|
y*b
发帖数: 3190 | 2 "A new Sigma Art series lens has leaked. It looks like Sigma is adding a
20mm f/1.4 DG Art to their already stellar Art series lineup.
Sigma 20mm f/1.4 DG Art Specifications:
Designed for 24×36 DSLR cameras
Lens construction: 15 elements in 11 groups
One large-diameter aspherical element
Two FLD elements and five SLD elements to best correct chromatic aberrations
In-lens HSM autofocus motor. New mechanism for full-time manual override in
autofocus mode
Total length: 129.8mm
Maximum diameter: 90.... 阅读全帖 |
|
e**n
发帖数: 5876 | 3 BF将至，m43镜头选择不完全指南 (2015)
需要反复强调的是: 决定最终画质的, 机身最多占到一半, 另一大半是镜头. 镜头才
是一个系统的灵魂.
可换镜头相机的精华就是要换镜头. 想用套头一镜走天下不换镜头就不应该买可换镜头
相机. 还不如买LX100, 等效焦距光圈相当于M43配12-37mmf2-3的镜头, 或者是APSC上
配一个16-50mmf2.6-4.1的镜头. 体积还小得多.
M43的精髓就在它的镜头群. M43镜头群数量多质量好,主要原因有2个:首先是有OP两家
在做,既有补充又有竞争, 其次M43是OP两家唯一的相机线,所以两家都是全力以赴做好.
而既有APSC,又有FF线的厂家,往往不会在APSC上尽力, 毕竟FF才是捞钱的产品线. 尽
量把用户从APSC往FF赶才是目的. 让APSC用户玩爽了,怎么在FF上捞钱?
O+做镜头的能力就不用多说了, P+也是很强, 收编了美能达很多骨干, 和Leica合作多
年也学了不少, 而且还是世界非球面镜最大的生产商, 前些日子还解决了非球面镜片洋
葱圈"onion-ring"的难题. "The end of oni... 阅读全帖 |
|
|
N*****e
发帖数: 2573 | 5 The first is an FE 50mm F1.8 prime lens, giving photographers a considerably
less expensive option compared to the Zeiss 55mm F1.8 currently on the
market. This compact and lightweight lens is priced at $249 and will ship in
May.
The other lens is the 70-300mm F4.5-5.6 G OSS, which is the longest FE-mount
tele-zoom available. It features four aspherical and two ED elements,
optical image stabilization, and a Nano AR coating to reduce flare and
ghosting. The lens offers a minimum focus distance o... 阅读全帖 |
|
N*****e
发帖数: 2573 | 6 The first is an FE 50mm F1.8 prime lens, giving photographers a considerably
less expensive option compared to the Zeiss 55mm F1.8 currently on the
market. This compact and lightweight lens is priced at $249 and will ship in
May.
The other lens is the 70-300mm F4.5-5.6 G OSS, which is the longest FE-mount
tele-zoom available. It features four aspherical and two ED elements,
optical image stabilization, and a Nano AR coating to reduce flare and
ghosting. The lens offers a minimum focus distance o... 阅读全帖 |
|
y*b
发帖数: 3190 | 7 "We reported a few days ago that Canon was going to announce a follow-up to
the Speedlite 600 EX-RT, and the specifications have now leaked out ahead of
the imminent announcement.
