如何在彩色冲卷机上作强迫显影

所谓强迫显影,就是在底片曝光不足的情况下,增加显影时间,强迫底片上的影像出现的显影方法。要进行强迫显影的胶卷应具备如下条件：１能确定胶卷感光不足;２胶卷感光不足应在１～１５档之间（快速片允许的范围还要大一些）。强迫显影的技术：就是显影温度不变,...     

误冲未感光的胶卷可以再用

我们在冲洗过程中,当通过安全灯发现有未感光的“白卷”时,稍经处理,仍可再用。首先将胶卷上的显影液冲净(约15分钟);再用吸过蒸馏水的棉花团将“白卷”上的水珠擦去;接着双手捏住胶卷的两头,让风扇吹干,卷入护纸即可。但要注意,此胶卷必须在1～2天内照完并冲洗完。另外,     

介绍两种高速胶卷

一、太行牌YJ-15染料型黑白全色高速胶卷该产品是化工部第一胶片厂新近研制成功的一种新型黑白高速胶卷,标定感光指数为400ASA(27DIN)。该胶卷有如下特点:(1)胶卷经曝光、冲洗加工后,形成的影像物质不是常规黑白胶卷的金属银,而是有机染料影像;(2)该胶卷具有可变感光度使用效果,故又称之     

区域曝光法在摄影中的应用

生活中，我们能够用彩色胶卷真实地再现五彩缤纷的世界，而用黑白胶卷只能拍摄出以黑、白、灰为影调的黑白照片。最佳的影像质量，最终取决于视觉效果。大多数人的视觉要求真实、完美地再现所拍景物。依于负正系统的传递特性，即拍摄时候有选择地曝光，冲洗时正确地掌握。美国摄影家Ａ·亚当斯最早提出了“区域曝光法”的观点。下面就区域曝光法，谈谈自己的认识。 区域的认识 “区域曝光法”是以实用的观点，对利用感光测定学研究光与感光材料相互作用的科学进行提练而形成的一套简单易行的工作方法。 首先，应使摄影者对自然界的景物在光…     

新产品☆新技术

世界感光最快的胶卷问世据法新社八月二十六日报道,制造樱花彩色胶卷的日本小西六摄影器材公司宣布,生产出世界上感光最快的3200度彩色胶卷。这种名为“柯尼卡彩色 SR-V3200”的新胶卷,为职业摄影师在处理光源有限的场面时,提供更广阔的选择范围。     

彩色负片的冲洗

彩色胶卷的种类很多,大体有负片、反转片和正片之分。既使同是彩色负片,由于型号和生产厂家不同,冲洗工序和配方也不尽相同。彩色胶卷冲洗药液的配制和工艺过程比起黑白胶卷要复杂得多。因此冲洗彩色胶卷需十分认真仔细,严格按照要求的冲洗     

用“乐凯”拍青春少女照

“乐凯”彩色胶卷色彩鲜艳 ,反差稍高。有人认为只适合拍摄社会题材 ,其实 ,只要应用得当 ,拍摄人像和青春少女都可以取得满意的效果 ,甚至拍摄婚纱照也十分不错。红衣少女要取得好效果 ,关键是曝光和冲洗。“乐凯”彩色胶卷反差偏高 ,在强烈阳光下难取得柔和效果 (在光比大的阳光下拍摄 ,其它彩色胶卷也难取得柔和的效果。编者注 )。因此选择适宜的光线曝光尤为重要。用“乐凯”拍摄青春少女 ,曝光一定要准确 ,有时为了表现少女白皙细嫩的肌肤 ,曝光可略为过度。在曝光不超过一档半的情况下 ,均能取得满意的效果。其次是冲洗 ,彩卷一般交专…     

柯达科技发展里程碑

1878年乔治伊士曼是首位证明感光干板便利性的人士之一。干板避免了以往使用玻璃片必须涂布,然后立即曝光,并在湿润的状态下进行冲洗的麻烦。1879年乔治伊士曼发明一款乳剂涂布机,实现批量生产感光干板。1885年推出第一卷伊士曼胶卷。1888年推出第一部民用相机,掀起业界研发同类产品热潮。1889年推出第一卷民用胶卷,改变人类影像世界的发展。1891年推出第一部可在日光环境下安装胶卷的民用相机,使相机的应用更加方便。(待续)柯达科技发展里程碑     

服务台

武汉全方同志来信说,我是一个业余摄影爱好者,想学习自冲彩色胶卷,请告诉应注意哪些问题?答:拍彩色照片,只要曝光基本准确,严格按照加工工艺冲洗底片,质量是可以保证的。用这种底片也可制作出质量好的照片。因此,彩色胶卷的冲洗     

