Sometimes, it's more difficult buying than selling.(sorry, i am not good at English) I met customers from USA,Poland,Iran,Turkey etc, generally speaking, they spent about 1 week in China. and they visited more than 10 factories here,that means, they visited 1.5 factories everyday,average.that's not a easy job, every factory will give you different information, it's a big problem that how you get the useful and correct information.i am sure, what suppliers give you is not always correct all the time, because whom you discuss with is always salesman, and some salesman don't know very well about this industry themselfes, for another word, they are not profeesional. but that not means the factory not professional. in Shenzhen,China, many owners of factory, they have been involved in this field for more than 10 years, they are pioneers.also, they are demostic sales man years ago. but a big problem is they can't speak english, luanguage is big obstacle for them. take my boss for example, he engaged in this field for more than 10 years, he knows very well about this industry, but he can't join the discuss. sometimes, our customer asked me, where is your boss?i said:sorry, he is not good at english. it will be much better if discuss with my boss. it happens.
Ok, let get to the point, how to choose a suitable LED display. maybe is a old topic. but as far as i know, many friends have no idea about this before they came to China. i choose the word"suitable", not "good". because different customer has different requirement. good does not mean suitable, but suitable does means good for you.
it always considered as a project when you want buy a LED display. so you should have a budget on it, 100,000, 80,000 USD? something like this. then, it's the details about your project, such as:
1. where will be the LED display installed? indoor or outdoor?
2. what message content is needed? videos, photos, or just characters?
3. what dimension will be your screen? width, height?
4. what will be the minimal viewing distance from your screen to the closest spectators?
5. what's the distance from LED screen to control system?
6. what's the installation type? inlay, pole, or something else?
after these information, you can get a general solution from the supplier. for example,you want an outdoor display for ad displaying, viewing distance is about 17 meters, you prepare 100,000 USD for it, and the supplier may recommend P16,Cree LED chips, 40 square meters. ok, this solution sounds good, then you may wanna check the quality, this is most important for you. you don't want spend 100 USD for a piece of paper. so, how to judge the quality, maybe you can consider based on below information:
1. Smoothness(plantness on surface)
Keep the smoothness within 1 millimeter to insure the image not been curved.it depends on assemble tech.
For indoor LED display, it should be more than 800cd/sq.m and for outdoor, it should be more than 1500cd/sqm. If brightness too low, the image will be totally vague.brightness depends on LED lamps you adopt and other factors
3. viewing angle
generally speaking, for outdoor displays, viewing angle for horizontal is about 110 degree, and for vertical is 90 degree. the larger the better.
4. white balance.
To show a pure white color, the ratio of RGB is 3:6:1, wacth if there is blue or red color in white color. This factor mostly depends on control system and LED lamps
5. color restorable.
The color on LED screen should consist with display resources to keep a good image.
6. malfuncation dot, mosaic
make sure there is no dead dot and mosaic on display
These factors are very important when choose a LED display, it’s diffecult to maintenance for some unprofessional customers.