|
For English version, please scroll down. ARRI大畫幅攝影機(jī)系統(tǒng)常見問題解答欲知詳細(xì)信息，請(qǐng)您點(diǎn)擊“閱讀原文”了解， 或復(fù)制以下鏈接至瀏覽器： http://www./largeformat/index_zh.html 瀏覽詳情。 如果本文未能解答您的疑問，請(qǐng)前往ARRI論壇 https://www./forum/ 提出.
問: ALEXA LF支持哪些錄制分辨率？ 答: 在LF片門全開模式下，整個(gè)影像傳感器都是有效成像區(qū)域，錄制分辨率為4448 x 3096（原生4.5K）。在LF 16:9影像傳感器模式下有三種選項(xiàng)：首先是原生3840 x 2160（UHD）；其次是在機(jī)內(nèi)從3840 x 2160下采樣到ProRes 16:9 2K（2048 x 1152）；第三種是在機(jī)內(nèi)從3840 x 2160下采樣到ProRes 16:9 HD（1920 x 1080）。如果您不需要較高分辨率，希望降低數(shù)據(jù)碼率，就可以采用這些下采樣方式。LF 2.39:1影像傳感器模式也支持用完整影像傳感器區(qū)域錄制4448 x 1856（原生4.5K）。 問: ALEXA LF是否符合Netflix的發(fā)行要求？ 答: 這臺(tái)攝影機(jī)的分辨率已經(jīng)超越4K，因此應(yīng)該是支持Netflix的。 問: ALEXA LF使用SxS存儲(chǔ)卡時(shí)支持哪些錄制幀率？ 答: 使用SxS PRO 存儲(chǔ)卡時(shí)的最大錄制幀率 問: 能不能在ALEXA LF上使用我自己的畫框線？ 答: 可以。除了機(jī)身內(nèi)建的默認(rèn)畫框線，您也可以利用在線工具ARRI畫框線生成器自由創(chuàng)作畫框線。 問: ALEXA LF能不能錄制MXF/ARRIRAW？ 答: 不能。目前ALEXA LF只能錄制傳統(tǒng)的ARRIRAW（.ari），也就是ALEXA Classic、ALEXA XT和ALEXA SXT系列攝影機(jī)通用的格式。 問: 為什么不再支持XR Capture Drive、CFast 2.0存儲(chǔ)卡或者小容量的SxS PRO存儲(chǔ)卡？ 答: 因?yàn)锳LEXA LF的數(shù)據(jù)碼率較高，繼續(xù)使用既慢容量又小的存儲(chǔ)媒介沒有任何意義。同時(shí)，我們也希望簡(jiǎn)化系統(tǒng)的復(fù)雜程度，縮短測(cè)試時(shí)間。 問: ALEXA LF有沒有內(nèi)建ARRI畫面風(fēng)格庫？ 答: 暫時(shí)沒有，未來會(huì)通過ALEXA LF的軟件升級(jí)包提供。 問: 監(jiān)看畫面可不可以放大？ 答: 暫不支持，但ALEXA LF的第一次軟件升級(jí)將帶來類似ALEXA 65上的那種縮放和放大功能。 問: ALEXA LF的外形有多大？ 答: ALEXA LF比ALEXA 65小得多，只比ALEXA SXT W長(zhǎng)、寬各多出12 mm。 問: 機(jī)身前面的三個(gè)螺絲是做什么用的？ 答: 這些螺絲與用戶的日常使用無關(guān)。在攝影機(jī)制造過程中，我們要精確調(diào)整影像傳感器的平面，使它與鏡頭卡口平面完美平行。這三個(gè)螺絲并不是用于調(diào)整的，更像是用于封口的螺帽，內(nèi)部也沒有與產(chǎn)品維護(hù)有關(guān)的零部件。 問: ARRI會(huì)推出一款A(yù)LEXA LF Mini嗎？ 答: 我們會(huì)就可行性進(jìn)行觀察，但現(xiàn)在還不知道。不管結(jié)果如何，考慮到如此高的數(shù)據(jù)碼率，制造ALEXA LF Mini的難度不會(huì)低。
