|
a*f
发帖数: 5682 | 2 可以用Ambient LightSensor测光, (不过准不准就看机器了, 尚未加入校正功能) 也可
以手动设置Exposure Value.
通过这个EV值来计算一定光圈和ISO下面的快门速度. 玩手动相机并且用Android手机的
同学们可以下来玩玩.
到market里面搜索Light Meter, 那个猫头做Icon的便是.
下个Vesion加入calibration功能 (不过大部分手机上的ambient light sensor很不准,
calibrate也calibrate不准:)
再下一个Version加入DoF计算
再下一个Vesion 加入超焦距计算. |
|
|
s********n
发帖数: 1865 | 4 我是对着落日逆光用300mm （70-300vc)/f5.6。快门速度优先，具体多少忘了，大概是1/250或者更快，因为风挺大，草晃的厉害。背景虚化而且是弱光。为了达到这个快门速度ISO调到600还是800忘了。直出RAW，背景还是看得出来，所以用LR把dark调低，高光部分加强。对比度加强。所以背景就变黑了。第一张顶上的叶子后面正好有一大块虚化的背景稍微亮了点，带点雾蒙蒙的感觉，于是留下了。第二张完全把背景去掉。
后来的处理图片的时候悟出一个道理：当时其实应该把光圈stopdown到8左右。这样DOF可以足以把那枝上的所有叶子都变得清晰。以后有时间再试试。 |
|
o*4
发帖数: 417 | 5 I usually use manual, but you could use AV or others. I decide F stop first
and let the camera decide speed because DOF is important for landscape
photos.
dep |
|
T****i
发帖数: 15191 | 6 你Flickr上的2011 spring 090 挺不错的。要是DOF再深一些就更好了。 |
|
s****m
发帖数: 229 | 7 啥镜头反接都行。50mm反接差不多1:1. 24mm的话放大可能3:1.
试过10mm反接，放大有7-8倍,但太难拍了。 DOF可能就一毫米。 |
|
a*f
发帖数: 5682 | 8 interesting composition, nice control of dof. I am not sure about the color
though |
|
a*f
发帖数: 5682 | 9 拍展品对景深的要求不大。大幅相机同样光圈下的景深也比DC小很多很多。有耐心稍微
花点时间研究一下的话，可以搜索dof calculator, 算一下比较一下，对你了解摄影原
理应该会有帮助。 |
|
t***e
发帖数: 2138 | 10 我觉得studio照有两个问题需要明确。
一个是光圈，对闪光灯的影响和对景深的影响。多人照起码要保证大家都在dof内。
还一个是光的摆放，invetse square rule，要么是多灯保障每个人都得到均匀的光照
，要么控制灯到主体的距离，使不同主体的光照强度不会有太大差异。 |
|
|
i*****t
发帖数: 2435 | 12 从自身使用DX和FX的经验来看，确实没有很大的分别。高感的提升是最直接的优点。其
它的例如DOF DR在曰常使用中的优点不是很明显。
★ 发自iPhone App: ChineseWeb 7.5 |
|
|
b*****t
发帖数: 3928 | 14 These questions are case by case, don't you think so? With modern flash
light and camera, setting aperture is no longer for how much amount of flash
light you can obtain, but how you want your ratio of flash light and
surrounding light to be as well as your desired DOF. |
|
a*f
发帖数: 5682 | 15 暂定名为景深
http://dof.io
Google+社区的好处是可以很方便把看到的图片转贴过来（一般都有+1button，没有的
话装一个chrome extension也很方便），自己上图也可以，普通尺寸不限存储空间，原
尺寸的话有15G免费空间。这样大大简化上图程序。以后我看到的好图好网站主要在那
里发布了。 |
|
|
i***f
发帖数: 10682 | 17 换尼康有51点对焦连拍快的机器。DOF在那里摆着，就是要靠机器快准加上使劲按。 |
|
i****4
发帖数: 79 | 18 Shutter Speed is measured in? second , time?
Aperture is measured in? opening ? f-stop? dof?
