Saturday, May 31, 2014

Chơi ảnh hay chơi máy ảnh?

Nhiều người phát biểu nghe phát mệt: chụp hình phải máy Full Frame, ống kính thì phải Leica, Zeiss này nọ thì chụp mới đẹp ?_? ăn gì ngu thế ? ... hình đẹp và phần cứng là 2 cái khác nhau, ko đồng nhất với nhau, vả lại trên Internet người ta coi hình của các bác chỉ biết nó đẹp hay xấu, có hồn hay ko có hồn, có nghĩa hay ko có nghĩa chứ người ta làm sao biết các bác xài máy khỉ ho cò gáy gì? Thích ảnh đẹp thì cứ tập trung vào việc làm sao cho ảnh đẹp, đồ hiệu thì cũng có thể làm cho ảnh đẹp đấy nhưng sao ko nghĩ đến những thứ khác nhiều hơn: sáng tạo, kỹ thuật, trao dồi tâm hồn của mình để thấy những điều đẹp đẽ hơn, thậm chí học hậu kỳ cho giỏi thêm.
Và cũng quá nhiều người Xì tu bịch để mà hùa theo vài người chụp hình nổi tiếng nào đó?_? nổi tiếng và chụp ảnh đẹp lại là 2 chiện khác nhau ko phải cứ nổi tiếng là làm gì cũng đẹp và chụp hình gì cũng đẹp, và chưa hẳn cái việc nổi tiếng là do chụp hình đẹp, cá nhân mình thấy các bác nổi tiếng nhờ cặp với gái đẹp thì đúng hơn, người đẹp thì làm sao mà chụp ra xấu? Sao ko thử chụp người không đẹp thành người đẹp?
Nghệ thuật không có đúng hay sai, chỉ có đẹp hay xấu, đẹp hay xấu phụ thuộc vào trình độ nhận thức, tư duy của mỗi người. Bạn có hiểu được cái ngôn ngữ người ta dùng để nói với bạn thông qua tấm ảnh không?a

Thursday, May 29, 2014

Macro photography: Understanding magnification

Photography, like any other art, demands both compelling content and expert technique to create a pleasing result. In my previous article, I discussed some of the aesthetic choices involved in creating a successful macro image. Technique, however, is an absolute must; it's the artist's tool to convey his artistic vision.

Nature, landscape and wildlife are some of the most technically challenging fields of photography, and macro photography comes with its own unique set of technical considerations. In this article I'll be discussing one of the most important ones; magnification.

Photographer Allon Kira making sure his image is technically perfect.
For macro photographers this often requires a great deal of concentration and patience, but the results are well worth it.

Some of the greatest challenges in macro photography arise from the simple fact that we shoot from very close distances. Thus the magnification of our subject becomes of primary importance. The magnification ability of a given lens is stated in its specifications but in my experience, few photographers understand the meaning and implications of this designation.

To understand the concept of magnification, it's worth taking a very brief look at how a photographic image is created. Every point in a given scene reflects light rays. The front element of the camera lens 'captures' these rays and then focuses them onto the imaging sensor, producing a projection of the scene at the location of the sensor.

This is a simplified diagram of the photographic process. Light rays reflected from an object pass through a lens, which then produces an image projection on the camera's sensor.


Magnification - or more precisely, the magnification ratio - is simply the relationship between of the size of the (in-focus) subject's projection on the imaging sensor and the subject's size in reality. Perplexed? Here are some examples. Suppose that we're photographing a small child, 1 meter in height. Imagine that the height of the child's projection onto the sensor is 1cm. The magnification ratio is 1cm/100cm, or 1/100. Magnification is typically notated using a colon, so we write it as 1:100, and pronounce it, 'one to one hundred', meaning the child is 100 times larger in real life than its image as projected on the sensor. Similarly, if the subject is a 10cm long lizard, and its projection on the sensor is 2cm long, the magnification ratio is 2cm/10cm or 1:5. The lizard is five times larger in real life than its projection on the sensor.

When your subject(s) fills the frame with no cropping involved, it is easy to determine the magnification ratio from a captured image provided you know the size of your subject and the dimensions of your camera's sensor, which can be found in the specifications section of the user manual.

Two thistle mantis (Blepharopsis mendica) nymphs, as positioned above are roughly 150mm across. The sensor on the camera is 22mm across. The magnification ratio is approximately 22mm/150mm, or 1:6.8. This dragonfly is about 60mm in width. Again, the sensor is 22mm wide, so the magnification ratio is 22mm/60mm, approximately 1:2.7.

