Orble - Wennie's blog

Wennie's blog

follow this blog

2 followers

1 daily readers

rank of 2616

E-mail Subscription

Receive an e-mail notification of new posts on this site:

Tips for Choosing a Digital Photo Frame

August 23rd 2010 01:45

With the popularity of digital frames, more and more people are interested in this gadget and eager to own a digital photo frame to display their photos dynamically and keep their vivid memory. And it is an idea gift to your families or friends.

When facing dazzling digital photo frames, are you confused? Today I will provide you some tips for choosing a digital picture frame. You can refer to some factors when choose a frame, including screen size, contrast ratio, screen resolution, brightness and view angle.

1. Screen Size

The screen size of digital photo frames is measured diagonally from a minimum of 1.1″ to a maximum of 15″. The optimal size is 7-inch and 8-inch because the digital photo frames of these two sizes can fit anywhere and blends into your home environment. The image ratio of most traditional photos is 4:3, while more and more cameras can take photos with 16:9 ratios, which will be a trend in the future.

2. Contrast Ratio

The minimum contrast ratio of Digital Photo Frames our naked eyes can accept is 250：1, and 300:1 ratio is qualified. Nowadays the contrast ratio of most digital photo frames is higher than the minimum standard. Of course the more, the better!

3. Screen Resolution

Maybe someone will ask how can a digital picture frame (800 x 600 resolution) display the photos you took by a 6MP camera with 2848 x 2136 pixels. Actually there is no need worrying about the different resolution between a camera and a digital photo frame. The built-in convertor can solve this problem easily when you copy the photos from a camera to a digital photo frame.

4. Brightness

The higher brightness, the clearer photos we can see. Presently the brightness of most LCD display is over 250cd/㎡.

5. View Angle

View angle involves the horizontal or vertical degree you can appreciate the digital photo frame. A minimum viewing angle is 120 degrees horizontal and 100 degrees vertical. The wider the viewing angles, the better.

Vote

Add Comments

[ Link ]

Posted By: sherry miller - Category: No Category

Email this Post to a Friend

Differences between Red Laser Pointer and Green Laser Pointer

August 23rd 2010 01:38

100 mW red laser pointer and 20 mW green laser pointer are almost same, red beam is easier transmitted by air, dust, and water vapor. But green beam is more easily identified by eyes. There are two main reasons:
One: the sensitivity of the human eye on the green beam is higher than red beam;
Second: the green beam scattering in the atmosphere is more than red beam.

Then we talk about the price of red laser pointer and green laser pointer. The most common portable red laser pointer on the market is emitting power by a laser diode, which means that as long as with battery and a laser diode, the red laser pointer can emit beam. And now the red laser diode technology is very mature (mainly used inside DVD drive), so the price is very cheap.

The principles of green laser pointer now on the market is the DPSS (Diode pumped solid state), that is need a pump source to excite general crystal to emit beam.

5mw green laser pointer generally need a 200mw IR laser diode to pump, and a perfect crystal cost is relatively high, resulting in the price of the green laser pointer is much higher than the red laser pointer. 532NM green laser pointer on the market uses 808NM laser diode PUMP Nd: YAG crystals, conversion efficiency is not 100%.

Green laser pointer is more expensive than red laser pointer that is because the cost of green laser pointer is higher. First of all, the conversion efficiency of green beam is less than 10% of the general that means 50mW green beam should come with a 500mW infrared laser tube. A high power IR laser diode at 808 nm pumps a tiny block of Nd:YVO4 generating light at 1,064 nm which feeds a KTP intracavity frequency doubler crystal to produce the green beam at 532 nm. This process is with very low conversion efficiency, so leading to green beam output is very low. In addition, KTP crystal is also very expensive, so the green laser is expensive.

Green laser pointers are extremely powerful than a red laser. The green beam emitted is much more noticeable.

Overall, 200mW red laser is similar to 20mw green laser effects, and power consumption is almost same. (But infrared laser tube is more efficient than green one).

From the quality, because green laser pointer structure is more complex, it is more likely to go wrong. Therefore, the failure rate should be higher than the red laser pointer.

Vote

Add Comments

[ Link ]

Posted By: sherry miller - Category: No Category

Email this Post to a Friend

External Hard Drive，Your Recovery Expert

August 19th 2010 07:36

Nowadays, your digital life may consist of digital photos, music, and videos from your camcorder, and they're all stored very near your fingertips, on the 120GB - 500GB hard drive in your PC. But when you have a problem with your PC, you have to take it to the repair center, and reformat the hard drive and reinstall Windows or Mac OS X. At that situation, your memories, your treasures and your digital life are surely all gone. However, you can avoid this by using an external hard drive.With capacities of 160GB to 500 GB, the external hard drive will let you back up all of your memories, and let you save it in a safe place, or use it to transfer your files to another computer.

In terms of the size, there is one sentence which can conclude, that is: small size, big wisdom. The smaller portable drive is easy to move, just put it in your pocket or using a laptop bag. While even the 500GB drive is just the size of woman’s makeup bag.

An external hard drive usually has three main purposes: first one is to expand your computer's storage capacity; second one is to backup your data and the third one is to share data between computers. It's very easy to use. What you need to do is just to plug it into the computer and then use it as an internal hard drive.

Generally, desktop external hard drives are based on the 3.5-inch internal hard drives and laptop external hard drives which are portable are based on the 2.5-inch internal hard drives.

An external hard drive connected to a computer often through these types of interfaces: USB 2.0, USB 3.0, FireWire 400, FireWire 800, and eSATA. However, laptop external hard drives are often bus-powered, which means that what it requires is only one cable for both data and power connections. Among those interfaces, the fastest interface is eSATA, which is theoretically as fast as your internal SATA hard drives, but the pity is so far support is limited to a few high-end motherboards or an add-on card which you may need to buy separately.

Finally, let’s take The 500GB 2.5" External Hard Drive as an example. Well, it's a hard drive so it's not going to drive your car, play MP3 or mp4 and tell you how to get places, but it will hold all of your important, shouldn't that be enough?This external drive is stylish, has a nice durable body, including a stand. In addition to its physical properties, the drive provides the best solution to keep data between different computers or to carry important information securely and conveniently. Further more, the high speed compatible USB 2.0 external hard drive can backup large amount of data files, and the stylish aluminum alloy casing design provides heat dissipation.

This external drive is idea for editors, musicians, filmmakers or those who just have a lot of memory and need to carry it around from computer to computer. It's sturdy, safe and works well, what else could you want in a hard drive, aside from a hug once in a while?Your text goes here

Vote

Add Comments

[ Link ]

Posted By: sherry miller - Category: No Category

Email this Post to a Friend

August 2010

3 Posts

Older Posts

3 Posts dating from August 2010

Email Subscription

Receive e-mail notifications of new posts on this blog:

[ View Blog Summary ] [ Create A New Post ]