Is this a labor of love or obsession? :lol: You decide! I am aware, both from this forum and the UK one that there are plenty of Pentax shooters who would like to get more out of the software that comes in the box.
I've enjoyed using the program, and now I've really enjoyed writing about how I edit RAW in PDCU4. Its kind of therapeutic, and helps to cement your working principals in your mind I find. I recommend it as a therapy to all! So here is my Mini Guide for all to peruse, and of course comment, dabate, correct and add to. I will gladly update it to take account of any new info offered.
Of course, I should say that this is entirely my own personal experience of the software, and only my own personal opinions. Enjoy.
Pentax Camera Utility (PDCU) , A Mini Guide; some In-Practice thoughts & a workflow solution
Prepared by Pentax shooter N McGregor, November 2012
This mini guide is intended to serve a wide range of purposes. It should be useful to those new to Pentax DSLRs and the RAW format in general, as well as those opening their new camera box and finding the software disc, who may not have any other RAW software ready to go. These people could read Part 1 for some helpful information which should set them up ready to start RAW processing.
Other more experienced photographers may just want some quick tips on getting the most out of the Pentax software, and need to know how to efficiently apply some key image adjustments, in which case they could refer to Part 2, covering workflow and functionality, and take some useful ideas from that. I am not claiming to be able to offer full guidance on every aspect of the program – either because I myself don’t have particular experience at that type of adjustment or because I choose to do something in a different program, in which case I am sure that some background reading and experimentation with the software will prove valuable.
As this is meant to encourage a practical approach, if you are trying out any of the editing techniques for the first time it is a great idea to have a shot open and work on it as you go and see the effect I am describing right in front of you. In any case, I hope this provides a good read and useful aid to anyone interested in Pentax cameras and the software supplied with them.
Contents:
PART 1 - Introduction to Pentax Camera Utility (PDCU) & RAW – Software Purpose & Scope – The RAW Advantage – Output (Development) from RAW to an Image File – Origins & Upgrades – Computer Resources – Camera Setup
Part 2 – Workflow & Functionality – Workspace Layout & Setup – Image Management – Image Information & Navigation Control – Key Processing Steps; building an efficient processing approach to image adjustments - Sharpness and Noise Reduction control during RAW processing - A Suggested PDCU Workflow; Exposure – Blown Highlights – Clipped Shadows – Contrast, Global Saturation, Sharpness – White Balance – Colour Fine Tune - Lens Distortion & Abberation Corrections - Conclusions
PART 1 - Introduction to Pentax Camera Utility (PDCU) & RAW
Software Purpose & Scope
The PCU software is currently included on disc sold with Pentax digital cameras that record images in RAW format. The version at this time of writing is 4.35. It can open the 'PEF' (Pentax proprietary) and 'DNG' (Adobe standardised) RAW file types, in addition to JPEGs shot on the cameras.
Its primary purpose is to act as the 'Raw Converter' or ‘developer’ for these PEF or DNG files - to convert them from a ‘raw’ camera sensor data format into a viewable and editable image format for a wide range of uses. Secondly it provides key global image adjustments such as exposure, white balance, noise reduction etc. All of these controls offer the possibility to alter these shooting settings after the event with no reduction in quality, just as if they had been set on the camera before shooting. This is considered a 'non-destructive' adjustment, a key advantage of any RAW converter software and a primary reason to choose to shoot in RAW.
In addition PCU offers software controls for those image adjustment and custom image parameters that can be set on the camera prior to shooting the images. This includes shadow & highlight adjustments, lens distortion & aberration corrections, custom presets such as Landscape, Natural, Portrait etc, and individual custom fine tuning including saturation, hue, sharpness and some fine contrast control for shadows & highlights.
The RAW Advantage
When considering workflow, and in which order to apply changes, the main thing to bear in mind is that the RAW file image data is not directly being changed (edited) by what you alter in the program, therefore there is no degradation or image quality reduction occurring just because you might be making many different setting changes and then going back and forward over it all again. In fact, all the settings you make are simply recorded as metadata and added to the file at the point that you save the shot into an image format (JPEG or TIFF). The RAW file will remain as it was when copied from the camera, to be archived for safekeeping, or used again if you want to try again and make further changes.
It is worth noting that we cannot actually ‘see’ the RAW image directly - the file is only a computer bits & bytes record of what data was recorded by the camera. It includes a small embedded JPEG file created by the camera’s CPU which is displayed (if set for image preview) on the LCD screen. Some image management programs will also display this small JPEG as a thumbnail to allow the RAW images to be seen within the program, but they will be low resolution and cannot be enlarged for detailed review. It is the conversion or ‘development’ process applied by PDCU that creates a full size / full quality image file to be generated and saved.