We've seen in the examples above that sensor size can be used to calculate magnification, but the degree of magnification itself depends on focal length and subject distance exclusively (assuming that the lens is not used with any extenders or magnifying filters). Sensor size does not alter magnification. With a fixed focal length and subject distance, an APS-C sensor, for example would just crop the frame compared to a full-frame sensor, not enlarge it. Magnification is a property of the projection, regardless of the size of sensor (or film format) you are using. With a full frame sensor you'd just make calculations using 35mm as the sensor width instead of 22mm, but the subject would then be proportionally larger, cancelling out the sensor size difference.

Sensor size does have an effect on the image's appearance though, a topic I will address in an upcoming article.

What happens if the subject is the same size in real life as its projection? If we shoot a 1cm fly and its projection on the sensor measures 1cm as well, the magnification is 1:1. The 1:1 ratio has an important meaning for macro enthusiasts. Technically speaking, macro photography means shooting at a magnification ratio of at least 1:1. Therefore, a 'true' macro lens has the ability to produce a magnification ratio of 1:1, or higher.

A small subject like this shield bug required approximately a 1:1 magnification.


At this point you may understandably ask, what's so special about a macro lens? Surely one can take any old 50mm f/1.8 lens and just move it closer to your subject until you reach 1:1 magnification. The problem, however, is that a regular lens will not be able to focus at such close distances. A more specific definition of a macro lens, then, is one whose minimal focus distance is short enough to allow photography of a focused subject in 1:1 magnification.

Let me take this opportunity to point out that many lens makers employ a very liberal use of the term, and happily write 'macro' on a variety of zoom and prime lenses that are not capable of 1:1 magnifications. This is a sales tactic, and you can easily find so-called macro lenses that can only produce 1:4 or 1:3 magnification ratios. One can, of course, produce great results with such lenses, and it is often possible to achieve higher magnifications on these lenses with the use of optional accessories. When shopping for a macro lens, however, you'll want to look carefully at the magnification specs; most 'true' macro lenses will actually have 'macro 1:1' prominently displayed on the barrel. That removes any ambiguity.

Once you have a macro lens, how do you accurately calculate its level of magnification at an arbitrary focus distance? The easiest way, by far, is to use a ruler, as shown in the examples below.
I photographed the ruler from a measured subject to sensor distance of approximately 65cm. Forty-four 1mm notches fill the entire width of the frame, thus the subject's projected size is 44mm. The width of my camera's sensor is 22mm. It follows then that for this lens, the magnification ratio achieved at this focal distance is 22mm/44mm, or 1:2.
In this image I moved the camera closer so that now thirty-three 1mm notches are visible in the frame. This 22mm/33mm relationship yields a magnification ratio of 1:1.5.
Finally, by moving the camera even closer, twenty-two 1mm notches are visible in the frame. As you'd expect, 22mm/22mm equals a 1:1 magnification ratio.


I should point out that with a regular macro lens, 1:1 magnification is achievable only at the very closest focus distance. Using a longer focus distance necessarily means the magnification will be lower. Indeed, for a fixed focal length, magnification is inversely related to subject distance. This relationship isn't linear, i.e. if I get a 1:4 magnification from a shooting distance of 40 cm, I won't necessarily get a magnification of 1:2 (twice that) from a shooting distance of 20cm. However, getting closer will always result in a larger magnification and vice versa, meaning that for our purposes we can use the terms magnification and proximity somewhat interchangeably.

Some subjects are so tiny they need extreme magnifications. This close-up portrait of a robber fly required a whopping 4:1 magnification ratio, meaning that the image projected on my camera's sensor was 4x larger than the fly itself.

There are cases (such as the image above) where we wish to shoot at magnifications greater than 1:1. These so-called 'extreme-macro' magnifications are possible using special lenses or other equipment, and I'll discuss how that's done in a future article.

Wednesday, May 28, 2014

Understanding Electric Readings-Watts, Amps, Volts, & Ohms

Watts, amps, volts, and ohms; what does it all mean? You don’t have to be an electrician to understand these terms. Electrical readings often mirror that of a simple comparison to your garden hose. How is that? Like a garden hose, electrical wiring has something running through it but instead, the substance is electricity instead of water.
Understanding basic electrical readings will help you comprehend how much heating capacity your electric fireplace will actually provide. Each of these readings is directly related to heating capacity.

Electric Readings - Watts, volts, amps, and Ohms

Source: E of Dreams
Editors Note: You can skip down to the bottom if you want sift through the technical jargon for a simple answer.

Basic Electric Formulas


Basic Electric Formulas

Here are the Basic Electric Formulas.