Shutter Speed controls? vactor? motion? duration of exposure? how fast the
subject move?
Aperture controls? intensity of light? duration? f-stop?
thanks |
|
b*****t
发帖数: 3928 | 19 Do u still own dof.io? It's on sale for $2888. LOL!
: 期待zhuzi或者yo出现。。。
|
|
|
y*********e
发帖数: 7269 | 21 ☆─────────────────────────────────────☆
anoia (阿诺,不能再这么烧器材了,痛定思痛) 于 (Sat Mar 31 21:23:22 2007) 提到:
条件如下
规定构图比例是3：2（135的）
系统一：中副，但是在底片上画个frame，限定了一个3：2的cropping ratio以方便
跟135系统的比较。现在有一个中副镜头lensA
系统二：135，有个135镜头lensB
field of view：lens A＝lens B
现在用系统一和系统二，对一群物体拍摄（有远有近），采用完全相同的构图（
cropping）
这个时候，拍出来的照片perspective是一样还是不一样（不考虑DOF,DISTORTION）
我的意见是，perspective只跟距离有关，相同的构图的情况下，FOV相同的系统
距离相同，perspective不变。
简单说，距离决定perspective，镜头的焦距则决定cropping
而shadowleaves的意见是中副的因为底片大小变了，所以perspective会有变化
（如果我没有理解s |
|
v********d
发帖数: 3531 | 22 昨天在学校里面来了个美女模特！
同学们都非常激动，这个老师特别鼓励大家shoot with available light. 现在的同学
们纷纷患上定焦头。几个小白的同学非常郁闷，IS也不能和定焦大光圈比！
最烧的还是85F1。2，现场有两个。一个owner特nice.大家聊了一会，他说，你要不要
试试？我激动阿！这就是传说中的圣镜！室内的modeling light不是很亮，我的50F1。
8要ISO800，60/F1。8。
这个基本可以做到高两档，ISO400，120，F1。2。非常sharp.好像是72的filter size.
感觉大头，就是比小头气派！拍了几张觉得很激动！后来回家才发现，全是糊的，想起
当时那大哥说的，太近的话，因为DOF太小，你会发现全是糊的，当时还不知道什么意
思！
后来又换了200F2。8，觉得不知道这个头有什么存在的意义？对焦很慢，USM的680美元
，比起70-200 F2。8就便宜了500元。但是，感觉200端，这么慢的对焦速度特气人！但
是这哥们是铁杆定焦粉丝，觉得就是定焦好！
体会了70-200F2.8 IS,觉得还是可以，不算太重！就是有点太 |
|
n*****s
发帖数: 10232 | 23 Here are the answers:
1) For an equivalent field of view, the small-sensor camera has at least 1.
6x MORE depth of field than a full-frame camera would have - when the focus
distance is significantly less then the hyperfocal distance (but the full-
frame format need a lens with 1.6x the focal length to give the same view).
2) Using the same lens on a small-sensor camera and a full-frame camera, the
small-sensor image has 1.6x LESS depth of field than the full-frame image
would have (but they wou |
|
o*******p
发帖数: 722 | 24 I shot some photos and video footage under various conditions. My
conclusions:
1. D90's iso400 is as good as iso100. way better than D80.
2. Video function is limited. No direct way to control shutter speed and iso
. Must use exposure lock, otherwise the results won't be good.
3. 5-min is not a bottle neck, but no autofocus is pain, especially for
shooting kids.
4. But the video quality is much better than miniDV, close to HDV.
5. The main advantage of D-Movie on D90 is that you can get 35mm DOF |
|
h******g
发帖数: 11250 | 25 技术贴来了!