Our Pentax DSLRs helpfully record shots in the DNG format as an option. Before I got my Pentax camera I used to shoot RAW on another camera brand, but I always chose to convert the files into DNGs for archive purposes. My thinking is that the DNG will prove a better bet in the longer term as it is more likely to remain supported by more RAW software in the future. The DNG records the same information as the PEF and I am not aware of any particular disadvantage to using it instead of the PEF. So I save myself an extra step in workflow as I no longer have to carry out the convert to DNG process – thank you Pentax!
Output (‘development’) from RAW to an Image file
Once you have finished making changes to a shot in PDCU, you have the option to 'Save As' and choose either JPEG or TIFF, and give a new filename and location for your newly created image file. What to choose ?
The JPEG option would give the same result as if you had set the highest quality JPEG for capture on the camera. This is good if you are satisfied that the image is fully ready for your intended purpose and you don't need to do any further work in another editing program.
A JPEG is an 8 bit image file, and you started with a 14 or 16 bit RAW from the camera, so there is some compression and reduction of redundant image data in the Save to JPEG process, but the file you produce will still have the same dimensions as was shot on the camera and will have plenty of resolution to make all the usual sized prints, so this is a very versatile option.
The TIFF option, which saves a 16bit uncompressed image file, is ideal for continuing editing work in another program. When opening this file in an image editor (Photoshop for example) you can work on it further and then choose to save it again as a 16bit TIFF with no compression. It is important to note though, that this non-compressed saving of a TIFF is not the same as the 'non-destructive' changes that were being applied to the RAW in PDCU. In standard image editing programs (such as Photoshop) whenever a file is saved the edits are written into the image data permanently. You can change them again, but this would involve further image editing and the risk of quality loss, so you need to be more cautious when working on an image file in this type of program than when using a RAW in PCU.
It is worth noting that there are now some combined RAW image converter & photo editing programs that continue a non-destructive sequence of changes to an image right through the whole process, even with edits that are not strictly to inherent RAW data parameters. The two main examples of this type of program are Apple Aperture & Adobe Lightroom. Both achieve this by holding in memory a series of image ‘states’ or ‘versions’ that can be saved out at any point, with a metadata record of each version adjustment settings linked to the RAW file and saved in the program database. But these are the exceptions – PDCU is a traditional RAW converter in the way that it records adjustments to a file and outputs to a new image format.
Origins & Upgrades
PDCU is created by the makers of a Professional grade RAW software program from Japan called Silkypix Developer Studio. Some of its adjustment controls are similar to those seen in the Silkypix program, and therefore you may find that in future you are interested in getting even more control over your RAW images, and so the Silkypix software might offer you a natural upgrade path. You would lose the Pentax specific in-camera settings I mentioned above which have been incorporated into PDCU especially for Pentax users.
In the meantime the PDCU software itself does evolve, and Pentax release updates available as free downloads to existing customers, mainly to incorporate new camera settings or features, but if we’re lucky we might over time get access to more advanced features taken from the full Silkypix program. Check for updates on the Pentax website. To download and install one you will need the disc supplied with your camera in the drive on your computer prior to installing the update.
Computer Resources
PCU4 does seem to me to use rather a lot of computer processing power. My average spec laptop (dual core, 3Gb ram) runs with high CPU cycles and the fan whirrs away fast when running the programme. Either this is due to inefficient use of computer resources or the program is carrying out some hefty image processing computations. I'll let you decide yourselves which of these you prefer to think of it as! But the result is that it is a rather slow program in operation. It is slow to load, with different parts appearing one after the other, and a bit slow to respond to inputs. The preview of the image can also be slow to update after making a change - on my system I’m talking of only a second or two, but it’s not at all instant.
If you set it to access a folder containing many image files it can make a bit of a job out of this as well - in my case I have 900 or so DNGs in my main ‘for edit’ folder and this can take the program between 30 seconds and a minute to sort out and display thumbnails initially - a bit of an annoyance when you just want to crack on, but not intolerable. However once it’s done this it then retains the thumbnails OK and you can scroll rapidly through your images to pick the one to work on. My personal message is ‘bear with it’ - yes, there are faster RAW converters available, but it’s free & the output you can achieve with PCU4 is high quality so it is worth waiting a little for it.