Watts

Watts means power.  An easy way to understand wattage is by plugging your finger into the end of a garden hose. You didn’t increase the amount of water flowing through the hose so why then, would the water flow at a higher rate and have a higher force? Since you reduced the size of the hole (gauge of the electrical wire), you increased the pressure (or voltage). This action propagates the substance at higher rates.
An increase in power is attributed to an increase in wattage. You’ll often see this reading on stereo systems, fans, microwaves, and just about anything that uses electricity. Watts are a measurement of electrical power (P). Power is equivalent to voltage times current. For the mathematicians out there: P = V x I
Current is a quantity that measures the volume of electrical flow between two pointsand is measured using amperage. Current is measured in amperage or “amps” for short.Amps measure the amount of electricity being used. Referring back to the garden hose analogy, amperage would be akin to the number of gallons of water was pumped through the water spout.
Current is abbreviated with the letter “I” not to be confused with “L.” Current is calculated using the formula created by Ohm’s Law: I = V/r. This can be read, “current is equal to voltage divided by resistance.”

Volts

Using our garden hose analogy, the voltage of electricity is akin to the pressure in a garden hose. Imagine a 1 inch hose with a little bit of water flowing through it. Twist the faucet open and you have a stream of water that creates pressure inside the hose. Similarly, the voltage of an electrical wire is determined by factors such as the size of the wire (gauge) and resistance (covered in the next section). Simply put, voltage tells you how much force is being exerted relevant to the wire.

Voltage Meter or Voltometer

A voltage meter or voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit.
Voltage is important because an overload (sending too much power through an undersized wire) can lead to blown fuses and tripped fuse panels. This is one of the trouble spots that can cause electric fireplaces to fail. Voltage is an actual measurement. Voltage is equal to current times resistance. V = I x r

Ohm’s ?

Watts, amps, and voltage all culminate into Ohm’s, a measure of resistance. Ohm’s Lawuses these 3 mathematical equations to demonstrate the relationship between electric voltage, current, and resistance. Resistance is measured in Ohm’s using the formula R = V/I. This is read as Resistance = Voltage divided by Current. Ohm’s law states that the current through a conductor between two points is directly proportional to the potential difference across the two points.
This is important because different types of metal carry different types of resistance because of their inherent physical properties. For this reason, certain metals prove to be better conductors and transmit electricity easily.

Most Conductive Metals

Here you can see the inside of different types of metal. Silver offers the least resistance but copper is a close second and is the most popular choice. Source: ntd-ed.org
Generally speaking, silver is the least resistive metal however, it has a high density. For this reason, most wiring uses copper or gold which has a lower density-resistivity level. If you’re really bored, you can check out tis table for a full list of resistivity of different types of metals.

Simplified Version for those Who are too Lazy to Read or Want the Short Answer

  • Amps measure the amount of electricity being used.
  • Voltage measure the pressure (or force) of electricity.
  • Wattage is a measure of electrical power.
  • Ohm’s measures the resistance between two points. The thicker the gauge of wire is, the more electrical current flow through from point A to point B.

Applying it in Real Life

So how does all of this translate into the warm air coming from your electric fireplace? Electricity is used to generate heat from an electric unit. The amount of electricity that can flow through your electric fireplace is directly relevant to BTU output. BTU is an abbreviation for British Thermal Units and is used to measure heat and cooling output for heaters and air conditioning units. Check out this post to learn how BTU’s work. Likewise, you can use this BTU calculator to determine how many BTU’s your home needs.
When it comes to electric fireplaces, the saying holds true; looks don’t mean everything. It’s important to understand how electric readings translate to heating efficiency. You can find details and specifications on all of the latest models from top brands like DimplexHolly & Martin, and Real Flame right here on Portable Fireplace.com.
This entry was posted on Wednesday, April 23rd, 2014 at 10:00 pm and is filed under How-to and DIY. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

http://www.portablefireplace.com/blog/electric-readings-watts-amps-volts-ohms/

Tuesday, May 27, 2014

How does all this work? HTTPS, SSL, certificates, CA, public and private keys, CSRs?

http://wpengine.com/support/how-does-all-this-work-https-ssl-certificates-ca-public-and-private-keys-csrs/

HTTPS, SSL, certificates, and all the other bits and pieces of browser security is complicated, and it’s hard to get a simple, clear explanation of what it means and what to do. Hopefully this will help.

CAVEAT

This description intentionally omits various details and exceptions. The purpose is to give a non-technical user a clear picture of how all this stuff works. Extra complexity would just cloud this clarity. Use references like Wikipedia and security books for completely precise information.

HTTPS AND SSL

SSL stands for Secure Socket Layer, and it’s a protocol that does two things:
  • Encrypts your data, which means no hacker can see what your browser sends to the server nor what the server sends to the browser.
  • Authenticates your website, which means it tells your browser “This website really is who it claims to be.” For example, that when you type your username and password into your PayPal account, that the website really is PayPal, and not a hacker posing as PayPal.
HTTPS just means “HTTP with SSL.” Just as “http://” means “this is a website,” seeing “https://” means “this is a website, and it’s using SSL to encrypt data and authenticate the website.
So when you want a “secure website,” i.e. a website with https, you’re saying you want us to support the SSL protocol. It turns out the encryption part of that protocol we can handle completely automatically for you, but the authentication part is a lot trickier. So the rest of this will be about authentication.

