How to know if the quality of an image is good for printing: criteria, superior quality photo prints | Saal Digital

Photo drawing in professional laboratory quality

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Photo draw: the criteria of a successful photo printing

Between the reality perceived by the eyes and that which is frozen on paper, there is a whole world, and especially a certain number of Notions and settings to take into account to limit this gap. This is precisely the objective of this complete guide to succeed in your photo prints: initiate you to the art of photography, as well as to the photo draw of your most beautiful shots.

To do this, we intend to provide you with the simplest answers to your questions, because affordable information is difficult to find, as the technical terms are legion in photography.

Of course, certain technical concepts must imperatively be understood, since they influence the quality of the photos, both digital and printed, such as the resolution of an image, the choice of suitable format, photo editing, etc. So let’s take stock of Basic criteria to know and their meaning in the art of photography.

What are the essential criteria: resolution, format, dimension, size, etc.

To find out which resolution to choose according to the photo draw, it is essential to understand the concepts in question. Indeed, the resolution of an image is directly linked to the printing format itself, correlated with the size and size of the photo.

Resolution of a photo

The resolution of an image or a photo is one of the determining factors to obtain a good quality printing. This varies according to the dimensions of a photo and the desired print size. Several concepts are to be understood when talking about a photo resolution.

  1. The number of pixels (number of points in a photo) determines the sharpness of an image. The pixels are measured horizontally and vertically, for example: 1204 x 1794 pixels. The more an image has pixels, the more good quality it is, because they are closer closer. In addition, the more a photo has pixels, the larger it is. It can thus be reduced without loss of quality, while the reverse is not valid, at the risk of obtaining a pixelated image (visible pixels). Nevertheless, the number of pixels is to be correlated with the size of the image.
  2. The MPX or Mégapixel is a unit of measure indicating the total number of pixels in a photo. It is determined by the power of the sensors of our cameras or smartphone.
  3. The DPI (number of pixels per inch or dots per inch, points per inch) is the resolution unit. It corresponds to the number of pixels in an image, to which we add the concept of dimension by a reference size measured in the incu (a thumb = 2.54 cm). It’s here Photo density. The human eye can only perceive “300 DPI”, it is not necessary to go above, under penalty of weighing down the photo unnecessarily.

The dimension and size of the photo

Between dimension and size, you could say that it is almost the same thing. Indeed, the nuance is subtle. However, it is important.

The dimension corresponds to the height and the width of a photo, associated with the number of pixels displayed on a screen. To put it simply, this is the dimension (implied “size”) of the image on the screen. The size, in the strict sense here, corresponds to the measures inherent in the photo printed on paper (or other physical support). The size is expressed in centimeters (or inch). We are talking for example about a 10 x 15 cm photo. The size of the image therefore corresponds to a printing format.

As we said, the resolution of an image (expressed in PPP or DPI) is not significant in itself. Choosing the right resolution for a photo draw is done with regard to the dimension and size of the photo.

What resolution (DPI) for what size of image: a simple calculation

Before even trying to know which format to choose for your photo printing, so you have to be interested in the resolution of the photo. In reality, it is the one who defines the format (size) to choose, at least if you want to obtain a quality image. In this regard, it is also necessary to define the quality level desired: standard or high definition quality (HD).

The answer seems obvious, everyone would prefer to print their photos in HD. Nevertheless, the price of prints with such a level of quality is higher, because the ink concentration is stronger and the paper much better. In addition, the level of quality also depends on printing format wish.

For example, a photo intended for a large format printing, or very large format (such as an advertising poster), does not impose HD quality or even a very high resolution. This may seem counter-intuitive, since the logic would like more an image to be large, the more its quality and its level of detail must be important. Except that in reality, such a photo requires a certain distance from decline to be seen in its entirety. Thus, the “faults” are invisible.

Resolution, format and quality are therefore intimately linked. The choice for each of its criteria must be made in compliance with a overall coherence. Nevertheless, a simple calculation allows you to include all its dimensions, in order to choose the print format adapted to the resolution of a photo. The formula is as follows:

  • For standard quality printing (150 dpi), the rule is to divide the number of pixels by 30, both on the height and on the width of the photo. Thus, the format adapted for a photo of 1200 x 1800 pixels is therefore 40 (1200/30) by 60 cm (1800/30);
  • For high definition printing (300 DPI), the number of pixels should be divided by 60. Thus, the ideal format for a photo of the same resolution is 20 x 30 cm.

The more a shooting is intended to be watched closely (photo album for example), the more resolution is high. It is recommended to keep a value of 300 dpi. On the other hand, a larger format, like a poster, gives very good results with a resolution of 150 to 200 dpi.

How to prepare your photos to print: the different steps

Now that we have discussed the main technical points and understood the different concepts to which they refer, let’s see how to make these settings in practice. Two types of settings are to be distinguished: those relating to the equipment (screen and printer for printing from home) and those concerning the technical information of the photos.

Camera adjustment: 300 DPI format, exposure speed, etc.

