Aperture in photography is a hidden an obscure feature that most amateur photographers ignore. All the cameras have aperture but can’t be controlled by all them. Mobile phones and tablets can’t control the aperture of their cameras. The same is true with cheap compact cameras.
Aperture affects mainly the depth of field and the shutter speed. Aperture is not the diameter of the lens diaphragm as it is the common misconception. Apperture is the ratio of the focal lenght to the diameter of the diaphragm.
That sounds scientific and is confusing at the start.
The human eye is actually a lens. Its sensitivity and accuracy in relation to its weight and size is beyond any image sensor of the present or the near future. Its diaphragm we called iris. It expands and shrinks acording to amount of light. The same happens with the diaphragm of photographic lenses. Like the the human optical nerves, the image sensor in order to bring good results has limits on the duration and the amount of light.
Focal length is not the distance of the image sensor to the furthest element of the lens as it is a common belief. It is the distance from the image sensor to the optical center of the lens. That’s why lenses with the same focal lenght have different physical lengths.
The physical equivalent of the aperture is a tunnel. If the tunnel has short distance (focal length) and has a big diameter (diaphragm) , it is bright inside. If it is very length and has small diameter, it is shadowy inside. That’s the reason why aperture has great importance in low light photography.
Aperture is written with the symbol f/. The f represents the result of the fraction between the focal lenght and the diameter of the diaphragm. The f is called f-stop. Most cameras uses standarised f-stop scale like f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16. The smaller the f-stop the more light the image sensor receives. The difference between each stop corresponds to the double amount of light is received. For example a lens with f/2.8 aperture receives the double light from the f/4 aperture.
The aperture is controlled in three ways.
Regulating only the diameter of the diaphragm. It is typically used in prime lenses. Prime lenses have a fixed focal length and can’t zoom.
Regulating only the focal length. It is used on cheap compact compact cameras with zoom and fixed diaphragm.
Regulating both the diaphragm and focal lenght of the lens. This is used in lenses with zoom and diaphragm blades .
In practice the aperture usually creates this effects on photographs:
Lower f-stops creates vignetting. Vignietting is the darkening of the photo’s corners. Sometimes is artistic, sometimes is unpleasant.
Higher f-stops produce sharper photos. The group f/64 was a group of photographers like Willard Van Dyke and Ansel Adams. The high f-stop f/64 on large format cameras produced sharpness evenly with great depth of field.
Lower f-stops accept the maximum light and permit the minimum time of exposure. Despite creating less sharp photos, it is the ideal setting in low light handheld photography. Human eye has approximately f/2.1 in darker places and f/8.3 in brighter places.
Lower f-stops create shallower depth of field. When lower f-stop is combined with larger focal length we have the bokeh phenomenon. Bokeh is the artistic blur of the out of focus backround and foreground. The object in focus is more evident. It is artistic and very usefull in portraits.
Higher f-stops create more lens flare. lens flare is the artifacts or haze created by a very bright source of light, like sun or a naked lamp. That can be artistic or unpleasant.
Lower f-stops conceal the presence of dust on the sensor or the lens.
Since the lower f-stops results in the beneficial bokeh but also to softer photos, the construction of sharp lenses with very low f-stop is very demanding.
That kind of lenses are called portrait lenses because bokeh helps the eye to focus on persons. They are also called fast lenses because they send more light to the sensor and require minimum shutter speed. Normal and wide angle sharp lenses below f/1.4 and telephoto sharp ones below f/4 cost thousands of dollars each. They make the difference between amateurs and professionals.
Even if it is a crucial thing for the quality of photos, most ordinary photographers are ignorant of the image sensor size they use.
Image sensor size is the most important factor of the camera’s cost. Manufacturers tend to conceal it and focus their marketing on other specifications. In the case of small cameras doesn’t even exist on their manuals and brochures. Consumer compare megapixel, body size, weight, optical zoom, connectivity and forget the most important which is the image sensor’s size.
Image sensors are cut from a big silicon disk called wafer. Silicon wafers are expensive. VERY EXPENSIVE. Usually only one in three wafers is pure enough to make sensors. A wafer can be cut in more smaller sensors than big ones. Since the wafer is circular bigger rectangular sensors create more waste space at the disk edges than smaller ones. So a small image sensor is by far more cheap than a bigger one and more profitable. Big sensors shouldn’t be related with more megapixels. Actually what counts more is the size of every individual pixel than the total amount of them. A bigger pixel receives more light than a smaller one. More light reduce the need of higher sensitivity ISO. Low ISO produce lower image noise and sharper images. Image noise is the equivalent of the grain in high ISO films. Big sensors are ideal in low light photography. That’s the reason why mobile phones no matter how expensive they are shot low quality photographs under poor lighting. It is impossible to insert a large sensor in such a slim device.
