Photo Focus

HDR photos - some finer points

2009-12-31T08:26:09Z

I am sure you have all read the tutorials, and know the basics of HDR photography. A good steady tripod, the camera set to aperture-priority, a range of different apertures, preferably taken automatically to minimise any movement, and hence 'ghosts' in your picture. Reading the posts on the different discussion forums, you will be advised by one person to always take 5 separately-spaced photos, whilst another will advise 7 or even 9. Some will say that 3 photos, spaced at 2ev, are sufficient. Who is right?

I'd like to suggest that to answer this question, you think a little about the REASON for taking a range of photos. We are trying to capture a high dynamic range such that all aspects of the photograph, from the darkest shadow to the lightest bit of sky, are correctly exposed. To combine these images, the Photomatix, Picturenaut, or whichever software, needs the raw data to work on. The software can't do something magical, and create data that isn't there. It is easy to stand in awe of the software, to give it the photos you assume it needs, then expect it to turn out a masterpiece. Sometimes it can, but often it doesn't, and one of the reasons that this happens is because the software didn't have a suitable range of light to start with.

So, instead of automatically setting your camera to 5, 7, or whatever number of images you are used to, I would suggest taking a little time to ensure that the data needed is really captured. Take a test image at the correct exposure, then examine the screen to see the range of light and dark in the scene. Determine the correct exposure to bring out the detail in the darkest area. Determine the correct exposure to bring out the detail in the lightest area. It is only when you have done that will you then know the range of exposure needed for the scene. Divide this range into 1-ev increments, and you will know how many shots you need to auto-bracket. Do this and you will never again be disappointed by a lack of detail in a dark or light area of your image.

HDR Photography - 2

2009-01-10T06:27:30Z

Some more of my recent HDR photographs for you to look at...

The Jaswant Thada at Jodhpur, Rajasthan, India

The Gadi Sagar at Jaisalmer, Rajasthan, India

The Fort Palace Museum at Jaisalmer, Rajasthan, India

The Nakki Lake at Mount Abu, Rajasthan, India

The Lake Palace Hotel on Lake Pichola, Udaipur, Rajasthan, India

The Kumbhalgarh Fort, near Udaipur, Rajasthan, India

The Adinatha Temple, Ranakpur, near Udaipur, Rajasthan, India

The above images, and others, are all available for licensing in a range of sizes, with original tifs at a much higher quality than the above. I have been taking travel photos for nearly 30 years. If you would like to commission me to take HDR or other photos for you, worldwide, please see the Contact page.

High Dynamic Range Photography

2008-12-16T08:50:29Z

I have recently been experimenting with HDR photography, and am very pleased with some of the results. HDR, which stands for 'High Dynamic Range' is a way of creating a more balanced image than is otherwise normally possible with digital photography. We are all familiar with photos where the foreground has lovely contrast and colour, yet the sky is washed out - a flat sheet of white with no clouds or other details that we are certain were really there. This is caused by the limited range of storable values that your camera can cope with - in other words, it just can't do the same thing that your eyes can. HDR photography attempts to solve this problem by combining a number of images taken of the same scene, but at different exposures, into one image.

Anyone can start to take HDR photos. All you need is a camera that can capture a series of photos at different exposures, preferably automatically in one burst, to minimise camera movement. You'll also need a tripod - yes I know they are a nuisance to carry around, but for HDR they are indispensable. Try one of the Manfrotto carbon fibre tripods - they are half the weight of a normal aluminium one.

Set your camera to Aperture Priority, and take a group of photos as follows: -2 stops, -1 stop, normal, +1 stop, +2 stops. This is a good range to start with. You now need some software that can combine the photos into one HDR image, then tone-map the result. Adobe Photoshop does this quite well, but I would recommend a standalone program that specialises in HDR. The one that beats the competition is Photomatix, from HDRsoft.

For best results, don't forget that HDR is just another way of taking photographs, not an end in itself. You still need to concentrate on the composition, layout, lighting, and look of the final image. HDR is just the 'icing on the cake'.