Here are some explanations in terms of camera settings (or smartphone), in order to obtain a naturally qualitative image and Limit retouching ::

  • Choosing the highest number of pixels to obtain a larger image, which will adapt to all printing projects, including large format printing;
  • Adjust the image resolution to 300 DPI, whatever the subject;
  • use large angles focal lengths or ultra large angles (UGA) for Landscape photos, with a small opening of the diaphragm (f/8 or f/16). A large opening is enough for photos of objects or people (portraits);
  • Adjust the speed (exposure time) to correlation with the chosen focal length (the larger the focal length, the higher the speed, X2 depending on the size of the sensor) and depending on whether the object is in motion or not;
  • Adapt the ISO according to lighting or brightness, because the less light there is, the more ISO are high.

Computer screen calibration and printer

When you want to rework photos to print them, it is imperative that the work screen is properly calibrated (or calibrated). Bad calibration will lead to a difference in colors once the photo is printed. For example, a blue on the screen could come out rather blue-green on paper.

The calibration of a screen with a naked eye is very complex, the best is to use a colorimetric probe. The settings to be made are in the advanced display settings (resolution and colors calibration). They concern a set of data such as brightness, gamma, color temperature of the white point, ambient light, etc.

When you want to print your photos yourself, it is also necessary to configure your printer well, but above all to choose your printer to print your photos at home. In general, a thermal printer gets better results for printing a photo than a laser or inkjet printer.

Regarding settings, we must therefore be interested in the printing resolution (Optical or interpolated resolution). It corresponds to the print quality and responds to the same principles as the resolution of an image. It is also expressed in DPI (Dots per inch) or PPP (point per inch). Obviously, the higher this number, the better, the ideal being to keep a minimum adjustment to 300 dpi for a photo (color or black and white).

Adapt the format and resolution of photos for the draw

Finally, you must correct the photo resolution values ​​before their printing, because a shooting carried out in 300 dpi is automatically transformed in the format supported by the screen, namely 72 dpi. It is therefore necessary to configure its software or the online publisher in 300 DPI.

In addition, the colorimetric profile of a digital image is the RGB (red, green, blue). If RGB is a mode intended to display an image on a screen, this is not the best mode for printing.

It is then necessary to inquire about the colorimetric profile used by the printer and on the recommended format to ensure that you go on the same work base. It is most often the CMJN mode (Cyan, magenta, yellow, black), because this profile adapts to all supports and types of prints (photo, display, flyer, etc.)). Some professionals may however prefer the ICC profile.

How to touch up your photos before print: the basics

Reading the above shows that a photo meeting all technical criteria is an essential in terms of print quality. However, this is not enough to obtain a quality visual result.

It is then that the photo retouching comes in. This phase is essential for embellish a photo and bring out all the shades of color and the subtlety of details. Even professional photographers touch up their photographs, in order to correct small exposure or lack of brightness defects for example.

In addition, retouching is inevitable when you want to print your photos on a support. While a screen emits light, the support chosen reflects it. A printed photo without retouching will necessarily be darker than its digital version. Sometimes chance do things well, the result can be completely original, even better, than the basic version, even if it is far from always the case. Photo retouching therefore aims to lighten photos.

This is why you must have already thought about the support to choose for your photo printing before retouching your photos, because depending on the specificities of the latter, the color setting will not be identical. Each component of the material must be taken into account (grammage, matt effect, shiny or satin, density, etc.) in order to make the right image adjustments and determine the level of finish of the picture.

As we said, it will then be necessary to clarify the photos intended for printing and enhance the colors to give them a deeper and more intense dimension, while correcting possible defects (lack of light, “red eyes” effect, deletion of elements, etc.) and adding possible artistic filters.

Most line photo editors allow the main ones Basic settings ::

  • Brightness and exhibition;
  • color temperature (dark tones and clear tones);
  • contrasts;
  • saturation;
  • white balance.

More developed software also allow larger retouching, or at least more precise, such as Photoshop, Gimp, Photofilter, Lightroom. These tools allow access to the histogram, in order to keep proportional settings, as well as a number of larger filters and features. Nevertheless, their mastery is much more complex than online publishers. Some more in -depth knowledge is therefore necessary to properly control the settings.

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Photo drawing in professional laboratory quality

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High -end photo paper of Fujifilm

Thanks to its many years of experience in the field of photographic processing, Saal Digital is able to provide reliable quality photo prints. Of course, photographic paper must also meet our requirements. We prefer professional paper of first quality Fuji Crystal DP II of Fujicolor. The combination of high -quality photographic treatment and first -class photographic paper guarantees the reliable quality of Saal Digital.

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Fineart prints on hahnemühle paper

When it comes to fine prints, paper requirements are also high. This is why it was decided to call on the famous German company Hahnemühle. Saal Digital associates Hahnemühle Rag® and Fineart Baryta Photo with high quality digital printing, guaranteeing exceptional clarity images and impressive details in the proven quality of Saal Digital.

Photo prints

Fineart prints are available in different formats. You can also select the desired orientation (portrait or landscape). In addition, we provide separate ICC profiles for all Fineart finishes.