Professional post-production for Digital Photography.

Image 1: On the left original picture, on the right side after touch-up result.

With digital advent, in addition to planning and execution the shot (with all stages: shooting preparation – set preparation – management of subject), which needs, especially for Beauty Photograph, a large group of technicians, photographer, art director, stylist, make-up artists, models, sets to optimize photo shoots, next phase of post-production is becoming crucial to have a professional product.“High end touch-up” is higly important to define the terms for this pics processing, so to find out less problems in the next post-production phase, in consideration of the specific requirements of customers.

Therefore is more correct to speak properly of Imaging, because photographer’s task is not only to take shot, but to work skill digitally the pics, to find an optimal solution to get the best from image. Photography field is therefore experiencing a new era with an increasing attention to digital images post-production.

For post production is meant phase that follow the shoot of a photo, so the whole process to get to final product, the image to be displayed or deliver to the client.

To achieve a post-production of professional level must fully understand the customer’s request and previously set a appropriate planning starting from shooting, possibly.

The techniques and procedures for process digitally images are varied and always more in number and completion; so they should be chosen depending on the result you want to have. The photographer must therefore focus more and more in training and knowledge of all news of this sector. Analogic photography would like to have a skill picture close to reality. In our today’s image society, however, the aim is always more and more to get a final result suited to the aesthetic research, artistic and personal content. So we have a increasing run to the last well know photographer… or shoot.

There are two general digital image processing depending if image is a portrait or landscape Photography.

For the Portrait Photography or more properly ‘Beauty’, as referring to the most aesthetic handsome, we should focus on subject virtually represented in general by models or human subjects, then all the techniques of Pro Studio Beauty Portrait; and landscape Photography in the knowledge of the HDR technique. Sometimes these techniques can be mixed, but it is important to know both the “high end touch-up.”

It’s good to keep in mind the change from Analog and Digital Photography due to the little “dynamic range digital” of the camera sensors, and the great chance that integrating photo-graphic-text image provide by digital software.

There are a lot of software available and can divided in two big groups: Raw conversion software and photo editing software.

Software for processing RAW files .
These kind of software are used to process RAW format files and convert into jpg. Commercial software for the processing Raw are the following: Lightroom; Nikon Capture NX2; Adobe Camera Raw; Canon Digital Photo Professional (DPP).

Some editing software use also free presets for RAW processing.

Professional digital cameras provide two essential types of files recorded in their memory cards: RAW file* (1) and jpg files. Jpg file is useful because it is very flexible and help to see best prewiew results. Jpg file need to study RAW processing to obtain a jpg file base in high quality to pass for edit software. In this step Raw is corrected especially for exposure, brightness, contrast, shielding, white balance, color saturation. To get optimized result must be made a calibration of monitor and printer that allows you to get a standard result to which all professionals printers or PC technicians can report without any hesitation. It’s important also to understand if you will mostly will use photographic paper or digital to be displayed on the screens of monitors. So to choose if adopts an encoding in CMYK * (2) in the first case and a RGB coding in the second one.

Photo editing software.
Pc software is used to process images, eliminating imperfections, insert text, graphics and to introduce artistic effects in photographs.

Main commercial professional photo editing software are Photoshop – PS – Adobe
and GIMP (free), and running under mpst know OS, operating systems: Windows, Mac, Linux.

Obtained jpg file from raw convertion we start to analyze problems for picture and look for most suitable techniques to be used with our editing sofrtware for final image. So we have to know main techniques and procedures for obtaining maximum results for our image.

To improve a pic using post-production there are a lot of tools provide by photo-editing software.

With photo editing software it’s possible to have an improvement of all picture or portions of it. In the latter case are used tools like rectangular, elliptical, freehand selection, intelligent scissors, fuzzy or magic wand, the most powerful is the layers mask. We’ll talk briefly because their use take it for granted.

Levels is one of the tools used to enhance contrast, brightness and reduce veiled in a photo. It acts the curve values of the histogram for separate colors or for all colors joined together (rgb). To eliminate veiled in the image, trying to move sliders leading them close the end of the curve where one begins to see the positive values; you can use also picks colors, a white point, one black and one gray.

Curves is the specific tool to improve contrast and brightness on the midstones. The best way to get it, it’s to form a S-shaped line diagonal graph with the dark frequencies lowed and the highlights increased.

