【次神级视频镜头】cosmicar/Pentax 8-48mm f 1.0 TV镜头，GH2高感救星！
本帖最后由 梦罗浮 于 2012-11-22 15:18 编辑大家都知道，松下GH2的高感是软肋，但是一旦有了cosmicar/Pentax 8-48mm f 1.0 TV镜头，那么高感基本不在话下
已经拿到手了，目前镜头有缺陷，法兰距过短，超广角不合焦，在求人修改
第一， 从品牌来讲，cosmicar是宾得的子品牌，著名监控摄像头制造商，从中心到边缘分辨率比其他牌子的TV镜头差距小，再说这个百万像素级的镜头，拍1080P足够用了
第二，从焦段来讲，cosmicar/Pentax 8-48mm f 1.0 用松下GH2打开光学扩展【远摄功能】后，是40mm-250mm，如果不扩展，还可以改屁股拉开少许距离，不需要X2 就能以微弱的暗角使用32mm-190mm的焦段
第三，从光圈来讲，f1.0的超大光圈，使松下GH2获得了暗夜之眼的美称的镜头，在晚上能在低ISO的情况下看清物品，GH2的高感差向来是软肋，即使GH3出来后，也只是接近佳能7D的高感，小底小画幅噪点比APSC 、全副明显，所以这个镜头解决了GH2高感弱问题,而且还实现了背景虚化和微距功能。
第四，从价格来讲，ebay这个二手镜头，新品曾卖到299美元，80新的都卖120美元，80新代购价是1098元，国内唯一的一只cosmicar/Pentax 8-48mm f 1.0镜头已经被我花了800块买下，我打算下个月买松下GH3测试下这个孤品镜头。
下面我放下国外这个镜头测试的视频
cosmicarPentax 8-48mm f 1.0镜头与松下14-140对比测试
http://www.tudou.com/v/0Wwbe8uFvCQ/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
cosmicarPentax 8-48mm f 1.0镜头高感测试，秒杀蔡司泰委顿25 1.4
http://www.tudou.com/v/IGXHPCKYvK4/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
cosmicar Pentax 8-48 f1.0与GH2
http://www.tudou.com/v/V5vKu6rUsds/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
cosmicar Pentax 8-48mm f 1.0镜头测试
http://www.tudou.com/v/5E9CxnVx94A/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
^16^最近玩CCTV镜头的还真多 本帖最后由 梦罗浮 于 2012-11-22 17:39 编辑
cosmicarPentax 8-48mm f 1.0镜头修改,据说改屁股除了能纠正法兰距过短，让f1.0~f4之间的光圈任意焦段可以合焦以外，还有就是可以不用开远摄功能而是用32-150mm焦段，但有轻微暗角
http://www.tudou.com/v/ySoesPhhG08/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
作者原话，哪个高人大大来翻译下，他说的什么？
hello,I am now going to show you how to easily modify the pentax 8-48 vs f1.0 under system m4\3
so looks like the lens is the modified
invented by me,the adapter allows you to change the minimum focus distance of the lens during filming for fixing the minimum distance at a comfortable focus is the bolt that is convenient fix the situation
so you can use this lens as a macro,not tinkering with it every time,but simply releasing catch,pull,or drag a bit like a trombone
in the normal position when the lens is infinite,it has a minimum focusing distance of about 1 meter,it is inconvenient when shooting,and can be easily solved by the construction of my adapter
Now I`ll show you what it looks like the adapter of my designs
adapter can be easily disassembled and has a very simple device
adapter consists of a shank of the lens which put on dural ring
it is easy to carve on a lathe from duralumin or aluminum pipe,but from the dural it will be stronger and more durable（made of aluminum,I did not)
Here`s a piece of this is obtained by a ring
internal diameter from one side to match the outer diameter of the end of the lens removed from the shank
ring should fit snugly to the very end of the lens so that there was no backlash and move it to the lens was smooth,with a slight effort
the reverse side of the ring can not be wearing.Because the back side of the ring corresponds to the inner diameter of the outer diameter of the limit switch of the lens
thickness of the lens and the trailer is the length of the distance to which it is necessary to fix the ring
well at this point the inner diameter of the ring must match the outer diameter of the lens liner
the lens was originally made for other tasks and its modifications under the M4\3 it is necessary to prepare
the end of the lens should be shortened on a lathe.the length of about 2-3mm ,need to be cut very slowly
and akuratno until until the groove is barely noticeable
it`s not as scary as you might imagine.After this procedure,you can unscrew the rear lens of the lens
aperture to look at and examine the internal structure of the lens,if you are interested in
I do not recommend it often,but to satisfy the interest of the lens unit can be
Now you need to look closely and try to understand what are the main features
This is the shank of the lens that you can unscrew the lens before the lens to shorten
This objective should be to cut the shank of the same length(about 2-3mm)on which you shortened the end of the lens itself.
in the shank of the lens are three screws that fix the shank on the lens
These need to unscrew the three screws,drill down and screw on the inside
screws must be shortened as well.approximately 1 mm from the acute side.they must be screwed into the shank of the lens and it is completely without looking beyond it. This is for the subsequent fixing the liner inside the ring
screws should be in the body of the shank and not to disturb him at the end of worn lenses
this is a very important point, because you can build the entire structure,and then not being able to set it up because of the fact that these three screws will interfere
in the ring with one hand,you insert the shank,which must be very tight to enter the ring
if the screws will interfere with their need to unscrew
Now on the shaft adapter can be screwes,"C-mount to M4\3"
C-mount adpapter shall fit snugly to the ring and liner,respectively,the shank should be sunk deep into the rings on their entire length,After that,the inside needs a little fix with three screws,but not much! so as not to distort the geometry of the ring
so we get a unique tool for shooting in normal conditions and in almost complete darkness.In addition,this lens can now be used for macro and aperture of 1.0 will give you a unique opportunity
To assess the uniqueness of this lens can be as soon as you need to fall to the night report.Its focal length 8-48 to GH2 vs mode 2X(not EXT mode) are transformed int 32-192.which markes it possible to stupendous filming in almost complete darkness in the ISO 6400
In the process of creating an adapter was broken a few lenses-you can make a financial support in its sole discretion for further work in this area,please contact me at practic@list.ru
And on my site GH2HD.com you can get the lates information regarding the shooting an the GH2 and tests of other lenses on M4\3 Thank you!