Big image sensors require bigger lenses in diameter. The bigger the elements of a lens the more expensive they are. That doesn’t have to do with the cost of the material like in the silicon wafers case. When an element of a lense is big requires more time and effort to be perfectly polished and multi layered than a smaller one. Imperfections are more visible, like barrel distortion, chromatic aberration, sharpness, flaring, clarity etc. Larger lenses are exponentially more expensive from small ones of the same materials and technology. For example full frame cameras have bigge lenses in diameter than crop sized compact cameras.
Under normal conditions the difference between small or bigger sensors is negligible. Outdoor daylight photography without shadows, or well lighted indoor photography doesn’t demand big sensors.
An iPhone can shot decent but boring photographs under ideal lighting. Impressive photographs are under special lighting. Sunset or sunrise, blue hour, artificial lighting in sports et are very demanding. A bigger sensor offers creativity to the photographer.
The bigger sensors have better dynamic range. Dynamic range is the difference of the amount of light the sensor receives from the brightest and darkest areas.
A classic example is photos during sunny middays. The shadowy and the bright areas can’t be captured equally well. In this case there is a large dynamic range of light. During a cloudy day there aren’t any shadows and the dynamic range is small. The large pixels of a large sensor copes with this problem better.
The size of a digital image sensor varies a lot. However for compability reasons with legacy lenses of the film era the main sensor is the full frame one. The full frame sensor has the same size of a 35mm film, 36mm length X 24mm width. Its aspect radio is 3:2. The aspect radio of 3:2 is considered the standar in photography. The 35mm film is named from the width of the perforated film gauge. 24mm width + 11mm holes = 35mm. The full frame sensor is considered big today. However the 35mm film was also known as small format film for amateur in comparison to professional medium format and large format films of the film era. The compatible lenses for full frame digital cameras are named EF by Canon and AF-S by Nikon.
The APS-C sensor size derives from the APS film. Advanced Photo System type Classic was introduced in 1996 a few years before the expansion of digital cameras. Its classic type size was 25.1mm × 16.7mm. It had a magnetic coating that could store informations like shutter speed, aperture size, aspect ratio etc. It was created to be more practical but not better than 35mm film. It was short lived. By 2002 the compact digital cameras were cheap enough to replace APS film cameras but not 35mm cameras yet. First mass produced digital SLR cameras appeared the early 2000. They were not affordable by anyone at the begging. Despite being compatible with 35mm lenses, they didn’t have full frame sensors. That came later. The size of the first dSLR sensors was similar to the APS-C. Even nowadays most dDSLRs have APS-C sensors because they are easier to be mass produced and offer good quality. Also most lenses are constructed for APS-C sized sensors. Canon name them EF-S and Nikon AF-S DX.
Every digital sensor bigger than full format (35mm) is named medium format. Medium format films were the choice of professionals. The 35mm film was inferior but cheap and good enough for amateurs. Medium format digital cameras are still very expensive. They have the same price of a car. Their quality is second to none. They offer by far more megapixels without reducing the size of pixels. Their Dynamic Range is perfect as their sharpness and light sensitivity. Additionally these lenses are not mass produced. That makes them very expensive. It’s a niche market. The dominant Canon and Nikon brands haven’t ever created a medium format digital camera. The both very prestigious and historical German Leica and Danish Hasselbald offer medium format digital cameras. These are cameras for the very successful professional photographers or the uber rich amateurs.
Micro Four-thirds sensor size doesn’t derive from a film size but from the 4/3 inch diameter of the common video camera tube. The standard aspect ratio of glass TV sets was 4:3. A Micro four third sensor has 17.3mm length and 13mm width. It is inferior than the previous sensor sizes. However the recent advances in low noise ISO and dynamic range have created four-thirds sensors with equal quality of a five year old APS-C sensor. The first mirrorless digital cameras in 2008 had a micro four-thirds sensor. Most mirrorless cameras still have micro four-thirds sensor. It is the only decent solution in high quality small cameras with reasonable price. It saved brands like Olympus, Fujifilm, Panasonic, Samsung that couldn’t compete with Nikon and Canon at the dSLR sector.
