1 - Preparing Photos to use as reference plates in Photoshop

1 - Preparing photos to use as reference plates in Photoshop CS2
Eric Maslowski

You will need two images of a face, a front view and a side view – ‘3D Data SK’ is an on-line resource which has hundreds of reference photos which can be used rather than having to take your own photographs.

You need to remove any distortion introduced by the lens, camera or photographer – the lens causes barrel distortion, so you need to remove this distortion to produce a flat image.

Lens Distortion is a filter. Go to Filter > Distort >Lens correction.
Tweek the ‘Remove distortion’ slider, which is similar to the spherize filter in previous versions of Photoshop, you can also use vertical perspective or rotate the image.

To use the ‘Straightening tool’ click and drag between two areas that are horizontal. Then release left mouse button and the image straightens up.

Select – filter > distort > lens correction. 
Look at symmetry of the image, so make sure that the person is fairly symmetrical. Unfortunately most people are asymmetrical naturally so you need to look at markers which may imply that the lens has tilted the image. Look at the position of pupils, ear lobes, nostrils and edges of the mouth.
Click on the ‘Straighten’ tool and drag between these different areas to see if the image is straight.
Using the ‘Remove distortion’ slider, slide back until fisheye effect is removed. The image flattens out.

Do the same for the side image.

Merge the two images together and make sure the key features line up.
This gives you two points of reference when modelling later.

Control A, Control C, then Control V to paste the image and move it to the side.
Go to ‘Image canvas size’ and extend canvas 200% to the right.

Take layer one and set opacity to 60-70 % so you can see the face behind it. Pick common points for lining up such as the side of eye or mouth. ‘Control T’ will put you into free transform mode, rotate the image slightly, move the centre to your reference point, so can line up all ref points at same time.

Return opacity to 100% and the clear up background with the eraser tool.
Double check results by using guide lines – rulers, click and drag guide lines to the centre of the pupils, under nose, through mouth and under ears or the top of the ears or eyebrows and you can then see how well you are lined up.

Crop the image
Save as Jpeg.

When using the lens distortion if you have complete control ptlens plug in which removes barrel distortion.