FAQ

WHAT IS THE LIFE SPAN OF YOUR COLOR PHOTOS?

 In Western Europe, galleries use RA-4 “C-Print” processing for LightJet prints. The life span of these images is preserved by applying a thorough cleaning (with running water during development) followed by ample exposure to warm UV light. The greatest damage to color photos is caused by direct sunlight. Paper quality and longevity of photos are directly correlated to the most important RA-4 production principle of using photo paper with a separate thousandth of a millimeter thick, three-color sensitive layer. Paper producers are constantly creating thinner, higher quality underlayers these days.  “Metallic” type paper, which contains the highest quantities of silver, is the most widely used for jewelry and automobile photography and should last longer than other papers. Note: UV factor lamination also prolongs image life, but often at the expense of distorting light and shadow.


WHAT IS TIFF FORMAT?


TIFF (Tag Image File Format) is the unofficial standard for storing images in their highest quality. Tif also supports 48-bit encryption, enables no-loss LZW compression and storage in layers. The best format for working with professional photographs.

 

 
WHAT IS JPG FORMAT?

JPG (Joint Photographic
Experts Group, the consortium, which introduced the format, also referred to as: Jpeg or Jpe), is a loss compression graphic format used for storing and transmitting images / bitmaps. Its biggest advantage is that it takes up less storage space than open formats and is therefore often used in web communication. However, due to loss of data during compression, the Jpg format is not suitable for high-quality professional reproduction of larger images. It can only support up to 24-bit encoding. This format is most commonly used by amateur photographers, as it allows them to store more images on a card. Repeated storage of Jpg formatted images is not recommended as data loss occurs with each new storage. The new no-loss JPEG 2000, based on wave compression technology, is not very widespread yet. It supports 16-bit encoding. Professionals prefer raw and tif formats.

WHAT IS THE DIFFERENCE BETWEEN DIGITAL MINILAB AND LIGHTJET ?

In terms of exposure there is no difference. Both are exposed by RGB laser on silver bromide paper. The main difference is maximum size and richness of color. For example, Fuji Frontier 350 is exposed at a color depth of 3x8 RBG bits at 25x38 cm, whereas LightJet is exposed at 3x12 RGB bits and 126x300 cm. This color richness is particularly evident in shadows, but can only be achieved if an image is scanned or photographed in raw format and then properly converted.

 

WHY DO BLACK AND WHITE PHOTOS DEVELOPED IN A MINILAB HAVE VARIATIONS IN SHADING?

 
This is usually caused by exposure on colored three-layer paper as well as poor calibration, both of which affect the neutrality of the image. Colored paper has multiple layers, each sensitive to a specific color. Color paper is naturally made primarily for color photography, making neutral black and white exposure difficult, but possible. In our photo lab, we know how to develop black and white photographs on Fuji and Kodak Endura color paper via both Frontier and LightJet printing without any visible coloration. Minor discrepancies will always occur when black and white photographs are developed on layered colored paper. Metametrix is an inevitable property of this process. The mono-layer nature of black and white paper is more stable for black and white photographs. FB Ilford Gallery black and white barytic paper, which we also work with, is one example.

 


HOW DOES LIGHTJET EXPOSURE WORK
?

Although we’re talking about printing, it would be more appropriate to speak of the OCE LightJet device as a digital exposure photolab. LightJet is a type of laser printer, the result of hi-tech space research, that makes use of three-color laser beams (red, green, blue) by burning the image onto silver bromide photo paper, which then undergoes a wet chemical process kown as RA-4. During exposure, the paper is firmly fastened to a giant internal cylinder where laser beams are directed via a rotating mirror. This technique ensures high geometric accuracy and results in zero distortion, even at the edges of the cylinder, as the RGB projects the laser across the entire surface of the paper at medium speed and with precision perpendicular light at every point. In addition to geometric accuracy, this process also guarantees high density, excellent color rendering and transition. LightJet can also work in 36bit color space, making use of 68 billion shades of color, resulting in unrivaled fidelity and color resolution, especially in the reproduction of shadows in continuous light at an optical resolution of approx 4000 dpi with no visible dots. For comparison, other photo printers are limited to 24 bits, or 16.7 million colors. To put it simply, the richness of color information compensates for lower resolution.

In the case of RGB data exposure, one pixel = one dot, which means that throughout the process the broadest spectrum RGB color is maintained without having to convert to the smaller CMYK color space, which on inkjet printers is artificially extended via "light" inks such as Lm and Lc.


WHAT
TYPE OF DATA IS BEST FOR LIGHTJET?


RAW
files in 16-bit RGB are optimal for simple conversion. You simply “develop” them into tiff files. Don’t risk losing your photo’s exceptional quality and richness of tone by reducing it to 8 bits. Instead of the usual 16 million shades of colors, the LJ works with 68 billion, which in practical terms means greater detail in the photo’s shadowy areas. It also partially compensates for resolution. Professionals tend to avoid the data loss resulting from JPG compression.


HOW
CAN I SEND DATA TO YOU?


You can send CD
-R or DVD-R files by post, or via any free Internet file storage server (www.uschovna.cz, www.leteckaposta.cz, etc.). You can also upload data to our FTP server. We will provide you with a username and password upon request. The time of processing will be faster if you send a short text file (Txt, Rtf) with information about the required size, surface and mounting requirements. On these pages you will also find a simple form for sending data via our ON-LINE DEPOSITORY.

 


WHAT
IS PHOTO RESOLUTION?

In digital photography the term resolution refers to the number of pixels per unit of length. However, we should determine what the resolution being mentioned actually refers to. In practice, people often regard resolution as the feature or setting of a device (scanner, camera, printer) and not the image itself.

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