如何拍摄清晰锐利的照片

澳洲大头

转自：http://www.digital-photography-school.com/advanced-tips-for-tack-sharp-images

一个老生常谈的问题：我为什么老也拍不出像网上看到的那样清晰的照片？我们也常看到一些拍清晰照片的技巧，比如拿稳相机、轻按快门、收紧胳膊等等。这些只是一个好的开端。

这样跟你说吧。我到现在还常常拍糊片。所有的专业摄影师都会拍糊片。不同的是他们不会把糊片贴出来。但是我敢说，我拍糊片的几率要比其他摄影师少的多。这是有原因的。拍摄清晰照片需要好几个方面的技巧。只有把这些技巧结合起来，你拍清晰照片的成功率就会大大提高。


Auto-Focus 按钮


一点不骗你，我与之交谈过的摄影师中，90%的人不用这个按钮。每次我问：你怎么对焦？答案都是半按快门对焦然后再按下去拍照。这样做的问题是，你每照一张相机就重新对一次焦。如果你的被摄物在远处而你和被摄物之间有人走动怎么办？你无法设置你的焦距。你只能等，希望你按快门时没人走来走去。


几乎所有的相机背后都有一个标有“AF On”的按钮。你可以通过相机设置将其设成Focus trigger。这样，你就可以用它对好焦距然后想照多少张就照多少张。焦点不再变动。快门就是快门，不再干对焦的活。



单点对焦


摄影师必须搞懂照相机替你做决定和你告诉照相机怎么做的区别。 大多数摄影师半按快门然后由照相机决定将焦点对到哪里。绝大多数情况下都没什么问题。这通常是因为被摄物比较明显，照相机很容易就找到被摄物的反差元素从而对焦。这种简单的方法大多数情况下都没问题。但是，如果你开始玩定焦镜头、浅景深，你的片子就会出现问题。

如果你用200mm的焦长、f/2.8的光圈拍3m远的被摄物，你的景深只有38mm！也就是说被摄物在2.98m处开始进入实焦范围，在3.02m处脱焦。你愿意把这38mm交给相机来掌握吗？要是它把焦点对到鼻尖上会怎样？你会发现你的被摄者眼睛糊掉了。

（以下有时间接着翻译）
Your camera should have a button (top right in image) that shows how the camera is focusing. The default is to have all the focus points on and the camera uses those points to decide where to focus. Instead, press the focus grid button and use the joy stick (bottom left in image) to decide where to set your focus point. Instead of a bunch of focus points popping up when your go to focus your subject, you will now only see the single focus point that you set. Now if you want to focus on your subjects eye, place your selected focus point over the eye and simply tap your AF-ON button. Your focus is now set for that mark in the frame. The only thing you need to worry about now is movement.

AI Servo Focus Tracking


Funny name, serious setting. Getting your camera off of “One Shot” can be revolutionary to your photography if you have yet to discover Servo focus mode. Here’s an example of how Servo works: You’re shooting a wedding during the end of the ceremony. You are at the end of the aisle and the wedding party is walking down toward you. You are shooting at f/2.8 because it’s dark and you want to let in as much light as possible. Your depth of field is 6 inches. With “One Shot,” your camera only focuses on the subject each time the focus button is pressed. You then have to press the shutter to take the picture. With a depth of field of 6 inches, and the wedding party walking towards you in groups of two, your window of opportunity to get your shot in focus is incredibly small. One strategy is to just try and be quick, pressing the focus button and shutter in succession as quickly as possible. Another strategy is to set a mark on the aisle as a window of opportunity and wait for each person to hit that mark, then take the picture. This is hit or miss though, and you only have one chance. You don’t want to take chances like this at a wedding!

Enter AI Servo
When you switch your camera over to AI Servo, everything changes. Servo was introduced as a standard camera setting all the way back in the 80’s, by request of several sports photographers who needed a better way of ensuring focus on moving subjects. With Servo activated, now your camera will track focus on the wedding party as they move toward you, and will keep updating every step of the way. This works whether the subject is coming toward, or moving away from you. In your menu settings, you can even adjust the sensitivity of the focus tracking.

Examples Using These Tips



This shot is from a meet and greet session with the band Jars of Clay, at a concert in Austin, Texas. The manager told everyone not to worry about taking pictures until after the show because any meet and greet pictures would be boring. I took that as a challenge. I sat patiently for the right moment and when I saw their lead singer make eye contact with my lens, I fired away.
With normal focus methods, this shot may not have been possible, and I don’t like taking chances. If I used grid focus, how would my camera know to focus on HIS face, and not something else in the frame? Instead of using the entire focus grid, I turned on a single auto focus point and placed that point over the lead singers face. I then used my back button to focus that point over his face and waited for the right moment. When he looked my way, everything was already done, all I had to do was hold down the shutter.





This is one of my favorite pictures I’ve taken. It’s my nephew Will being spun around by his dad Billy (my brother in law). I think the image embodies the love between a father and a son, and what better backdrop than fair grounds? With factory set focus methods, the probability of pulling off this shot would have been slim to none. Sure, you can spray and pray, and hopefully you will end up with a keeper, but what if you don’t? The moment is gone! For this shot, I had a single point activated in my focus grid and used AI-Servo to track my nephew as he spun around in circles. Because I had back button auto focus on and Servo tracking, I was able to hold down the focus button to track focus as he spun around. This allowed me to track focus using my thumb and hold down the shutter with my index finger. Trust me, this stuff becomes crucial when you start using shallow depth of field like in this shot.