CERTIFICATES

Certificate is a document that your website shows a browser to proclaim its identity. It “certifies” that the website is who it says it is.
It includes web-stuff like your domain name (e.g. “paypal.com”) and also identification-stuff like your company’s name, address, phone number, and so forth. Some certificates provide more information than others, but this is the general idea.
Simple enough, but the trouble is it’s not authentication. Because: Although PayPal provides a certificate identifying themselves as PayPal, a hacker could just as easily provide that same certificate to the web browser! How does the browser know that this certificate is to be trusted?
CA stands for “Certificate Authority,” and it’s a company who will verify for the browser that a particular website’s certificate can in fact be trusted. All browsers come pre-loaded with special security files listing dozens of CAs whose opinion it will trust.
So it’s not enough that your website provides a certificate, it needs to be a certificate that has been certified by a CA. This is called a Signed Certificate, because the CA has “signed their name” to your certificate so that the browser will trust it.
To get a signed certificate you first need to select a CA. There are literally dozens of CAs; some examples you might have heard of are GoDaddy, Verisign, but if you search on Google you’ll find a zillion of them. Prices range from $50 to $5000 depending on lots of factors. You’ll need to consult with your CA or a technical consultant to decide what’s right for you since there’s lots of details and trade-offs.
Next you’ll need to generate other documents which you provide to the CA in order for them to process and issue your precious signed certificate. I know, like Alice and Wonderland you’re going further down the rabbit hole…

PUBLIC AND PRIVATE KEYS

Private Key is a secret password that your website keeps and which you never ever ever let anyone have access to except your hosting company and your CA. Unlike your email password, this password is really long, typically 1024 characters or more. That’s a good thing — a human being never needs to read it, only machines, so it’s good to have something so massive that it really is literally impossible for anyone to guess it.
The private key is a required component of SSL because it’s part of how it does the encryption part of its job. It’s also a required component of the certificate and the CA’s approval, because what you’re really saying is this:
“This secret, private key XYZ is something that only me, the real website, knows. So I want you, the CA, to verify to him, the browser, that this certificate (my identity) is one and the same with this private key. So then when I use that private key to send encrypted stuff to the browser, the browser will be certain I’m who I say I am, and we’re in business.”
But wait — if you use the private key to encrypt data, doesn’t that mean the browser needs that same private key to decrypt the data? And then the private key isn’t a secret anymore! Don’t worry, that’s not how it works. It’s like this:
When your security tool creates one of these special private keys it also creates a corresponding, matching Public Key. This is a different password, but also really long, like 1024 characters. The public and private keys are a pair with the following very useful feature:
Data encrypted with the private key can only be decrypted with the public key. (And vice versa.)
So here’s how this all gets put together:
Your website keeps the private key secret, and encrypts everything with that key. The public key is placed inside that certificate as yet another part of your website’s identity, just like your domain name and phone number. When the CA certifies your certificate, it’s telling the browser, “Yes this is the real-life identity of this website, and furthermore that’s the public key of this website, so you can trust anything that you can decrypt with that public key.”
Since only the private key can encrypt stuff for that particular public key, only you, the real website could be talking to that browser, providing that certificate, and that’s how the browser knows you’re actually you.
It’s also why you need to keep that private key secret. It’s also why you will need to give that private key to us, your hosting provider, because we’ll need it to encrypt data coming from your website.
Now there’s only one more thing you’ll need to get this friggin’ certificate certified by the friggin’ CA:
CSR stands for Certificate Signing Request, and it’s the official document you give to a CA asking them to “sign” your certificate, thus finally getting you that “signed certificate.”
The CSR essentially just combined all the stuff we just discussed — the public key, the certificate you want signed, etc — in a standard format. There are security tools which generate CSRs depending on what fields you need to fill out and using your keys.
It’s a common mistake to think the CSR is the same thing as a signed certificate, but as you can see that’s not at all the case. The CSR is literally a request, not a signed certificate. Only a CA can provide you with a signed certificate.

GETTING IT ALL LIVE AND WORKING

To host your HTTPS-powered website, we’ll need two things:
  • Your private key (so we can encrypt data)
  • Your signed certificate (so we can provide that to browsers)
We don’t need your public key, CSR, or any other things you might have generated along the way.
You can purchase and configure an SSL Certificate in the User Portal by following this guide.Please note, we only offer SSL on our Professional and above Plans.