問: 為什么要使用一種新的鏡頭卡口？ 答: 更大的影像傳感器需要用更大的鏡頭卡口來優(yōu)化鏡頭設(shè)計(jì)。與參數(shù)相同但采用直徑較小的PL卡口的鏡頭相比，使用LPL卡口可以讓全畫幅鏡頭做得更小、更輕，光圈更大。傳統(tǒng)的PL卡口無法發(fā)揮現(xiàn)代全畫幅鏡頭的設(shè)計(jì)優(yōu)勢(shì)，因?yàn)樗闹睆绞歉鶕?jù)Super 35影像傳感器確定的，它的法蘭距長(zhǎng)度也必須照顧到采用反光鏡快門的膠片攝影機(jī)。 問: 為什么LPL鏡頭卡口的法蘭距不小于44 mm？ 答: 這是為了兼容現(xiàn)有的ALEXA攝影機(jī)。 問: LPL鏡頭卡口能夠使用在其它ARRI攝影機(jī)上嗎？ 答: 可以。目前有兩種版本的LPL鏡頭卡口：“ALEXA LPL鏡頭卡口”用在ALEXA Classic、XT、SXT和LF攝影機(jī)上；“ALEXA Mini LPL鏡頭卡口”是用在ALEXA Mini和AMIRA上的，不過，它的LBUS接口在AMIRA上不起作用。 問: LPL鏡頭卡口能夠用在其它廠牌的攝影機(jī)上嗎？ 答: 如果對(duì)方愿意，我們可以為其它廠牌的攝影機(jī)提供LPL卡口的使用授權(quán)。 問: LPL鏡頭卡口能夠用在其它廠牌的鏡頭上嗎？ 答: 如果對(duì)方愿意，我們可以為其它廠牌的鏡頭提供LPL卡口的使用授權(quán)。 問: 我能不能在ALEXA LF上直接使用現(xiàn)在的54 mm PL鏡頭卡口？ 答: 可以，現(xiàn)有的PL鏡頭卡口可以匹配ALEXA LF。然而在測(cè)試中，我們發(fā)現(xiàn)將LPL鏡頭卡口和PL-LPL轉(zhuǎn)接環(huán)搭配起來，比單獨(dú)使用PL鏡頭卡口更能夠提高畫面四個(gè)角落的通光量，因此我們建議始終將二者搭配使用。 問: 為什么LPL鏡頭卡口上只有一組LDS觸點(diǎn)？ 答: LPL鏡頭只在12點(diǎn)鐘位置有LDS觸點(diǎn)，它們接收LDS-2和/i信號(hào)。在LPL鏡頭卡口上，PL-LPL轉(zhuǎn)接環(huán)有兩種安裝方式：12點(diǎn)鐘位置或3點(diǎn)鐘位置。兩種安裝方式都支持LDS-1和/i。
問: 我能在ALEXA LF上使用變形鏡頭嗎？ 答: 可以，在ALEXA LF上使用Super 35或全畫幅變形鏡頭都十分簡(jiǎn)單。ALEXA LF的取景器和監(jiān)看輸出信號(hào)都能夠以目前的變形寬銀幕壓縮系數(shù)（1.25x、1.3x、1.5x和2x）拉伸還原畫面。全畫幅變形鏡頭使用LF片門全開影像傳感器模式（左圖）。Super 35變形鏡頭使用LF 16:9影像傳感器模式，它的畫面高度與Super 35 ALEXA使用6:5變形寬銀幕影像傳感器模式時(shí)完全一樣，后期裁掉兩側(cè)的畫面（右圖）。 問: 我能在ALEXA LF上使用PL卡口鏡頭嗎？ 答: 可以。將PL-LPL轉(zhuǎn)接環(huán)安裝到LPL卡口上，就可以使用所有的Super 35或全畫幅PL卡口鏡頭了。每一臺(tái)ALEXA LF都標(biāo)配了這款轉(zhuǎn)接環(huán)，讓您在現(xiàn)場(chǎng)迅速切換PL和LPL卡口鏡頭。 問: 在ALEXA LF上怎么使用Super 35鏡頭？ 答: 有許多種方式，這里介紹三種最常見的用法： 1. 使用畫面擴(kuò)展器 您可以加入一種畫面擴(kuò)展器，以光學(xué)方式放大畫面來覆蓋LF片門全開影像傳感器模式的整個(gè)成像區(qū)域，球面鏡頭和Super 35變形鏡頭都支持這種方式。不過，您需要留意幾個(gè)問題：
