First, it would be better to choose the biggest resolution you can afford, and turn on the anti-aliasing. It can be found in the game advanced video options. It would look much better. Even if your computer can't follow, it does not really matter, since you are there to take pictures, not play seriously. Also, some graphic cars offer an override of the original game's resolution, which will look even better. For example, many sharp edges, such as the ones seen in trees or metal fences still look quite "ugly" without an override.
Do your best to provide screenshots where the related subject can clearly be identified. Don't crop too much, it is always better to clearly see the context surrounding the subject, but don't provide screenshots where the main subject is too far either. Try to be as artistic as possible, it cannot kill this wiki to provide good-looking screenshots, and be careful not to have too much ground/water in the screenshot, which is a mistake many people do, even in real life photography. It is always better to have more sky/ceiling than ground/water.
Also, while the GoldSrc games save screenshots in BMP, the Source games save them in JPG. The compression of the latter is too high and cannot be changed, so reduce the size of the image to lessen the JPG compression artifacts, or use Fraps to save them in another format, then convert them in JPG with a program that allows choosing JPG compression. So, avoid Paint at all costs, and prefer Photoshop or IrfanView.
If you want to provide screenshots for general settings where the player's presence is irrelevant, you can hide the HUD ("hud_draw 0" in GoldSrc and "cl_drawhud 0" in Source), the crosshair ("crosshair 0" in GoldSrc; "cl_drawhud 0" hides both in Source) and the weapons ("r_drawviewmodel 0" in GoldSrc and Source and "impulse 200" in Source only) with the console. Use also "noclip" to have a better freedom of movement, "god" to be safe from possible crossfire or a great drop when you disable "noclip", and also "notarget", so that almost every entity ignores you. That makes you practically invisible, you can take all the pictures you want without being bothered. See these examples of an empty screen: example 1, example 2.
Also, do not take screenshots from customized/tweaked canon games, like FakeFactory's Cinematic Mod or GameBanana offers. Prefer the original models and textures, the only canon render.
To be more faithful to the original games, prefer taking screenshots in Half-Life rather than Half-Life: Source, unless you want to showcase the differences between the two games.
For the same reason, HD models should be used only in Blue Shift and Decay screenshots.
If you want to upload game logos from the game files or anywhere else, it would be better if they were in PNG. Also, if a SVG version is available, it is much better.
All pictures should be uploaded to the Half-Life site by using this page, Special:Upload (You have to have an account and be logged in to upload an image.
Warning: do NOT upload images that do not have anything to do with this wiki, which is not an image repository; they will be deleted. However this does not apply to user images (to be used only on your userpage): however the information template is also mandatory for them.
However the above code offers no formating options and so all images should follow the Wiki image markup language. The wiki markup language will only work if no capital letters are used. Most images on Half-Life should follow this Wiki format:
[[File:Pick up that can2.jpg|thumb|right|Example image caption.]]
Please DO NOT upload anymore small thumbnails or pictures of Images that already exist on the Half-Life wiki! If you want to use this image, [[File:Station 7.jpg]] then link to that image! DO NOT upload a smaller version.
So here is [[File:Station 7.jpg]]:
If you want to show a small version then all you have to do enter the following code:[[File:Station 7.jpg|200px]]. The "|200px" code allows you to make the picture any size you want just by changing the number as shown here where the 200px makes the image 200px wide:
DO NOT upload a small version of an existing picture!
Options can be combined, and vertical bars ("|") are used to separate options from each other. The options can be put in any order. An unknown option is taken as the caption text, but this seems to appear only if thumb is specified. If there are two or more unknown options, the last one upstages the rest.
Here is the description of the options other than the caption text:
right
The image is right-aligned, and text floats to the left of the File: [[File:Pick up that can2.jpg|right|70px|]] (shown on the right).
left
The image is left aligned, and text floats to the right of the File: [[File:Pick up that can2.jpg|left|70px|]] (shown on the left).
center
The image is centered, and...
the text following the image starts below it: [[File:Pick up that can2.jpg|center|70px|]] (shown above).
none
The image is put at the left, and...
the text following does not float to the right (or to the left, obviously), and starts below it: [[File:Pick up that can2.jpg|none|70px|]] (shown above).
sizepx
This option renders a version of the image that's [size] pixels wide (e.g. [[File:D-Halo.jpg|right|50px|]] shown on the right). Height is computed to keep aspect ratio (i.e. the shape of the image)
What is between the last vertical bar and the closing brackets ("]]"), void or not, is taken as the last option, and works as usual. For instance, when the last option is right, the image is right-aligned, and text floats to the left: [[File:Pick up that can2.jpg|70px|right]] (shown on the right).
This text is displayed.In particular, if the last option is the void text (that is, if there is nothing between the last vertical bar and the closing brackets), the caption is not displayed: [[File:Pick up that can2.jpg|thumb|This text is not displayed.|70px|left|]] (shown on the left) and [[File:Pick up that can2.jpg|thumb|This text is displayed.|70px|right]] (shown on the right).
With this option, the embedded image is shown with its actual size enclosed by a frame, regardless of the "thumb" or "size" attribute, and the caption, if any, is visible in the frame. Without the options left, center, and none, the image is normally on the right: [[File:Pick up that can2.jpg|frame|thumbnail|50px|OPic]].
With none of the options other than sizepx and alternate (caption) text, an embedded image is rendered inline.
text text text text text text text text text text text text text
[[File:Pick up that can2.jpg|150px|The Palace of Westminster]]
text text text text text text text text text text texttext text
[[File:Vort Ep2.jpg|100px|This is a globe.]]
text text text text text text text text text texttext text text
gives
text text text text text text text text text text text text text text text text text texttext text text text text texttext text text text text texttext text text text text text text text text text text text text text text text texttext text text text text texttext text text text text text text text text text text text text text text texttext text text text text texttext text text text text texttext text text text text texttext text text text text texttext text text text text text
Use [[File:image name|alignment|type|size|<div style="text-align: center;border:none">Caption</div>]]
For example, [[File:Pick up that can2.jpg|right|thumb|100px|<div style="text-align: center;border:none">Pick up that can.</div>]] produces a caption in the center. However, this syntax is not recommended for long captions (for example, captions involving long, descriptive sentences running more than one line), for which the regular image syntax should be used. You can also specify the color of the border, like "border:solid grey".
If you want to make a link to the description page for an image, use a leading colon before "File:" in an intra-wiki link, like this: [[:File:Pick up that can2.jpg|STS-32 crew]] which yields: STS-32 crew
To make a gallery of Images you can use the following code:
<gallery widths=140 position=center captionalign=center hideaddbutton=true><!--- DO NOT ALTER THESE CODES --->
File:Pick up that can2.jpg
File:Pick up that can2.jpg|Captioned
File:Pick up that can2.jpg
File:Pick up that can2.jpg|[[Help:Editing|Links]] can be put in captions.
File:Pick up that can2.jpg
File:Pick up that can2.jpg|Full [[wikipedia:MediaWiki|MediaWiki]]<br />[[wikipedia:syntax|syntax]] may now be used…
</gallery>
Please add the proper category below the image you upload. Most common categories can be found here. If it does not exist, create it, but be really sure it does not exist!