H. Technical basics


H.01 How can I apply keywords to my photos?

You can use software such as Lightroom, ACDSee, Aperture or iPhoto/Apple Photos to apply keywords to your photos. Most programs allow you to create templates, so you don’t need to apply common keywords manually every time.
You can also apply keywords on our website once the photos have been accepted. Please separate keywords with a comma. All keywords must be in the keywords field. Caption, title and file name are not considered by the Zoonar search engine.

H.02 IPTC data

IPTC data gives you the possibility to apply information like keywords, caption, title, author name and copyright to your photos. The exact field name can vary depending on the software you use. The following fields are relevant for Zoonar:
Title
Enter a short and descriptive title, the maximum is 256 characters
Caption
Here you can enter a longer description. The maximum is 2,000 characters.
Author / Author name
Here you can enter your full name or a pseudonym. If left empty Zoonar will enter your username here.
Keywords
Here you enter all the keywords. Zoonar requires a minimum of ten keywords. Please only use German or English keywords

H.03 Imperial measurements

Few countries, e.g. the USA, still use the imperial measurement system. One inch equals 2.54 centimeters. Twelve inch give one foot, three feet give one yard. One yard is 91.44 centimeters.

H.04 Resolution

The unit of measurement for resolution is DPI and PPI. DPI stands for dots per inch and is used for printing purposes, PPI stands for pixels per inch and is used for electronic displays. The smallest picture element is a pixel.

H.05 What is a pixel?

A pixel is a single picture element or “dot”. Digital photos have millions of pixels, each pixel has a certain luminance and color value. The more pixels a photo has, the higher the resolution. The higher the resolution the more details you can see in a picture, but file size increases accordingly. Zoonar requires photos with a minimum of 6 million pixels or megapixels.

H.06 What is 300 DPI and is it important?

300 DPI means that a photo will be printed with a resolution of 300 dots per inch. The higher the DPI the more detailed a print will be. 300 DPI is the common resolution in commercial printing, which equals 118 dots per centimeter, however the imperial measurement is used much more widely. Zoonar only accepts photos which can be printed in DIN A5 size at 300 DPI resolution.
IMPORTANT NOTICE: DPI have no real meaning for digital photos. The deciding factor for printing quality is the number of pixels in a photo. A photo with a size of 6,000x4,000 pixels and an embedded DPI of 72 can still be printed at best quality in poster size. Whereas a photo with merely 600x400 pixels and an embedded DPI of 300 can still only be printed in stamp size if you want a high resolution print.
You can change the DPI value for digital photos arbitrarily, i.e. change 72 DPI into 300 DPI. You merely need to open the “image size” menu in your photo software and deactive the “resample” option and enter the new DPI value. This will not change the number of pixels in your photo. The DPI value is merely relevant for printers. It has no meaning for digital photos and electronic displays.

H.07 What camera resolution is required?

Zoonar requires 6 megapixels.

H.08 How can I convert units of measurement?

If you want to convert from centimeters to inches you have to divide by 2.54. E.g. DIN A4 is 21.0x29.7 cm which equals 8.27x11.69 inches. A table with common DIN sizes follows.
DIN A0 = 84,1 x 118,9 cm
DIN A1 = 59,4 x 84,1 cm
DIN A2 = 42,0 x 59,4 cm
DIN A3 = 29,7 x 42,0 cm
DIN A4 = 21,0 x 29,7 cm
DIN A5 = 14,8 x 21,0 cm
DIN A6 = 10,5 x 14,8 cm