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photo:printing

digital photographic printing

Introduction:

  • printing digital images involves several steps:
    • decide on what printer & paper you will print to as this determines how you will proceed:
      • you may need to assess your image for ability to crop to the appropriate image aspect ratio and size.
      • will you require fine detail, high dynamic range fine art monochrome print? then use Ultrachrome ink on high gloss paper or on a new baryta paper such as Ilford Galerie Gold Fibre Silk.
      • is your image a mood scene that would print best on a textured surface or a canvas?
      • in general images with smooth tonal areas are better on smooth papers rather than textured, and thus smooth paper is probably a safer choice for most images.
      • for fine prints, the heavier the paper the better (eg. 300gsm), and many use archival quality cotton rag papers for matte or the newer baryta papers for higher DMax and extended color gamut in the deep blues and greens without being too glossy (eg. Ilford Galerie Gold Fibre Silk).
      • see also:
    • decide on color space of image, monitor, image editing tool and printer:
      • most cameras use sRGB by default so unless you shoot with medium format digital backs or your printer requires it, most people would use sRGB as that is what their monitor will display.
        • as yet there are no monitors that have a color space the size of the AdobeRGB space.
        • most consumer printers require it in sRGB, but if sending it to a magazine or graphic designer they may need it in AdobeRGB. 
        • Abobe RGB (1998) has a wider gamut than sRGB, in particular, it can contain colour data for richer cyan-green midtones, orange-magenta highlights, or green shadows than can sRGB, but unless the printer can print the extended gamut (eg. newer high end inkjet printers), you may still be safer just using sRGB.
      • if using a commercial printer, you may need to consider converting to duotone or variant:
        • although an 8-bit gray scale jpeg image can hold 256 gray tones, commercial CYMK printers can usually only print up to 50 gray tones. 
        • to get around this, you can convert your image to 8bit grayscale in PS then convert to a duotone (2 inks used), tritone (3 inks used) or quadtone (4 inks used) which allows increased tonality in the print.
    • ensure your computer monitor and software is colour calibrated so that you can best judge how to edit your image for the effect you want - see color calibration
    • before you go and start changing colours in your image, check that you are not colour blind or you may end up with results that look good to you but may not be as good to the remaining 95% of the population.
    • process the RAW image
      • consider adjusting curves to ensure adequate dynamic range is captured:
        • recover burnt out highlights:
          • eg. use recovery setting in PS CS3, or try settings such as:
            • recovery = 0; exposure to a negative value as needed; blacks = 0; brightness eg. +50, contrast eg. +38; fill light as needed for shadow detail; tone curve = strong contrast;
        • recover dense shadow regions:
          • even using Ultrachrome K3 inks on matte paper, shadow details will not be obvious when pixel values are below 12-15 on a 0-255 scale (ie. 8bit).
          • eg. use “Fill light” setting in PS CS3
        • then use Camera Raw Parametric Curve function
      • consider applying a small amount of “capture sharpening” on the RAW file to compensate for blurring due to the anti-alias filter (ACR v4.0 and Lightroom v1.1 and higher have this facility) 
      • consider using DxO Optics Pro 3.5 software to minimise mosaic artefacts before creating a 16bit TIFF
    • edit the image to the desired effect:
      • clone out any undesirable features
      • consider using LAB color mode to adjust colours/contrast if image looks dull with lifeless colors or limited color range.
      • consider adding hue to blown areas using LAB color space:
      • consider improving portraits:
      • consider adjusting levels:
        • Image/Adjustments/Levels move left slider to left edge of histogram, move right slider to near right edge of histogram and adjust middle slider for desired contrast effect.
      • consider adjusting saturation
      • consider reducing fog/haze:
        • Filter/Sharpen/Unsharp mask. Apply the following settings: Amount 60 Radius 20 Threshold 0.
      • consider improving skin tones:
        • Image/Adjustments/Selective Color choose red channel and move Cyan slider to minus 20 to minus 40.
      • consider adding vignetting effect:
        • use burn tool, set to soft brush at larger than image size, and 20% exposure, first do highlight setting until can just see a darkening, this sets the scene for re-doing it with the mid-tone setting.
      • consider adding some “creative sharpening”
    • crop &/or resize image to the desired print size at the printer's dpi output
    • apply final sharpening AFTER final image resizing for printing
      • historically, this was done using PS “unsharp mask” or QImage's equivalent, but now many use PS CS3's “Smart Sharpen” tool
      • consider applying USM in luminosity channel in LAB color mode to avoid color artefacts from sharpening.
      • see tutes on using USM:
          • view image at 100%
          • set amount to 500%, radius to 5 and then adjust threshold so noise is not accentuated
          • then reduce radius so halos do not obscure detail (usually to 1-3 for a 8mp image)
          • then reduce amount to give best effect, usually when halos no longer visible but their effect is.
    • consider adding a final noise to give a little texture
      • Filter/Noise/Add Noise, and set the amount at 1
    • save file as per printer requirements eg. 8 or 16bit RGB TIFF (maybe needed to be in MAC format)
    • the print when viewed under daylight conditions should closely resemble what you saw on your monitor.

