HDR One Advisor No2 – A Castle on a Hill
Welcome to the second edition of HDR One Magazine’s HDR Advisor. I would like to start with a thank you to everyone who commented and sent messages of support after the first article in this series. As I said previously, it is through discussion that we all learn, and I for one am very pleased to be sharing in this great base of knowledge that HDR One Magazine generates. Please keep your comments and your images coming.
This edition’s image comes from India and poses a different set of challenges to the image that we looked at previously. The photographer’s comments were that he was trying to achieve a dramatic effect but felt that he was not achieving the image he perceived in his mind.
Above: The original image.
On first seeing the photograph as a small low-resolution image on Facebook, it looked okay, if a little fake in the sky. However, once downloaded and opened in Photoshop, other problems soon became apparent, the biggest of which was the total lack of sharpness in the focal point of the image (the castle on the hill). Other problems include a massive amount of dirt and dust on the camera sensor, a lack of tonality in the processed sky and slightly yellow greens. So lets analyse it.
The three-image set was produced on a Sony Alpha A700 Camera at the following settings for the middle exposure:
Lens: Sony DT 18-200 F3.5-6.3
Exposure mode: No Data
Shutter speed: 1/90 sec
No fill flash
Producing this range of images:
It is at this point that the biggest problem with this image becomes apparent. Firstly, the middle exposure is over exposed, leaving a decided lack of contrast in the base image. The next, and bigger problem is that I suspect this image to have been shot using one of the camera’s auto modes, as when I open the bracketed images, the under exposed image has a different aperture value to the other two, and the range of shutter-speeds also make no sense for an HDR exposure set, as the camera has compensated for the change in the aperture.
The over exposed image uses 1/60 sec @ f/6.7 making it about -1.5 stops off the middle exposure, while the under exposed image uses a shutter speed of 1/200 @ f/6.3, which to my reckoning (which has been known to be wrong in the past) gives an over exposure of 1&1/3 stops.
While there are no real rights and wrongs on the image processing side of HDR, there are most definitely wrongs on the technical side of capturing the image, and a mixture of aperture values is one of the biggest mistakes people unfamiliar with the HDR process can make. It is critical that all the aperture values are the same throughout your HDR sets. This is for a variety of reasons. Firstly, as you change the aperture, the depth of field alters making certain parts of the image soft or totally out of focus. Secondly, changing the aperture value on your camera can change the tonal range captured in the images. Also, for me, f/11 does not give enough depth of field for this type of image in the first place, so an aperture of f/6.3 will make the image totally soft, as the focus point is somewhere in the middle of the wall leading up to the castle at the top. When this is mixed with a “correct” exposure that is already slightly over exposed, the results will not be pleasing.
I suspect this image set was shot in this way to avoid using a tripod, but as I said in the last edition of HDR Advisor, any good HDR photographer must use one as it is critical, not only for being able to have a better exposure range, but also for making sure that the subject has not moved between exposures, as your hand will move, no matter how still you try to keep it. Images that are not perfectly aligned will look soft no matter what sharpening software you use, so for optimum results, this is the only way to ensure each exposure is the same and at the correct exposure and aperture.
Due to what I have explained above, there is a cast of softness throughout the image, and most of the detail in the castle is soft to the point of being totally out of focus, making this a very difficult image to work on. To get another opinion on the best way to go about the processing, we contacted NIK Software and had one of their imaging experts process the set. The results were not encouraging as can be seen below. While the processing is great, as you would expect, the final image is muddy and the problems with the sharpness of the castle remain and do not have the high impact dramatic effect that the photographer had in mind. I think the image is now also contrast heavy, which has brought out a lot of detail, but has made the overall effect very dark and a little dingy. However, there is nothing like a challenge to get one motivated so, let’s have a go.
For this image set, we are going to use Photomatix Pro to get our base image and then both Adobe Photoshop CS6 and various tools by NIK software to achieve the look that we are going for. I am also going to use a technique that I would not normally employ, but feel may work well in this case, and that is to make a five image bracketed set from one exposure using the Camera RAW feature in Photoshop. Due to the lack of depth in the underexposed image, which I would normally use to make the other exposures, I will have to use the overexposed middle shot instead. This will probably result in lost detail, but I will do my best to correct this later in the process using Photoshop.
The first thing I will do however, is to open the RAW file I am going to use in Photoshop and then run it through NIK’s RAW Pre-Sharpening software. This will allow me to punch up the detail before making the other four, bracketed images and hopefully correct some of the softness from the low aperture used.
Once I have okayed this and the software has taken me back to Photoshop, I then save the RAW image as a jpeg. It is at this point that I will create the bracketed set using the Camera RAW feature in Photoshop. First dismiss the image that was open and then reopen the same file again. Be warned, you must click on the tab in Photoshop preference for all images to be opened through Camera RAW in order for this step to work. Once the image has appeared in the dialogue box, use the exposure slider to alter the image exposure to one of the missing bracketed images and then hit okay. This will open the image at the new exposure setting. I won’t do anything else at this stage other than saving the image to a new folder that I created using the exposure setting as the filename, i.e.: +2.jpg. Repeat this step until you have a full set of exposures, which in this case is five, +2, +1 -/+0, -1, -2.
