Saturday 7 June 2008

Digital Macro Photography

In my last post I wrote about the use of computer image editing software and how it can be used to enhance digital macro photography. The post was written with the aim of assisting in the choice of which image software to buy for post processing digital images.

This post is going to be about the software required to process RAW data files. Most cameras that are capable of high quality macro photography will be able to produce RAW data files. This means that the camera records the data exactly as it appears on the camera sensor. When the camera records JPEG files it uses file compression to make the files smaller. The camera will also make changes to the original date by applying a set of parameters to it automatically. All this is done instantly as the image is captured and written to the memory card. Some photographer are happy with the quality of the JPEG images.

There are some real advantages to working with the cameras RAW file format. The RAW data on your memory card will have additional information that has been recorded and attached when the image was captured. The image remains editable without loss of data from the original image and the original data can be changed and converted to a JPEG (lossy conversion format) or TIFF (a loss less conversion format) as many times as you like. This means that you can change the white balance after the photograph has been taken without any degradation of the image. In fact the change will be exactly the same as if captured within the camera itself. As the photographer you have ultimate control over the amount of sharpening applied to the photograph. Changes can be made to the exposure and contrast levels ensuring that every photograph you take is has perfect exposure. The advantage of being able to convert a RAW file multiple times makes it possible to combine aspects of the same image with different exposures. Making it possible to solve problems of overexposure and underexposure by using a combination of RAW file conversion software and image editing software. Converting the RAW files to JPEG or TIFF file formats makes them readable by your image editing software such as Adobe Photoshop or Coral Paint Shop Pro. With this type of image manipulation it is possible to rescue digital images that would have gone in the bin if taken as JPEGS. I just want to reiterate this point about converting RAW files multiple times using different settings. This is a powerful tool for salvaging under and over exposed digital images. It is obviously best to get the image right with the camera as this saves post processing time. One of the biggest challenges for landscape photographers is dealing with an extremely bright sky. The bright sky will often confuse the camera's metering system into underexposing the landscape. If these digital images are captured in JPEG format there is only a limited amount of post processing that can be performed to rescue the photographs. A similar situation exists in macro photography with dark backgrounds. The use of RAW data files can be of real benefit in these situations. Knowing how to get the most from RAW data files will give you a real advantage as a photographer. All you need is a keen eye and the ability to know when to stop making adjustments and save the file.

RAW conversion software is available from several different software developers. Like image editing software the various free conversion software is generally fairly average and usually not worth the time and effort of downloading and installing it. Adobe Photoshop CS2 (and onwards) has a built-in RAW data file converter(Adobe Camera RAW) and is a good example of why you should avoid free conversion software applications (although not strictly free it is not very good – unlike Adobe Photoshop itself which is absolutely excellent!). The main problem with RAW file conversion appears to stem from the fact that all the major camera manufacturers are pulling in different directions. This means that a really good RAW conversion program for one camera may be poor with another brand of camera. There could even be a big difference between the cameras of the same brand or even between revisions of some camera models. This makes recommending a particular RAW conversion package a difficult task. Instead I will try to give as much information as possible about the most popular conversion software currently available.

It really is remarkable that so many photographers are reluctant to post process their digital images. In such a competitive field as macro photography this can prove to be a huge advantage. If you are new to digital macro photography I suggest that you begin acquiring your set-up with RAW data files in mind. This means ensuring that you have adequate file storage and processing of large file sizes.

Lossy File Compression
The term “lossy” is applied to file compression when data is lost during the saving process. When the file is saved data compression takes place making the file smaller as a consequence. An example of a lossy file format is a JPEG (Joint Photographic Experts Group). This file format was designed to be compressed to make smaller files that could be transferred more easily. JPEG and similar lossy file formats are used for websites images because they retain enough quality and are quick and easy to upload. The main advantages being that they take less space on the server and ensure that pages load quickly in internet browsers. This was an important development in the dark days of 56k modem speeds using dial-up connections. Even with the advent of broadband internet connections web surfers are not prepared to wait for pages to load. When building websites it is worth remembering that there are still people using slow connection speeds.

The data lost during compression process will gradually cause degradation of the digital image. Each subsequent time the .JPG image is saved further data will be lost and the file size will continue to decrease along with the quality. Although this is not specific to macro photography it is useful to know the difference between “lossy” file formats and “loss less” file compression. If you are working with lossy files it is important to make sure that you do not save your work more times than is necessary. In fact I would recommend working in a loss less format until the work is completed. Save the work in a loss less format and then save a copy in the lossy file format that you require.

