Showing posts with label Photograph. Show all posts
Showing posts with label Photograph. Show all posts

Tuesday, April 14, 2009

13 Tips for Improving Outdoor Portraits

With my very first digital SLR there was a sigh of relief, everything was going to be so much easier now and I didn’t have to think anymore.

You know the scenario; you pull the camera out, charge the batteries, go for a walk around the house and down the street taking the same pictures you have taken every time a new camera came into your life. “This is great!” you think to yourself, “this is going to make my life so much easier!” I was wrong… In fact, I was dead wrong.

There are three very simple things that improve all photography, including portraits. To this day, there is no trick I have found that replaces the need forproper exposure,white balance, andsharp focus. Today’s digital cameras have less exposure latitude than a roll of Kodak gold film. In-camera metering systems have become much more advanced, but the sensors still lack the seven ƒ-stop exposure latitude that negative film has.

1) Never select all of the focus points for portraits, pick one.

When you pick the autofocus option that allows the camera to select focus points, you are doing your portraits a terrible disservice. This feature of a camera is usually designed to pick whatever is closest to the lens and focus there. In some cases, like with my 1DS Mark III, the camera will choose a cluster of focus points and make a “best guess” based on averaging the distance between all of the chosen points. Using one focus point gives you, the photographer, ultimate control.

2) Always focus on the eyes.

The eyes are the windows to the soul, and should be the focal point of any good portrait. Not only are the eyes the most important part of a good portrait, but they are the sharpest element on the face and should be left that way. When you are shooting with a wide aperture value focused on the eyes, the lens’s bokeh will aid in softening the skin as well.

Image by Geomangio

Image by Geomangio

3) Shoot wide open for shallow depth of field.

There are quite a few reasons to invest in a fast lens capable of wide aperture values; the most common is for shallow depth of field. Now that you can shoot at ƒ2.8 or ƒ4 you should use it. Most fantastic natural light portraits are from wide aperture values and it is all because of the wonderful smooth background blur we call “bokeh”.


4) Never, ever, shoot a portrait at less than 50mm; try to stay at 70mm or higher.

The last thing you want to hear from a client is “Why does my head look swelled?” Any focal length below 70mm can distort your subject, however it doesn’t become very noticeable until you are below 50 MM. The compression effect of a telephoto lens will also increase the blur of bokeh. Most of my portraits are done between 120mm and 200mm.

5) Always shoot in RAW.

A thousand times these words have bellowed from my mouth, and it will surely come out a million more. Raw is an unmodified compilation of your sensors data during the time of exposure. It is your digital negative. When you shoot in JPG format, everything but what the image processor needs to make a shell representation of the image you intended to capture is stripped away. For every edit you make to a JPG, you lose more data. With RAW, you can make a vast range of edits before creating the JPG. How can this make you portrait better? Think about the last time your white balance was set incorrectly, and you tried for hours to remove the color cast only to destroy the image with every attempt. RAW would have saved you by allowing you to fix the color before opening the image for retouching.

6) Always bring a gray card or a piece of a gray card for white balance.

You got me, gray cards aren’t free. However, $5.95 US for a cardboard Kodak gray card is darn close. To avoid confusion, I am going to explain this backwards. When opening Adobe Camera Raw or any other RAW image editing application there is always a way to select a custom white balance. Usually it is an eyedropper of some kind that you can use to click on what you think is neutral gray in your image. Imagine a world where your photo shoot involved 4 locations and a total of 800 images, and all day the camera was set to Auto White Balance. That is 800 different white balance values, a post production nightmare. If, at each location, you have your subject hold the gray card on the first shot, you will save hours of work. When you open location one (200 images) in your favorite post production application, all you have to do is click the eye dropper on the gray card, select all and synchronize the rest. Precious hours have been saved. (If you plan on taking your time, it may be wise to do this once every 30 minutes or so to compensate for the changing light of day.)

7) Shoot in the shade (Avoid direct sunlight)

Direct sunlight is harsh, makes your subject squint, and creates hard directional shadows and unpredictable white balance conditions. When shooting in the shade, there are no more harsh shadows, only smooth milky shadows created by your subject’s natural features. With proper exposure and white balance, you can make these shots look amazing.

8) Shooting carefully on an overcast day.

Natures softbox is a giant blanket of clouds. A good heavy blanket of cloud cover can help you enrich your colors, and make some very smooth and pleasing shadows.