Shadow & Highlight is a tool used to recover detail on the shadows and highlights. You have to use it remember that intensive use can introduce noise in the image.

Unsharp Mask is a tool to increase the contrast and sharpness. It’s a tool to use with moderation not to have annoying halos especially in the edges. In this case, the filter should be applied only in the center using an unsharp mask.

Noise reduction.
It’s a tool used to reduce the noise of the picture. Reduce the noise of digital photos can make loose detail. Color noise tool cut noise very well and while preserving overall detail reduce vividness of color. To achieve maximum results it’s better to use masks.

The mixer channels is use expecially to get a black and white picture better than the simple desaturizzazione colors tool. Red channel increases contrast; green increases details; blue increases noise.

Now we have ending to remember basic tools we can divide analysis according to subject, so will speak about portrait Photograpy and landscape Photography. We start analyzing digital techniques to get the best by human body and face.

Professional Post-production techniques: portrait and beauty.
Digital photo editing touch-up fashion, portrait and beauty requires many skills to use software and well know final goal we want to get for image.

The technique focuses basically elaborating skin of models, called “skin softening & smoothing”, which concerns elimination of all imperfections (wrinkles, pimples, pores too visible or too little visible, acne, scars, hair, various blemishes).

For digital skin “smoothing” we can use different solutions. Use of specific techniques depend on quality of image that we have, low or very high resolution and problems we can see in the photo.

Work have to be non-destructive not to compromise picture, so we try to work primarily for changing selectivelly texture of skin or just color.

If defects are very mild, simply select the tools clone (copy a selected area) associated with the Healing Brush tool (repair area). We have to select an area close the part to repair and passing mouse on it holding down key control (Ctrl). The skin has special features depending on the parts where it is located, so this tool should be used by choosing a larger sample area close the area to remodel.

Alternative is to use a blur filter duplicating image and adding a layer mask in black (full transparency). At this point we can drawn with a white brush the areas to modify. This system is particularly destructive, therefore it’s better to have a moderated use. The ideal is when we have a picture in low resolution or poorly sharped.

For a professional touch-up, you should use tecniques much more evolved and combine them together. High End Retouch uses combination of the following techniques: frequency separation, pixel dodge & burn, global dodge & burn.

Frequency separation technique.
FS it’s a complex procedure that separates color from detail (skin weft) by treating them with specific filters. The digital image analysis technique shows that high frequencies of the image contain information about retail (sharp lines in white, gray and black), while low frequency ones related to color. Skin imperfections will find together mixed with texture in the high frequencies; therefore needs selectively separate these irregularities for a perfect correction. In this way we will have a perfect skin free from blemishes that respects the original texture of regular pores.

Early attempts proposed to use only two instruments: “gaussian blur filter” (low frequency) and “high pass filter” (high frequency).

Apply only “high pass filter” it’s not a perfect solution because it is not very suitable on darker parts as it produces gray pixels, then the way professional suggests alternate it to another filter more powerful in situations of perfect exposition called “apply image”. We will use “high pass filter” for overexposed areas; we will use apply image in regular and darker areas.

Image 2: Low frequencies - Contains the color information
Image 2: Low frequencies – Contains the color information

Let’s start to describe the technique.

We have to copy the image on two different levels: the first copy in a upper level will contain the high frequency processing so texture of skin and second copy will have just low frequencies and therefore colors informations and shades.

We start working lower level -low frequencies- disabling visibility for high frequencies level. For low-frequency level we apply gaussian blur filter with a value of radius in the way that is not present details but only shadows (usually 15 radius is perfect).

Image 3: High frequencies - Contains information about skin texture
Image 3: High frequencies – Contains information about skin texture

Now let’s go on high frequencies level reactivating the visibility and applying filter – “apply image” with the blending – subtract and the following parameters: for 16-bit (layer frequencies separation – low frequencies layer – invert – channel rgb – blending add – scale 2 -offset 0; this frequencies provides results very close to real image with an offset of 1/32767); and 8bit depth (layer low frequencies separation – channel rgb – blending subtract – scale 2 – offset 128; frequency separation of 129 / 32k or 1/256). Apply the blending linear light levels. At this point you start working searching pixel of skin not perfect using various tools clone stamp, healing brush and brushes, optimizing the image.

