Cookie Cutter

Just experimenting with an iPod touch and a few apps. Not really my cup of tea but an interesting way of forcing oneself to think outside the box and trying to do something unique with very common “tools”. Limited resolution, a very deep depth-of-field, a set focal length and a hard-to-hold device are some of the challenges to overcome.

These two through-the-viewfinder (ttv) images were made with an app called TtV Camera. The first seemed suited to the gloomy overcast view through a dirty window! Most of the TtV “templates” are too dirty for my taste but otherwise realistic. Or as realistic as a digital iPod camera using low-res cookie-cutter templates trying to emulate the view through an old film camera finder can be!

The image below was made with a very interesting app called Slow Shutter and a little hand panning.

Highs and Lows

High dynamic range (HDR) imaging is one of those techniques that divides photographers. To some purists it's just not “real” because it uses more than one frame. To others it looks unnatural due to exaggerated colours and contrast. Another group loves the drama and boldness of those very same exaggerated colours and contrast. Personally, I'm in yet another group that likes subtle HDR, the variation that should be hard, if not impossible, to pick as HDR. It allows images, as you would expect, a wider range of brightness while still appearing natural. The trick, I think, is to do this with a sensitivity to the subject matter and reality.

The human eye and brain combine to take in a far wider range of brightness than digital or film ever could. But our brains also know when we are looking at an image rather than reality. Our brains expect the bright sunlit highlights of a photograph to be brighter than, for example, a bright yellow leaf in shadow. So giving similar brightness and contrast treatment, or visual importance, to all areas of an image will look unnatural.

Here's three frames from the camera. The left one isn't of much use as it's too dark. The middle image has the highlights just under control but little shadow detail and shows the limitations of a single frame. The right hand image has overexposed highlights but some nice shadow detail, again showing the limitations of a single frame. Below are three ways of combining these three frames.

On the left is a “flat” HDR merge. This has promise and could be massaged to produce a pleasing final result. But note how the trees at top-centre have similar brightness and contrast range to the rock bank on the left.

The central image has been given the high contrast and over-the-top colour HDR treatment. Again the left rock bank and distant trees are similar in brightness and contrast. As is almost everything in the frame. Sure it's bold, but it's bold everywhere which leaves the viewers eye roaming wildly, never settling down. Trying to work this image into a visually pleasing three-dimensional scene would be impossible.

The right hand image is a manual combination of the three frames. Stacked as layers in photoshop, brightest on top, I've gradually erased parts of the top and second layers. Each small section of the image now has reasonable contrast but the different brightness of each section now allows a journey through the image. The forest on the left now has dark shadows and the distant trees now look... well... distant! Sure it's no masterpiece, but with a little burning and dodging as shown below it can be worked into a pleasing capture of what it really looked like, not just to my eye, but to my mind.

Deep South

I thought I should post a little technical explanation as I've been asked a few times about the mechanics of a shot like this. I'm a great believer in photographic gear being the least important ingredient in a good image. But sometimes there's a minimum of gear and technique required. For star-trails the basics are a sturdy tripod, a digital SLR with a fully charged battery, a torch, a locking shutter release and a free bit of software. Even a compact digital camera with manual controls can work, but image quality with longer exposures is always going to be an issue.

While these ingredients seem simple, there's a few traps for the unwary. The first is seeing what your aiming at! Without a bright subject it can be very difficult to see through the eyepiece or even use a live-view lcd screen. The easiest answer is to take some short test shots at high ISO until it's right. Then you realise that focussing becomes an issue! Manual focus is a must and can be done through the eyepiece if there are bright lights in view, although stars usually aren't bright enough. A magnified live view is the best answer but without that, my favourite technique is to test the best focus point of a lens (for infinity) during the day and make a note. Then it's easy to set. Provided you have a torch handy. And don't forget to turn off any lens or body image stabilisation. Once focus and framing is sorted, attach a locking remote control, set the “drive mode” to continuous, select 30 seconds in manual mode, the lowest ISO, and an aperture of f4 or faster.

It might be tempting to put the camera on “bulb” mode and shoot a 30 minute exposure. But longer exposures lead to vastly more digital “noise” which is blotchy unwanted colour, especially in the darker areas of an image. So short (30 second) images are the way to go. Take, then check, one test image. Then lock the remote on and pull out a good book. Or settle back and watch the sky for a while. The stars will make a full circle in almost 24 hours so a total time of 2 hours will give you 1/12 of a circle, centred about the south celestial pole for those us down under. The end result below was from 150 30-second frames or 75 minutes worth.

One the photos are downloaded, the next step is to stack them together. My choice is the excellent and free program called StarStaX (for win, mac & linux). The end result should look good unless you've included a test shot by mistake, bumped the tripod or the lens has become covered in dew! With a bit of processing you can bring out the fainter trails and, in the example above, I reduced the brightness of the city lights by using only one frame for that area.

I hope that doesn't sound too daunting. Unlike many things in life, it's easier than the instructions would suggest!

Proof

Creating a book, or an exhibition, is a great way to focus the mind on ones own photography. It also leads to doubt, troubles, clarity and hopefully a clear and well-defined end result.

I've just received a “proof” of my first limited edition book called Flow that will be available late in 2011 and hopefully at an exhibition in February.