9) If you must use hot, hard, bright light…

Always try to control the direction, use some kind of reflector, and try to mimic a studio light. Putting the sun directly behind your subject isn’t a good idea, unless you are trying to make a silhouette. When the sun is at my back, I have the subject look off camera (away from the sun) and get very nice results. Another great trick is to wait for a cloud to move in front of the sun, this usually creates a very bright yet contrasted look.

Image by Meredith Farmer

Image by Meredith Farmer

10) Use an existing reflector.

For example, my guess is that about 75% of the delivery trucks on the planet are white. These big white delivery trucks can make amazing fill light reflectors as long as they weren’t painted with an off white. (A yellow tint can change the white balance in your shadows.) Picture framing outlets and craft stores always have medium to large sized pieces of foam core lying around that have been left for scrap. They are usually more than happy to part with these scraps, and if not, chances are there are pieces by the dumpster.

11) Learn the sunny ƒ16 rule.

Why? So you have a baseline for proper exposure in your mind to work with if no other tools are present. The sunny ƒ16 rule states that on a sunny day, with your aperture value set to ƒ16, your shutter speed will be the inverse of the current ISO speed. For example, if your camera is set to ISO 100, and your aperture value is ƒ16, your shutter speed will be 1/100th of a second. On a cloudy day (or when in the shade) you simply use ƒ8 instead. If you own either an incident light meter, or gray card use either for the most accurate exposure instead. (Note: the procedure for metering exposure with a gray card is not the same as a custom white balance.)

12) Bring a sheet and a few spring clamps from home.

Leave the expensive 200 thread count sheets on the bed. You already got them? Well go put them back. You know that cheap old sheet you stuck in the corner of a closet to use as a drop cloth the next time you paint? Go get it. (Another option is to buy the cheapest, lowest thread count, white top sheet you can find.) A queen size sheet is an amazing, cheap, diffuser. Sort of a sever foot soft box for the sun. Wrap an edge of the sheet around a branch or clothes line and clamp for a side light. (Anchor the bottom corners with rocks to keep it from blowing into your image.) Clamp all for corners to anything you can above your subject for an overhead light.

13) Keep the power-lines and signs out!

We have already discussed keeping your camera focused on the eyes; keep your mind focused on the image as a whole. Power lines, signs, long single blades of grass, single pieces of garbage, sometimes even trees can be serious distractions from the overall focus of the image… The person you are photographing.

Last, and most important, have a great time shooting, enjoy what you’re doing and it will show in your work, and the expression of your subject.

A few Bonus Tips on Shooting on Cloudy Days

Clouds are wonderful. They create a giant blanket of natural sunlight diffusion to make your images rich and powerful. The clouds can fool your mind in ways you can’t imagine, much like your mind corrects for the natural white balance throughout the day.

When you are shooting on an overcast day, custom white balance is especially important. Every day is completely different for color, and that color depends on two things. First, the time of day, as most people understand white balance and how it changes throughout the day. Second, you have to account for all of the wonderful things that light has to pass through before it hits your subject.

Pollution changes the color of the light from minute to minute even if your eyes don’t see it, your camera does. On a cloudy day, pollution particles are being carried around in the sky by little tiny prisms; water droplets. Now your sunlight is passing through nature’s prism and reflecting off of pollution particles in infinite directions.

Don’t forget to white balance with that custom, tricked out, six dollar piece of cardboard, your Kodak gray card.

The ultimate secret to shooting on a cloudy day is a compass. (You either tipped your head like a confused Chihuahua or just had an epiphany.) I am an experienced, internationally published photographer, and rarely can I see where the sun is coming from on an overcast day. The light isn’t omnipresent; it’s just diffused, softened and scattered. Sunlight on a cloudy day is still directional, and your subject still has a dark side. Use a compass to find out where the sun is, put it at your back and shoot like mad. Never again will you look at an image after and wonder why the sky is blown out when it was so cloudy, or why the clouds look great but your subject is dark.


