One of the greatest strengths of Lightroom is that adjustments that have been made to an image, the rest of the photos of the same series can be transferred, so you do not have to perform the same work over and over again. This saves an enormous amount of time. Of course, this works best if you have exactly the same camera settings used for these images to record each image.
Lightroom can also be used for tethered shooting with popular DSLRs. You can connect to your computer and thus see your photos on the screen while you record so during a shoot your camera. This gives you the ability to see fine details. This function is mostly limited to Canon and Nikon cameras; very new cameras are not immediately but only supported by Lightroom months after launch.
Lightroom also offers a powerful range of options for organizing and filtering your photos. You can provide them with labels, markings, colors and ratings and view your photos on a map if they contain GPS data. This is especially useful if you are a professional photographer with tons of photos.
It is with Lightroom also possible to perform color correction in video. One can use for this some, but not all adjustments, which can be used in photos. The procedure is a little counterintuitive, but it produces excellent results. This requires that you capture a still image, then carry out the processing and finally copy the settings / adjustments of the processed image on the video clip. This function may be overlooked when you are done it does not explicitly attention.
You can also directly designing in Lightroom photo books that you can then save as PDF or send to a printing company called Blurb. Blurb is a US company, but they print now also in the Netherlands, so that orders do not have to be sent overseas. All those who are often disappointed by the discrepancy between the appearance of the images on the monitor and the printout can be happy that you can also download a color profile for the Lightroom softproof feature on the Blurb website now. This can simulate how the picture shall look if Blurb prints them. This allows you a finer tuning of colors, so that they are adapted to the gamut of the printer Blurb. Lightroom also allows you to create color profiles for soft proofing your own printer.
*** Why upgrade Lightroom 4 ***
A somewhat unfortunate reason to upgrade is that Adobe will offer no further updates for older versions of Lightroom. That new raw data formats are no longer supported and must be transferred using the free Adobe DGN converter in the DNG format. If you want to use Lightroom's tethered shooting with latest cameras, you have no other choice but to use the current version of Lightroom. And even then you may have to wait a few months until Lightroom supports the new camera.
The changes from version 4 to version 5 include mainly small improvements of existing features, but there are a few changes that I think are worth mentioning:
1. Changes of tools for repairing
In version 4, the tool for the repair has a correction of circular areas allows that it was good to remove dust or other small items. For tasks such as the removal of long, hair standing on end, the tool was less suitable. In version 5, the tool for the repair works now fortunately for the correction of areas in all forms, ie one these problems must not now additionally fix with Photoshop or other image editing software. The tool works on the whole, as the tool for content-aware patch in Photoshop CS6.
2. The new radial filter tool
The radial filter tool allows you to make local adjustments to a circular or elliptical area of your image. Note here is that you get the same result if you use an Adjustment Brush that this would take longer.
3. The new Upright Tool
The Upright tool enables correction of the perspective of a photograph so that lines are parallel (find something that architecture photographers apparently quite important, but hardly is of wider interest).
4. Smart Preview
You can now edit preview versions of photos, even if the original picture is not accessible (if it is stored, for example on an external hard drive, but this is not currently connected to the PC). This is useful for people with a large catalog you want to edit their pictures on a laptop, without the risk and inconvenience, the external hard drive everywhere to accept.
The installation took about 10 minutes. Updating my Lightroom 4-catalog with about 50,000 photos on the Lightroom 5 format took about 1 hour to complete.
*** SUMMARY ***
I use Lightroom very often, and it's really always a pleasure to use the program because it is very well designed, very flexible and very powerful.
I can both for professional photographers and advanced amateurs for Lightroom recommend unreservedly.
If you have version 4, you already have almost all the benefits of version 5; I therefore believe that an update is really only worth it if the new features are particularly relevant to your needs.