2. 后期裁切Super 35成像區(qū)域 如果使用LPL鏡頭卡口搭配PL-LPL轉(zhuǎn)接環(huán)，那么Super 35拍攝的畫面是支持后期裁切的，不管是變形鏡頭還是球面鏡頭效果都很不錯(cuò)。使用變形鏡頭時(shí)，在LF 16:9影像傳感器模式中，畫面高度正好與ALEXA Super 35 6:5影像傳感器模式的完全一樣（見左圖）。ALEXA LF 16:9錄制的分辨率是3840 x 2160，ALEXA S35 6:5是2578 x 2160。如果使用球面鏡頭，您可以選擇LF 2.39:1影像傳感器模式，它最高支持150 fps（右圖），這種模式的成像區(qū)域大小能夠容納ALEXA Super 35 3.2K和ALEXA Super 35 2.8K。大多數(shù)ARRI Super 35鏡頭的像圈都能夠覆蓋3.2K，但某些第三方廠牌的Super 35鏡頭無法做到，但所有的Super 35鏡頭覆蓋2.8K是沒有問題的。 3. 利用Ultra Prime和Master Prime鏡頭的照度圈
鏡頭制造商所保證的光學(xué)品質(zhì)是指鏡頭成像圈內(nèi)的畫質(zhì)，在鏡頭的整個(gè)照度圈內(nèi)都有光線射入，但成像圈之外的部分就難以保證畫質(zhì)了，但ARRI鏡頭的成像圈和照度圈都非常大。因?yàn)橐酝行┯脩粼谀z片攝影機(jī)上拍攝Super35格式時(shí)會(huì)忘記把取景器遮片從N35換成S35（N35畫幅比S35?。?。在這種情況下，為了保證實(shí)際畫幅上的成像品質(zhì)，我們把的鏡頭成像圈和照度圈做得非常大，比其它大部分廠牌的Super35鏡頭都大。
在測(cè)試中我們發(fā)現(xiàn)，Master Prime 35鏡頭的照度圈在焦距較長(zhǎng)時(shí)能夠覆蓋LF 16:9影像傳感器模式（UHD - 3840 x 2160）。因此，制作團(tuán)隊(duì)可以大部分采用Master Prime拍攝，遇到廣角畫面時(shí)也許借助一兩支Signature Prime鏡頭來拍。請(qǐng)注意，MP 35/LF 16:9組合的水平視角和MP 26/S35 2.8K組合（轉(zhuǎn)換系數(shù)1.33x）的一樣。Ultra Prime鏡頭也是這個(gè)原理，事實(shí)上，最近有一部德國(guó)的Netflix劇集《暗黑》就是用ALEXA 65和Ultra Prime鏡頭拍的。 問: 我能在ALEXA LF上使用Leica M鏡頭嗎？ 答: 目前不可以。如果需求量高，我們會(huì)專門開發(fā)一個(gè)Leica M鏡頭卡口。 問: 其它廠牌的全畫幅相機(jī)鏡頭能不能用？ 答: 有可能，但我們需要先做評(píng)估。
ARRI發(fā)布大畫幅攝影機(jī)系統(tǒng) (0.12 mb) https://100-assets./arri_assets/lf_assets/downloads/cn/ARRI%E5%8F%91%E5%B8%83%E5%A4%A7%E7%94%BB%E5%B9%85%E6%91%84%E5%BD%B1%E6%9C%BA%E7%B3%BB%E7%BB%9F.pdf ARRI大畫幅攝影機(jī)系統(tǒng)_官方新聞圖片 (5.7 mb) https://100-assets./arri_assets/lf_assets/downloads/cn/ARRI%E5%A4%A7%E7%94%BB%E5%B9%85%E6%91%84%E5%BD%B1%E6%9C%BA%E7%B3%BB%E7%BB%9F_%E5%AE%98%E6%96%B9%E6%96%B0%E9%97%BB%E5%9B%BE%E7%89%87.zip
ARRI Large-format Camera System Frequently Asked QuestionsFor more information and details, Please click 'read more'， or, visit the offical webpage link: http://www./largeformat/index_zh.html. If you have a question not listed here, please ask in the ARRI Forum https://www./forum/.