If we add togheter in a trasparency level the two level (bass + HF) we will have exactly the image that we are dealing, Image 2 + Image 3 = Image 4

To apply high pass filter proceeds as for previous creating two levels high and low frequencies. Go to high frequencies level and choose from filters – Other – high pass filter – choosing a radius by moving it until you see the texture of the skin around, optimal value should be 4. Apply the filter and select 50% opacity and blending linear. Then proceed to work on low frequencies level cut visibility of higher level, continue choosing Gaussian Blur filter with a radius equal to the one selected for high frequencies. Then apply filter and back on visibility at high frequencies proceed with retouching with the various tools healing brush, stamp and brushes.

Dodge & Burn.
The Dodge & Burn, D&B is a digital technique that changing lights and shadows to get a better image. All the software have a default Dodge/Burn tool that is very fast to use, having a brush that lighten or darken the colors of image. You pass from one to another by pressing O key and Alt in the same time.

Shading or global D&B is best procedure to change traits and physiognomy.
Pixel D&B is ideal to darken around the eyes, eyebrows, lips, profile, to correct skin problems, light and unwanted shadows.

Shading said Global D & G.
Start procedure creating a new layer in blending “soft light” with the tick “fill with Overlay-neutral color (50% gray)” then with the tool brushes touch-up artistically going expecially to darken the dark and lighten lights to get more contrast and have moere 3d effect and opposit in the areas unclear.

Pixel D & G.
To make a Dodge & Burn without use automatic tools need to create a folder calling D&B and creating immediately a new level calling Dodge to which we associate a curve adjustment, light midtones pulling up the curve in the center to make visible the shaded areas. After hiding the adjustment level curves fill the layer mask with black. Now we need to create a second level called Burning and proceed as the previous level asking the curves but by darkening the midrange. Dodge and Burn are two levels that darken and lighten points depending on the level selected. To change from white to black use X keyboard shortcut. To better understand the areas where we need to touch-up needs to create a new level of Hue / saturation and totally desaturate it. Above this level, we create a new level curves amplifying the effect by creating a curve that must be modified as needed to illuminate more the parts on which we must repair. D&B can produce excessive saturation of colours of the image; then to restore it we have to create a new folder and two levels, in the first one we applies hue/saturation and desaturate completely and in the second exasperate saturation. Then we proceed to saturate or desaturate the parts that interest us with a microsurgery work.

In Gimp, Dodge & Burn tools is activated from image menu – tools – Drawing Tools – Dodge/Burn or directly from the left panel by clicking on the icon. To change from dodge to burns and vice versa just use the keyboard shortcut key combination Shift + D.

Frequency separation beauty Technique + D&B with GIMP.
For technical beauty, there are many tutorials and videos for photo shop software; missing instead for open source (free) GIMP. So we have concentrated our efforts to provide a touch-up similar to that of the commercial program and the happiness of the many who can not afford a much more expensive program fee.

Procedure is simpler because it need just copy twice on two new levels basic image by calling the lower LF (low frequency) and HF (high frequency). In low frequency level select the gaussian blur filter with a radius about 18 or more suitable for our image and apply it to the level. Now need to go to high frequency level and select extract grain mode. Duplicate this layer and erase visible on high frequencies level. On the duplicated layer we’ll call again writing high frequencies and select again “grain extract” mode. For high frequencies touch-up it’s better to use a clone tool, while remodeling low frequencies is more powerful the Healing Brush tool. We can create the following control for Dodge & Burn. For the edges we can add directly a white mask to the high frequencies; best tool for this purpose is a brush with about 20% opacity or the clone tool. For Burn we have to create a new level with trasparency and filling with white, then select soft light or overlay mode. Then on the same level we create a black mask. In this way we have total control on intensity dark or light. At this point, using these two techniques FS and D&B would have a perfect skin.

Image 5: GIMP alternative software for professional editing.
Image 4: GIMP alternative software for professional editing.

Another indispensable work for a flawless touch-up is to consider other face and body details.

To enhance face look you can work increasing the brightness and contrast of the eyes. With the clever scissor tool we select feathered the cornea and apply curves or levels.

To attract observer’s eyes it’s very important to enhance the lips arranging well its contours

To edit the model’s shapes is perfet to use liquify filter in Photo Shop.

In Gimp this tool is located in filters – distortion – IWarping.

