Saturday, January 20, 2007

Photography techniques Ball lightning

Cause of ball lightning

Ball lightning is one of the few phenomena that are widely accepted in the popular and scientific community as being real, although none of the many theories can fully explain all reports of people who observed ball lightning.

The more 'successful' theories explain ball lightning as being caused either by glowing carbon fibres, 'maser' of the air (microwave amplification), gas discharges and such. Probably there are several different kinds of ball lightning that can be caused by different mechanisms. Whatever its cause, ball lightning is quite rare and very exciting to witness, if you are interested in lightning and thunderstorms.

Ball lightning is mostly witnessed as being a spherical glowing ball usually a few centimeters or inches in diameter, similar in brightness to a 100-Watt light bulb. It may exist several seconds, drift through the air, drift through glass panes or be connected to a metal structure, and it may end silently or explosively.

Ball lightning is said to occur mostly during active thunderstorms, and many reports seem to come from relatively flat areas (not mountainous). Almost every storm may produce ball lightning but they are rarely seen.

Photographing ball lightning

I have never seen a photograph that clearly shows ball lightning. Many if not most photos I have seen either show streaked photos from artificial light sources or powerline failures (sparks or fireballs originating from powerline transformers and such). Other photos possibly show ball lightning but very far away.

The best tactic to have any chance to document ball lightning is to have a digital camera ready to use at all times during a thunderstorm. That camera must have a lens attached and be turned on. But even that tactic may not work. The only possible ball lightning I have seen existed so shortly that I didn't even have time to grab my camera, even though it was ready to take pictures.

A photo that shows a streaked light purportedly being ball lightning often turns out to be fake. There is even more reason to be suspicious when the photographer didn't see anything unusual during the exposure.

Some possible causes for fake ball lightning photos

As said above, most photos that purportedly show ball lightning are either faked or accidentally show something else. Some possibilities for misidentification of ball lightning are:

  • powerline faults, usually in the form of sparks or plasma arcs at transformers ('pole pigs' as they are called in the USA).

  • photos of lightning while the tripod-mounted camera was bumped during the time exposure. Even though the lightning may not be blurred, because the bumping of the camera could have occurred before or after the flash, any foreground light such as a streetlight will show curious tracks along the photo with a bright ball of light at one end (the location where the streetlight appeared during most of the time exposure).

  • fireflies that fly through the camera view; since they light up only briefly, they will show a short track of light in the frame.

  • fireworks and flares.

  • glowing sparks that jump away from the contact point of lightning with ground the instant it strikes.

Top Ten Digital Photography Tips---5. Horizon Line Mayhem

For some mysterious reason, most human beings have a hard time holding the camera level when using the LCD monitors on their digicams. The result can be cockeyed sunsets, lopsided landscapes, and tilted towers.

Part of the problem is that your camera's optics introduce distortion when rendering broad panoramas on tiny, two-inch screens. Those trees may be standing straight when you look at them with the naked eye, but they seem to be bowing inward on your camera's monitor. No wonder photographers become disoriented when lining up their shots.

Finding horizontal lines.
Figure 5. How do you square up an image in the LCD viewfinder so it appears "level" when you view it later on the computer? Look for nature's horizontal lines and use them as guides. Sometimes you can use the line where the sky meets the ocean, other times you can use a strip of land as your level. In this case I used the shoreline of a mountain lake to help me align this composition. (Canon PowerShot G2, Aperture Priority exposure set to f-8, polarizer filter)

What can you do? Well, there's no silver bullet to solve all of your horizon line problems, but you can make improvements by keeping a few things in mind.

First of all, be aware that it's important to capture your images as level as possible. If you're having difficulty framing the scene to your liking, then take your best shot at a straight picture, reposition the camera slightly, take another picture, and then maybe one more with another adjustment. Chances are very good that one of the images will "feel right" when you review them on the computer. Simply discard the others once you find the perfectly aligned image.

If you practice level framing of your shots, over time the process will become more natural, and your percentage of level horizon lines will increase dramatically.

