Posts Tagged ‘speed’

Keeping Your Camera Functioning In Arctic & Sub-Zero Temperature

Most SLRs cope remarkably well with freezing temperatures. I’ve had no problem using Canon EOS SLR cameras below zero for weeks on end, often down to -20°C and in extreme down to -30°C. This article is for those trying to keep such a camera going under expedition conditions, such as an icecap crossing or mountaineering expedition in the arctic: ie no power sockets, adverse weather, sleeping in tents on the ice and for a period of weeks. However much of the advice also applies to using a camera in cold conditions generally.

Two Main Technical Problems To Overcome Are:
1. Condensation
Condensation forms when moving from a cold to a warmer environment, you don’t need to worry about damage to your camera moving from a warmer to a colder environment. Even in arctic conditions the temperature inside a tent is often well above zero yet well below zero in the shade. this means there is often a temperature gradient when bringing a camera into a tent which leads to condensation forming. Condensation on the front element or view finder is an inconvenience, but condensation on the electronics can give permanent malfunction, and condensation in the inside glass elements can write off the camera off for hours or days till the lens totally dries out.

2. Reduced Battery efficiency
Batteries are many times less efficient in cold weather due to the reduced speed of the chemical reaction that powers them.

Tips For Reducing Condensation:
1. Place camera in plastic bag
The camera should be placed inside a polypropylene freezer bag, loosely knotted or twisted and then placed back inside the camera bag. You don’t want to put a waterproof bag around the entire camera bag as any moisture in the camera bag would then condense on the camera body. Ziploc bags, and Ortlieb style dry bags may sound better but often don’t fit neatly inside the camera bag and are much heavier and more expensive. The freezer bag also has the major advantage that you can stuff it below your camera in the bag when not in use, but you need to take spares for when it gets damaged.

2. Use camera bag insulation
The padding on most camera bags (especially the holster style common on expeditions) offers some insulation value which can reduce the dramatic temperature change, when moving from environments of different temperatures.

3. Try and warm up slowly
If there are environments of differing temperatures try and make the warm up process for the camera as gradual as possible.

4. Avoid breathing on the lens
Obvious maybe, but If you need to clean the lens just use a camera cloth to avoid ice forming.

Tips For Dealing With Reduced Battery Efficiency
1. Carry multiple batteries
As a rough guide plan to take 2/3 times the number of batteries you’d need for equivalent shooting in temperate climates. My personal strategy if to take multiple batteries for an extended trip in the wilderness rather than deal with the uncertainties of solar chargers. This makes planning easy as one can ration a battery to last a given amount of time.

2. Warm batteries by keeping close to skin
Carry your spare close to your skin so your body can warm then. An apparently dead battery can be given more life by warming in this way so on very cold days you may find yourself rotating batteries in this way.

3. Adjust shooting style to conserve power
Accept you will get less out of your batteries so adjust you shooting style to conserve power. The biggest thing you can do is turn off after shot preview and reduce to a minimum previewing your images later. Addition power saving tips to get the most out of your battery are to turn off image stabilisation, don’t use flash and minimise half-press pre-focus.

By Quintin Lake

Photographing In Dark Indoor Setting

1. Camera Stability.

You will be taking long exposures, and any camera motion could impact the quality of the image. Try to utilize a monopod or stabilize the camera on the back of a theater seat. Do not hold the camera in front of you without support.

Some cameras and lenses have stabilization features which help, but will not be able to compensate for large movements in the camera. If you have an SLR, you may want to tuck your elbow into your belly, relax, hold your breath and gently press the shutter button.

2. Equipment.

A digital SLR with a fast (2.8 or better) lens and the ability to capture images cleanly at high sensitivity is best. If you are using a point and shoot, you may have some challenges in getting clean images in a dark room.