Here are a few HDR photos from my recent trip to India. The camera is a Nikon D300, with 12-24mm and 18-200mm lenses.

The Jami Masjid at Fatehpur Sikri, Uttar Pradesh, India

Vinai Vilas Tank at Alwar, Rajasthan, India

Suraj Bhavan at Deeg, Rajasthan, India

Lohagarh Fort at Bhatatpur, Rajasthan, India

City Palace at Jaipur, Rajasthan, India

Amber Palace at Jaipur, Rajasthan, India

Nur Mahal at Jaipur, Rajasthan, India

Pushkar Lake at Pushkar, Rajasthan, India

Junagarh Fort at Bikaner, Rajasthan, India

Lalgarh Palace at Bikaner, Rajasthan, India

Meherangarh Fort at Jodhpur, Rajasthan, India

The above images, and others, are all available for licensing in a range of sizes. I have been taking travel photos for nearly 30 years. If you would like to commission me to take HDR or other photos for you, worldwide, please see the Contact page.

Focus Problems with Nikon D300 body and 18-200mm lens

2008-03-14T14:16:14Z

I am now the proud owner of a Nikon D300 camera, and a couple of Nikkor lenses. During my 20+ years of taking travel photos I have moved from Olympus OM1 to OM2 to OM4 (and accompanying Zuiko lenses), and then more recently to digital. I bought a small Sony DSC-P43 when a need arose to produce photos to illustrate adverts when down-sizing my possessions on eBay. This little camera subsequently travelled to Africa on my last Overland journey, and excelled itself in a range of difficult environments, providing me with some outstanding, albeit low-resolution images - you can see them on my 'Travelling Tim' blog pages. I realised that if I wanted to continue to produce the quality of digital photographs that I had previously captured on film with the Olympus cameras, I would need to quickly move up-market. After much research, I decided on the latest in the Nikon semi-pro range, the 'D300'. To accompany it, I chose the Nikon AF-S Nikkor 18-200mm 1:3.5-5.6 G DX SWM VR ED IF, and the Nikon AF-S Nikkor 12-24mm 1:4 G DX SWM ED IF.

Whilst experimenting with my new camera, and taking a variety of test shots, I soon noticed that when I zoomed into images taken with the Nikon AF-S Nikkor 18-200mm lens, they were never as well-focused as I expected. After some searching on the internet, I quickly realised that I wasn't alone in this, and found comments such as "Not to worry...this is a common problem with the 18-200mm lens", which was both comforting - I was not the only one, and yes it can be fixed; and annoying - that I had to waste time with this at all, and why couldn't Nikon have adjusted things properly before they left the factory!

I checked the D300 Manual. Nothing in the index, nothing in the Focus section. It was only because I'd read about it on the Internet that I persisted, eventually tracking down a small section entitled 'AF Fine Tune' on page 327. Ironically, the picture on that page shows adjustments being made for an 18-200mm lens! A suitable chart for setting up the focus, and a suitable method of performing the adjustment was needed. From the posting mentioned above, 2 resources were found:

Jeffrey’s Autofocus Test Chart

Nikon D70 Focus test chart

I tried taking a range of test shots using these focus charts, but found it rather difficult to determine the best results within a small range. I then took a series of photos outdoors, using different 'AF Fine Tune' settings for each.

Lightroom is a good program to open the RAW files with, but it is hopeless when comparing each shot, due to the amount of time it takes when loading each file. What was needed was to be able to view a small, highly zoomed section of each image, and to compare these sections simultaneously.

In the end, my favourite method was to zoom in with Lightroom at the 3:1 setting, then screen-grab a small section of the image and convert to .png. I would then open all these small photos together on the screen, and found it much easier to see which was the best, and consequently which setting I should use for each lens. As it turned out, I needed -6 for my 18-200mm lens, and -2 for my 12-24mm lens. Don't use these figures yourself, though. You will need to take a series of test shots to decide what your own settings should be.