Loss-Less File Compression
The difference between lossy and loss-less file compression is fairly obvious. The loss-less compressed data allows the original data to be accessed. Loss-less compression often results in larger file sizes although it is possible to compress files further using archival algorithms to create ZIP and RAR archives. Loss-less compression is also used for graphic files such as GIF (Graphics Interchange Format) and PNG (Portable Network Graphics) files. These are often used on websites for logos, avatars and graphics. Some files can fall into both categories and be lossy and loss-less. A good example of this would be a TIFF (Tagged Image File Format). Using a loss-less compression format for your digital images throughout your photographic workflow makes it possible to retain fine details captured within your photography. This can be a very significant difference in the world of macro photography where fine detail is of utmost importance.

RAW Conversion Software
I recently downloaded as many trial and demo RAW processing programs as I could find and have diligently tested some of them. I am not going to write a comparative review of them all but will instead point out some of the good and bad points of each software program. To test them I would take a macro photograph (of a house fly) and adjust the exposure and white balance before sharpening the image and converting to JPEG and TIFF file formats.

DxO Optics Pro
This is a very comprehensive piece of software with an impressive and professional slate grey user interface. It does not just look good but has an array of detailed and powerful filters and tools. I have read on internet forums that the program is not intuitive to use but I had no problems setting up a project, making a few small exposure adjustments and converting RAW files to JPEG and TIFF formats. If you were to find the program confusing to use you may find it comforting to know that it comes with an 58 page user manual! I was very impressed with the speed of the file browser and the general smooth running of the software. To fully discover the potential of this software would take a long time. The program runs downloadable modules for the camera and lenses that you are using. The modules can be quite large and I was unable to find one for one of my lenses. This is the only concern that I have about using DxO Optics Pro as my main RAW conversion software.

Bibble 4.9 Pro RAW
Bibble is a smaller and less comprehensive RAW file editing software program. It has an adequate user friendly interface and is intuitive. Bibble Labs have included some interesting, useful and innovative features. I like the inclusion of Noise Ninja for the removal of digital image noise. This often occurs as a result of using a high ISO value in low light conditions. Bibble Pro RAW is not a very comprehensive software package in itself but has been developed to be customised by the addition of plug-ins. There were a couple of features that I really liked about Bibble Pro RAW, specifically the “fill light” filter is very good. I noticed that the software allows image adjustments to JPEG files. This is not always possible in RAW conversion software. Lens correction and highlight recovery are both notable features of this software. Although Bibble did everything that I had asked of it, overall I felt disappointed by the programs performance. I found Bibble to be a little bit too slow with a distinctive time lag when making image adjustments. Overall it is still a very good RAW converter and worthy of consideration if you are looking for a RAW conversion program that is less expensive than the brand leaders.

Phase One - Capture One Pro
The best raw conversion software that I have used (by a country mile) is Capture One Pro developed by Phase One. In recent weeks I have downloaded as many trial copies of RAW conversion software that I could find on the internet. Out of all the programs that I have used so far Capture One Pro came out on top. I wouldn't go as far as saying that it was perfect because it isn't by any means, but it does everything well enough to meet my exacting standards. I find that I can utilise the workflow side of the program because it suits my own personal way of working. The output option allows multiple file types including JPEG and TIFF which makes life much easier. Capture One Pro is available for both windows and apple mac computers. Phase One state on their own website that “Capture One is recommended and used by professional photographers around the world”. I have little doubt that is the case but it is also a great program for amateur and semi-professionals to use as well. This is because the software has a more intuitive interface than some of the other programs on the market. If you are a perfectionist looking for pixel perfect digital images and a quick and painless photographic workflow solution, this is the software you need. Like all top software developers and manufacturers you can get a trial (or demo) copy. I fully recommend that you try before you buy just to make sure the software is agreeable with your computer system.

I hope that you found the information in this article useful. There are still several RAW conversion programs that I have not got round to testing. Hopefully I will find time to review some more programs in a subsequent post. Lasersoft's Silverfast DcPro Studio and Silkypix Development Studio 3 both have a good reputation for RAW conversion but I have not got round to installing and testing them yet.

Marvin Africa

No comments: