Modern Photography/Online publishing
Differences to print mediaEdit
Typically, online images are smaller and therefore less detail-oriented than printed images. Their purpose is often to illustrate text, draw attention or identify a subject in a general manner, rather than to provide a detailed image for long term visual exploration by the audience, as in a traditional large format gallery print.
Things to keep in mind when shooting for online publishing are therefore the desired output size, which will usually be small, and the purpose of the image(s) within the overall communication.
For example, if you were shooting a subject for Wikipedia, you would want a very clear shot of the subject, unobstructed if possible, to suit the documentary nature of the medium. Because Wikipedia articles are rarely dominated by images, you would want to fill the whole frame with the subject. If you are able to stage the subject and choose a time and/or manipulate lighting conditions, such concerns would also affect your choices.
By contrast, if you were shooting for a highly visual site, such as a portfolio, nature destination or photography-focused website, then you would very likely have different concerns.
In all cases, however, you are less likely to be publishing in very high resolution, and very unlikely to be presenting images alone, with no or minimal context, where the image itself is the subject, as in the traditional gallery print format. In addition, in almost every case, publishing online means publishing in the RGB colorspace, which is the native colorspace of almost every modern camera. Therefore, you are quite unlikely to need to worry about colorspace conversions.
Finally, as with publishing in any medium, you frequently have a unique set of constraints given by the online environment, chiefly space (for example, how many megabytes your image may be at a maximum), maximum resolution (how many pixels wide by how many pixels high, at a maximum) and time (online publishing tends to be very immediate, with short deadlines).
Due to the limited resolution imposed by finite bandwidth and mobile devices, the output of most cameras needs to be downscaled (downsized, resized, reduced, squashed, etc.). While many applications will allow the resizing of images, few allow you to customize the result. When reducing the size of an image, it is generally necessary to apply a filter such as Photoshop's Unsharp Mask (USM) to regain the visibility of certain details in the newly reduced resolution. Typically, if a website, browser or online publishing platform resizes an image in an automated fashion, it will not do as good a job as a human eye with a sharpening tool such as a USM filter. In the browser case, it is even worse, because different audiences on different devices with different resize algorithms will get different results! Therefore, if at all possible, it is best to resize your images to the precise resolution of the publishing location in a manual fashion, ahead of time.
Dots per inch (DPI) is a print-world measure. While some people can usefully use the term with reference to digital media (for example typography professionals considering the utility of various highly technical font procedures against various classes of viewing device) the rest of us should simply avoid thinking in terms of or using the term dots per inch (DPI) whatsoever with reference to online publishing. (This goes for allied terms such as pixels per inch (PPI) as well.) This is because screens, though historically frequently asserted to have a 'standard' pixel density of 72 or 96 dots per inch, in fact vary stupendously, from as low as 72 to over 600, as well as varying from huge wall-screens (75") to pocket screens (mobile phones and electronic watches). Save yourself the hassle of all this variety, and think in pixels!
Online Publishing PlatformsEdit
This section outlines some of the major online publishing platforms that you may wish to explore with your images.
Blogs are private, traditionally timeline-oriented publishing platforms that allow you to combine multiple media types in to a coherent 'article'-like format. Blogs can be a great way of getting your content online and are particularly well suited to particular types of communications, such as travelogues and photojournalism. Most blogging platforms also allow the organization of articles by keywords, categories or automatically extracted 'tag clouds' (component phrases) in addition to time, which can make discovery and retrieval easier. Some of the biggest blog hosts, such as blogspot, are however banned in certain countries (such as China) due to their presumed or real historical association with anti-government expression, so be sure to ensure that your selected platform operates smoothly in your target area before launching in to an international photojournalism or travel photography project!
Instagram is the undisputed king of social media photography sharing. Unfortunately, however, the very vibrant community has been seriously impacted by commercial posting, and it can be hard to develop meaningful audience relationships. The instagram team is apparently (early 2016) working on this problem, but for the moment expect to put a lot of time in and get just a little time out. One of the best features of the platform is its subscription feature: if you meet a prospective client or friend, they can 'follow' you and will automatically be notified of all future images you post. This can be a great way to work on a word-of-mouth client base and to highlight ongoing work.
Image hosts are very simple websites that tend to be single-image centric, though some now allow associating multiple images together in some fashion. They tend to be useful when you don't have a website or web presence of any other type, a single high resolution image must be shared, and/or the frequency of sharing is highly sporadic.
There are various, generally web forum based photography communities online. These may range from being camera manufacturer specific, to style-specific, to geographically delimited, to completely open. Many communities have rules regarding what can and cannot be posted; be sure to check the rules before participating.
Wikimedia Commons is the media store underlying the Wikimedia projects, such as Wikipedia. These web properties collectively receive billions of pageviews per day, and can be an excellent platform to get your work seen. If you are a particularly good photographer, Wikimedia sometimes even has sponsorships available to assist defraying your expenses.