CHAINED CERTIFICATES (NEEDED ONLY SOMETIMES)

About 10% of the time your CA will require you to use something called a Chained Certificate. If that’s not the case for you, you can skip this section.
Here’s why this happens: Remember the web browser has a list of CAs which the web browser trusts. Now suppose you used a CA which was not in that list. The browser won’t accept your certificate because, although it’s signed, it’s signed by a CA which in turn the browser has no reason to trust! This unknown CA could just as easily be a hacker.
To get around this, your CA will provide you with another certificate that says “I’m a CA you should trust, and look, I got this other CA to certify that I’m a trustable CA, and you do already trust that CA.”
In short, your CA passes the buck to a trusted CA, therefore creating a “trust chain.” The browser trusts your website because your CA says so, and it trusts your CA because another CA says so, etc., until we get to a CA the browser trusts implicitly because it’s in that “official list of trusted CAs.”
If this is the case for you, that’s fine! We just need you to send us that additional certificate so we can provide the complete chain to the browser. Your CA will be able to give you that document.

DEDICATED IP’s

You can only have a dedicated IP provisioned for your site if you have an SSL certificate. You have to have the SSL certificate first before we make the request to get the dedicated IP for your site.


Apple Server - OpenDirectory intergrate with ActiveDirectory

I drove myself crazy reading a lot of people set up their Triangles called Dual Directory, Golden Triangle, Magic Triangle... But you will clearly understand how it all work with this image below from MacSysadmin Magazine.

Clients still use Active Directory for user authentication, while Open Directory supplies Managed Preferences only.

Every Profile Manager instance is an Open Directory Master. Apple has included a local group in Mac OS X Server called Profile Manager ACL. Users and groups from any directory domain that can be viewed in dscl can be added to this group. Adding objects to this group enables them to authenticate to the MyDevices portal but not administrate. Kerberos isn’t really used here, nor are nested groups. You’ll apply policies directly to Active Directory groups in Profile Manager.

Start by enabling directory services debug logging:
odutil set log debug
disable the debug logging:
odutil set log default
Now when you attempt to join Active Directory, you can look at the log at /var/log/opendirectoryd.log to see what’s occurring.

To disable encryption:
/usr/sbin/dsconfigad -packetencrypt disable
To reenable encryption:
/usr/sbin/dsconfigad -packetencrypt allow
When capturing traffic for the following ports:
UDP 53 - DNS
TCP 88 - Kerberos
TCP 389 - LDAP
TCP/UDP 464 - Kerberos Password Changes (KPasswd)
TCP 3268 - Global Catalog (LDAP)
To capture traffic over the built-in Ethernet connection to a file called “capture.out,” you could use the following syntax for tcpdump
tcpdump –K -i en0 -s 0 -w capture.out port 88 or port 464 or port 53 or port 389 or port 3268

Setting Up Profile Manager

Prepare: HostName, ComputerName, LocalHostName, Static IP, DNS: A, PTR record
apple.mydomain.vn - 192.18.1.3. Go to Server app

Profile Manager is built on top the web service, APNS and Open Directory


Start the web service (click ON slider) and View Server Website

Click on Profile manager service (DO NOT CLICK ON ON/OFF SLIDER)

At the Directory Administrator screen, provide the username and password you’d like the Open Directory administrative account to have (note, this is going to be an Open Directory Master

Account Name: administrator
Pass: yourp@ss

The Open Directory master is then created. Even if you’re tying this thing into something like Active Directory, this is going to be a necessary step. Once Open Directory is setup you will be prompted to provide an SSL Certificate.

This can be the certificate provided when Open Directory is initially configured, which is self-signed, or you can select a certificate that you have installed using a CSR from a 3rd party provider.
You will then be prompted to enter the credentials for an Apple Push Notification Service (APNS) certificate. This can be any valid AppleID.

When the assistant closes, you will be back at the Profile Manager screen in the Server application. Here, check the box for Sign Configuration Profiles

=> Import mydomain.vn certificate


Finally Click ON to start Profile Manager -> http://apple.mydomain.vn/profilemanager/
Login with adminitrator yourp@ss

Integrating Mac OS X Lion Server's Profile Manager With Active Directory

Bind to Active Directory

System Preferences, click on the Users & Groups System Preference pane and click on Login Options. Then click on the Edit… button for the Network Account Server. From here, click on the plus sign (“+”) and enter the domain name into the Server field.

Once bound, you will see the server listed. At this point, if you try to authenticate to the MyDevices portal as an Active Directory user, you will be able to authenticate, but you will not have permission to enroll devices. To log in, access the web service at the address of the server followed by /MyDevices https://apple.mydomain.vn/mydevices.

Provide the user name and password to the service. The Active Directory users are unable to access the MyDevices service. Nest Groups Using Workgroup Manager

Click on Logout and we’ll fix this. There is no further configuration required for the Active Directory groups to function properly in regards to how they work with the server. However, we will need to open Workgroup Manager and nest some groups. You might think that you’d be doing something all kinds of complicated, but notsomuch. You also might think that you would be nesting the Active Directory users and groups inside Open Directory groups, given that you have to enable Open Directory in order to use Profile Manager. Again, notsomuch. To nest the groups, browse to the local directory and then then click on the com.apple.access_devicemanagement group.