3. Flash Off.

Most indoor settings that allow photography specifically state “no flash photography”. In many cases, you’ll just ruin the existing lighting, distract the other viewers and get yourself ejected from the event. Also, from seating distance and angle, many on-camera flashes will be largely ineffective.4. Exposure parameters. You will generally need to set your camera for high ISO or sensitivity (800 to 1600, some newer cameras will go to 3200 or more), low shutter speed (depends on your subject), and wide open F-stop (2.8 to 4.0). For those of you with point and shoot cameras, there may be a “night mode” or other preset which will attempt to deal with these conditions.

4. Shutter Speed.

Integral to the exposure parameters above, you’ll need to set a preferred shutter speed for the activity being photographed. Indoor sports events are often well lit, but you’ll still want to stop motion at 1/120 or faster speed. Indoor dance performances may be much darker, but also require at least 1/60 to 1/100 to stop motion.

Speeches and plays may have less motion, so you may be able to drop below 1/60. For images of still items such as museums, you can afford to drop to a low speed to get a better exposure at higher f-stop or lower sensitivity. Just remember that low shutter speed amplifies the need for camera stability.

6. Underexposing.

Sometimes, to get the right shutter speed, you may not have enough sensitivity and aperture to get a good exposure. Instead of lowering the shutter and getting a guaranteed blurry image, keep the shutter where you need and underexpose the image. In your image editor, you can push the exposure a couple of stops and get a good image, even though it looked too dark on the camera preview.

7. White Balance.

Getting this right in the camera will save you time. Many SLR’s have a white balance custom fuction, where you photograph a white or gray image and tell the camera to use that for your white reference. If you can’t do that, try the canned settings on the camera and review the playback of samples to see the best playback of color tones to the actual room colors. Or, you can shoot RAW and fix it at import.

8. Focus.

Often cameras will have trouble focusing in dark settings. You may want to switch to manual focus, compose a test shot at the same distance to your subject, playback and zoom in the image to verify crisp focus on your subject. Then you’ll avoid the “hunting” and missed focus of your images when the action starts.

9. Post Processing.

I already mentioned pushing dark images and adjusting white balance. Another good tool for dark image editing is noise reduction. When you shoot at high ISO, you often get digital noise on the image. Running a noise reduction will remove some of that noise, but at the expense of image detail or sharpness. You’ll have to weigh the amount and benefits of noise reduction in your case.

Please make sure that you don’t take photos where you are not allowed, but given permission and these techniques, you can take some great indoor images in dark settings!

By John Huegel

How to Take Great Photos of Holiday Lights

At this time of year, many of the world’s cultures and religions celebrate holidays that involve lights. While the use of lights and candles is often explained in terms of the rites of the particular culture, most scholars agree that the lights came first; the explanations followed. After all, since humans gained control of fire, light has been used to illuminate the darkness – especially, during the depths of winter – rather than curse it.

There are some photographic subjects where it makes little difference whether you use a digital camera or a film-based model to capture the image. The colors and warm glow of holiday lights is not one of them. If you’re not careful, you can run into trouble with a digital camera. All photographers interested in getting great holiday photos should read this article. Pay close attention to the special digital section written by NYI’s digital expert Jim Barthman. While today’s auto-everything cameras can do a lot of things following the wisdom of built-in programs, taking pictures of lights and candles is one area where you’ll want to exercise some control.

At this time of year, many of the world’s cultures and religions celebrate holidays that involve lights. While the use of lights and candles is often explained in terms of the rites of the particular culture, most scholars agree that the lights came first; the explanations followed. After all, since humans gained control of fire, light has been used to illuminate the darkness – especially, during the depths of winter – rather than curse it.

Christians explain the candles, tree lights, and Yule log in terms of the birth of Christ and the Star of Bethlehem. The impact of these lights – if not the explanation – is so powerful that even modern-day Buddhist and Shinto Japan is ablaze with lights and decorations at “Christmas time.” And, in the same dark days of the winter solstice, Hanukkah is the “Festival of Lights” celebrated by Jews around the world.