Camera Setup
Now that you’re going to shoot RAW images, what do you need to have set on the camera before taking pictures? The easy way to do this on Pentax DSLRs is from the Control Panel (INFO button). Here you can move around the key camera settings and select your preferences.
Obviously firstly set RAW capture - either PEF or DNG. There is no quality setting option for RAW because the file always records the maximum amount of data from the sensor, so can be considered the highest quality automatically. You also have the option here to record RAW + JPEG, and this might be useful if you want to use a JPEG immediately from the camera, say for printing or uploading to the web, but would also like the option to improve the photo in the future.
The other key settings on the control panel are Shadow / Highlight adjustments & Lens Distortion / Chromatic Aberration Corrections. Having these active on the camera will mean that when the RAW file is opened in PDCU then these settings will already by applied – you can see the effects and make further changes if needed. This could save a bit of time on the computer especially if shooting a lot of similar images. However, bear in mind that this does increase the time it takes to display the shot on the rear LCD screen (or the last shot of a burst) – this is because the camera’s CPU has to process the adjustments before the embedded JPEG is displayed, and this delay of a few seconds could interrupt your shooting if you rely on quickly checking the preview on the LCD. Leaving the adjustments off will give you fairly instantaneous previews. As you can easily activate these adjustments in PDCU, my recommendation is to leave them off on the camera.
Finally, the Custom Image Parameters (accessed with the right hand button on the four-way controller) cannot be deactivated as such – you always have one preset selected at all times. This will affect the preview image displayed on the LCD, so it makes sense to choose a setting that has a helpful effect on the LCD. Personally I set ‘Bright’, which a provides a bright image (unsurprisingly) with average contrast and saturation. If you are using PDCU with only RAW capture then there’s not much point in making detailed Custom Image Parameter settings on the camera, as these can be more easily applied and experimented with on the computer.
Part 2 – Workflow & Functionality
Workspace Layout & Setup
The program is spilt into three ‘panels’, left, centre & right. You can click and grab the dividing lines between panels and move these, therefore changing the relative sizes of each panel within limits. It makes sense to make the left panel narrower than the right, as the right contains the main editing controls in tabs, so you want a good amount of room to move on the right panel. The centre panel will display the image preview so you want this as big as practical, leaving the left panel narrower as it only needs to show a histogram and a folder view of your computer system. The left and right panels are each again divided into top and bottom ‘sub-panels’, which you have to drag up and down over each other as you change tabs.
The program uses a modular concept - every key editing function (like Exposure / Tone or White balance) and image review resource (like a histogram, Image Preview, folder view) comes on its own individual tab. You can specifically choose which of these modular tabs to display for use or not, and this is set under the Window menu. As well here you choose here whether to show the left and right panels at all, and if the centre panel tabs are vertical or horizontal.
There are 3 different ‘views’ you can access, using the three buttons ‘Browser, Laboratory, Custom’ at top left. The idea is that you can configure what components of the program you want to see under each main view, so whatever panel and tab layouts you set after clicking one of these buttons will be retained for future use. In practice I find I only need one main layout design so I only use ’Custom’, but you have the option of the others if its helpful.
My personal preference is as follows - (after clicking the Custom button), under the ‘Window’ menu, choose ‘Display in whole pane’ - this gives the most space to your main preview image and your folder view for choosing images. Then I would add ticks to the following tab options - Image data, Highlight Adjustment, Colour Fine Tune. This adds these important adjustments to your collection of tabs on the right panel. I remove the tick by Favourite as it doesn’t have much purpose in my view.
Now that you can see all the useful tabs it is time to rearrange them more helpfully. Useful tip – right-clicking any tab on the name gives options for repositioning that tab, eg moving it to top right, bottom right, top left, bottom left. An intuitive arrangement is to set the following tabs to ‘top right’ – Exposure/Tone – Highlight Adjustment – Custom Image – White Balance. These four sets of controls will provide the initial key adjustments, having the most immediate impact on your image, and you will be able to click between them quickly with them all together here on the top right.
This leaves the following set to Bottom Right – Colour Fine Tune / Lens Aberration Corrections / Noise Reduction / Map / Image Data / Rotate /Shift
With your histogram open on the bottom left you are now ready to get working on your shots!
Image Management
One of the main things to consider when working with RAW files is that they are not a true ‘image’ file format (ie a ‘raster’ type file). There are many variations and camera-specific metadata items supported by each different one. Computer operating systems may not be able to display the image thumbnail by default, so generally you need specialised software both to develop and adjust the images, and also to view and manage your collection. Because of this most RAW converter software includes components or even specific modules to view, manage, catalogue and otherwise organise your RAW files. Some are more sophisticated than others and it would be fair to say that image organisation is not one of PDCU’s main strengths.