Click on the lock icon to unlock the directory domain, authenticating when prompted.

Click on the Members tab and then click on the plus sign (“+”) to add members to the group. Workgroup manager -> View -> Show system record

Then in the menu that slid out, click on the domain browser at the top of that menu and select the Active Directory entry.


Test Access

Drag the user or group from the menu into the list of members and then click on the Save button.
Now log in again using the MyDevices portal and you’ll be able to Enroll. From within Profile Manager (log in here as a local administrator), you’ll see all of the users and groups and be able to apply policies directly to them by clicking on the Edit button for each (the information isn’t saved in the directory service on the server, but is cached into the directory service client on the client when using Mac OS X 10.7, Lion based clients).

To enroll devices for management, use the URL -> https://apple.mydomain.vn/mydevices/

To Sign Certificate -> Create a CSR from Certificate Management from Server.app, then open Certificate Authority on Windows Server 2008 create a Code Signing from Certificate Template -> use command line to sign the CSR file



 Reference:
http://krypted.com/iphone/setting-up-profile-manager-in-lion-server/
http://krypted.com/mac-security/integrating-mac-os-x-lion-servers-profile-manager-with-active-directory/

Monday, May 26, 2014

Sunday, May 25, 2014

104 year old Stanislaw Kowalski completes 100 metre sprint


"I wish everyone lived to my age and in such health as I have.
For them to not know what a doctor is, you don't need doctors.
One shouldn't eat too much in the evening, it may cause sickness
The medicine is expensive, doctors are somtimes difficult to reach and then what?
It's better not to eat enough that to eat too much"

His secrets:  Avoid stress, don't eat too much and at night, lots of sleep and the occasional vodka.

Saturday, May 24, 2014

Friday, May 23, 2014

Enable PHP 5.5 Opcache on Ubuntu 14.04 with Nginx and PHP-FPM

OPcache improves PHP performance by storing precompiled script bytecode in shared memory, thereby removing the need for PHP to load and parse scripts on each request.

Making the switch from APC to Opcache now that it's standard with Ubuntu 14.04. All the tutorials seemed to be on Apache so thought I'd share what I did. The first change and restarting php I believe is all you need to do while the other changes are for performance and will vary based on your needs. If others have recommendations or additional advice please pipe in!

sudo vim /etc/php5/fpm/php.ini

Change:
;opcache.enable=0 to opcache.enable=1

Change:
;opcache.memory_consumption=64 to opcache.memory_consumption=128

Change:
;opcache.max_accelerated_files=2000 to opcache.max_accelerated_files=4000

Change:
;opcache.revalidate_freq=2 to opcache.revalidate_freq=60

Then restart:
sudo service php5-fpm restart
sudo service nginx restart

Nhạc sĩ Nguyễn Ánh 9 thẳng thừng chê Mr Đàm, Hà Hồ

Với thâm niên 60 năm trong nghề, nhạc sĩ Nguyễn Ánh 9 cho rằng thị trường âm nhạc Việt Nam hiện nay chỉ có giải trí. Ông nói: Việt Nam hiện tại chỉ có giải trí, không có nghệ thuật. Bây giờ, nhạc để xem nhiều hơn là để nghe. Người ta làm giải trí kiếm tiền, coi qua rồi bỏ chứ hiếm người tâm huyết làm nghệ thuật. Điều này khiến tôi buồn lắm vì con đường nghệ thuật của mình không có những người chung chí hướng để làm tốt vai trò nghệ sĩ.
- So với thế hệ trước như ông, giới ca - nhạc sĩ Việt hiện nay có gì khác biệt đáng nói?
- Hồi xưa, người nhạc sĩ viết ca khúc từ những cảm xúc thật của họ, họ viết ra để chia sẻ niềm vui, nỗi buồn cho mọi người chứ họ không viết nhạc để bán. Còn bây giờ, nhạc sĩ viết nhạc theo yêu cầu đơn đặt hàng nên âm nhạc không có hồn, không có cảm xúc thật của người sáng tác.
Ca sĩ bây giờ đa số chỉ chú trọng ăn mặc, make-up cho đẹp và lên sân khấu hát thì sau lưng có một đám múa. Nhưng ít chú trọng đến xúc cảm âm nhạc, không để tâm hồn vào bài hát.
Hồi xưa, có những giọng ca còn để tiếng đến bây giờ như Lệ Thu, Thanh Thúy, Thái Thanh… nhưng bây giờ những ca sĩ hát giọng tốt đếm trên đầu ngón tay, đã vậy lại bị vướng vào kỹ thuật thanh nhạc.
Tôi nói có lẽ sẽ đụng chạm đến những người học thanh nhạc. Người ca sĩ học thanh nhạc hát phải phát âm cho tròn chữ, và cố gắng đưa giọng mình cho tròn trịa, giọng ngân cao vút… nhưng quá mải lo kỹ thuật nên hát không có cảm xúc!