Once ended the individual selective surgeries we can move to give the image an overall color balance more interesting. A good technique to render a uniform skin colour is to duplicate a new levels and choose fusion color and saturation mode.

There are further images processing to create more artistic images as the Dragan, Dave Hill effect. A touch-up to extreme levels that transform the images with retouching techniques stolen by environment film as “Matte Painting”, “computer generated” 3D elements and pictorial effects.

We can also find think to submit our touch-up subject in a different environment than one of the original photograph. In this case we speak of submissions. Subject’s contours is getting by entering the alpha channel in the image layer and skill cutting with clever scissors. Then proceed copy and past the clipped subject in new image.

In addition to the psubmission you can cut out the subject, but to apply feathered a background blur to get a simulated Bokeh.

Andrzej Dragan effect.
It’s an image processing with skin color greenish/grayish, marked with increased contrast and sharpness of details like wrinkles and hair, which makes a dramatic effect.

Dave Hill Effect
The Dave Hill effect is a image tha look between photography and illustration. On Camera Raw proceed in this way: the functions Clarity (definition), and Vibrance (color) are at maximum value as fill light, goes black darkened to have higher contrast and low saturation. It’s good idea to open an unsharp mask with radius 1 and amount about 60%.

HDR High Dynamic Range.
It ‘s a digital image processing technique which consists in the selection of different shots of the same photo exhibitions in different light exposure.

In this way some programs are able to extend the range of the light cameras * (3), and obtain images with detail much more skill and bright. Even normal editing programs can expand dynamic range using a single frame or several frames by applying layer masks.

HDR is used in when there is very wide dynamic range in a situation, ie simultaneous presence in an image of areas largely underexposed and areas with widely overexposed. In this situation you must make at least three shots with different exposures and modify the images digitally with this HDR technique.Digital images should be mainly processed in HDR 16 bit for optimal results.

Vectorial 3d.
With specializations of digital touch-up is more and more an evolution towards the image obtained with 3d software vector that have a huge visual impact.

* (1) Raw file allows you to correct any errors that may have been committed during the shooting, as a wrong white balance and a wrong image exposure, give possibility to recover 3-stop in the exposure.
* (2) In addition two traditional encodings there is another one called LAB: LAB color defines each color as a combination of green, magenta (A) and blue and yellow (B), with brightness detected separately.
LAB histogram is central position and has more possibilities for processing than traditional RGB.
* (3) Maximum range of digital sensors is 8 stops, very limited compared to human eye which has a range of 13 stops and the same film analog 35mm too.

J.Feliciani                                   English version supervised by M. Zoho


Parte I:Storia della Fotografia.
Parte II Tecnica fotografica.
Parte III …ancora sulla Tecnica della fotografia.
Parte IV Fotografia Professionale e Artistica.
Parte V: Leggi, Privacy, Copyrights, Liberatorie.
Parte VI: Paparazzi e Deontologia del fotografo.
Parte VII: i sensori degli apparecchi digitali [videocamere e fotocamere].
Parte VIII: l’Elettronica delle fotocamere digitali professionali.
Parte IX: Cellulari e Smartphone per la ” Fotografia “.
Parte X: Set fotografico, Piano, Allestimento e Illuminazione.
Parte XI: Fotografia per il ritratto e glamour.
Parte XII: Processori e firmware delle Fotocamere professionali.
Parte XIII: La Fotografia Fashion – Moda.
Parte XIV: Book, composit, agenzie, riviste, calendari, posa in passerella, Informatica per la Moda.
Parte XV: Post-produzione Digitale Professionale per la Fotografia.
Parte XVI:Semiotica Fotografia
Parte XVII: Fotografia in Iran
Parte XVIII: Smartphone per la Fotografia
Parte XIX: Computer per la Fotografia

2 risposte a “Professional post-production for Digital Photography.”

  1. Hi Feliciani,

    Thank you for your extremely well thought out and presented document about all the post production processes we have to go through to achieve an optimal final product. Now that anyone can take a “good” shot, the difference between the amateur and the professional is what we do with out shots once we have taken them.

    1. Many thanks Angela, yes, is right this the accurancy in the post production that make difference. A big deal of work but the procuct is top end quality… Thanks to find us and I hope you come back to see other news! JF

Lascia un commento

Il tuo indirizzo email non sarà pubblicato. I campi obbligatori sono contrassegnati *