抗眩光如何。。 坐等测试 喜欢不抗光晕的 本帖最后由 freedomer123 于 2012-11-20 22:31 编辑
上车床改口的话要小心，其实有一种工业摄像机的sensor是1"的ccd，那个镜头群很多都可以直接用在gh2上面，不用开2倍远射哦，开了二倍就变成2／3没什么景深了,不过你用二倍的话为什么不用B4的头呢？对我而言短一点的焦距比大一点的光孔更有吸引力哦
另外，1“的镜头富士在生产，可以问问看
收下学习了 我在想，如果松下GH3挂这f1.0大光圈镜头拍视频，弱光下那就用不了很高的ISO 明显锐度有很大差异啊
这样折腾你累不累啊 还是安心上5D2好了 这样的镜头CCTV 还不如接2/3的镜头画质好 而且抗炫太差 玩是可以 但是所谓神级 还是言过其实了 本帖最后由 梦罗浮 于 2012-11-21 13:40 编辑
我是有5D2，挂着卡尔蔡司T*28-85
但我要组3机拍片，婚庆、会议记录用
1号机 佳能5D MARK II 卡尔蔡司T*28-85 佳能50小痰盂及近摄圈，负责精彩写真视频
2号机 松下GH3松下14-42 cosmicar 8-48负责全程录像+2号精彩写真视频
3号机 松下GH1松下14 F2.5 负责全程录像
所以我买这大光圈的TV镜头目的是让GH3这个副机有时候能做主力拍精彩写真视频，毕竟5D2不能老摄像，有时候还得拍照 除了蔡司，一切都是浮云。要挣钱还是上家伙吧。 http://www.tudou.com/v/zNmZaQgopBk/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
台湾色友用GH2加这个镜头拍的
不错，钱少有钱少的玩法，量力而行，别烧过头。 色友用PENTAX 8-48拍夜景
http://www.tudou.com/v/kzZnA8Um7ro/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
色友用PENTAX 8-48拍杨千嬅，后期调色过了，果然强大
http://www.tudou.com/v/eatlIV2iAE0/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
以下是宾得Q转接PENTAX 8-48样片
视频色彩没有松下头好 色友pentax 8-48拍阳明山花季之旅
http://www.tudou.com/v/4Wuv5ZVhAL8/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
天天不回 发表于 2012-12-6 00:15 static/image/common/back.gif
视频色彩没有松下头好
这镜头玩的是高感，秒杀松下头 GH1能用不? 国外松下GH2 cosmicar 8-48 F1.0雨天测试
http://www.tudou.com/v/QjEr_JCuKA0/&rpid=1165633&resourceId=1165633_04_05_99/v.swf
期待改好后实拍效果。。。 本帖最后由 梦罗浮 于 2012-12-28 20:58 编辑
原来这镜头法兰距太短造成大光圈近处不合焦、无限远不合脚，多谢瑞德船长帮我改法兰距，车坏3个转接环才得以精确使这镜头符合M43的法兰距，大家有需要改法兰距口的都找他吧！等镜头到手后，我会拍摄样片给大家看！
我的这个头也基本改好了，基本无损改的，还是C口。
法兰距太精细了，精度以0.05mm计。 按道理说这个头也可以改在bmcc上面了？ 本帖最后由 清风幽玄 于 2013-3-22 21:30 编辑
改好后的样子
http://img03.taobaocdn.com/imgextra/i3/23840822/T2bSrzXnBXXXXXXXXX_!!23840822.jpg
关键是调整相面距（法兰距）并固定好后口困难，来去不能差0.05mm，为改后口，牺牲了一个腾龙50/2.8^07^
http://img03.taobaocdn.com/imgextra/i3/23840822/T2lVzzXjXaXXXXXXXX_!!23840822.jpg
现在广角端和长焦端无限远，最大光圈合焦都没问题了，没有GH2，接EP1拍2张看看吧。像场是小，没有GH2的2X是没法用。
广角端http://img03.taobaocdn.com/imgextra/i3/23840822/T2nxzAXaRXXXXXXXXX_!!23840822.jpg
长焦端
http://img02.taobaocdn.com/imgextra/i2/23840822/T22QvzXXFaXXXXXXXX_!!23840822.jpg
这样改成原生C口的好处是还可能用在尼康1或这宾得Q系列上，不知效果会怎么样。
清风幽玄 发表于 2013-3-22 21:29 static/image/common/back.gif
这样改成原生C口的好处是还可能用在尼康1或这宾得Q系列上，不知效果会怎么样。
是的，宾得Q还能转接D口8毫米电影镜头，把复古进行到底！ 梦罗浮 发表于 2013-3-23 13:29 static/image/common/back.gif
是的，宾得Q还能转接D口8毫米电影镜头，把复古进行到底！
不知道这个镜头能覆盖S16的底不？
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