尋找極光之旅準備篇 -- 極地拍攝

小妹很愛攝影，為了極地之旅，不惜花費買了部單反，希望將美好的回憶收藏。但在極凍的天氣，相機好易壞....

以下是一篇有關極地拍攝注意事項的文章，大家可參考參考：

關於極地攝影我個人有兩次經驗,
南極北極兩部份不太一樣,
(南極是搭船,北極我從芬蘭進去)
大致上要注意的事情有:

氣溫

其實DSLR是耐得住的,就算到零下五六度基本上運作都很正常,
不加電池把手也沒關係,只是會異常耗電!

但是在超過零下二十度事情就不太一樣了!

零下二十多度就要注意快門可能會有凍結的現象,
而且相機會非常容易當機!
這種情況就建議加上電池把手,比較可以維持正常功能,
但是另外要注意的是腳架的球形雲台,
零下二十多度放個幾分鐘,用力轉一下大概就斷了,
所以得小心點^ ^"

另外,人一定要做好保暖,零下二十度最好不要站著不動超過十分鐘,
很容易會凍傷...>""<

冬天 冰島雷克雅未克:最低氣溫零下五度
芬蘭羅凡尼米:最低氣溫零下三十度 (近北極圈)
夏天 南極半島: 最低零下十度

鏡頭焦段

如果是去南極,強烈地建議一定要帶望遠鏡頭!!!
 IATTO(國際南極旅遊組織)規定,不得靠近任何生物"五公尺",
(也不准餵食,嚇牠們等等)
雖然那些生物根本就沒在怕人類,會自己跑來跑去,
有時候會近到連五公分都沒有,
但是對於捕捉一些畫面,像是鯨魚浮出海面噴水,
企鵝游泳時跳出水面,冰河崩解等等無法靠近的情形,
有支300mm以上的鏡頭會如虎添翼^ ^

(我自己因為是揹背包,加上帳蓬睡袋重量已達十八公斤...
所以我就犧牲了攝影器材== ==) (我體重也才40公斤...行李太重了>0<)

低角度拍攝
這時候我就很羨慕有Live View的相機了....
當然有垂直觀景器也行...

低角度拍攝有什麼問題呢?

因為...因為...南極整個地上的都是大便 == ==
(對不起破壞大家的美夢了...)

腳架

基本上可以不用帶,
因為時間不一定夠讓你慢慢拍,在南極登陸時間可能很有限
端看你的船和行程決定,
加上上下橡皮艇都要背腳架,可能會很麻煩 >"<

拍攝極光

拍極光用DSLR是最好的選擇,
因為可以自由調整ISO,加上可以拍完一張趕快修正曝光秒數,
不會讓難得的回憶錯過!

ISO盡量設在800,鏡頭光圈最好大於3.5,曝光秒數約15~30秒

極光其實非常非常微弱,所以曝久一點是沒關係的!
(記得關閉雜訊抑制,和封閉觀景窗)
極光出現時間很短暫,因此要盡快把握時間!

然後,
北極地帶比較適合拍攝極光,
南極大陸由於旅遊季節和形式的關係,應該是無法拍攝極光的!

測光

這個頭就很大...
因為南極陸地顏色是黑的(很黑~)
但是有雪的地方又超白超亮,
控制反差和正確測光就很難== ==

我自己的D5D怪怪的,點測雪地 +1~1.3EV都不準 (時暗時亮)
分區測光+1~1.3EV就準多了== ==
加上南極天氣和光線變化很快,
所以也會影響相機判斷!

這方面, 底片就好多了,寬容度比較好~

Cold weather photography presents numerous challenges to photographers and their equipment. From drained batteries to frostbit fingers, cold weather photography is a completely different prospect than hot weather shooting. While there are some simple solutions to most cold weather photography problems, these solutions may not be the ones you would first think about.