Read more: 13 Tips for Improving Outdoor Portraits -http://digital-photography-school.com/13-tips-for-improving-outdoor-portraits#ixzz0CbQIYzQ4

Wednesday, March 18, 2009

『一周回顾』4款新单反镜头+1DsMarkIII上市预测

上周一共有四款副厂新镜头发布,有趣的是,其中有三支为超广角镜头,两支为鱼眼-DSLR厂商们继续利用超广角的视觉冲击诱惑消费者-即便在实际使用中,这种超常规焦段的广角镜头的利用率几乎为零。

四款新镜依次如下:

图丽:
AT-X M35 PRO DX 35mm F2.8;微距镜头,APS-C画幅(也就是说像场无法覆盖Nikno D3等全幅机身)提供Canon EF以及Nikon AF两种卡口,12月底上市,预计上市价格71400日元-按照惯例,实际销售价格应该在40000日元以内;

AT-X 116 PRO DX 11-16mm f2.8;APS-C画幅,支持C/N,2008年2月末上市,94500日元;

Sigma:
10mm f2.8 EX DC fisheye HSM,鱼眼+超声波对焦马达,C/N/S卡口,95000日元,12月上市;

4.5mm f2.8 DC EX Fisheye HSM-目前最广的APS-C画幅广角镜头,对焦行程极短,上市价格12万日元,上市日期未知

除此之外,1Ds Mark III将在本月底正式在日本上市,预计售价90万日元;松下-Leica的14-150 f3.5-5.6因为供货问题推迟一个月上市-最新日期为12月,17万1000日元。

『一周回顾』4款新单反镜头+1DsMarkIII上市预测

成为专业摄影师的15个必备条件

成为专业摄影师也许是每一个摄影爱好者都会有的梦想-每天都能拍照,专业的器材,用摄影作品的收入生活、养家、支付房贷(也许还有人想用这个"浪漫"的职业来找到自己的另一半)。 然而,真正的专业摄影师的生活,其实并不那么潇洒自如?

下面是一个专业摄影师需要具备的一些素质与能力,看看你能接受几条?

1.不断"失业",有时不知道自己下一份工作是什么,有时又必须彻夜工作好几天
对大多摄影师来说,工作总是在长时间等待后不期而至,你能过好那些空闲的日子吗?

2.接受临时任务,快速完成拍摄、编辑,并第二天中午前把照片送到编辑处
对所有摄影师来说,工作的期限总是越来越紧。

3.熟练现有的工作方式,同时能不断学习新技术,并在第一时间使用它们
摄影在不断变化,不会停止,你也得是。

4.能适应"颠沛流离、居无定所"的生活,另外,你的交通工具并不总是飞机-有时你需要搭卡车,有时你需要睡在地板
杂志摄影记者们把那些可以从屋顶的破洞里看到四颗星星的地方昵称为"四星级酒店"。

5.在新闻发布会中,你必须能够拍到与众不同的照片
所有的新闻发布会都一样,但必须让它们看起来不同

6.能够为了图片编辑的需求放弃自己的创造力
编辑需要可以说明问题的照片,而不是展示你个人技巧的那些。艺术属于画廊而非报纸头版。

7.熟识你拍摄的对象,尤其从法律角度来考虑
版权法难以预料。你需要知道哪些建筑的照片可以供给商业用途,而哪些是受保护。(比如艾菲尔铁塔白天的照片可以出售,但夜景就不行。)

8.知道RF ,RM ,CC ,FR 和RR 的区别
作为一个专业摄影师,你需要知道版税和他的几种缩写。 RF:免费;RM :受限版权;CC :创意保护;FR:全分辨率图片; RR:有限分辨率

9.能够制作图片专辑
把照片做成组照比仅提供一批照片更容易吸引客户。因为组照不光可以展示才华,更表明你是一个可靠的摄影师

10.在没有项目的时候,可以教授摄影或写书
这可帮助你保持基本的生活来源,拒绝那些不喜欢的工作,同时保持对摄影热情

11.可以和不同阶层的人们轻松地交流, CEO ,总统,以及他们的司机
作为专业摄影师,也许你前一天还在拍某位总裁,第二天就要给一群工人拍。你必须能够适应不同的拍摄对象和环境

12.与客户,编辑以及代理人保持良好合作
摄影是商业化的,认识的人和你的才能一样重要。你必须知道如何去组织和维护你的关系网

13.能在告诉别人怎么做的同时,乐于接受别人的命令
作为一个商业摄影师,你需要告诉模特如何摆姿势,同时,又需要按照别人的命令去拍摄

14.知道如何处理合作与竞争
摄影师们可以是一个很紧密的团队,也可能时刻都在为了出一张最好的照片而竞争。你需要知道什么时候应该合作,什么时候该为完成自己的工作而固执