适合于理工科新手，文科新手可跳过公式直接看讨论。
一、景深(DOF)
人眼所能分辨的最小距离是d
假设d=0.1mm
如附件一所示，根据相似三角形，有
v1-v d |
|
s**********s
发帖数: 7387 | 26 ☆─────────────────────────────────────☆
kathyy (om1n) 于 (Mon Feb 16 22:51:55 2009) 提到:
http://www.canonrumors.com/2009/01/video-with-any-liveview-eos-camera/
俄国人写了个类似EOS Utility的小程序，可以在电脑上capture Canon DLSR liveview
stream，1024x680像素（EOC Utility似乎只有640x480）输出成avi, 帧率跟usb写入
速度有关，20-30fps.程序还很不完善，在继续更新中，比如0.1.4版还没有EOS
Utility的DOF preview功能，要取得最大光圈以外的其他光圈需要按相机上的景深预览
，450d就玩不了了。
☆─────────────────────────────────────☆
kathyy (om1n) 于 (Mon Feb 16 23:57:26 2009) 提到:
☆──────────────────────── |
|
|
|
|
|
|
c********y
发帖数: 30813 | 32 1st, DOF covers most of error from recompose.
2nd, when on tripod, i'd rather use liveview for even better focus accuracy.
3rd, so you still want to recompose?
4th, if recompose wastes time, how about changing focus points?
preferred |
|
s*******g
发帖数: 3332 | 33 我平时（用5D)90%以上用中心点focus，然后re-compose,因为我觉得切换focusing
point太慢，re-compose快多了，而且中心对焦点最准最快。
大多数情况下没什么focusing的问题，但是在dof比较浅的时候确实focusing point会
不准，这个我上周用85L在公园里拍照的时候深有体会。
不过Nikon的51点对焦点太集中了，我感觉实用性并不是很好，更多是噱头。 |
|
c******q
发帖数: 2995 | 34 1. by "with larger aperture", you mean aperture larger than? 2.8? 3.5?
sorry im not familiar with DoF of different apertures...
2. LV is acurate, but indeed slow..
3. "way better off using a focus point closer to the ideal position than
using center focus point"
agree, only if you have a good AF system, like Nikon or 7D, 1D.....
for other Canon machines, and even worse--the where-is-my-red-point Pentax
machines, better use center AF....
thats just my two cents..... |
|
b**********8
发帖数: 1002 | 35 larger the aperture, smaller the depth of field. when you set your lens to
F1.4, your dof is usually as thin as an inch or two.
Liveview is useful, on some occasions. But I find it clumsy and unnecessary
most the time. For instance, when i shoot a flower or bug from a camera
mounted on tripod, there's no need to recompose, so using viewfinder is just
as effective.
You know what is the most ironic portion of this discussion is that finally
someone is bringing the photographer(s) rather than equip |
|
a***n
发帖数: 1500 | 36 Better Construction + MLU + DoF Preview.. If someone values that?
On the other hand, 550 has main sensor Live View, better FPS and arguably
better high ISO performance.. |
|
f******h
发帖数: 609 | 37 That could be one way out...
But in most of the cases the left hand is holding on the lens instead of
camera. So it's not convenient to reach the DOF bottom.
Thanks. |
|
a***e
发帖数: 27968 | 38 the dof is right next to lens,
very easy to reach, unless you are using those telephoto |
|
s**********s
发帖数: 7387 | 39 i'm pretty sure tilt will work. however, w/o tilt it's also very practical
to include the entire pic in the DOF.
the first pic is shot by 21mm (31mm in 135 format), which gives a hyperfocus
of 0.5m-inf at f/22 when focusing at 1m. DA21 has a closest focus of 0.2m,
but honestly, i don't think she shot at that close (DA21 @ 0.2m means 1:6
magnification ratio and i don't think that flower is so small).
In a sunny day, f/16 @ ISO 100 will give 1/100 sec, and f/22 @ ISO 100 is
about 1/50 sec. even at |
|
k****t
发帖数: 12697 | 40 效果很显著是指? MF? STOP DOWN 观察DOF?
你用转接头吗? |
|
|
|
|
w*******8
发帖数: 139 | 44 我是说以数字的形式显示在LCD上
景深预览就是个摆设 |
|
|
|
|
|
w*******8
发帖数: 139 | 49 根据光圈，焦距和物体距离就可以算出来吧。这些信息都已经有了，为什么不用呢？ |
|
|