Equipment Problems

Condensation

• What is Condensation?
  Condensation is a photographer's nightmare. Just like a pair of eyeglasses fogging up when changing temperatures rapidly, a camera lens (and the inside of the camera) can fog up with condensation. Condensation is water forming on surfaces that are significantly colder or warmer than the air surrounding it. Technically, this means that if your camera goes into an area where the air is warm condensation will form if the camera is colder than the dew point. The opposite is also true. If your camera goes into a cold air area and the camera is warmer than the dew point then condensation can form.
• How to Avoid Condensation?
  The basic way to avoid condensation is to gradually bring your camera through these extreme temperature changes by sealing it inside a bag containing air the same temperature as the camera is acclimatized to. This way, any condensation forms on the bag instead of the camera as the air and camera gradually equalize to the new environment. In practice, this usually results in the photographer freezing in his/her car because he/she doesn't want to wait for the camera to cool off when he/she gets to the photo location.
  
  
• Hidden Condensation Cause
  Another source of condensation is the photographer. If you breathe on your camera you risk fogging it. The heat from your eye could also cause problems on the viewfinder. If your viewfinder fogs due to photographer body heat it is almost always only an inconvenience that does not affect the rest of the camera. You should, however, refrain from putting your camera in your coat as this could raise the temperature of the camera and lens itself enough to create problematic condensation.

Remember that condensation can form inside the camera as well. Beyond the moisture not agreeing with any electronic parts, the moisture could freeze in very cold conditions and completely ruin the camera.

Drained Batteries

Batteries lose their charge more quickly in cold weather. When shooting in cold weather it is essential to carry spare batteries for all of your equipment. Lithium batteries are a good choice as they are better at holding a charge than the older chemical compositions to begin with. You can also keep the spare batteries in your coat pocket or other relatively warm spot. However, be extremely careful not to let the batteries be too warm as this could cause condensation when they are placed back into the cold equipment.

Photographer Problems

Exposed Skin

• What is in Danger?
  We all know to wear a coat when we go outside in the cold, but we often forget about our hands and faces. For your face, consider a ski mask to reduce the amount of skin exposed to the wind and cold. This can also help reduce the amount of water vapor you breathe onto your camera. A photographer's fingers and face are the most endangered in cold weather shooting. Often a photographer will take off his/her gloves while shooting in order to better handle the camera. This exposes your fingers not only to the cold but also the wind. Even if the ambient air temperature is not below freezing, the wind chill may be cold enough to cause frostbite.
  
  
• Protecting Your Fingers
  Fingers cause a bit more problems for photographers. Fear of dropping the camera and difficulty in managing the controls with heavy gloves often leads photographers to forgo gloves altogether. This leads to quickly numb fingers and is a fast track to frostbite. Depending on how cold the conditions are, you may even be at risk for your fingers freezing to the metal on the camera. Layering your gloves is an excellent solution to frozen fingers. Wear silk or other fine mesh gloves first (even women's nylons with a few extra seams make great first layer gloves). Over these gloves add a pair of fingerless crafter's gloves. These not only add warmth, but can also help cut down on hand fatigue. The final layer are your normal cold-weather heavy gloves. These will be removed whenever you are shooting so a cord to hang them around your neck is needed to prevent losing them. Your fingers will still get cold with the crafter's gloves and under gloves (but more slowly). Try keeping a hunter's chemical heat pack in your coat pocket for quick reheating of your hands in between frames.

Wet Feet

Even when wearing very well insulated boots, your feet can become damp from perspiration or a poorly placed step that puts you in snow higher than your boot tops. Wet skin is in major danger of damage from cold. Keep extra socks with you at all times for emergency changes. Keeping a couple of kitchen dish towels with you will also allow you to dry off your feet before changing socks.

Slipping

In cold conditions, almost any surface can be covered in ice. Photographers are notorious for not paying attention to their surroundings while they are focusing on a subject. Be sure to pay attention to where you are stepping and wear footgear with good traction in order to avoid a nasty fall.