Top Ten Digital Photography Tips---4. Macro Mode Madness

Remember as a kid discovering the whole new world beneath your feet while playing on the grass? When you got very close to the ground, you could see an entire community of creatures that you never knew existed.

These days, you might not want to lie on your belly in the backyard, but if you activate the close up mode on your digital camera and begin to explore your world in finer detail, you'll be rewarded with fresh new images unlike anything you've ever shot before.

Even the simplest object takes on new fascination in macro mode. And the best part is that it's so easy to do with digital cameras.

Close up mode.
Figure 4. Nature looks much different, and sometimes more compelling, at close range. (Canon PowerShot G2, Programmed exposure, spot meter, Close Up mode, flash off)

Just look for the close up or macro mode icon, which is usually a flower symbol, turn it on, and get as close to an object as your camera will allow. Once you've found something to your liking, hold the shutter button down halfway to allow the camera to focus. When the confirmation light gives you the go ahead, press the shutter down the rest of the way to record the image.

Keep in mind that you have very shallow depth of field when using the close up mode, so focus on the part of the subject that's most important to you, and let the rest of the image go soft.

Where Do You Store Your Digital Photos?

Do you have a ton of photos in your collection? Perhaps you've been taking many photos over the holiday season or during your last vacation. Where do you store all those photos?

This article will run through some ideas on digital photo storage so that you know how to approach the storage issue in future.

Essentially, there are a few options you have when it comes to storing photos - memory cards, hard drives, CD/DVDs and online storage.

Using Memory Cards

Of course, one lazy way to 'store' your images is to leave them all in your camera's memory card. Not a very good idea. For one thing, you need to clear out space in your camera's memory card to take more photos, so you certainly should try storing them elsewhere. Think about it - if you're snapping 5 megapixel images very frequently, I guarantee you that even a 1GB memory card will run out very quickly.




A SanDisk 512 MB CompactFlash memory card
 

Using Hard Drives

After you import your images from your camera to your computer (usually via a USB cable), you should have those pictures stored in your hard drive. Hard drives are pretty cheap these days. For $100, you can get a branded 160 GB hard disk (that's enough to store about 32,000 pictures at 5 megapixel resolution each!).


The Seagate Barracuda 160 GB hard drive

Based on personal experience, I'd say the only problem with hard drives is the uncertainty of the data safety. I'm talking about hard disk crashes and virus infections. If your computer is used by all family members, there is a small chance the hard disk may crash due to virus infections ( e.g. from surfing the web). To avoid this, I'd recommend using CDs and DVDs as your back option.
 

Using CDs and DVDs

Right – if you're not using a memory card or hard drive to store photos, the next best option might be to use CDs or DVDs. A CD-R can typically store 650 MB worth of photos and a DVD-R can store 4GB of photos. You'll need a CD burner or a DVD burner, along with a CD or DVD burning software to burn those photos. One good example of such software is Nero Burning ROM.



The Sony DRX710UL External DVD Burner

Personally, I prefer to store my photos in DVDs. When burning DVDs, I will set each DVD to be a multi-session DVD. This means I can burn, say, 1GB worth of photos on one session, leaving 3GB of DVD space for another burning session.
 

Storing Your Photos Online

Another good option is to store your photos online. You can either use online photo sharing sites or upload them to your own website . This is a great way to share your photos with friends and family without the hassles of emailing photos. Some of the photo sharing sites allow you to specify logon passwords for specific users to come online and view private photos. You can also read my guide on sharing your photos for more information.
 

Conclusion

Well, I hope you now have a better idea of how to store your photos. Besides using memory cards and hard drives, one can use CDs, DVDs or store them online. Whichever way you choose, remember to file them so that they are easy to find. Here's a guide to organizing your photo collection to help you along. Good luck and remember to backup your treasured photo collection!

6 Tips for Shooting Great Sunset Photos

If you like taking sunset photos, you're not alone. Many photographers I know love to take shots of sunsets. Perhaps its because they imbue a sense of peace in us.

Perhaps they're a challenge to take given the same time window during which the sun sets.

This article will show you some tips for shooting beautiful sunset photos. Once you master the basics, it gets easier and easier.
 