Years ago, taking great photographs of holiday lights was difficult because the films of yesteryear weren’t very sensitive. They had difficulty recording an image in the low-light of a candle, for example.

No longer. Technology has solved these problems. There are great color films that offer high speed – ISO 800 and higher – with very little grain. Digital cameras include ISO 400, 800 and even higher settings.

In addition, most photographers today rely on auto-exposure with their point-and-shoots or SLRs. Unlike the light meters of old, which were often “fooled” by low-light situations, today’s meters in auto-exposure cameras are able to give good readings even in low light.

This is an important point because holiday lights usually look their best when shot without added light. In fact, this is Rule One when it comes to getting good pictures of lights: Turn off your flash. Let’s repeat that: For most pictures of holiday lights, turn off your flash!

Note that we said “most.” There are a few occasions when you will want to add light, but usually you won’t.

So this brings us to the question: When should you use your flash, and when should you avoid it? Let’s look at a few examples, starting with photos taken indoors.

Look at these two photos of the same beautifully decorated Christmas tree. The picture on the left was taken using flash. We see the tree and we see the lights – but not the lighting – and ornaments on it. When this is the effect you want, use your flash.

On the right we see the same tree, only this time the flash was turned off. What we see, in effect, is the lighting of the bulbs themselves – and this lighting is bright enough to also illuminate the tree and the ornaments. The effect is totally different.

Which is better? It really depends on your objective. The first example might be better to show what a great job you – or the tree trimmer in your family – did on the tree. The second example is better in showing off how great the lighted tree looks. Each has its place.

Now, let’s remember one important point if you’re taking a picture without flash: You’re probably going to need a slow shutter speed. This means you may need to mount your camera on a solid unmoving surface to avoid camera-shake. A tripod is best.

When else might you want to use your flash? Let’s say the subject of your picture is your kids under the tree. How are you going to light their faces? On the one hand, you may find that the Christmas-tree lights are sufficient and give a very soft glow to their cherubic expressions. Or maybe it is Christmas morning, and they are lighted by window-light that is streaming into the room. In these cases, you don’t need your flash. But, on the other hand, maybe you don’t have enough light to really see their faces. Then you may have to use your flash. How do you know which way to go?

One approach is to shoot both ways, then select the better image. We think a better way is to plan ahead and meter your subject. Remember that Guideline One of the Three NYI Guidelines for Great Pictures is to decide on your subject before you do anything else. In this case, you’ve decided that the subject is the faces of the kids. Guideline Two is to draw attention to your subject. One method of drawing attention is to make sure your subject is well-exposed. So meter the light that falls on their faces from the lighted tree. Get in close and meter just the faces! If there’s enough available light for a well-exposed picture, shoot it. If not, use your flash.

Now let’s move outdoors. Here we see elaborate lighting and decoration on houses, stores, and streets. Again, if you want to capture the lights themselves, don’t use your flash.

One other tip for outdoor lights – you’ll get the best results when you shoot at twilight. That way, you’ll capture some color in the sky, rather than the pitch-black tone that will be recorded on film later at night.

But what if you want to take a picture of your friend in front of a brightly lit display?

You want to capture both the bright lights and your friend. If you use flash, you get your friend, but you’re in danger of minimizing the bright lights behind. On the other hand, if you don’t use flash, you get better detail of the lights but your friend is reduced to a silhouette.

There’s an answer. Many of today’s point-and-shoot cameras both film and digital have a funny-looking setting that looks like this:

This setting tells the camera that you want the flash to fire (which will light your friend in the foreground), but that you also want the lens to stay open long enough to record the lights in the background. In fact, the symbol for this setting on many cameras is sort of a hieroglyph that tries to indicate “person at night in front of lights.” Your solution to getting light on your friend’s face and capturing the light display is to use this setting. The flash exposes the face. The long exposure captures the lights.

