Life Behind A Lens

Introduction
Once you’ve finished the image that you’re working on, you’ll want to save your image somehow. When you open the Save As dialogue, you’re met with a vast range of different formats and the choices can be somewhat daunting if you aren’t sure what they all are. Sop, this guide aims to address some of those issues and to provide you with suggestions as to the file formats that you are more likely to use as a photographic/digital artist, uploading art to Redbubble.

The List of Formats
When you open the Save As dialogue box, at the bottom there’s a small ‘expand’ square with the words Select File Type (By Extension) next to it. If you click on the little square, a list of some 36 file formats opens up in the window. Here it is;

• GIMP XCF image – The standard GIMP file format.
• Alias Pix image – An image file format that isn’t commonly used (as far as I can tell)
• AutoDesk FLIC Animation – A 2D & 3D Computer Aided Design File Format
• bzip archive – A compressed file format, like a windows zip file
• C source code – A basic programming language..
• C source code header – As above.
• Digital Imaging and Communications in Medicine image – A format used in Radiology
• Encapsulated PostScript Image – click here for more info
• Flexible Image Transport System – A file format mainly used to transmit scientific data
• GIF Image – A compressed file format, used a lot on webpages
• GIMP brush – Used for painting in GIMP
• GIMP brush (animated) – As above
• GIMP pattern – A small image used in GIMP to create effects
• gzip archive – An archive file format
• HTML table – HTML coded image format
• JPEG image – Possibly the most commonly used file format
• KISS CEL – Another pallete image file format (similar to a bitmap)
• Microsoft Windows icon – A small file, used on computer desktops etc
• MNG animation – Very similar to a PNG file, but can cater for animations
• PBM image – A ‘lowest common denominator monochrome file format’
• Photoshop image – A PSD file that can be opened in Adobe Photoshop
• PNG image – A lossless compression file format (Good for Redbubble t-shirts!)
• PNM image – A portable bitmap image type
• PostScript document – A basis of PDF files
• PPM image – A portable bitmap image type
• RAW image data – Minimally compressed image format (most digital SLR’s will shoot in this format)
• Silicon Graphics IRIS image – A 3d Graphics system
• SUN Rasterfile image – The native bitmap format of the Sun UNIX platforms
• TarGA image – A Raster Graphics file format
• TIFF image – A reasonably common file format under the control of Adobe
• TIFF image – As above (This appears twice in my list.. Not sure why…)
• Windows BMP image – An image format used in MS Windows
• X BitMap image – A Bitmap image format that contains ‘C’ source code
• X PixMap image – Very similar to an X BitMap
• X window dump – The file format used when you take a screenshot on your computer
• ZSoft PCX image – An old DOS imaging standard

Arrrrrgggghhh! Which ones do I want??!
Panic not, although I’ve listed information about each of the file formats above, we are likely to need only a few of them under normal circumstances for use on Redbubble (or other art sites of a similar nature). Here they are;

• GIMP xcf image
• GIF image
• JPEG image
• PNG image

XCF Files
While you’re working, it’s always a good idea to save your image as an xcf file every 10 to 15 minutes or so (or when you make a major change). There’s nothing worse than spending an hour or two doing something and then having a power outage before you get around to saving it. I generally keep a copy of a finished image as an xcf file for a few weeks as well, just in case I decide that there’s something I want to change.

GIF Files
Gif files are fairly good for banners or other graphics containing text that you’d like to upload to Redbubble. The file size is reasonably small, and any text on your image doesn’t go all fuzzy when you shrink it. (PNG files can also be used for this and look just as good)

JPEG Files
A lot of people use the jpeg file format to upload photographs or other similar art to Redbubble. The file size is reasonable and there isn’t a great deal of information loss. When you are saving as a jpeg file, it’s always worth setting the quality of the image to 100%. I’ve never set it anything below that.

PNG Files
The png format is the only format that can be used to upload as a t-shirt design on Redbubble. It has a lossless compression (which means it looks awesome no matter how much you compress it) and it supports transparency (which is great for t-shirts so that you don’t get a square of colour, as well as your design, on your t-shirts). Many people also upload artwork to RB in the PNG file format, so feel free to experiement and decide what works for you.

The compression settings on PNG files do make a massive difference to the file size. Once finished, I will normally save a png formatted image with a compression level of 1. Setting it to zero just makes the image size huge and it takes me forever to upload it. Setting it to 9 will make the file size really small, but although it has ‘lossless’ compression, it must affect it in some way.