I myself use a standalone Image Management Program which can display and organise any RAW file, and I use this to launch images into other editing programs. So I cannot offer any huge insight into this aspect of PDCU. But there are some essential features that I will mention, and then I’ll list briefly a few useful features that might be helpful.
By default PDCU is set to monitor the contents of one folder on your computer, and it will display the contents of this folder in the centre panel on running. Because of the performance issues I talked about earlier, it is not a good idea to keep changing the folder that is monitored when using PDCU as this will keep taking a long time and get really annoying! So I suggest you get organised on your computer and just put all the RAW files you might want to work on into one folder – call it ‘Pentax for editing’ or ‘DNGs to Process’, something like that. Then set PDCU to monitor this folder – open the options dialogue by clicking the ‘cogwheel’ icon on the toolbar – open the ‘File Management’ tab – click the browse button under ‘Home Folder’ and choose your pre-determined folder. Under ‘Folder at Startup’ select ‘Home Folder’.
At the point of saving your work on a RAW file you will be choosing to ‘Save As’ a JPEG or TIFF, and you’ll also have to nominate a folder to put this output file into. It makes sense to use a different folder for these processed image files, eg ‘New Pentax TIFFs’, or ‘JPEGs 2012’ etc, so on the same ‘Image Management’ tab under ‘Default Destination’ click on Browse and select your nominated folder, then click ‘Always Use this Folder’. Now you won’t have to worry about choosing a folder each time you save a new image – your shiny new JPEGs or TIFFs will be where you specified waiting for you.... yes, they will be shiny!
In the centre panel now there should be two tabs – one with the name of your home folder and the other ‘Preview’. The home folder tab will display all your RAW files as image thumbnails and now you can click on one to select it (a blue border appears around it), and after a few seconds when clicking on the Preview tab you will see you shot much bigger, ready to be worked on. Any adjustments you make will be applied to this one image only.
If you have a number of similar shots and want to apply the same adjustments made to the first one to any more, try this – in the Home Folder tab select the file you have already worked on, then right click on this selected thumbnail – from the context menu that appears choose ‘Copy Parameters’ – now select the RAW file that you want the same settings applied to also, and right click on that one – now choose ‘Paste Parameters’. The second file will now appear in the Preview tab with all your previous settings applied to it automatically, and you hopefully will only need to make a few minor adjustments, saving a lot of time.
A lot of the settings within the Options dialogue are related to various image management functions, but mostly the defaults are OK, and as I’ve said I don’t use the program for organisation. If you choose to do so then some of the additional tabs here are worth exploring. One setting which may have general significance is on the ‘Image Display’ tab – Pixel Interpolation, with three options; Nearest Neighbor, Bilinear & Real Zoom. I wasn’t sure really myself on how these would affect the preview image, so I queried it on the UK forum, and Team Member John Riley kindly suggested that Real Zoom might equate to ‘Bicubic’, which samples diagonally as well as across & up & down, so would presumably be best for photos. So I suggest you try this setting first and compare with the others if you’re unsure – have a look at what happens to your image just after making a major adjustment to see any differing effects as it updates.
Image Information & Navigation
The main reference you have to monitor image exposure & contrast is the histogram tab, by default on the left panel at the bottom. Make sure the panel is wide enough to fully show the right hand edge of the histogram, or you risk missing seeing any blown highlight information.
The Histogram will be your guide to ensuring that you have enough visible detail in the shadows and highlights (the darkest & brightest part of the image), and that there is a well distributed spread of dark tones, midtones and highlights (high contrast), should this be appropriate for any particular image.
On the right panel , the Image Data tab provides a wide range of camera shooting settings captured with the shot, eg Ev compensation, aperture, shutter speed, iso, white balance, flash mode etc. Some lens specific data will only appear with DA equipment.
The Map tab allows you to move around the preview after it has been zoomed in by using the + button on the toolbar – you drag the box around to move the zoomed preview to where you want it. The ‘fullscreen’ button on the toolbar restores the preview to full size.
Key Processing Steps - building an efficient approach to image adjustments
Successful RAW editing rarely takes a purely linear direction. There will always be certain types of adjustments that it makes sense to work on initially and other that follow naturally, but be aware that making one change to a particular setting can often require a matching correction to another – one example would be an exposure increase that caused highlight to blow out, needing a highlight reduction adjustment to bring them back. Another could be a global saturation increase that caused one dominant tone to become too strong, so you might respond by reducing slightly just that one colour area.