1″ sensor is a the more recent popular sensor size. The size of one inch sensor is 13.2mm length X 8.8mm. Nikon names it CX format and puts it in his mirroless cameras. Sony uses it in his premium compact and super zoom cameras like the series of compact Sony Cyber-shot DSC-RX100 and super zoom Sony Cyber-shot DSC-RX10. The one inch sensor is the smallest size for serious photography. Mobile phone after 2007 with first iPhone had gradually elbowed the digital compact cameras with tiny sensors. The 1″ inch sensor is big enough for quality photos and small enough to be inserted into small compact or mirrorless camera. It has reopen the gap between mobile phones and very small digital cameras.
Smaller sensors are measured in fractions of the inch. For example the legendary Nokia Lumia 1020 mobile phone has a 2/3″ 8.8mm X 6.6mm image sensor with the amazing 41.3 megapixel. The iPhone 5 with its decent camera has a 1/3.2″ 4.54mm X 3.42mm sensor. The iPhone 6 plus with its electronically stabilized lens has a 1/3″ 4.8mm X 3.6mm image sensor.
Crop factor is relative to size of an image sensor. Crop factor or Focal Length Multiplier FLM is the ratio of the diagonal length of a full frame image sensor to the diagonal length of the actual image sensor. The typical diagonal length of image sensors are: Full Frame 43.2mm, APS-C 30.1mm and Micro 4/3 21.6mm. For example if the camera has a full frame lens its crop factor is (43.2/43.2=1) 1. If the camera has an APS-C sensor then the ratio is (43.2/30.1=1.43) 1.4 crop factor. If the camera has a micro 4/3 sensors then the ratio is (43.2/21.6=2) 2 crop factor. That ratio in practice affects the field of view of the lens. In simple words a 100mm lens of a full frame (crop factor 1) camera when is put on a APS-C (crop factor 1.43) camera acts like a (100 X 1.43 = 143) 143mm lens. On a micro four thirds camera (crop factor 2) it acts like a (100 X 2 = 200) 200 mm lens. The smaller the sensor the more powerful a telephoto lens is. Super zoom compact cameras have small image sensors in order to avoid lengthy lenses.
In Windows operating system a user only sees disks when he clicks the computer icon.
Are they real physical disks? How a disk is configured in Windows?
The story is long and starts from the early home computers. I don’t write personal computers because this is a trademark from IBM, also known as PC.
_Drive is the machine that reads and writes the storage medium. The medium can be a cassette, a floppy disk, a hard disk, CD, flash memory etc. To be more clear the cassette is medium of data but alone can’t be accessed. It needs a cassette drive. The same with the CD or Floppy Disk. Of course floppy disks drives are obsolete today. However cassette drives still reign in the enterprise computer sector.
The professional cassette drives are very expensive, but the data cassettes still offer immense and the most affordable data storage today. The common HDD and SSD are acronyms for Hard Disk Drive and Solid State Drive. In the case of a HDD the data medium is the hard disk enclosed by a meta box with a motor and heads which read and write data to the disk. In the case of SSD the medium is chips with transistors on an electronic board. Driver and drive are not the same. Drive is hardware, driver is the software which helps the operating system to control the Drive. Usually the operating system includes the proper drivers but some times extra software is needed for an new drive which is named driver. For deep control and informations about the physical drives in windows type DISKPART . DISKPART shows more details and has more commands than the Disk Management. To view the physical drives use the command LIST DISK . The drives are named as DISK 0 for the first, DISK 1 for the second ,DISK 2 for the third etc. What we see at clicking the computer icon of windows is not necessarily physicall drives but partitions or volumes too. For selecting the drive you want to use type SELECT DISK 0 for the first physical drive or SELECT DISK 1 for the second etc. The command CLEAN erases everything from the selecting disk.
_Partition as the name suggests is a partition of the disk. It is used mainly on HDDs and SSDs. There are many reasons to partition a disk. The first is the economical. Nowadays the rotational hard disks are very cheap and I avoid partitioning. However 15 years ago it was a tool to make a single hard disk very usefull. You can install different Operating Systems on a single hard disk. For example in a single disk I created four partitions. On the first I installed the legendary Windows 98SE, on the second the revolutionary Windows NT 4.0 and on the last two partitions the simple and beautiful Corel Linux.
At the start the first selection of the boot loader was between Linux and Windows and if I selected Windows, the next selection was between Windows 98 or Windows NT 4.0 . For achieving that I had to partition the hard disk into four partitions with different sizes. Linux needs two partitions. Usually the biggest partition was dedicated to Windows 98.