Saving an image
Once you have finished you image (and have been saving it every 10-15 like a good artist in the xcf format), you’ll want to save it in a format that you can use on RB.

To do this, goto File->Save As and a dialogue box will open. You can then select your file type (jpeg or png, for the most part), name your file, and save away.

Saving as either of the above file types will give you an options dialogue (especially if you’ve been using layers). You’ll need to flatten or export the image and then set the compression level. The reason for the export/flattening is that neither jpeg or png files understand what layers are, or how to use them.

So, there you go.. You’re now an expert on the file formats in GIMP. Have fun with your art & design! :))

I’m presently working from my notebook with my Vodafone mobile internet connection..

The reason for this being that my BT broadband is offline due to technical problems at a substation a few miles away.

When the connection dropped out, I gave BT a ring from my mobile to see if it was my connection here or a more general fault, such as above.

Naturally, I was met with a recorded message. This message went as follows…

‘Welcome to BT Home Broadband. We are presently experiencing some technical problems at our Chelmsford Substation in the area code of 01245. This is causing failings of broadband internet connections in the local area. For more information, please visit our website at www.bt.com/help/broadband…’

So in order to find out what the fault is with my internet connection, I need to use my internet connection...

Thank you BT!

This is the second part to my other layers guide and is designed to give an overview of manipulating layers in GIMP.

In order to get the most from this guide, it’s worthwhile downloading this layers.xcf image from my website as it the image I’ve used to show the effects.
Once you have downloaded and opened the image in GIMP, you should see something like this:

The image contains 5, easy to spot, layers. Background (which is black) and then 4 layers with coloured rectangles in. Red, Blue, Yellow & Green. I’ve named each of these layers to their corresponding colour, to keep it easy to see what’s happening.

Now it’s time to play with them! :))

I’ve split this guide down into individual tasks and, while you can follow it through from start to finish, it’s not neccessary. If there’s a part that you already know, just skip it and move on. :))

1. Moving Layers Up & Down
In this part, I’ve decided that I want to reverse the order of the coloured layers so that instead of them being ordered Green->Yellow->Blue->Red they end up being Red->Blue->Yellow->Green

• Click on the Red Layer so that it’s highlighted.
• At the bottom of the layers window, click on the up arrow (as mentioned in Part 1 of this guide) until it is placed on top of all the other layers.
• The Red Layer Should now be hiding parts of all the other layers.
• Now, click on and select the Blue Layer.
• Click the up arrow twice, so that it ends up between the Red Layer & Green Layer.
• Select the Yellow Layer and click on the up arrow once, so that it finishes between the Blue Layer & the Green Layer
• If all has gone to plan, your image should look like this;

Now, we need to put them back again to their original order. (From top to bottom) Green->Yellow->Blue->Red.

2. Playing With Opacity & Modes
In this part, we’re going to look at what happens when we play with the opacity settings of a layer. So, first of all, bring the Background Layer to the top, as we did in section 1 of this guide, so that our image looks like this:

• Go to the Opacity Slider towards the top of the Layers Window and move it from 100%, down until you get to around 50%. Anywhere between 45 and 55% will do for this.
• What we’ve done is to make our Background Layer half see through. In this case, the effect has been to darken the colours of the four rectangles in our image.

Note: Incidentally, we have just carried out the most basic method of applying a texture to an image. Which is to place a layer over the top of our image and then adjust the opacity to taste. Well done you! :))

• Now onto the modes. If you keep your Background Layer selected and open up the modes dialogue box you’ll see that there are a range of different things that you can do. Because we are using solid colours, the effects of some will look very similar but we can play with them and see what happens.
• Spend a little while now, changing the modes of the Background Layer and seeing what the different settings do to the colours underneath. If you fancy being clever, try adjusting the opacity and modes of the Green, Yellow, Blue & Red Layers as well.
• When you’re done playing, return all the modes to normal, set all of the opacity levels to 100% and place the Background Layer back to the bottom of the pile of layers.

Note: You may have noticed that when you moved the Background Layer to the top of the pile and reduced the opacity, that a series of grey squares appeared anywhere that there wasn’t a coloured rectangle. This area would appear transparent in a finished PNG (useful for t-shirt designs) or GIF image. It will appear as white in a JPG file.