For this reason it makes no sense to try and detail any particular sequence of working as correct. Ultimately what you end up with in output is simply what the controls are finally set to at the point you choose to ‘Save As’ – it makes no difference to the output what order you did things in getting to that point. So I will only try to offer a suggested route along the way – you will always find yourself working back and forth through the control tabs finding your way, and the process becomes quicker and more intuitive as you gain experience.
Sharpness & Noise Reduction control during RAW processing
It is generally accepted that sharpening an image is best left to the end of a processing workflow. This is because the ideal level of sharpening is dependant on the particular output purpose – for example, an image that will printed out very big to hang on the wall will benefit from more sharpening than one that is to be used on a website only.
Also, if an image file (eg JPEG or TIFF) is worked on in standard photo editing software, excessive sharpening at the start can lead to quality degradation as additional editing processes are applied.
So the best advice I can give is as follows; in PDCU (like all adjustments) it makes no difference to quality when you set the sharpness control. But, if you are intending on continuing to edit the output image file in another program (eg Photoshop) then keep the sharpening setting to the minimum needed to correct for the inherent softness of the camera sensor (or not with a K5IIs !!)
My suggestion is for portraits and other softer scenes + 1, landscapes, macro and other detailed subjects + 2. Final additional sharpening if needed for the intended output would then be applied in your chosen photo editing program, ideally applied at the end of that working.
If on the other hand you are going to Save a file from PDCU and use it to print from directly, then increase the sharpness settings proportionately. You should check the effect on the preview at a zoomed setting, say 50 – 100%, but for prints up to A4 then add an additional +1 or +2 to the sharpness for the situations mentioned above. For much bigger enlargements you may need settings of +5 or +6.
For web only display (at any size) then more average settings are appropriate, say +2 to +4 depending on the subject matter.
My own preference is to carry out noise reduction later using different software, so I cannot make detailed suggestions about PDCU’s noise reduction features. The principle would be similar as for sharpening; ie if you are outputting JPEGs for immediate use then take control of noise within PDCU using the Noise Reduction tab. You will not be able to apply your enhancements selectively or target specific elements (such as shadows only, or sky only). This is a real limitation here, and one reason why I leave noise reduction to later in my workflow.
If using PDCU as a RAW converter and initial ‘developer’ prior to further work in another program, then there is a case to be made for not reducing noise before exporting the file (to a TIFF say). This is because you will lose some sharpness and detail across the whole image, and then you’ll just end up having to restore this detail later by some means, which may or may not work well. Any noise that is exported out into your new file can easily be dealt with later, and if you can apply noise reduction selectively in another program then you will be able to retain the maximum possible detail in either shadow or highlight areas while still minimising or eliminating visible grain or colour type noise.
A Suggested PDCU Workflow
1) Exposure, Shadows & Highlights – Open the Exposure / Tone tab and check the image in the preview and histogram. Assuming that the exposure was reasonably accurate when shot, it is common for RAW images to need a modest increase in exposure in processing. Assess the histogram and preview and make your adjustment until you feel the main brightness level is good – there are 1/3rd stop increments on the slider. Watch the right hand edge of the histogram to see if the brightness data
(the grey shading) travels up the right edge of the graph – if it does you have what is known as ‘blown highlights’, meaning overbright areas where no detail can be seen. If the shaded gray has travelled up the left-side edge then you have ‘clipped’ shadows, or pure black with no detail. If both edges of the graph are free of brightness data then you have captured the full dynamic range, and you will only be concerned with the overall brightness and contrast you prefer.
2) Blown Highlights – open the Highlights Adjustment Tab, click the apply box. Reduce the over-bright areas by moving the DR Expansion slider right. As you do you will see the brightness data on the histogram move downwards from the right hand edge, and then once it’s at the bottom the shaded areas will contract from the right edge moving left, leaving clear space in its place. As there will now be visible detail in these brightest areas, we have a ‘Dynamic Range Expansion’ – ie visible detail across a wider range of brightness values than before.
You have further controls to use in this tab and these need some consideration. You can control the balance of the content of detail that is restored in these blown highlight areas, a very sophisticated and useful tool. What content might there be ? Well, it depends on what the subject was that had highlight detail blown out. To look natural you might need to restore either pure toneless ‘brightness’ data, or more saturated colour toned data. Some examples might help – say the brightest blown out parts of your picture were on white clouds, or the foaming tops of some crashing waves – for these cases you would want to restore pure white brightness; allowing colour data here might cause a dominant colour tone to become visible (eg blue from the sky to bleed onto the cloud if WB had been set to daylight). To prevent this move the top slider right towards ‘Preserve Brightness’ and watch your highlights until the correct amount of pure bright tone is restored.