But, again, watch out here. The long exposure – typically, one-quarter of a second long – requires that you steady your camera to avoid camera shake. Once again, we advise you to use a tripod.

There’s one other key area of holiday lights – candles.

This young boy’s portrait was made with a point-and-shoot camera using just the light of one candle which was about two feet from the boy’s face. Normally, the camera’s flash would have fired, but it was turned off by the photographer.

Even at ISO 800, the exposure for this photograph was lengthy, probably about half a second. That presented two dangers – either the camera would move and blur the picture, or the boy would move. Since he wasn’t using a tripod, the photographer braced his elbows on a table to minimize camera shake – not as good as a tripod, but better than nothing. Recognizing the problem, he shot several frames of film. When he examined the prints, here’s what he found: One was no good because the boy moved. The second was no good because the camera moved.

But in this frame, he got what he wanted: Both the boy and camera were still enough to produce a stunning photograph. While the photo isn’t razor sharp, it’s sharp enough to convey the warm feeling clearly.

By the way, he relied on the exposure meter in the point-and-shoot that he used for this great picture. As we said before, old-style amateur cameras were not good at calculating proper exposure in low light. They were really designed for bright daylight. But you can usually trust the meter in today’s cameras.

Mel Wolk’s sensitive photo of two boys with a Menorah on the last night of Hanukkah combines light from the nine candles with some sort of overhead room lighting, or bounce from a flash (probably off the ceiling) that gives clear illumination to the boy’s faces and garb. How do we know that the lighting is not just from the candles themselves? One clue is that the lighting in not as warm as the first photo we looked at. Candle light is rich in reds and oranges, which we don’t see here on their faces.

Secondly, the candles are not strong enough to produce the bright white on their yarmulkes (skullcaps). Our conclusion is that there is additional light in the room, and that light is bright enough to add light to the young subjects, but not so bright that it overpowers the light of the candle flames.

One thing we are certain of, Mel did not use direct flash here! Can you imagine what effect the harsh direct light of the flash would have on this photo?

So, to take great holiday photos in this season of lights, we offer you these four tips:

  • Turn off your flash unless you have a very good reason to use it.
  • Use a fast ISO – we suggest ISO 800.
  • Avoid camera shake.
  • Use a tripod…or, at least, brace the camera. Trust your camera’s built-in meter.

Special Tips for Holiday Lights with Digital Cameras by Jim Barthman

Digital cameras add some new twists to the holiday light photography challenge. In fact, some consumer-level digital models struggle in low light situations. Here’s why – the cost to manufacture a CCD or CMOS chip that is super-sensitive to a wide range of tonal (light) values is expensive. You’ll find these expensive chips in digital SLRs, but not in your $100 point-and-shoot model. One way to compensate for this deficiency is to use a cheaper image sensor and then process the digital signal with proprietary software. This can cause some problems. Let’s look at the most important ones.

Problems
Digital ISO

Increasing your film speed makes a lot of sense when photographing subjects in low light. However increasing the ISO setting in your digital camera isn’t always the best idea. In order to improve the sensitivity of an electronic image sensor, the digital signal is “amplified”. Amplifying a digital signal is like turning the volume up on your radio as loud as it will go. At the maximum volume every hiss, pop, and scratch is heard and, depending on the quality of the equipment, quality is diminished. The same thing happens in a digital camera. When the ISO setting is increased, every image artifact and defect is magnified.

To achieve the best image quality, you might try working with a slower ISO setting to start. If you are having trouble getting a good exposure, increase the ISO as needed. You might even try using the Auto ISO setting and see how the camera chooses to handle exposure.

Digital Noise

Regardless of the ISO setting chosen, most inexpensive digital cameras produce “noise” during long exposures. Noise is caused by the small electrical disturbances that are present in every electrical system. In order to capture a weak light signal, such as a subject in low-light, longer exposures are usually needed. The longer a digital camera shutter is open, the more electrical noise is recorded as well.