It is only at this point that I can then run the images through Photomatix to make the base file for further editing in Photoshop. I load the image images in the normal way, but forgo the ghosting options, as this image will have no issues since each of our exposures have been created from the same image. However, as the files have all been created from the same image, the software does get a little confused and asks me to confirm the range of exposures. I choose the 1 stop option and press continue. For this set, I will use the following settings:
Color Saturation: 46
Detail Contrast: 0
Lighting Adjustments: -0.1
Smooth Highlights: -26
White Point: 0.250%
Black Point: 0.084%
Micro Smoothing: 8.9
Shadow Smoothness: 44
Shadow Clipping: 37
I then left all the other adjustments at their default setting before hitting okay to process the file. I then saved the file as a TIFF, making sure the open in Photoshop option was checked. Although I have not gone into a great deal of detail here about what I have done and why in Photomatix, you can read Curt Fleenor’s excellent article (http://www.hdrone.com/2012/09/17/understanding-the-adjustment-sliders-in-photomatix-pro/) which gives a breakdown of what effect each slider has on an image in Photomatix. I would really recommend this for anyone who is new to HDR, or struggles to understand the various options available within the software.
Above: The image going through the Photomatix software.
On opening the image in Camera RAW, I will also make a few adjustments, just to take some of the greyness out and add a little more contrast. Here are the settings:
As usual, I also try auto contrast on opening the image in Photoshop, which pulls out yet more of the contrast in the image. After this I will run the image through the single image tone mapping facility in Nik’s HDR Efex Pro 2. This will help to pull out detail in the sky and to put back some of the detail in the tree line, which has lost definition during the process.
Above: NIK Software’s HDR Efex Pro 2
The image at this point is still muddy, so I once I go back into Photoshop, I will run it through levels. I am looking for a histogram that covers the entire tonal range, and this image is now just about there.
At this point, I am going to use a piece of software that has been described as both the HDR Photographer’s best friend, or best kept secret, dependent upon who you speak to. This is Nik Software’s Color Efex Pro 4. I could wax lyrical about this programme all day and love using it on my own stuff. Due to its unique ‘recipe’ system, it allows the user to layer many different filter effects, one over the other to build the image into whatever was envisaged when taking the original shot. However, it would take me all day to fully describe all the filter options within Color Efex 4, so I will only explain those that I have used in creating the final image for this article.
As always with HDR software, there is no right or wrong way to go about using it, however, you must watch for halos and Chromatic Aberration developing within the image. For this ‘recipe’, I used four filers: The Contrast Colour Range, the Detail Enhancer, The Bi Colour Filter and the Graduated Neutral Density Filter. The contrast Colour Range filter allows me to direct where the contrast in the image is, removing it from areas that I think are too contrast-heavy, when adding to those that are too insipid, while the detail enhancer pulls yet more detail out of the clouds and sky. This does create a little noise, but that is easily corrected later in the process. The Bi Colour filter feature allows me to add and mix two filter colours together and then blend then seamlessly to add real drama to the picture, while the Graduated Neutral Density filter allows me to rein back the foliage which has gone a little out of control and yellow under the other filters. This image is now looking really great, and a few last steps will see it finished.
Above: NIK Software’s Define 2.0.
After okaying the filter set I have used, I then put the image through Define 2.0 to clear up the noise created during the previous process, before opening the hue and saturation tab in Photoshop. Despite the filters, the foliage in the foreground of the image is still a bright yellowy green, and this process will correct it. This is a good tip for anytime the green look un-natural in HDR. Once you have opened the tab (Image>Adjustments>Hue/Saturation), click on the Master tab and select the Yellow Channel. Pull the saturation slider into the minus points until the greens once again look natural and then press okay. This works great on images that have many different shades of green and makes them look far more realistic.
Above: Altering the greens in the foreground using the Hue/Saturation tab in Photoshop
There were two further steps that I took to finish the image. Firstly, the image is still on the dark side. To correct this I will use the levels sliders in Photoshop (Image>Adjustments>Levels). Instead of just hitting auto, I move the highlights, shadow and mid-tones sliders at the bottom of the histogram display until I have a natural, but dramatic looking image. This easy step can make all the difference and certainly makes this image look far brighter and less heavy. At this point I will also correct the slight chromatic aberration created during this process by using the Lens Correction feature in Photoshop (Filter>Lens Correction> Custom tab) and using the sliders to neutralise the white line that has appeared between the sky and the castle.
My Final step is to put in a little sharpening using NIK Software’s Sharpener Pro 3.0. I put just a hint of sharpening in here, as the processing has been so heavy up to this point that it would be very easy to make this image look over sharpened at this point. Once this is done the image is finished.
I will leave it up to the those reading this article to decide if I have made a positive difference and which style they prefer. I could have replicated the red sky using any number of techniques outlined in this article, however I choose not to, as my personal preference to make this image dramatic was for the cloudy and menacing sky with a brighter foreground. This is purely subjective though and I Iook forward to your comments on the matter. If you do have any opinions on this article, or would like to have seen me handle any aspect of this process in a different way please take the time to write a comment.
Above: My version of the image. Below: The original.