The increasing rate of the hard disk capacity is not the same like in Ram or CPUs and it usually surpass the expectations of programmers. My first disk in 1997 was an enormous 6 GByte Quantum and costed 100,000 drachmas around 300 dollars. After 18 years a 6 TByte (6,000 GByte) disk costs the same for one thousand times bigger capacity. In 1997 the windows 95 I had, was recognizing only FAT12 and FAT16 formatting systems. FAT16 however had a limit of two GByte partitions. So I had unwillingly steparated the hard disk into three partitions. After two years in 1999 I installed three operating systems on a single disk and I wanted each operating system to access the files created by the other two operating systems. Windows 98 could recognize only FAT32 and FAT16, Windows NT 4.0 only NTFS and FAT16 and Linux only EXT2 and FAT16. So the common formatting system was FAT16 which restricted the partitions to 2 GByte. Next in 2003 I wanted to have both windows XP and Mandriva Linux which was the successor of my beloved Red Hat linux. Windows XP could recognize FAT32 and NTFS formatting systems and Linux Mandriva EXT2 and FAT32. This time the common formatting system was FAT32. However FAT32 has restrictions. Under Windows XP the biggest partition with FAT32, I could format was 32 GBytes. Also FAT32 doesn’t permit files over 4 GByte. Again I had created unwillingly many 32 GByte partitions. Nowadays hard disks are very cheap but most laptops don’t have more than one disk. You can’t install an operating system like windows on a usb hard drive. If you want to have multiple operating systems on a laptop the partitioning is the only way. OS X and its boot camp is a nice case of multiple operating system on a single disk.
The main kind of partition is the active. The active partition is the partitions which is bootable and usually holds the operating system. Only one partition can be made active. In the case of multiple operating systems on a disk, a boot loader program on the active partition redirects to the selected operating system on different partitions. A hard disk which it isn’t bootable doesn’t need an active partition. Usually the usb hard disks don’t have active partitions.
Under windows FAT32 a disk is restrict to one primary partition and one extended partition. Only the primary partition can be active and only that can have the main files of the operating system. Of course the primary partition can be inactive without operating system. The extended partition is always subdivided into one or multiple logical partitions. That was a relic of the DOS and windows95,98,Me era. After the windows NT 4.0 and Windows XP and the advent of NTFS formatting system the rules are relaxed and the primary partitions can be as many as four. For a detail view o Partition type DISKPART command and afterwards LIST PARTITION.
The informations about how a disk is partitioned are stored in area which is the old MBR (Master Book Record) or the new GPT (GUID Partition table). In the MBR the informations are stored in one place and if that place is corrupted the data on the disk is unreachable. The GPT store the informations in multiple places and is more robust. The MBR is old and has limitations. Only four primary partitions are permitted and more crucially the biggest drives it can support is 2TByte. That was a big obstacle to the expansion of bigger than 2TByte disks. The GPT is not supported by all 32bit versions of Windows including windows XP,vista,7,8. The 4 GByte limit of memory in a 32bit OS is not such a problem as the 2 TByte hard disk limit. Windows XP 32bit, 64 bit and earlier versions of Windows can’t be installed on GPT disks. The MBR dates back to 1983 and it’s time to be changed.
A disk under windows can be configured as Basic or Dynamic. A Basic disk support all the properties written before. A dynamic offers RAID capabilities inside Windows without RAID hardware. It is not offered in all versions of windows. It is a premium feature and only professional and above editions provide the RAID functionality of Dynamic discs. The windows don’t use directly the RAID name due to copyright issues. Instead windows uses the spanned, striped and mirrored disk which are equivalent to RAID configurations.
Finally what is Volume? The computer icon on windows shows disks with their assigned letter. That letter distinguishes the Volumes of an operating system. So a volume can be a primary partition, a logical partition, a whole disk, or a combination of dynamic disks (mirror disks, stripped disks or spanned disks). Volume is what the user see and doesn’t have to care what lies behind it. To view the volumes type the command DISKPART and afterwards LIST VOLUMES.
The last 18 years I’m a computer user, I faced three times a great loss of data from corrupted disks. In computing there are two kinds of people, those who lost files and those who will loose files. Every hard disk will eventually temporary or permantly fail after three to ten years.
The obvious and easy answer to this problem is making a back up. That process is good but its boring and time consuming. A proper backup should be done continously and incrementally.
The time machine application of OS X is a nice solution. Back Up has two disadvantages. First the automatic interval of incremental Back Up can take a day. Second, a complete restore of a failed hard disk can take five hours or even more.