Image aspect ratio:

  • image aspect ratio is just the width divided by the height, but it has crucial importance when choosing a print size because if the print size aspect ratio differs to your image aspect ratio then you must either do:
    • crop the image so that the ratios match
    • use borders in the print which will be unequal in width
    • manipulate your image via transformation in an image editor to get to the printer image aspect ratio but this will result in a distorted image.
  • film camera aspect ratios:
    • 35mm film is 36×24 = 1.5
    • medium format 6×4.5 = 56mm x 41.5mm = 1.35
    • medium format 6×7 = 56mm x 69.5mm = 1.24
  • digital camera aspect ratios:
    • 1.5 ratio (ie. 3:2):
      • full frame 35mm = 36×24 = 1.5
      • Nikon DX 15.6×23.7 = 1.52
      • Canon 1.6x crop digital SLRs = 15.1 x 22.7mm = 1.5
    • 1.33 ratio (ie. 4:3):
      • Olympus, Panasonic 4/3 = 13.5 x 18.0mm = 1.33
      • the default ratio on the Olympus 8080 is 4:3 ie. 3264×2448 pixels (ratio 1.33) which is the same as most computer monitor screen resolution is such as 1024×768 or 800×600
        • the Oly 8080 can be changed to 3:2 (ie. 3264×2176) to assist with some photo lab printing (ratio 1.5)
  • printing aspect ratios:
    • 1.5 ratio (ie. 3:2):
      • 4“x6” = 100x150mm
      • 8“x12” = 200x300mm
      • 10“x15” = 254x381mm
      • 12“x18” = 305x457mm
      • 20“x30” = 508x762mm
      • 24“x36” = 610x914mm
    • 1.414 ratio (ie. international paper sizes):
      • 5“x7” = 130x180mm actually 1.4
      • A5 = 5.8“x8.2” = 148x210mm
      • A4 = 8.2“ x 11.7” =210x297mm 
      • A3 = 11.7“x16.5” = 297x420mm (NB. printable area at Image Science is 11.4“x15.4” = 290x391mm using Epson 7800 )
      • A2 = 16.5“x23.4” = 420x594mm
      • A1 = 23.4“x33.1” = 594x841mm
      • A0 = 33.1“x46.8” = 841x1189mm
    • 1.33 ratio (ie. 4:3):
      • 6“x8” = 150x200mm
      • 12“x16” = 300x410mm
      • 30“x40”
      • 36“x48”
    • other common print ratios:
      • 8“x10” = 200x250mm = 1.25
      • 10“x12” = 250x300mm = 1.2
      • 11“x14” = 280x360mm = 1.29
      • 16“x20” = 410x508mm =1.25
      • A3+ = 13“x19” = 1.46
      •  

Resizing images to print:

  • printers usually print at 250 or 300dpi, thus if you are wishing to print at a larger size than your image resolution, the software will “interpolate” the image to “add pixels” to make it look smoother and thus minimise the jagged edge artifacts that would otherwise be visible.
  • as long as you have a good quality image to start with, an 8 megapixel image should be able to be interpolated up to A2 size at 250dpi with very good image quality, likewise, a 5 megapixel image should be able to get to A3 size.
  • as a general rule, the largest high quality print in inches can be determined by dividing your horizontal or vertical pixel count by 200 (divide by 250 for exhibition quality prints).
  • there are different methods of achieving this:
    • bicubic interpolation:  a standard interpolation method included in many photo editing tools including Photoshop, PaintShop Pro and others.
      • in Photoshop:
        • for prints smaller than 11″x14″, use the crop tool, set desired size and dpi and simply crop and save as required.
        • for larger prints, go to Image/Image Size, in Document Size, switch the option in the drop down menu from inches to percentage. Only do this on the top “width” option: replace 100% with 110% and click okay. Make sure Constrain Proportions and Resample Image options on the lower left are clicked on. The image will increase in size by 10%. Do this until you have reached the size you want. It’s amazing! Great results at sizes up to and beyond 40 inches.
    • QImage (Vector):  A photo printing application that includes interpolation of output (by Digital Domain).
      • uses a new proprietary algorithm called “super resolution” which is designed to upsize an image up to 16x of the original without loss of sharpness but may increase noise and add a vibratory ringing artefact at high contrast interfaces.
    • many others, see reviews on:
  • choosing a print size:

Colour calibration:

Final, pre-print sharpening:

  • digital images need to be sharpened as a last step before printing - ie. AFTER any edits and resizing for printing.
  • most people use the Unsharp mask filter in Photoshop to do this
  • alternatively, one can use Photokit Sharperner for better results.
  • beware that excessive sharpening will enhance noise artefacts.

