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Our suggested approch to preparing your image files
This page details a simple approach to preparing files captured on a digital camera (or scanner) right through from downloading the file to saving in a format suitable for high quality inkjet (or giclee) printing.
We are not saying this is the only or the best way to prepare images for printing; it is just the approach we use and find works well for us.
We are not going to go into step by step keystrokes; we are just going to detail the basic steps you need to go through. There are many excellent books, magazine articles and on-line courses which do cover in great detail how to do the various steps: if you need such detailed instruction we can refer you to these resources.
The steps involved are normally done using a photo editing application such as Photoshop, Photoshop Elements, Lightroom or one of the other software packages available. All use broadly similar concepts, but since Photoshop is one of the most popular packages, here we will assume you are using that.
- Open the downloaded file and immediately save it as either .tiff or .psd
- Crop and rotate the image to correct any intrusions around the edges of the frame and fix crooked horizons etc
- Adjust the black point and white point in the image - this is best done early on. (The ideal tool for this is Levels)
- Clarify the midtones, this helps give the image luminosity (Curves is a good tool to use for this)
- Correct any colour cast or white balance issues next (again use the Levels tool)
- Make any colour adjustments now using Hue / Saturation controls, but be careful to use them cautiously to avoid garish / unnatural colours
- Up until this stage, all adjustments made have been on the whole image. Now is the time to make local area adjustments (such as dodging or burning in small areas, opening up dark areas without lightening already bright areas, making colour adjustments to specific areas of the image, etc). These steps are best done with adjustment layers and layer masks.
- Now clean up the image to correct any problems such a flare, dust spots, noise or other unwanted elements. (The Clone and Spot Heal tools are useful for this).
- This is important. DO NOT SHARPEN the image yet. Save the unsharpened layered image as its own separate file. This is your master file from which you should make files for printing at specific sizes.
- To prepare your image for printing, you now need to resize the file to the print size you require, at an appropriate resolution, using the Image Size function.
- Go back to your photo editing program now and crop the image to the actual print size you require.
- Now is the time to sharpen your image. As image size influences the degree and amount of sharpening required, this is why it is left until last. There has been a lot written and published about sharpening techniques (including techniques for selective area sharpening) and we can send references to these. However as a starting point we suggest you use the Unsharp Mask filter and try the follow settings:
- Once you are happy with the sharpening, you can now flatten the file (merge the layers to a single layer using the Layer, Flatten Image command), and save it as .tiff (image compression: None) or .jpg (image quality: Maximum). We recommend including a reference to the print size in the file name for easy reference - for example img2203_24x16.jpg
To get best results, turn off Resample Image and first enter 200ppi as resolution, this will then show the maximum print size you can have at this resolution without any interpolation of pixels. Now enter 360ppi as resolution, this will show the size the image will print at this resolution. If the required print size falls within this range simply enter the print size you require and the resolution will be adjusted to fit. Note that this method doesn't provide a specific height and width - unless the original image pixels match these dimensions. To get a specific print size, adjust one dimension to fit the required size with the other dimension showing larger than required - you can then crop the sized file to the desired print size.
To get a print size larger or smaller than indicated when entering 200 and 360ppi you need to turn Resample Image on again.
To get a larger print size, enter print resolution 200ppi and select Bicubic Smoother from the dropdown menu then enter the required print size - again so that one dimension is the required size and the other is larger.
(If you need to enlarge an image by a large amount it may be better to use specialist software such as Genuine Fractals, please contact us if you need help with this).
For a smaller print size, enter print resolution 360ppi and select Bicubic Sharper from the drop down menu and enter the required print size.
| Amount: | 140 - 180 | (lower for soft subjects, higher for highly detailed subjects) |
| Radius: | 1 - 1.6 | (generally higher for larger sized prints) |
| Threshold: | 3 - 6 | (low gives high sharpness, but can also exaggerate noise) |
Your file is now ready to send to DigitalPFP for printing.
If you need any further guidance, please feel free to contact us for advice. We do try to help whenever we can.