The best solution is RAID 1 (Redundant Array of Inexpensive Disks). As its acronym indicates, it is an inexpensive solution of data safety. The same data is written and read in at least two disks at the same time. The probability of both disk failing simultaneously is extremly rare. There are many kinds of RAID types. Initially RAID was based on hardware. A RAID card or an embedded raid controller on the motherboard was needed. Hardware RAID offers speed and reliability. Nevertheless modern operating systems and fast CPUs can emulated RAID without any use of special hardware.
Windows 7 professional and OS X Lion 10.7 offer software RAID 1 with some limitations. Of course the hardware RAID is the best but software RAID is equally safe.
Windows 7 professional doesn’t use the name RAID 1 for copyright reasons. Instead it uses the mirrored disks name. Mirrored disks can’t be created through USB. From my experiences SATA disks directly connected to the motherboard work fine as mirrored disks. In desktops its easy to add two extra disks and make them mirrored.
On laptops the case is different. Most laptops have one bay for hard disk and one for the DVD drive.
Some bigger ones 17″ and 18″ have two bays for HDD. Again this doesn’t help to create mirrored disks. The drive in which the windows 7 professional operating system is installed can’t be mirrored afterwards. Althought Windows 7 professional can be clean installed from the beginning on a ready made two mirrored disks.
For laptops a DVD caddy bay can help.
Removing the DVD drive we replaced it with a caddy DVD drive that accepts a hard disk. That way a typical laptop can at least have two hard disks or even three.
The way of creating mirror disks is simple under windows 7 professional or Ultimate. (Not all windows 7 versions offered mirrored disks. Windows 7 starter, basic or premium don’t offer that potential).
Right click the computer icon and select Computer Management. You must have logged in as administrator. then select disk management. Now the first step is to make the hard disks we want to mirror, as dynamic. Second step is to right click and select mirror disk from one of the two disks and from the next window insert the other disk to be mirrored.
That’s all. A new hard disk will appear on My Computer which is actually a bunch of two disks. In case one of the two disk failed the windows will try to fix the problem and notice the user. Otherwise a classical backup will be needed and a replacement disk to be mirrored. One way or another the data won’t be lost.
On OS X the disk utility app permit the Raid 1 with usb disks.
This is very convenient and safe way to expand your data storage. Also theoretically you can clean install an OS X opeeating system on RAID 1 disks. The way of creating a RAID volume on OSX is far easier than in Windows 7 Professional.
I entered the computer world in 1997. I wasn’t a DOS user neither windows 3.11 user and I regret for losing that era. I started from the golden age of Internet and CDs. Of course my first computer was a windows primitive desktop. It was an ugly beige box with a 150MHz pentium and 16 MBytes memory and 1Mbyte graffic card. Only the respectable Sony display was decent enough.
In 1997 Steve Jobs had just returned in Apple. Also the arogant Rainbow importer of apple computers was the worst computer company I have ever met. So an apple computer wasn’t a choice. In 2004 I bought an eMac with PowetPC processor. It was a great computer but I couldn’t find good video encoding software which was my basic interest that time. Additionally hardware wasn’t compatible with mac like nowadays. I wasn’t impressed due to the lack of specialized software. That wasn’t the case with my second apple intel computer. The MacBook Air 2011. It was a game changer for me. A goodbye to the dark age of windows.
I’m a four year avid user of OSX. I feel like a MACaddict. This is my review about the new apple macbook retina 2015. For someone new to apple computers, it is not a bad choice. Its design is amazing and definitely the future of ultraportables.
I will start from the negatives. First of all the price. When you buy apple, you buy innovation. You buy what the others will make affordable after two years. You either wait and have old affordable technology or you choose apple. This may sound dogmatic but is true. Aple differs because it combines software with hardware seemlessly . 2.000 euros for a notebook is much. Apple since the first iMac, after has a hight price tag. It is true that the recent years the price of macbook has lowered. But on which MacBooks? The old technology MacBooks. The new retina macbooks are still expensive.
As usual the apple computers can be customized. The same is true with macbook retina. The best configuration with 512 Gbyte SSD and 1.3 GHz intel core M raise the price to 1.950 euros. The basic configuration 254 GByte SSD, 1.1 GHz intel M core is at 1.450 euros. Still I’m not impressed. The www.cpubenchmark.net for the best optional cpu for macbook retina ,the Intel Core M-5Y71gives a mark at 2.919. Now the best optional processor for the MacBook Air mid 2011 is the 1.8 GHz (i7-2677M) dual-core Intel Core i7 with 4 MB shared L3 cache.