15.当你的照片出现在画廊,头版,或者是书店时,可以享受到的自豪
专业摄影师是份艰难的工作,但是它也会给你丰厚的回报

你不可不知的12条经典摄影技巧——Photography Tips Top12

摄影是一门技术,同样也是经验的积累。下面是无数摄影师的经验汇聚而成的12条最经典、实用的摄影技巧Tips,将其熟记于心,将帮助你应对很多难以掌控的拍摄场景。推荐收藏。

1.Sunny 16 Rule (阳光十六法则)
"Sunny 16 Rule"是在没有测光表时,正确估算日光下曝光数值的方法,所以这条法则只有在阳光充足的情况下适合使用。将光圈设为F/16,快门与ISO同步,或者略快。如,ISO设为100时,快门应该设为1/100秒(1/125秒)。所以,根据这个法则,在海滩上摄影时,应该使用F/22光圈,在多云时应使用F/11光圈。

2.Moony 11,8, and 5.6 Rules (月光11,8和5.6法则)
如果你想拍摄月亮,那么这里有一条很好的法则。快门与ISO同步的时候,拍摄满月用F/11光圈,弦月的时候用F/8光圈,新月则使用F/5.6光圈。

3.Camera Shake Rule (相机抖动法则)
当你手持相机拍摄时,快门的速度不能小于镜头焦距的倒数。如果快门速度越慢,那么拍摄抖动时就越可能降低锐度。如果用50mm焦距的话,快门就要达到1/60秒以上为宜,只有当环境实在昏暗时,用闪光灯、脚架或者把相机放在硬物上防止抖动。

4.Anatomical Gray Card (灰板法则)
随身携带18%的中灰度板是拍摄的利器。可是如果身上没有灰度板怎么办呢?可以将手掌摊开面向阳光,对手掌进行测光,然后加一档曝光。

5.Depth of Field Rules (景深法则)
当被摄无题比较深的时候,应该对焦点选择在景深的前1/3处,因为这样,对焦点后的景深是之前的2倍。各种光圈和焦段组合都可以使用这个法则。记住,光圈越小,焦距越短,距离被摄物体越远,景深就越大。

6.Largest Digital Print Rule (数码冲印尺寸法则)
如果你想把你的作品打印成大尺寸的照片时,照片的尺寸不能大于数码图片的长宽像素各除以200.如果你对作品要求很高,那么至少得除以250。

7.Exposure Rules (曝光法则)
在处理数码照片时,最普遍的法则是保证高光区曝光准确,低光区随他去。可是当处理负片,特别是彩色负片的时候,你最好增曝一档。

8.Quick Flash-fill Rule (快速闪光输出法则)
当你的相机不能自动输出控制的闪光灯时,将闪光灯的感光度设为胶卷的二被。如果对主体测光,机身选择光圈整档,闪光灯设为同样的光圈。这样,照片的阴影区会比主体的亮度低一档。

9.Flash Range Rule (闪光距离法则)
这个法则很简单:距离乘以2,感光度乘以4。例如,你的闪光灯在ISO 100时,有效距离为20英尺。如果你想使闪光灯的距离达到40英尺时,则需要ISO 400。

10.Megapixel Multiplier Rule (像素翻倍法则)
如果你想使数码相机的分辨率增倍,那么很简单,就是要像素翻两番。

11.Action-stopping Rule (捕捉动态法则)
这条法则是根据角度与速度的经验公式而来的。如果物体沿着镜头的轴线运动你能够用1/125的快门捕捉下,那么它追至于镜头轴线的运动能用1/500捕捉下来。也就是说,如果物体沿镜头轴线称45度运动,只需要1/250的快门速度。

12.Sunset Rule (日落法则)
拍摄落日时,要对落日上部测光,但是不能让太阳出现在你的取景器中。如果想让日落看上去比实际晚一小时,可以在曝光补偿中减1。

Monday, October 8, 2007

景深的实际拍摄照片

先介绍几个概念:

1、焦点(focus)

与光轴平行的光线射入凸透镜时,理想的镜头应该是所有的光线聚集在一点后,再以锥状的扩散开来,这个聚集所有光线的一点,就叫做焦点。

2、弥散圆(circle of confusion)

在焦点前后,光线开始聚集和扩散,点的影象变成模糊的,形成一个扩大的圆,这个圆就叫做弥散圆。

在 现实当中,观赏拍摄的影象是以某种方式(比如投影、放大成照片等等)来观察的,人的肉眼所感受到的影象与放大倍率、投影距离及观看距离有很大的关系,如果 弥散圆的直径小于人眼的鉴别能力,在一定范围内实际影象产生的模糊是不能辨认的。这个不能辨认的弥散圆就称为容许弥散圆(permissible circle of confusion)。