3. Duplicating & Deleting a layer
After playing with our layer modes and opacity we should now have returned our image to it’s original state, as it was downloaded. If you’ve experimented so much that you can’t do that, simply close and re-open the *layers.xcf (provided you haven’t saved it, of course lol)

• Now we’re going to duplicate the Background Layer, move it to the top of the pile of layers, play with it’s opacity and then delete it again.
• Select the Background Layer
• Go to the 4th icon in at the bottom of the layers window and click that. (That’s the Duplicate Layer icon)
• You should now have another layer, called Background Copy. Like this;

• Select the Background Copy Layer and move it to the top of the image as in section 1.
• Adjust the Opacity of the Background Copy Layer to about 50% again and you should now have an image, similar to the one in Section 2, but with the whole image in solid colour. Like this;

• Now, we’ve decided that we don’t want that Background Copy Layer after all. Select it and then click on the right hand icon at the bottom of the layers window.
• Our Background Copy Layer is now gone.

Hope that some of you find this information useful. The next step with what you’ve read here is to experiment with some of your own images that have more variation than just 4 solid colours to it. Something that might be worth looking at as a next step from here is using layers to produce a Selective Colour effect to an image. A tutorial for which can be found on this blog. That tutorial also includes using a layer mask to generate an effect.

Have fun with your layers!

I had a request, the other day, for an easy-to-follow tutorial on using layers in GIMP as most tutorials on the web tend to be specific to a purpose and can be a little confusing.

So, the aim of this Guide is to give a basic overview of layers in a non-specific way. This part covers what layers actually do and the window that’s used to control them. Part two contains a basic overview of creating and manipulating layered images.

Theory Of Layers
Before we can work with layers effectively in GIMP (Or Photoshop, for that matter) we need to understand what they are.

I tend to think of Layers as transparent acetate sheets, like those used on the old style overhead projectors, that can be placed over the top of each other to provide different effects. By ‘colouring in’ different parts of an acetate sheet, we can hide, change or obscure the layer(s) underneath it.

Indeed, I had teachers when I was at school (especially in science) who would use the principle to label, say, the parts of a heart after us students had all tried to name the ventricles, aortas and other bits and pieces. The principle in GIMP is exactly the same.

However, because we are using digital ‘sheets’, we can do much more with them and produce many more varied effects. Things like selective colouring (where we cut out sections of our top ‘sheet’ to make parts of the ‘sheet’ underneath visible) to applying textures (where our top ‘sheet’ is half see though so that we can partially see the ‘sheet’ underneath).

Of course, there are times when we might use multiple sheets (selective colour with a texture applied and some motion blur, perhaps) and this can, in the end, become quite complex, especially if layers are a somewhat unfamiliar concept.

The Layer Window
Here is our Layers window. Practically everything that we might want to do to a layer, as a whole, can be done in here and it’s the key to working with them.

Going from the top we have:
Mode – This makes it possible to change an entire layer to do a great variety of things. One of the common ones that you may come across is the Overlay mode. This is used with textures quite a lot.
Opacity – Makes your layer more see through, or less. (0% is completely transparent, 100% is completely solid)
Lock – Locks the layer so that it can’t be moved or changed.

Under those settings is the layers window itself, that holds all of the layers in your image.

The eye symbol makes the layer visible or invisible, essentially allowing you to turn the layer ‘on or off’. Then you have a small ‘preview’ of that layer and then there is the layer label. The one visible above is called ‘background’. The GIMP default for the first or ‘base’ layer. It’s a good idea to rename layers as you work, so that you know what each of them does.

At the bottom of that window, there are some small icons. From left to right:
New Layer – Creates a layer at the top of your pile
Move Layer Up – Uhuh, no prizes for that one
Move Layer Down – Or that one
Duplicate Layer – Will make an exact copy of the selected layer and put it on top of the pile. I use this in Selective Colouring. I duplicate the original image layer and then convert it to B&W, before cutting holes in it with a paintbrush.
Anchor Layer – If you copy and image and paste it into an image you’re working on (such as applying a texture on top of an image), it will initially appear as a floating layer. By clicking the anchor, it will ‘stick’ it to the layer directly underneath it
Delete Layer – Don’t like it? Bin it! :-)) This will delete the selected layer.

Note: All of these tasks (and many more) can be carried out by right clicking on a layer

Part 2 of this guide will include information on basic manipulation of layers within GIMP