Alternatively, you might have had blown highlights reflected from one side of a flower petal, or maybe bright hotspots on a cars paintwork – in these cases move the top slider left towards ‘Preserve Colour’ and watch your highlight areas until you see a natural amount of colour tone restored. After this you can fine tune the colour tone with the second slider, giving emphasis to either the dominant primary colour tone or the underlying hue tone – move between ‘Preserve Saturation and Preserve Hue’ to get a good result.
Following all this it makes sense to work again a bit with the DR Expansion slider back and forth to adjust the overall highlights level, checking the right edge of the histogram to ensure the data stays away from the right edge.
3) Clipped shadows – Back on the Exposure / Tone tab, looking at the left edge of the histogram, and checking the darkest parts of the preview, from the dropdown box ‘Shadow Correction’ choose from low / medium / high. You will see the grey shaded areas at the left edge of the histogram move down the edge and contract to the right as the shadow detail is brightened.
If it is important to be able to see details in all shadows (not always the case in some photos – you have to judge that) and the ‘High’ setting has not pulled all the data up from the left edge, then you can pull the ‘Dodge’ Slider to the right to increase shadow details more aggressively – be aware though that this slider has the effect of increasing brightness to a lesser degree to other areas of the image, so you may have to balance this with a corresponding Highlight Correction adjustment or reduction in Exposure setting. Look carefully at the brightened shadow areas to be aware of any high noise levels that this processing may have caused. It can be removed later, but this will in itself cause blurring to the detail that you have revealed – it is a compromise type of situation, so go for a fair balance.
Following these first 3 steps you have achieved an image with a dynamic range fully within the visible spectrum, and so can safely proceed to controlling the contrast balance and other adjustments.
4) Contrast / Global Saturation / Sharpness
These are grouped together because in PDCU they are controlled through settings in the Custom Image Parameters. Open the Custom Image Settings tab. Firstly decide on the best Preset from the dropdown box at the top – the top choices are Bright / Natural / Portrait / Landscape / Vibrant etc and are the most useful to us here.
From what I can see the additional presets further down (such as Scene – Kids, or Candlelight, would be more useful if shooting JPEGs on the camera and you weren’t going to do more processing. They mainly alter contrast, sharpness, saturation and white balance settings to predetermined defaults, but in my view as we’re working on the computer we might as well take full control manually. By all means try any to see if they work well with your image.
The main presets will change your shot in the following key ways; Bright – exposure boost, average contrast, average saturation, sharpness increase; Natural – lower exposure, average contrast, low saturation, sharpness increase; Portrait – exposure boost, low contrast, low saturation, lower sharpness; Landscape – neutral exposure, contrast increase, high saturation, higher sharpness; Vibrant –exposure increase, average contrast, neutral saturation, higher sharpness.
Once you have set your choice of preset, now place a tick in the box ‘Set Contrast’. The group of sliders below will now become active. It is not only contrast here - we have saturation, hue and sharpness also. Then there is a main brightness control and two contrast controls (the up & down facing triangles). These work like a single contrast slider divided in two – one for the brighter half of the image, one for the darker half – eg in a landscape the brighter half slider (up triangle) would affect the sky and sunlit grass areas. The darker half slider (down triangle) would affect the shadows and poorly lit parts of the scene. These adjustments apply to a wider range of brightness tones, whereas the Highlight Adjust / Shadow Correction controls used before only affect the very outer extreme tones. Watch the histogram as you move them and you will see much bigger chunks of the shaded areas moving back and forward with your inputs.
Now assess the image following the preset change – check the histogram again. Make fine adjustments to improve what the preset has produced – eg, alter saturation, use the Hue slider to correct any dominant poor colour cast, use the higher contrast slider (up triangle) to reduce brightness in the sky, or conversely in a portrait it might be used to increase brightness on the face. Then you might use the lower contrast slider (down arrow) to darken a less lit background in the portrait.
Once you are happy with the overall contrast you might as well set the sharpness now, as it’s here on this same tab, if you already know what the ideal setting would be based on the output, as talked about earlier.