- Thanh Lam, Mỹ Linh giọng hát rất đẹp, cái gì cũng tốt nhưng đều bị vướng kỹ thuật thanh nhạc nên nhiều lúc nhạc cảm không có, tâm hồn bài hát không có. Hồng Nhung hát tốt hơn Mỹ Linh, Mỹ Linh tốt hơn Thanh Lam. - Theo ông, những ca sĩ được phong hàng diva như Hồng Nhung, Thanh Lam, Mỹ Linh, Trần Thu Hà có bị vướng vào kỹ thuật thanh nhạc?
Đơn cử, nghe Thanh Lam hát bài Cô đơn của tôi, tôi buồn lắm! Nó không ra cái cô đơn, thua một ca sĩ nghiệp dư hát vì hát không có hồn dù giọng đẹp thiệt! Thanh Lam hát những bài sâu lắng nhiều khi đóng kịch nhiều hơn là hát. Mà đóng kịch phải như người diễn viên, người ta nhập hồn vào vai diễn đó, ví dụ Kim Cương trong Lá sầu riêng, cô là nhân vật cô gái đau khổ tên Tâm chứ không phải là nghệ sĩ Kim Cương, phải quên Kim Cương đi! Ca sĩ cũng phải hát 'nhập vai' như vậy mới ra ca sĩ.
Trần Thu Hà thì khôn hơn, biết cách lợi dụng kỹ thuật để áp dụng. Nhưng mấy người được như Trần Thu Hà? Người nào cũng phô trương, tôi phải hát giọng cao tới nốt đó tôi mới là ca sĩ, còn hát chưa tới thì chưa phải là ca sĩ. Cái đó là sai lầm tai hại vô cùng và không ai chấp nhận.
- Hai nữ ca sĩ đang nổi tiếng nhất trên thị trường hiện nay là Mỹ Tâm và Hồ Ngọc Hà, ông đánh giá tài năng của họ ra sao?
- Mỹ Tâm chỉ hát nhạc Pop bình thường thôi, nhưng được cái là sáng sân khấu, xử lý bài hát chính xác. Mỹ Tâm cũng có những ca khúc hát không tới, gặp bài nào hát tới mới hay, như Cây đàn sinh viên, Ước gì... Mỹ Tâm hát chỉ hợp với tuổi trẻ. Về tính nghệ thuật thì Hồng Nhung, Trần Thu Hà hát xong có để lại ấn tượng, còn Mỹ Tâm chỉ nghe vui mắt, vui tai, nghe qua xong rồi thì thôi, không để lại ấn tượng gì hết.
Mỹ Tâm được cái là may mắn rơi vào đúng thời điểm không có ai cạnh tranh, từ đó nổi tiếng và khi nổi tiếng rồi thì rất khôn khéo đầu tư vào hát, múa, sắc đẹp để giữ vị trí. 
Hồ Ngọc Hà hát chỉ nghe chơi thôi! Giọng Hồ Ngọc Hà yếu lắm, khều khào không à! Hồ Ngọc Hà đẹp, có vóc dáng sân khấu, chịu khó múa… cái gì cũng đẹp nhưng giọng hát thì lại không được. Khi diễn tả nội tâm, Hồ Ngọc Hà diễn kịch tính nhưng đóng kịch chứ không thật. Ca sĩ hát phải biến mình thành nhân vật trong ca khúc mới hiểu nỗi đau làm sao. Không lẽ, ngoài đời mình buồn là phải hét, gào thét? Đâu phải vậy! 