Q: What recording resolutions are available with the ALEXA LF? A: In LF Open Gate sensor mode, the entire sensor at 4448 x 3096 can be recorded (native 4.5K). In LF 16:9 sensor mode there are three options: first, the native 3840 x 2160 (UHD) can be recorded. Second, the camera can downscale 3840 x 2160 to ProRes 16:9 2K (2048 x 1152). Third, the camera can downscale 3840 x 2160 to ProRes 16:9 HD (1920 x 1080). Those downscale options are there if you want to reduce the data rate and have no need for the higher resolutions. In LF 2.39:1 sensor mode, the sensor area of 4448 x 1856 can be recorded (native 4.5K).
Q: Is this camera Netflix compatible? A: Since the camera has a resolution of more than 4K, it should be Netflix compatible. Q: What are the frame rates of the ALEXA LF with SxS cards? A: Maximum frame rates with SxS PRO cards
Q: Can I make my own framelines for the ALEXA LF? A: Yes. In addition to the default framelines built into the camera, there is also the online ARRI Frameline Composer https://www./fileadmin/adapps/frameline_v4/index.php?camera=ALEXA which allows the creation of any frameline your heart desires. Q: Can I record MXF/ARRIRAW with the ALEXA LF? A: No. At this point in time the ALEXA LF records the traditional ARRIRAW (.ari), which is the same format recorded by the ALEXA Classic, ALEXA XT and ALEXA SXT family of cameras. Q: Why do you not support XR Capture Drives, CFast 2.0 cards or the smaller capacity SxS PRO cards anymore? A: This is because the slower and smaller capacity media don’t make sense with the higher data rate of ALEXA LF, and because we wanted to reduce complexity and testing time. Q: Is the ARRI Look Library included in the ALEXA LF? A: Not yet. The Look Library will be part of a future software update for the ALEXA LF. Q: Can I magnify the monitor image? A: Not yet. A zoom and magnify feature very similar to that of the ALEXA 65 will be part of the first software update for the ALEXA LF. Q: What is the size of the ALEXA LF? A: The ALEXA LF is significantly smaller than the ALEXA 65, and only 12 mm longer and wider than the ALEXA SXT W.
Q: What are those three screws in the front of the camera? A: The screws have no relevance for the user. They allow us to adjust the sensor planeness (being perfectly parallel with the lens mount surface) in manufacturing. While these three screws are not the actual adjustments but rather capping screws, there are no user-serviceable parts inside. Q: Will there be an ALEXA LF Mini? A: We are looking into the feasibility of this but we do not know yet; in any case, it would be difficult because of the high data rates.
Q: Why do we need a new lens mount? A: A larger sensor needs a larger lens mount for optimal lens design. The LPL lens mount allows the design of full-frame lenses that are smaller, lighter and have a faster T-stop than equivalent lenses designed for the smaller PL lens mount. The traditional PL mount would compromise modern full-frame lens design; its diameter was based on the Super 35 sensor size and its long flange focal depth was dictated by the fact that film cameras had a mirror shutter. Q: Why is the LPL lens mount flange focal depth not even shorter than 44 mm? A: Because we wanted it to be compatible with existing ALEXA cameras. Q: Can the LPL lens mount be used on other ARRI cameras? A: Yes, there currently are two versions of the LPL lens mount. The 'LPL Lens Mount for ALEXA' can be used on ALEXA Classic, XT, SXT and LF cameras. The 'LPL Lens Mount for ALEXA Mini' can be used on ALEXA Mini and AMIRA. However, the LBUS connector on this mount will not work on an AMIRA. Q: Can the LPL lens mount be used on other manufacturers’ cameras? A: We are licensing the LPL mount to other camera manufacturers if they wish. Q: Can the LPL lens mount be used on other manufacturers’ lenses? A: We are licensing the LPL mount to other lens manufacturers if they wish. Q: Can I attach the existing 54 mm PL lens mount to the ALEXA LF? A: Yes, the existing PL lens mount fits on the ALEXA LF as well. However, in tests we have found that a combination of LPL lens mount and PL-to-LPL adapter lets more light through in the corners than the PL lens mount, so we recommend always using the LPL lens mount with PL-to-LPL adapter.