Photographic Printers:

  • publishing photos as a book:
  • commercial:
    • mega-size printers:
      • HP 5000 60“ wide inkjet printer using UV inks, takes 45min to print a 5'x15' print on HP Glossy UV media at 150dpi from a 275Mb scan of a 6×12 image upsized to 695Mb and using Posterjet to RIP. An advantage is the motorised take up spool that minimises risk of paper buckling. $US15,000.
    •  
  • professional fine art pigment ink printers:
    • there is nothing as important to a fine arts photographer as seeing their own work in print, exactly as composed and intended.
    • Epson has long dominated the high end fine art printers for Mac or PC, but now Canon and HP have announced new printers to compete.
    • In 2005, digital monochrome photographic printmaking technology entered a convergence zone that has finally resulted in printmaking that fully supports quality monochrome fine art images:
      • Epson's Ultrachrome K3 inks used with the Epson 4800
        • The new K3 Photo Black ink was designed from the ground up to create a pigment of carbon black, with an outer microencapsulation of resin polymer that would allow the black ink to adhere to the surface of high-gloss paper as though it were “one with the surface.”
        • this is available at Image Science in Melbourne using the Epson 7800.
      • stochastic RIP software to generate the monochrome image:
        • Colorbyte Software's ImagePrint takes the Epson printer to the next level
          • ColorByte has constructed a method of balancing its use of the UltraChrome K3 color inkset to use only cyan and magenta in order to neutralize the gradation of the monochrome inks. What this means is that the archival life of the print is greatly enhanced because of the intelligent use of the neutralizing inkset in ImagePrint.
      • high quality paper to maximised the D-max of monochrome prints:
    • Canon imagePROGRAF iPF5000 (2006):
      • A2, 17” wide carriage 12 ink printer, introduced 2006 that will retail for less than $US2,000. 
      • Individual ink cartridges are large, heads are self cleaning and user replaceable, and paper paths include roll, front, rear and paper tray. 
      • In addition to the usual Cyan, Magenta, Yellow, Light Cyan, Light Magenta, Matte Black, Photo Black, Light Black, and Light Light Black cartridges, Canon has added Red, Blue and Green. 
      • over 30,000 nozzles into two 1” print heads with 4-pl (picolitre) ink droplets
      • No cartridge changing is required when switching from matte to glossy papers.
    • Epson 4800:
      •  
    • Epson R2400:
      •  
    • Canon Pixma Pro 9500 (2006):
      • A3+ 13“ wide 4800 x 2400 dpi resolution at 3 picolitre drop size3 or smaller
      • 10-colour ink system with “LUCIA” pigment ink with a 3-ink mono system
    • Canon imagePROGRAF i8000:
      • 44” wide; 2400×1200; 12 ink; Lucia pigment ink; 4 picoL drops; A0 print in under 7 minutes; 111kg; 
      •  
    • HP Photosmart Pro B9180 (2006):
      • The eight high-capacity HP Vivera 38 Pigment Ink Cartridges, with new patented waterproof 5 HP Vivera inks, that can print up to 80 A3+ prints.
      • four HP 70 dual-colour printheads feature 8,448 nozzles
      • can select from the two types of black inks: photo black for high contrast black and white photos with deep, rich blacks, or matte black
      • said to produce instantly dry, waterproof prints that resist fading for up to 200 years when framed under glass.
    •  
  • prosumer:
    • HP Photosmart 8750 (2005):
      • A3+, up to 13“x19” prints, ethernet port, memory card reader
      • 9 HP Vivera inks in 3 cartridges with disposable printer head in each cartridge.
      • Photo Gray produces better B&W prints than prosumer Canon printers to date.
      • optional Black ink cartridge for faster B&W text printing (must replace the Photo Gray cartridge)
      • see HP website RRP $AU899.
    • Canon Pixma MP960:
      • A4; 7 Chromalife ink; 9600×2400;  scanner included for film, negs;

Viewing monochrome prints:

  • see also: dynamic range
  • a high Dmax print can only be created from an ultrasmooth surface. If we want a high Dmax print based on inkjet technology, it is only possible to do so based on an ultrasmooth and high-gloss surface. Forget using fine art paper if you want a high Dmax print—it is not possible.
  • a high Dmax photographic print needs to be viewed under ideal conditions in order to perceive the full potential of the print. 
  • The ideal gallery setting is in having a single, point source spotlight illuminating the image, from a high angle of only 30 degrees from the wall. Diffuse lighting, be it natural or manmade, is a disaster for high Dmax prints.
  • Additionally, the ambient light reflected in the room needs to be minimized, with an ideal value of 18% to 36% reflectivity from the paint of the walls—not stark white walls, as so many photographic galleries are accustomed to using.
photo/printing.txt · Last modified: 2018/08/03 00:38 by gary1