I took this shot during a family shoot last spring. I was having a tough time getting this little guy to open up to the camera and I had to figure something out quick. I noticed a ledge (as seen in the background) and made a bet with him that there was just no way he could jump off that ledge because it was only for big boys. Well, that was all it took! Within seconds he was up on the ledge with a smile on his face, ready to prove me wrong. Again, I used Servo focus tracking and held it down during the jump using back button focus. I grabbed this frame as he made a bit of a rough landing.





This image was taken at Carlsbad State Beach in southern California. This surfer girl noticed my camera and came running up the beach to greet me and talk photography. She was also a photog and wanted to make sure I didn’t get a shot of her wiping out! As she walked back out to catch some more waves, I grabbed this shot of her. I placed a single AF point over her back, then held down Servo focus tracking so my camera would keep her in focus as she walked away. When the moment was right, I held down the shutter to capture a hand full of frames. This was the winner. Conclusion
These focus tips completely rocked my world when I discovered them, and they will always be part of my work flow, now and in the future. I probably use AI Servo about 90% of the time. The only time I don’t is when it’s too dark for the camera to focus without an assist beam from a flash. To use a flashes focus assist grid you have to be in “One Shot” instead of AI Servo (at least as far as I can tell). I don’t see any reason to ever go back to using my shutter button for focusing. I have never looked back on that front! And as far as grid or single point AF goes, it’s pretty much the same story. I use my entire grid maybe 1% of the time.
If these tips are new to you, I urge you to stop what you are doing and give them a shot. I will admit, using back button focus and single AF points takes some getting used to, but eventually it becomes second nature. At this point, I can switch focus points on my grid in the blink of an eye, and using the back button for focus is instrumental in placing those points of focus on their targets.

柞里子

转自：




一个老生常谈的问题：我为什么老也拍不出像网上看到的那样清晰的照片？我们也常看到一些拍清晰 ...
澳洲大头 发表于 2010-12-17 09:07

还真就是老生常谈。嘿嘿。

幸福剧团

MyNameIs

类似的东西我在日志里转贴过，现在看来应该是部分翻翻译的这篇文章。
感谢。

lao5

基本的技巧要年年学月月学天天学

jimbo

我还正在琢磨这几个按钮的功用呢，大头这顺来的及时呀。。。

澳洲大头

我还正在琢磨这几个按钮的功用呢，大头这顺来的及时呀。。。
jimbo 发表于 2010-12-17 10:43

    我也是。从说明书上了解到它的功能，但从来没用过。这回一定要试试。。。。。

袜贩

你这不是和猪猪唱对台戏吗？ 她强烈主张不清楚的片子才是好片子嘛。

再说，用我们C家的相机解释，不觉得有张别人志气，灭自己威风之嫌吗？

这个AI servo对焦也不尽然都好，特别是在兔子上。我拍球赛基本都是用这个。它在兔子上的问题是，兔子的暗藏辅助对焦点只有9个，而且都非常集中在中间很小一块地方。一旦目标脱离了中心点，很容易对焦点就跑到背景上了。而尼康D300/D700在这方面要好的多。它们有51个之多，分布面更广，更容易跟踪移动中的目标。

珞珈山

在拍风景时，还是手动对焦比较可靠，也是对好一次后，想拍多少就拍多少。

问题多

e-p1上这个功能特好用。我现在用的5D镜头不能自动对焦了，所以我全靠爪子对焦，嘿嘿。

Stone

很好的教材，谢大头分享！

Stone

这个AI servo对焦也不尽然都好，特别是在兔子上。我拍球赛基本都是用这个。它在兔子上的问题是，兔子的暗藏辅助对焦点只有9个，而且都非常集中在中间很小一块地方。一旦目标脱离了中心点，很容易对焦点就跑到背景上了。而尼康D300/D700在这方面要好的多。它们有51个之多，分布面更广，更容易跟踪移动中的目标。
袜贩 发表于 2010-12-16 19:18

这就是为什么无敌兔拍体育飞禽不好，要用7D来拍。。。嘿嘿，再上个7D吧。。。19点对焦把整个取景器都包下来了。

moonbay

看到过摄影师按那个AF-ON，可还是习惯性地半按-全按老一套。时间一长，这些好功能都忘了。大头

rpan

我上周和老满讨论此事，认为摄影就是凭感觉。当然，感觉要靠平时积累。我到觉得珞珈山已是接近专业了。这主要是指时间和精力的投资。我想大都是玩玩而已。能做更好当然更好。毕竟我们已不能三十年后再改专业吧。享受生活，时间这才是最重要的。想象很多已离开我们的同龄人，我们够满意了。为什么叫老满呢？

袜贩

这就是为什么无敌兔拍体育飞禽不好，要用7D来拍。。。嘿嘿，再上个7D吧。。。19点对焦把整个取景器都包下 ...
Stone 发表于 2010-12-17 16:07

不会买7D的，要上也是5D3了。到时迫于竞争压力，必然会大幅改进被人病诟的自动对焦系统。