5) White Balance
On the White Balance tab you firstly have a dropdown selector for the standard camera presets. These include As Shot / Daylight / Shade / Cloudy / Fluorescent / Tungsten / Flash. By default PDCU will display ‘As Shot’. If you had set Daylight, for example, on the camera when shooting then in PDCU you will still have ‘As Shot’ selected, in which case the ‘As Shot’ selection will look the same colour-wise as selecting ‘Daylight’. Try out the other presets to see the effect they have on your image.
As is common to many types of photo software, PDCU has some ‘eye dropper’ selectors to click onto the image to choose a ‘grey point’. We have three available here. The idea is that you would find a neutral grey area of your photo (or select 3 slightly different grey areas to get an average) and the program will calculate an appropriate white balance setting that should eliminate any dominant colour cast. Or you might have placed a grey card in the image for this specific purpose. This is a good theory, but in practise it may often prove difficult to identify what is a truly neutral grey tone, and a lot of clicking on different places can result in lots of jumping around between different colour casts on your image.
My own personal approach, in situations where it is critical to set an exact white balance where none of the presets is accurate, is to use a manual setting on the camera when shooting. Check your camera instructions for this technique, but you will be either pointing the camera at a white or grey item to set the WB, or (as I prefer) using an Expodisc which covers the whole lens and neutralises all tones to pure grey. This setting is then stored by the camera as an updated ‘Manual’ WB, effectively your own personal preset now, and this setting will be remembered until you take a new one. So when you open the image in PDCU, you will still see ‘As Shot’ selected, but this time ‘As Shot’ will be your own manual setting.
I see the advantage of this approach to be that as you are preparing the shot you can actually compare the exact colours of things that are in front of you with how they appear on the LCD screen. The manual setting has the option of fine tuning also to exactly match object colours if this is critical.
So the idea is to get as close as you can with one of the presets, and then you have two sliders for further fine tuning – magenta – green / amber – blue. For most outdoor shots the amber – blue will be most significant as you can control the ‘warmth’ of the image directly with this. The magenta – green controls are most commonly associated with correcting artificial lighting casts, but they also have a use outdoors, maybe some magenta to tone down overly green foliage, or for portraits using magenta again to remove a sickly green tone on skin.
The sliders effects are quite subtle, but you have very powerful control in this tab, and good choices here can really make your photo.
6) Colour Fine Tune
Open the Colour Fine Tune tab. This is a good point in the workflow to carry out this colour work, just after setting the global white balance. Some primary tones are likely to have been affected by the white balance adjustments you made, eg red & yellow tones (such as autumnal foliage) will have increased saturation already as a result of any increase in amber you made in white balance. If this is too excessive in the most saturated areas you can tone these down a bit in Colour Fine Tune without pushing the overall colour balance back away from your amber input earlier.
White balance inputs will affect the global underlying tonalities, whilst colour fine tune adjustments will firstly be effective on the most saturated pixels on the chosen colour channel. In PDCU we have this most interesting ‘Colour Wheel’, a segmented circle of primary & secondary colour channels. Each individual colour ‘segment’ has a dot at its centre which you move around in all directions within the one segment. As you move the dot a line extends from the centre point attached to the dot, giving a visual guide to the extent of the position change you have made. Be aware that the actual colour of a segment is only a median (averaged) representation of a somewhat wider range of true tones that the segment controls.
Moving the dot outwards in a straight line toward the edge of the circle increases the saturation of that specific colour, and conversely moving inwards towards the centre of the circle reduces the saturation. The really exciting part here is the flexibility offered by 360 degree movements within each segment. Moving the dot in any other direction (ie towards or away from an adjacent colour segment on the wheel), will have a proportional toning effect towards that ‘next door’ colour. If you are simultaneously moving towards the outer edge or inner edge then you are carrying out multiple colour edit inputs with one movement – ie changing the toning balance gradually from one colour to another and simultaneously increasing or decreasing the saturation of your newly fixed colour.
This is a very different concept to traditional saturation edit controls (such as in Photoshop) where you choose either a ‘Master’ channel for the whole image at once, or select red, green, blue, cyan etc from the a dropdown box and then control only that channels saturation strength. In PDCU you are changing colour balance tonalities and strengths in one movement.
This is the time to experiment a bit and fine tune the saturations and specific colour tones on your image. For example, under sunlight, foliage in a landscape is mostly under the yellow channel. If you increased amber under White Balance to add to the general warmth in the scene, you might wish to bring back some of the pure greens that were apparent in the foliage. So you would take the yellow segment dot and slowly move it across towards the adjacent greener segment, watching your trees and bushes as you go. Once the green starts to come through you could change direction on your movement either outwards (boosting the new green tones) or inwards (lessening the saturation if the green is becoming too strong). This feature provides a very powerful way of defining the specific tones and saturation levels in your image.