Author Jack Jackson Much is written in magazines about cold weather photography but the advice is often inaccurate, given by journalists or photographers who have never really experienced really cold conditions! Here Jack Jackson offers advice from real world experience. Simple point and shoot cameras and cheaper SLR cameras will be unreliable in really cold conditions and due to the reduced performance of batteries it is best to use mechanical cameras rather than electronic ones. Modern cameras do not require winterization with thinner lubricants for cold conditions but do get them serviced before you go. Where batteries are used, Silver Oxide is best where button cells are required and Nickel Cadmium or Lithium batteries are best for heavier use, always carry several extra spares, kept in a warm pocket. Modern electronics or LED displays often fail until the camera warms up again, then you may have to remove batteries from the camera and then replace them again to reset the electronics. Many quality camera manufacturers supply remote pocketable battery packs with fragile connecting wires to the camera. These are fine in the rare situations where you can use a tripod but are useless in active situations, if you must use them, tape them to your arm inside the sleeve on the hand that always supports the camera. Body At temperatures below zero Celsius, avoid touching metal camera parts with bare skin, it can stick to the metal and be torn off, be especially careful of your face. Some photographers' place stick-on tape over the metal parts that may come into contact with their faces. Wear silk or nylon inner-gloves inside your main gloves for use when handling cameras. Keep your main gloves attached by tape around your neck to avoid losing them while handling the cameras or to hungry sledge dogs. Do not keep cameras under your coat when they are likely to be needed for use. If you do, when you bring a camera out, perspiration from your body will freeze on the lens and viewfinder making them unusable. Even if kept in a waterproof bag under the coat, the camera will be considerably warmer than the surrounding air so unless the humidity is zero there will be problems with condensation. Unseen condensation inside the camera can also freeze on the shutter gearing, giving slower than chosen shutter speeds or jamming it partially open. Hold your breath when holding the camera to your eye, exhaled breath can freeze over the eyepiece. Most exposure meters give incorrect readings on snow, particularly if you want the correct exposure for any people in the scene, in this situation either use an incident light meter or take a close reading from near-grey coloured clothing. If this is not possible, overexpose readings taken from the snow. For faces, use a spot-meter reading directly from the face. Pure snow and ice scenes are best photographed with side lighting and slightly underexposed. Snow is a good test for the quality of your skylight filter, cheaper versions produce a pink cast. Keep a filter over the lens and have a chamois leather handy for drying the filter in snow or spray, be extra vigilant for filters, eyepieces and screws working loose and falling off. Wind will have an extra cooling effect, to avoid both this and problems with condensation, cameras can be kept ready for use in padded camera bags or pouches. For extreme terrain and pack animals use indestructible, 'O' ring sealed plastic cases with padding. Never enter a warmer building or a tent without first placing your camera equipment into a sealed case or polythene bag, if you do not, your equipment will soon be covered in condensation. When inside, give the equipment time to reach the new ambient temperature before taking it out to clean it or change film. If there are rats, a common occurrence in fishing or mountain huts, shut your synchronization cables away as they like to nibble at them. FILM Due to having less layers of emulsion, Kodachrome film is thinner and more flexible than E6 process film and therefore less likely to tear during wind-on when cold. However, in extreme cold there is still the chance of getting streaks on the film due to the discharge of static electricity so wind and rewind film slowly, it is best not to use a motor wind. CLOTHING Modern western clothing is considerably more efficient at keeping you warm than any Eskimo, animal-skin clothing. This is particularly true of footwear where double-layer, hunting boots are much cheaper than double-layer climbing boots. It is most important to have dry socks and dry inner layers for your boots, either carry spares and change them every day or dry them out by keeping them next to your body in your sleeping bag overnight. A warm four-season sleeping bag is essential, tiredness from lack of sleep is a prime cause of accidents. Do not forget to wear warm headwear, as a cold brain will imperceptibly cease to function. ETIQUETTE Apart from asking permission before photographing local people, if you return to an Eskimo or any Third World community carrying prints of people taken on a previous visit, make sure that those shown in the pictures are still alive before passing them around. In the Third World most people die young, often from accidents. About the author Mountaineer, diver, photographer, lecturer and author, JACK JACKSON has travelled the remoter areas of Asia, Africa, Europe and the Far East since 1967. Regularly photographing in extreme conditions from the heat of the Sahara Desert to the cold of the Arctic and from high mountains in the Himalayas to the depths of the sea where he specializes in shark photography. Nikon Cameras (UK) staged an exhibition of his underwater photography in 1989. Author of 14 books, Jack has won several photographic awards and two book awards. He is a Fellow of the Royal Photographic Society, a Fellow of the Royal Geographical Society, a member of the Alpine Club, the Climbers' Club and the Scientific Exploration Society and is a consultant to the Expedition Advisory Centre.