and delete all but the best one of each.

Opening the file in Photoshop 7.0, I crop, rotate and zoom out so that I have the largest view possible on my screen of the whole image. Then, with the painting next to me for visual reference, I adjust the Levels accordingly.

Then the Colour Balance. My source files are usually too blue, so I move the pointers slightly away from Blue and Cyan. Then, I adjust the Saturation. With my photos, the red is often very over saturated. I sometimes have to move the red saturation down to around minus 15. That's usually enough to get the colours and tones right. Tweak around if necessary. I occasionally use the Brightness/ Contrast too.

Stand back and look at both the painting and the PC screen together. Take a break, then look again with fresh eyes. If there's someone else around, ask them for a second opinion. Getting this right is important, especially if you are going to be uploading a version of this image on-line for a potential buyer to look at. Then, I zoom in to 100%, and use the Unsharp Mask to bring it crisp into focus. Don't overdo it. I always find the image needs a bit of sharpening, and always leave the sharpening till last. I Save As jpg to my "High Res Edited" folder, (image quality maximum).You may want to save to a lossless file type instead, but high-res jpgs have always been fine for my purposes.

Now for making images suitable for my website. I reduce the Image Size, so the longest dimension is 850 pixels. Zoom in to 100%, and use the Unsharp Mask to focus. I then Save For Web at a quality setting I'm happy with in the preview screen. I tend to save them at very, perhaps unnecessarily, high quality. The file size is usually around 200k. If you're worried about people downloading useful versions of your images, you may want to reduce the longest dimension and/or image quality.

I then create the thumbnail image, using the same Save For Web process as before, but making the longest dimension 157 pixels.

Note: I always sharpen in 100% view.

This next part is VERY IMPORTANT. When you close Photoshop after having done all this, and it asks you if you want to save the changes, click NO. You've already saved the web version's. You don't want to reduce your high-res edited version to 157 pixels long! If you click Yes by mistake, like I regularly do, it's not disaster. You still have the Source Image in the source folder. It just means you have to do all the digital editing again.

Edgeworth Johnstone is a contemporary artist from Muswell Hill, North London, UK. He specialises in expressionist figurative paintings, but also makes other art work such as drawings and block prints. Browse the online gallery on his website for affordable original art work.


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