A beautiful and scenic sunset photo
 

Tip 1: Get a Full View

When shooting sunsets, it's important to position yourself so that you get a full view of the sunset. An example is to perch yourself on a high point. Another good idea is to catch the sun reflecting off water. I also like to photograph the sun setting between the leaves of trees. Think about different, creative ways of viewing a sunset. It will help enhance the beauty of your shots.
 

Tip 2: Keep Shooting

Here's another tip for shooting sunset photos. Keep shooting! This is very important because there is only a small time window during which the sun sets. Get in as many shots as you can and select the best. With practice, your sunset photos will start looking better and better.
 

Tip 3: Clouds

When shooting sunset photos, clouds make a nice backdrop. Clouds add color and texture to an otherwise uninteresting photo. Try to look for cloudy skies to add more variety and texture to your photos.
 

Tip 4: Shooting Off-Center

Another tip I recommend is to shoot the sun off-center. It's not essential to keep the sun right in the center of the photo. You can position the horizon at bottom of the frame, so that you can highlight the sky, or perhaps focus on a subject in the foreground. Try this, you can get many interesting silhouette effects.
 

Tip 5: Use Multiple Exposure Settings

A good thing to try is to try multiple exposure settings. I use a technique called bracketing (which simply means shooting the same picture at different exposures) to get the best shot. If the picture is too bright, underexpose it and vice versa. To bring out details of a person in the foreground, try using the fill flash or night mode. Experimenting with exposure is very important for getting the best looking sunset photos.
 

Tip 6: Zoom In

Always bring along a telephoto lens when shooting sunsets. That way, if you suddenly have an urge to make the sun larger and more impressive, you can simply zoom in. Some of the best shots of sunsets I've seen are done with long focal lengths in this manner.
 

Conclusion

Sunset photos are a pleasure to take. However, they do pose challenges that are unique. Exposure settings can be tricky, and there is a limited time window to take your shots. Try to apply the above tips in your next sunset photo shoots – I'm sure you'll start getting better results. Happy shooting!

5 Tips for Photographing Fireworks

Imagine you're at a celebration event, camera in hand, waiting for a fireworks display. There's a certain excitement when you shoot pictures of fireworks. Maybe it's because the lights move so fast. Maybe it's because shooting these pictures require tricky exposure settings.

In any case, I find shooting fireworks to be one of the most interesting types of photography. To help those who are new to this genre of photography, here are some good tips to follow.

A spectacular display of fireworks
 

Tip 1: Remove UV or Polarizing Filters

This is always my first tip to photographers shooting fireworks. Remove the UV or polarizing filters from your camera before the fireworks display. I have, on many occasions, forgotten to do this and the results were often disastrous. By the time I got the lenses off, I'd have missed several minutes of the fireworks display.
 

Tip 2: Right Angles to the Wind

Try to position yourself at right angles to the wind. Positioning yourself in this manner ensures that the light bursts in the fireworks streak across you as you snap pictures. This creates the interesting fireworks streaking effect you see in so many photos out there. The other advantage is that smoke will be blown out of your frame faster, giving rise to nicer, cleaner shots.
 

Tip 3: Bring the Tripod

Fireworks (and night photography in general) require long exposures. As such, always remember to bring your tripod along for the occasion. Ensure that you set up the tripod and try out some sample exposure settings way before those fireworks come on.
 

Tip 4: Focusing

As the fireworks display comes on, I think it's pretty important to focus on the first few bursts of fireworks. Taking the time to do this will ensure that you have nice, well-focused shots subsequently. Many amateurs tend to get excited once we see and hear the fireworks, and forget about focusing altogether.
 

Tip 5: Background

Another thing to look out for when photographing fireworks – check the background of the picture. Ensure that there are no city lights or moon in the background. The presence of these lights will diminish the impact of the fireworks display.
 

Conclusion

In summary, fireworks are a beautiful thing to photograph. However, they do present a special challenge in that the lights come out for only a short time. Moreover, the exposure settings can be tricky. If you keep practicing though, I'm sure that one day you'll become an expert at photographing fireworks.