So, it seems we have a double-edged sword.

Increase the ISO to achieve faster shutter speeds and you will amplify noise and other image problems.
Reduce the ISO and shutter speeds are slower. As a result, you will record inherent noise that might not be seen in a “normal” exposure.

Limited Dynamic Range

To make things worse, digital cameras have a limited dynamic range. Image sensors are only sensitive to a specific range of brightness. Anything outside of that range is recorded as pure white or pure black. This can result in an image without shadow or highlight detail.

Solutions

Here are a few ways to solve these problems. Noise can be reduced with software. In fact some cameras offer in-camera noise reduction features. Proprietary software is used exclusively, yielding uneven results. Test your camera’s capabilities before committing to this feature. There are many noise reduction software products on the market today, some as stand-alone applications and others which are plug-ins that work in conjunction with your favorite image editor. This means you can select a camera with noise reduction or address any problems later in the digital “darkroom.”

Timing is Everything

As we noted earlier in this article, when shooting holiday lights outside, I find that the best exposures can be made at twilight. Twilight is after the sun has set but before the dark of night. This fleeting balance of light and shadow will yield the brilliance of the lights while maintaining details in the shadow. Don’t underestimate shadow detail to help establish your composition. Consult your camera’s manual for details on your white balance options and how to adjust them. In the finished photo the viewer will perceive the twilight photo to be taken at night.

When shooting holiday lights inside, try turning on lights in the room to increase the ambient light, rather than using a flash. Flash can produce a harsh, high-contrast quality that obliterates the brilliance of the light. A carefully positioned incandescent light can work increase the ambient light without overpowering your holiday lights.

Shoot Two Exposures

One way to extend the tonal range of a digital image is by making two exposures of a scene. Shooting in Manual mode, make one exposure configured to capture the best highlight detail. Make a second exposure to capture the best shadow detail. Then combine the two exposures in Photoshop as separate Layers. Using the Eraser tool remove poorly exposed areas to reveal detail and take advantage of the best parts of each Layer/exposure. Using this technique you could extend the tonal range well beyond the possibility of any single exposure made with the same camera. Of course this requires a strong tripod to ensure both compositions match perfectly. Consider using a remote control to reduce the possibility of camera movement.

Accomplished photographers may also create two separate images – one favoring highlights, the other shadows – from a single RAW file.

Turn Off Automatic White Balance

In many photographic situations white balance is a godsend. By automatically neutralizing extreme color casts, believable digital color is rendered without breaking a sweat. It is important to remember, not all photos require white balance. Tone down the rich, saturated colors of a sunset and you’re left with nothing. Attempt to white balance a fireworks display and you end up with dull lifeless, de-saturated bursts and streaks of light. Holiday lights should be treated similarly. By turning off the auto white balance feature you are sure to capture the exaggerated colors the holidays have to offer.

You could try turning off white balance altogether or even experiment with any of the other manual settings to find a color balance that suits your visual needs. Either way is a better bet than giving the decision to the camera.

Test, Test, Test

The immediate feedback of digital photography begs you to test your exposures to determine what works best. Take advantage of the metadata that most digital cameras embed inside every digital picture you make. Metadata can include camera make and model, exposure, flash, white balance and other important information that can help you to determine what works and what doesn’t work. This means you don’t even have to take notes! To access your digital image metadata, open a file in Adobe Photoshop.

Choose File > File Info. The File Info dialog box appears. Select the Camera Data option on the left side of the screen.

The Camera Data screen reveals shutter speed, aperture, ISO settings, lens focal length, flash settings and even the metering modes.

Holiday lights are usually around for more than a couple of days each year, take advantage of this by shooting early in the season and then re-shooting if you have too.

Digital cameras offer some real benefits for holiday season picture taking. As look as you pay attention to the drawbacks we’ve mentioned, you should get great results.