不同的厂家、不同的胶片面积都有不同的容许弥散圆直径的数值定义。一般常用的是:

画幅

24mm x 36mm

6cm x 9cm

4" x 5"

弥散圆直径

0.035mm

0.0817mm

0.146mm

35mm照相镜头的容许弥散圆,大约是底片对角线长度的1/1000~1/1500左右。前提是画面放大为5x7英寸的照片,观察距离为25~30cm。

3、景深(depth of field)

在焦点前后各有一个容许弥散圆,这两个弥散圆之间的距离就叫景深,即:在被摄主体(对焦点)前后,其影像仍然有一段清晰范围的,就是景深。换言之,被摄体的前后纵深,呈现在底片面的影象模糊度,都在容许弥散圆的限定范围内。

景深随镜头的焦距、光圈值、拍摄距离而变化。对于固定焦距和拍摄距离,使用光圈越小,景深越大。

示意图1

示意图2

以持照相机拍摄者为基准,从焦点到近处容许弥散圆的的距离叫前景深,从焦点到远方容许弥散圆的距离叫后景深。

4、景深的计算

下面是景深的计算公式。其中:

δ

——

容许弥散圆直径

f

——

镜头焦距

F

——

镜头的拍摄光圈值

L

——

对焦距离

ΔL1

——

前景深

ΔL2

——

后景深

ΔL

——

景深


FδL2


前景深 ΔL1=

——————

(1)


f2 + FδL



FδL2


后景深 ΔL2=

——————

(2)


f2 - FδL




2f2FδL2

景深 ΔL =

ΔL2 + ΔL2 =

——————



f4 - F2δ2L2

从公式(1)和(2)可以看出,后景深 > 前景深。

由景深计算公式可以看出,景深与镜头使用光圈、镜头焦距、拍摄距离以及对像质的要求(表现为对容许弥散圆的大小)有关。这些主要因素对景深的影响如下(假定其他的条件都不改变):

(1)、镜头光圈:

光圈越大,景深越小;光圈越小,景深越大;

(2)、镜头焦距

镜头焦距越长,景深越小;焦距越短,景深越大;

(3)、拍摄距离

距离越远,景深越大;距离越近,景深越小。

5、一些计算实例

网上有些在线计算器,有兴趣的网友可以参考:

摄影光学计算器

Windows版本的可下载的计数器在

f/Calc

(1)、200/2.8对焦在5m时,f/2.8的景深:

δ

=

0.035mm

f

=

200mm

F

=

2.8

L

=

5000mm

ΔL1

=

60mm

ΔL2

=

62mm

ΔL

=

122mm

结论

:

该镜头在用f/2.8拍摄时,清晰范围是从4.94m~5.062m,景深很浅。

(2)、200/2.8+2X=400/5.6对焦在5m时,f/5.6的景深:

δ

=

0.035mm

f

=

400mm

F

=

5.6

L

=

5000mm

ΔL1

=

30mm

ΔL2

=

31mm

ΔL

=

61mm

结论

:

该镜头在配合2X增距镜后,主镜头用f/2.8拍摄时,景深是(1)的一半。


景深的实际拍摄照片

摄影:什么是景深

景深的控制在摄影技巧中有着举足轻重的地位——它能直接影响照片主题的突出,以及画面的整体效果(层次感)。

  • 什么是景深

使被摄物体产生较为清晰影像的最近点至最远点的距离就是景深。也是被摄物体能清晰成像的空间深度。在景深范围内景物影像的清晰度并不完全一致,其中焦点上的清晰度是最高的,其余的影像清晰度随着它与焦点的距离成正比例下降。

因此可以得出(或者简单来说):景深的深浅取决于焦点的位置。

  • 如何控制景深

调节焦点的位置,景深也就自然而然得到相应的调整。相信大家都知道影响焦点位置的因素:光圈,焦距,摄距(物距)。

这三者与景深的关系如下:

  1. 光圈大,景深小;光圈小,景深大。
  2. 焦距长,景深小;焦距短,景深大。
  3. 物距近,景深小;物距远,景深大。

以上三种关系是控制景深的常用的方法。当然了,在不同的情况下,具体的操作也会有些不同。大家多多尝试就能体会到其中的奥妙了~