Speedlite 600EX II-RT (Google translated)
Covers the angle of view of 20mm-200mm
Coverage of 197ft / 60M (ISO100)
Continuous firing is 1.5 times faster from 1.1 (CP-E4N 2 times faster at the
time of use)
Up to 5 can control the flash of the group
Dust and water resistent
The new design of the accessories group
Dot matr... 阅读全帖 |
|
v***v
发帖数: 5504 | 8 Adorama 有150 gift card, 准备按板上egon大拿推荐买 42.5mm f1.7, 具体是这个吗
？大拿买的f1.2超我预算了。
Panasonic Lumix G 42.5mm f/1.7 Aspherical Power O.I.S. Lens for Micro Four
Thirds Lens Mount
发信人: egon (schiele), 信区: PhotoGear
标 题: Re: gx85指哪儿打哪儿的机枪扫射
发信站: BBS 未名空间站 (Sat Jul 2 00:20:39 2016, 美东)
兴趣爱好, 就不考虑性价比了. btw, 42.5f1.7比45f1.8强. 包括性价比 |
|
p**********t
发帖数: 1098 | 9 不是说搞这个吗？
我又miss掉啥了？
BTW，我的相机也买了。
Panasonic Lumix G 25mm f/1.7 G Aspherical Lens for Micro Four Thirds Lens
Mount |
|
G****t
发帖数: 1799 | 10 Tamron 17-50mm f/2.8 XR Di-II LD Aspherical [IF] Autofocus Lens 如何啊？
谢谢！ |
|
S*1
发帖数: 622 | 11 这个头也差不多。你不升级全副的话千万别买24-70就好，大，重，贵还没广角。原厂
的16-85也可以。不嫌大的话可以考虑sigma 18-35 f1.8, 素质绝对是残副最佳，不过
得挑个不跑焦的。
: Tamron 17-50mm f/2.8 XR Di-II LD Aspherical [IF] Autofocus Lens 如何啊？
: 谢谢！
|
|
uj
发帖数: 324 | 12 Tamron SP 24-70mm F2.8 Di VC USD
Sigma Art DG 24-105mm f/4 HSM DG OS Aspherical Lens Nikon
现在借用同学的d750 我自己只有d5300
现在只能买一个镜头，选哪个？好纠结。 |
|
D***3
发帖数: 12712 | 13 1 Sigma EX DG Aspherical 15-30mm F3.5-4.5
原包装，配套全 9成新
2 Sony SAL50F14 50mm f1.4
3 美能达 50mm f1.7
4 美能达 100-300mm f4.5-f5.6
5 sigma 18-250mm f3.5-f6.3 dc hsm
6 sigma 100-300mm f4.5-f6.7 dl
7 tamron 70-300mm f4-f5.6 ld di |
|
b*****e
发帖数: 5133 | 14 哪个算一代啊？
适马24-70 f/2.8 aspherical EX收购价成色好的180刀
适马24-70 f/2.8 EX DG收购价成色好的就可以近300刀
卖出价再贵几块也正常，恶霸卖家手续费和PP手续费一收也咬掉一块肉了
拍卖有脑子发热最后几分钟不断加价一定要拍下的我们当然也拦不住了，呵呵 |
|
D***3
发帖数: 12712 | 15 适马24-70mm/F2.8 有四代
带ART的是最新第四代 带HSM没ART的是第三代
EX DG是第二代 EX Aspherical是第一代 ..... |
|
b*****e
发帖数: 5133 | 16 适马挺会折腾的，哈哈。不过24-70搞好了的确有点难度
[在 DRGX3 (飝驫) 的大作中提到：]
:适马24-70mm/F2.8 有四代
:带ART的是最新第四代 带HSM没ART的是第三代
:EX DG是第二代 EX Aspherical是第一代 ..... |
|
N**E
发帖数: 596 | 17 俺不懂磨镜子，不过这镜子不是asphere的话，应该还好吧。最近的GMT的预算已经到
700million了。韩国的加入是U. Texas为主拉入的。澳大利亚似乎想搞个fiber optics
的instrument。 |
|
M****o
发帖数: 4860 | 18 他应该也不止三篇paper，只是这三篇是得奖原因吧
The entropy formula for the Ricci flow and its geometric applications
G Perelman - arXiv preprint math/0211159, 2002 - arxiv.org
Abstract: We present a monotonic expression for the Ricci flow, valid in all
dimensions and without curvature assumptions. It is interpreted as an
entropy for a certain canonical ensemble. Several geometric applications are
given. In particular,(1) Ricci flow, ...