欠曝与迫冲的效果和应用

欠曝种类摄影时曝光不足俗称“欠曝”。欠曝通常发生于两种情况下。①无意识欠曝　多产生于对胶片感光度的误读 ,或相机感光度定位盘定位与胶片标度不符 (指自动曝光类相机 ) ,这类情况多半出于不熟悉摄影常识的一般爱好者。由此造成的曝光不足 ,可称为无意识失误。②有意运用欠曝　摄影者为解决某些环境与条件方面的欠缺 ,甚至追求某种创作表现效果而故意采用欠曝拍摄 ,并设定配合增感显影冲洗措施 ,以求达到预期的效果。无意识失误与有意运用欠曝 ,二者间层次不同。有意欠曝必须配之以迫冲 ,即增感显影。增感显影并不仅仅是对欠曝光胶片采…     

Graphics Processing Unit-Based High-Frame-Rate Color Doppler Ultrasound Processing

Color Doppler ultrasound is a routinely used diagnostic tool for assessing blood flow information in real time. The required signal processing is computationally intensive, involving autocorrelation, linear filtering, median filtering, and thresholding. Because of the large amount of data and high computational requirement, color Doppler signal processing has been mainly implemented on custom-designed hardware, with software-based implementation - particularly on a general- purpose CPU - not being successful. In this paper, we describe the use of a graphics processing unit for implementing signal-processing algorithms for color Doppler ultrasound that achieves a frame rate of 160 fps for frames comprising 500 scan lines times 128 range samples, with each scan line being obtained from an ensemble size of 8 with an 8-tap FIR clutter filter.     

Surface-Driven High-Pressure Processing

The application of high pressure favors many chemical processes, providing higher yields or improved rates in chemical reactions and improved solvent power in separation processes, and allowing activation barriers to be overcome through the increase in molecular energy and molecular collision rates. High pressures—up to millions of bars using diamond anvil cells—can be achieved in the laboratory, and lead to many new routes for chemical synthesis and the synthesis of new materials with desirable thermodynamic, transport, and electronic properties. On the industrial scale, however, high-pressure processing is currently limited by the cost of compression and by materials limitations, so that few industrial processes are carried out at pressures above 25 MPa. An alternative approach to high-pressure processing is proposed here, in which very high local pressures are generated using the surface-driven interactions from a solid substrate. Recent experiments and molecular simulations show that such interactions can lead to local pressures as high as tens of thousands of bars (1 bar = 1 × 10⁵ Pa), and even millions of bars in some cases. Since the active high-pressure processing zone is inhomogeneous, the pressure is different in different directions. In many cases, it is the pressure in the direction parallel to the surface of the substrate (the tangential pressure) that is most greatly enhanced. This pressure is exerted on the molecules to be processed, but not on the solid substrate or the containing vessel. Current knowledge of such pressure enhancement is reviewed, and the possibility of an alternative route to high-pressure processing based on surface-driven forces is discussed. Such surface-driven high-pressure processing would have the advantage of achieving much higher pressures than are possible with traditional bulk-phase processing, since it eliminates the need for mechanical compression. Moreover, no increased pressure is exerted on the containing vessel for the process, thus eliminating concerns about materials failure.     

Ultra-Rapid Monobath Processing

Monobaths hove been formulated in which a high-speed film (Kodak Plus-X Reversal. SO-273) can be processed in 2.5 sec. at 120 F to a fog level of 0.32, a gamma of ～0.85, and a speed comparable to that obtained with normal D-19 processing. The high contrast resolution values are also comparable to those of a D-19 control. These monobaths are based on the use of organic complexers as the fixing agents, in particular, αthioglycerol, and ore stabilized with antimony potassium tartrate. Monobaths so formulated and stabilized exhibit optimum processing capability for at least seven days at 120 F and show no noticeable sludge formation.     

精益粉体加工

发达的食品工业一定能给消费者提供更多更丰富的产品。我们不论生活在何处都希望能够享受到世界上各类食品。为满足人们的爱好,超市的货架上总是摆满了多种多样的产品。生产水平和产品品种总是随着消费者不断改变的需求日益提高和发展。模切、烫印在包装印刷行业发展中的所发挥的作用与日俱增,特别在高档包装产品的印后加工工艺中,对提高产品附加值,增加视觉欣赏力方面更是不容忽视,各印刷厂家也都纷纷在这一块增大了投资比例,以获取附加利润值,在一定程度上,对模烫设备的正确合理的选择就成了投资成败的关键因素,本文就模烫设备的发展过程和国内外模烫设备发展做以简单分析,以供行业同仁参考。     

精益粉体加工

发达的食品工业一定能给消费者提供更多更丰富的产品。我们不论生活在何处都希望能够享受到世界上各类食品。为满足人们的爱好，超市的货架上总是摆满了多种多样的产品。生产水平和产品品种总是随着消费者不断改变的需求日益提高和发展。