- Bằng Kiều cũng giọng tốt như Trần Thu Hà nhưng sau này khoe giọng quá, cố hát lên cao vút để không ai bắt chước được. Thành ra, Bằng Kiều hát bài Buồn ơi chào mi của tôi khiến khán giả ở dưới sững sờ luôn! Tính lại thì hiệu quả sân khấu có nhưng tôi mở băng ra nghe thì phải nghe Tuấn Ngọc hay Xuân Phú, Trọng Bắc hát.- Với các giọng ca nam đang nổi tiếng như Bằng Kiều, Đàm Vĩnh Hưng, Quang Dũng… ông đánh giá ra sao?
Quang Dũng hát được vài bài của Trịnh Công Sơn chứ không phải là tất cả. Còn Đàm Vĩnh Hưng chỉ được bề nổi vậy thôi, tôi không cho là ca sĩ đúng nghĩa. Tôi chỉ cho Đàm Vĩnh Hưng là một người hát. Đàm Vĩnh Hưng cố hát nhạc xưa, nhạc vàng mà hát có ra đâu! 
Đàm Vĩnh Hưng hát bài Ai đưa em về của tôi, tôi bảo ‘con đừng hát bài của bố nữa, tội nghiệp bố lắm’. Tôi không thích, tôi nói thẳng luôn. Đàm Vĩnh Hưng nói ‘nhưng con thích hát nhạc bố…’, tôi nói ‘nhưng con không nên hát nhạc của bố thì hay hơn’. Thật ra, giọng Đàm Vĩnh Hưng nửa Nam nửa Bắc, cách thức hát cũng không có và lối hát cũng vậy. Hồi xưa, Đàm Vĩnh Hưng mà đi hát thì chỉ xứng là ca sĩ loại C hát lót chứ không được vào hạng ca sĩ chính của phòng trà đâu!  
- Ngoài danh ca Tuấn Ngọc thì những giọng ca nào khiến ông hài lòng nhất?
Giọng nữ thì tôi thích Ngọc Anh, Hồng Nhung, Ánh Tuyết, Trần Thu Hà… Nguyên Thảo nếu tiếp tục hát như ngày xưa thì rất hay. Ngày xưa, Nguyên Thảo hát cho thỏa đam mê còn sau này, bị gò bó vào kỹ thuật như Mỹ Linh để khoe giọng và vô tình giết chết tình cảm. Vừa rồi làm đĩa than của tôi có 2 bài Nguyên Thảo hát. Cách đây 6 năm, Nguyên Thảo hát Buồn ơi chào mi xuất thần luôn, nhưng giờ Nguyên Thảo để tâm đến kỹ thuật nhiều nên tình cảm không còn, so ra khác hẳn.
Giọng nam thì ngoài Tuấn Ngọc còn có Trọng Bắc, Lê Hiếu… Tuấn Hiệp lúc trước hát tốt, tôi thích nhưng giờ chạy theo hát nhạc vàng bị mất chất.

- Không phải! Nếu đem so sánh Tuấn Ngọc với Đàm Vĩnh Hưng, người ta vẫn thích nghe Tuấn Ngọc hát nhiều hơn, đúng không? Nghe Tuấn Ngọc hát thấy nó khác liền, hát ra là cảm xúc đến với người nghe chứ không phải gắng gượng. Tại vì Tuấn Ngọc đã sống trong bài hát đó, khi hát Tuấn Ngọc để tâm trạng vào bài hát, nói lên tâm trạng của nhiều người. Ví dụ khi mình bị người yêu bỏ, nghe Tuấn Ngọc hát Buồn ơi chào mi, nghe nó đã lắm!- Với những đánh giá này, phải chăng gu thưởng thức âm nhạc bây giờ của khán giả quá khác với ông, bởi đơn cử, Đàm Vĩnh Hưng đang được phong là ‘ông hoàng nhạc Việt’?
Tuấn Ngọc vẫn là giọng ca số một dù tuổi tác, thời gian làm cho giọng của Tuấn Ngọc không còn được đẹp như ngày xưa nữa, nhưng cái xúc cảm vẫn là Tuấn Ngọc và xúc cảm càng ngày càng sâu hơn.
- Vậy theo ông, thị trường nhạc Việt sẽ đi về đâu?
- Đây là vấn đề lớn, cả một thế hệ chứ không phải đơn giản, ăn thua là cách giáo dục của gia đình với con em làm sao. Nếu trong một gia đình chỉ có tối ngày đi kiếm tiền thì tinh thần nghệ thuật của họ chết rồi, bị tiền bạc chi phối hết. Thành ra, họ cũng không chăm sóc con cái, cứ cho tiền là xong. Họ cũng ỷ lại tiền, đưa con vào trường này trường kia, mặc con muốn làm gì thì làm. 
Theo tôi, thị trường nhạc Việt vẫn đang nằm yên. Rồi từ từ, nhạc thị trường sẽ rớt dần và tới một giai đoạn nào đó, nghệ thuật sẽ lên ngôi. Nhạc thị trường tự động phát sinh rồi sẽ tự động chết bởi những gì không hay sẽ không tồn tại. Tôi tin tưởng như vậy. Đời tôi không thấy nhưng đời con, đời cháu của tôi sẽ thấy điều này.
- Sau 60 năm cống hiến cho nghệ thuật, điều ông mong muốn nhất là gì?
- Tôi chỉ mong muốn duy nhất là có nhiều nghệ sĩ tử tế và người nghe nhạc tử tế. Tất cả những gì cứ để thử lửa đi, đốt cách mấy thì vàng cũng vẫn là vàng. Mình hãnh diện là người Việt Nam không thua ai hết!
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