Cited by 1079 Related articles All 39 versions Cite [PDF] from arxiv.org
Ricci f... 阅读全帖 |
|
l*****1
发帖数: 137 | 19 用一个焦距是979 （200/tan（arcsin（0.2）））毫米， 直径大于400毫米的
aspheric透镜来准直，准直后的激光直径就是400毫米，我想这么大的直径发散角应
该很小吧？用一个3维移动平移台精确调整透镜跟光纤之间的距离，也许就足以控制
1200米外的光束直径为400毫米了。没有实际经验，纯属臆想，仅供参考。 |
|
|
|
|
w*******y
发帖数: 60932 | 23 is going for 151.99 after rebate with promo code TAMRON1X13X , pretty nice
deal for this lens
Here's the , there are quite a lot of lenses that are eligible for the
rebate.
|
|
|
|
|
w*******y
发帖数: 60932 | 27 Dell has the Sony Alpha NEX-3 DSLR Camera (Black) with 16mm Lens for $400
with free shipping. Normally $500.
Hightlight:
# 3.0" TFT TruBlack LCD display, 720/30p HD video capture
# 14.2 MP APS-C HD image sensor, 8 separate scene modes
# 12,800 ISO, HDMI port, Memory Stick/SD/SDHC/SDXC memory
Link:
http://accessories.us.dell.com/sna/productdetail.aspx?sku=A3803
dont for get the add it up program and all the other cash back program to
sweeten the bitterness of tax.
Free shipping
Tech Specs
General... 阅读全帖 |
|
|
w*******y
发帖数: 60932 | 29 Link:
http://shop.benq.us/ProductDetail.aspx?id=282
code 1031$$
MX810ST
Refurbished
BenQ PRJ MX810ST WHITE PROJECTOR XGA 2500 ANSI Lumens Short Throw
Super clarity for small-sized spaces
Having a hard time to get your audience going? Featuring 4600:1 high
contrast, 2500 ANSI lumens, XGA resolution, 3D ready projection, interactive
whiteboard capability and LAN/USB/wireless Display, the MX810ST gives you a
81" big picture in a mere distance of 1 meters, stunning colors, crisp-
clear text and l... 阅读全帖 |
|
|
|
w*******y
发帖数: 60932 | 32 Buydig.com has the "Tamron 17-50mm f/2.8 XR Di-II LD Aspherical [IF] SP AF
Zoom Lens for Canon EOS Digital" open box closeout lens for $230 with free
shipping after coupon code: SeasonsDigging10
Link:
http://www.buydig.com/shop/product.aspx?sku=TM1750XRDIEOSOB
The description says it's NEW guaranteed in perfect working condition, but
it is sold in "AS IS" condition, NO return and NO warranty. (But it states:
"Tamron USA 6-Year Warranty" in the Box contents Tab ).
Used ones are selling with ... 阅读全帖 |
|
T*******t
发帖数: 9274 | 33 也是银色的。就是小 一号的cv50/1.5啊。哈哈。有意思 |
|
|
|
|
T*******t
发帖数: 9274 | 37 ebay已经拍到500多了....我就不忍了.... |
|
|
|
h******g
发帖数: 11250 | 40 我烧起来快，出东西慢，家里堆积东西太多，有些一年只用两三次 |
|
T*******t
发帖数: 9274 | 41 我也差不多....
最近算是出了不少东西... |
|
|
z****6
发帖数: 10776 | 43 我今天也收到这个email了，看了一下内容，觉得和上一本差不多？
1. Introduction 10
1.1. The camera designation 10
1.2. The lens designation 11
2. Leitz history 1849-2012 11
3. Leica Prototypes 14
3.1. Ur-Leica and Handmuster 14
3.2. Null-series (Versuchs-serie) 14
3.3. The Kodak invention: movie film 15
3.4. Barnack’s idea 16
3.5. The decision of Ernst Leitz 17
4. Leica I (A) to Leica Standard 18
4.1. Leica I (A) 18
4.2. Leica I (C) 20
4.3. Leica I (B) Compur 20
4.4. Leica I (A) Luxus 20
4.5. Leica Standard (E) 21
5. Developm... 阅读全帖 |
|
u****u
发帖数: 2308 | 44 我贪图便宜买了个Promaster 17-50mm f2.8 XR EDO Aspherical (Nikon mt)，效果不是
很满意。你要不要试试看？希望不是镜头的问题。。。 |
|
|