7) Lens Distortion & Abberation Corrections
Accessed on the Lens Abberation Correction Tab, these controls include the following types of corrections – vignette, barrel / pincushion distortion, & chromatic aberrations.
Firstly we find the vignette option. This is termed ‘Marginal Luminance Correction’. Presumably someone at Silkypix has got out their Japanese-English dictionary to come up with that. I interpret it as meaning the lighting values (luminance) at the edges (Marginal – ‘at the margins’). This common brightness falloff at the corners of a photo is mostly evident at wide angles (more so on cheaper zooms) and at wider apertures. It is often most discernable with these conditions on the sky section of landscapes (ie top left and top right corners), but would equally affect the bottom corners as well.
You have two sliders, the top one for setting the focal length of the shot, and then the other for a Compensation setting setting. Annoyingly this defaults to 100, giving a ludicrously strong effect immediately, so I always reduce the compensation slider to zero, then tick the apply box. Check the focal length slider is correct and then gradually move the percentage slider to the right to introduce more brightness at each corner. If you want, for creative effect, you can reduce the slider to introduce a specific ‘vignette’ appearance. For wide angle shots you are probably looking at around +8-12, and this increases proportionately as the focal length increases, maybe +30-40 up to 100mm or so. But you be the judge based on the extent of any visible darkening at the corners. The effect is more apparent in deep dark (polarised for example) skies, less so where there is more complex textures such as trees and foliage.
Next are the Distortion Correction sliders, this time a ‘Correction Balance’ and Compensation (strength) option. We also have here an ‘Auto’ box, and alternatively ‘Manual’. The Auto function will only be available for DA or possibly similar functioning lenses from independent brands. If this is available then by all means tick the box – this should produce a result similar to having the correction enabled on the camera. I have used this sometimes, but I have felt that it seemed a bit excessive, and also it crops in too far for my liking, so I mostly click Manual and use the sliders to achieve a reduced effect. I make no claims to much knowledge in this field of complex lens corrections, so I just use the slider to reduce any obvious barrel or pincushion effect. The Correction Balance slider adjusts the weighting given to the correction to either the centre or edges of the image, and the Compensation slider simply controls the amount of the set correction.
What we are mainly concerned with here are any obvious curved lines that should be straight. On modern Pentax lenses this is not generally a huge problem as far as I understand, but it can be significant on cheaper wide-angle zooms and some independent branded primes, or older K mount equipment. My suggestion would be to use this feature here to reduce the most obvious poor effects if you have them, and if you have any really complex or extreme distortions, then study up a bit and try out some other software that offers more sophisticated control specifically in this area.
Finally the Lateral Chromatic Abberation section deals with this type of optical phenomenon, which causes what is known as ‘Colour Fringing’ (often Purple, or ‘PF’). These controls also have the ‘Auto’ and ‘Manual’ option. Again, Auto will act in the same way as having the function active on the camera, and Manual gives you fine control over the red and blue channels. Zoom in on any aberrations (eg. fringing, often purple where extreme contrast lies along thin edges, such as then outlines of trees against a bright sky), and work the sliders to see the effect. Again, if you have a complex situation and multiple aspects of fringing then you might be advised to read up a bit and research on any alternative software that offers more comprehensive control.
Conclusions – (For now)
If you’ve got this far then I am sure you have prepared your photo beautifully (and you deserve a medal!). You have made use of the most important and key RAW image adjustments in Pentax Digital Camera Utility, and hopefully have extracted the very best out of your Pentax digital image. All that remains is to choose from the menu ‘Save As’ and select JPEG or 16bit TIFF from the dropdown. Give the image a name at this point or it will just default to the camera file name, and send it to your chosen computer folder for new images.
The RAW file will remain intact where it was before, with all of your adjustments recorded within the file. If you open it again in PDCU then everything will be set up as you left off and you can make further adjustments if you want, and then ‘save as’ a second version if you choose.
That’s all I’m going to cover for now. If you’re seeing this in a forum thread then please offer all of your own advice, and any corrections or additional points I may have missed – it would be much appreciated and I will gladly join in any debate! I will update in the future to incorporate any such corrections or other info and if the programme itself should change. In the meantime, happy RAW converting!
NIGEL MCGREGOR, LONDON UK, NOVEMBER 2012
