Friday, 2nd January, 2004

Siobhan's Photoshop Tutorial #1

A few people have noticed that the style of a lot of my most recent pictures has changed dramatically. This is due, in part, to the wonderful advice given to me by Emma M from Cincy who told me the importance of lighting when doing a photoshoot (ie, it's no good just plonking yourself infront of a camera and pulling a face — if you light it interestingly you get a much better result) but also to a lot of Photoshop fiddling that I do after I download the pictures

I suppose you could almost call this "cheating" — but most of the time I'm just trying to compensate for stuff like colour casts, and maybe trying to smooth out some rough edges. The results aren't accurate pictures of me — they're stylised.

So, what I thought I'd do is show an example of what I do to a picture, since people were asking me about them. I dunno, maybe it's the lecturer in me trying to express herself...

OK, if we start off with one of the pictures that Pauline took of me — I made the fatal mistake when I was with her of cocking up the settings on my camera, so a lot of them came out with a red cast:

OK, so what's wrong with this photo?

• It's a bit too yellowy/red
• I have red-eye
• My face is too shiny
• My nose is totally dominating my face and looking a bit gnarly
• The flash has made the area around my eyes look lumpy

I could just play around using the Variations... command (Image > Adjustments > Variations...) and add green and blue to the midtones to try and cure the colour balance, but that wouldn't be half as much fun

First of all, it's always a good idea to work on a duplicate of an image (Image > Duplicate...)- even though Photoshop has the wonderful History palette, it's always sensible not to work on an original.

Next, open up the Channels palette (Window > Channels) and use the little drop-down menu at the top right to split the image into it's three channels:

This gives us three images — one each for Red, Blue and Green:

?? ??

Interesting sidepoint: RGB channels work in a way that you wouldn't expect. You can see in the above images that there is almost no detail at all in my face in the Red channel (the first one) whereas my lips are really dark in the Green one. Also, the Blue image is always the one where you get the most JPEG noise. For that reason, I hardly ever use the Blue channel.

OK, so now the fun starts. Using the Move tool (keyboard shortcut: 'v') drag the red image on top of the Green one and line them up. Then, in the Layers Palette (Window > Layers) set the composite mode (at the top left) to "Hard Light":

...Which gives us this:

Now, that in itself is pretty cool — but I want the lighting to be more soft, so I apply a Gaussian Blur of about 5 pixels to Layer 1 (Filters > Blur > Gaussian Blur...) and I drop the Opacity of the layer down to 75% using the Layers Palette

All very lovely, but now I've lost definition, so I need to build up some more layers. First of all, I add a Levels layer (Layer > New Adjustment Layer > Levels...) and brighten things up a little:

...and I duplicate the background layer, drag it above Layer 1 and set the composite mode to "Linear Burn" and the opacity to 20%. Basically, this uses the dark areas from the Green channel to bring a little definition back into my face.

It's getting there, but there still isn't enough contrast in my face, so I drag the Red channel onto the image again, making sure that this new layer is at the top of the Layers Palette, to use the mouth and eyes to really bring some detail into the face. (Composite mode "Linear Burn", Opacity 41%)

Perfect All pretty.

One thing to bear in mind is that this isn't an exact science. Every time I do this it takes a different combination of layers, opacities and composite modes to achieve a result I'm happy with. The trick I feel is to develop an eye for what different channels and layers will achieve, and then to play like hell until you come up with a combination that works.

Well, this is all well and good, but it would be nice, would it not, to bring a bit of colour back into this? First off, I'm going to duplicate this new black & white photo, merging the layers as I do so (I could of course just flatten the image (Layer > Flatten Image) but that would mean that I'd not be able go back and play with the layers at a later date).

So, duplicate the image and click on the "Duplicate Merged Layers Only" button

Then drag this new image over onto the original colour image (see why I worked with a duplicate now?) and set the composite mode to "Luminosity":

Which gives me this:

...which I believe is perfect, apart from the fact that I seem to have really bad red-eye in this shot.

Red-eye is a problem with a lot of photographs — it happens because the flash of a camera goes off when your pupils are wide because they are adapting to the dark, and because they don't have enough time to close to adapt to this new bright light, the light gets reflected off the back of your eye, and since your retina is red, you get red-eye There are 101 ways to get rid of it — lots of cameras have a pre-flash that goes off before the main flash, giving your eyes time to react — but if a photo has red-eye, the way I get rid of it is to desaturate the colour of the eyes.

(OK, so this works for me because I have dark eyes — if my eyes were green or grey or something, I'd have to find another way...)

I use the Sponge tool with a brush size about the same as the eye to gradually remove the colour from the offending eyes:

It's a bit of a trial-and-error thing — if I desaturate it too much my eyes look dead. Fortunately, Photoshop has the wonderful world of multiple undos...

Anyway, the final image is this:

...which I think you'll agree is quite cute

Does this seem like hard work? Too much hassle? Well, maybe — but it means that with a Layer Palette like this:

I can turn this:

..into this:

Next week: Siobhan's Photoshop Tutorial #2: Using the Stamp Tool to get rid of underarm hair...

...

You're not going to believe this, but it's January the 2nd, and I've just seen an ASDA advert on television for Easter Eggs...