Q: Why is there only one set of LDS contacts on the LPL lens mount? A: LPL lenses will only have LDS contacts at the 12 o’clock position and accept LDS-2 and /i signals. The PL-to-LPL adapter can be mounted in two ways on the LPL lens mount: in the 12 o’clock and in the 3 o’clock position. In both mounting positions, the PL-to-LPL adapter supports LDS-1 and /i.
Q: Can I use anamorphic lenses on the ALEXA LF? A: Yes, the use of anamorphic lenses for Super 35 or for full frame is easy. ALEXA LF can de-squeeze images from all current anamorphic squeeze ratios (1.25x, 1.3x, 1.5x and 2x) on the viewfinder and monitor outputs. For full-frame anamorphic lenses, use the LF Open Gate sensor mode (left image). For Super 35 anamorphic lenses, use the LF 16:9 sensor mode, which has exactly the same height as the 6:5 anamorphic sensor mode on Super 35 ALEXAs, and crop the sides in post (right image).
Q: Can I use PL mount lenses on the ALEXA LF? A: Yes, a PL-to-LPL adapter fits securely into the LPL mount and allows the use of all Super 35 or full-frame PL mount lenses. This adapter ships with each camera and allows fast switching between PL and LPL mount lenses on set.
Q: How can I use Super 35 lenses on the ALEXA LF? A: There are many methods for using Super 35 lenses with the ALEXA LF. Here are three of the most common ones: 1. Using an image expander
You can use a third-party image expander that will optically magnify the image to cover the full sensor in LF Open Gate sensor mode. This works with spherical as well as anamorphic Super 35 lenses. However, you should be aware of a number of issues:
2. Cropping the Super 35 area in post
Using the LPL lens mount and the PL-to-LPL adapter, it is possible to shoot with a Super 35 lens and crop the image in post. This works great for anamorphic and spherical lenses. For anamorphic lenses, the LF 16:9 sensor mode happens to be exactly the same height as the ALEXA Super 35 6:5 sensor mode, which is used for anamorphic lenses (see left image). ALEXA LF 16:9 sensor mode captures 3840 x 2160, and ALEXA S35 6:5 is 2578 x 2160. When working with spherical lenses, you can use the LF 2.39:1 sensor mode, which runs up to 150 fps (right image). Both ALEXA Super 35 3.2K and ALEXA Super 35 2.8K fit within the image area recorded in this sensor mode. While most ARRI Super 35 lenses have an image circle that covers 3.2K, the image circle of some third-party Super 35 lenses does not cover 3.2K, but all Super 35 lenses cover 2.8K. 3. Using the illumination circle of Ultra Primes and Master Primes
Lenses have an image circle within which the manufacturer guarantees the optical quality and an illumination circle where there’s still light, but of undefined quality. Both circles of most ARRI lenses are very large, since we wanted to make sure that if a customer shot Super 35 on a film camera, but had forgotten to switch the lens mount from N35 to S35, they would still get an image. Because of that our lenses have a bigger image circle and a bigger illumination circle than most other Super 35 lenses.
Q: Can I use Leica M lenses on ALEXA LF? A: Not at the moment. We would have to build a special Leica M lens mount, which we will do if there is enough demand. Q: What about other third-party full-frame photo lenses? A: It might be possible, but we would need to evaluate this.
ARRI Large Format Camera System - Press Release (0.05 mb) https://100-assets./arri_assets/lf_assets/downloads/en/20180202_arri_large_format_camera_system_en.pdf ARRI Large Format Camera System - Media Pack (5.7 mb) https://100-assets./arri_assets/lf_assets/downloads/en/20180202_arri_large_format_camera_system_press_pictures.zip
|
|
|