The www.cpubenchmark.net for the i7-2677M gives a mark at 2.882.
So both laptops with four years difference have the some performance. Why then I should change my MacBook Air mid2011 with the macbook retina 2015?
In four years Intel has succeeded to lower the power consuption from 17 watt to 4.5 watt with the same performance. It is a technological leap.
That creates three big differences. The aesthetic, the weight and the noise. The lack of airfan permits a slimmer design. The lack of big copper cooler reduce the weight. No airfan and no rotational HDD bring no noise at all.
Even the last fanless computer of Apple, the ill fated Power Mac G4 Cube was fanless but not noiseless due to the HDD. A noiseless computer was an early dream of Steve Jobs. First attempts were a failure and the dream remained a dream during his lifetime.
Macbook retina 2015 is very slim. It is so slim that actually no conventional data port can fit. Only the earphone jack and a new type of USB, the slim USB-C.
A micro USB is slim enough to be fitted but if you want to avoid an extra power port, the micro usb is underpowered. I dislike USB-C even if it is a necessary evil. I also desliked the early preference of apple to thunderbolt than USB 3.0 . Apple has a long history of proprietary or less popular data connectors like SCSI, FireWire, display port and the recent thunderbolt. That confuses consumers. The inevitable USB-C adapters raise the cost further and add weight and bulk.
The retina display sounds impressive with its tremendous resolution. The reality is that in most cases it doesn’t help. The osx select the retina resolution when the app is written for retina display. Otherwise a non retina display compatible program will show very small icons and letters. The OSX tries to magnify applications or downscale the resolution. The result is both inferior from a conventional no retina display. For multimedia applications retina display is second to none. For office applications is not really essential. As the time passes nearly all mac software will be retina compatible.
What I like in macbook retina is its slim design and its lightness which is comparable to the first generation of iPads. It is fully aluminium even at the place between the display and the main body which in MacBook Air is a black plastic strip.
I strongly believe that it will replace MacBook Air as the forthcoming low powered processors will be faster.
The first generation of MacBook Air 2008 was critisized for being too slow. After 2011 Macbook Air’s optional faster processors were equal to the base models of MacBook Pro 13″. The market of x86 CPUs is stagnated lately. Only the ARM processors in mobile phones and tablets has a marvelous progress. The extra low powered CPUs is the next bet from Intel. Intel after 2008 produced the low powered Atom CPUs but they failed due to their very inferior perfomance. Netbooks are gradually replaced by affordable ultraportables.
The keyboard and trackpad is what you expect from such a small and slim computer. It takes time to be accustomed. Small computers are not ideal for fast blind typing. Only the expensive models of Lenovo thinkpad offer really good keyboards. The trackpads of apple and all the trackpads in general can’t be compared to a mouse. Since macbook retina hasn’t got a proper USB port only a compatible bluetooth mouse can be used without the mess of adapters.
In comparison with MacBook Air the macbook retina is not upgradetable or reparable at all.
For example in the case of MacBook Air, battery and SSD are replaceable, the same with fan even if MacBook retina doesn’t have one. In Macbook air anything is glued and soldered . The iFixit site which I appreciate a lot, gives 1 in 10 score, the lowest in repair ability. iPhone has 6 in 10 and you can’t say that it isn’t compact.
It describes the Babylonian law about various things including economy. According to the law the debtors were forgiven after three years. The sixth Babylonian King Hamurabi knew about economy and respected the entrepreneurial efforts of his subjects in Mesopotamia . It is one of the earliest know economic laws in history.
The code was inscribed in stones and some of the still survives.
Babylonians was the first to issue money in clay tablet form. Also were the first who created interest rates. The credit was invented in ancient Mesopotamia.
The Incas of the Latin America despite their advanced civilization didn’t use any kind of money.
The precious metals were only useful for aesthetic purposes like jewlery and religion.
Gold was considered to be the sweat of sun and silver the tears of the moon. So when the Spanish conquistadors arrived they couldn’t reallize the lust of invaders for this metals.
The accumulation of vast quantities of this mettals by the Spanish however led to their temporary depreciation. It is said the nearly all the gold and silver of the world have a percentage of the Incas precious mettals.
Agias Dinamis church (Holy Power in English) is a peculiar church in the center of Athens. It was built during the 16th century maybe upon the ruin of an Ancient Greek temple dedicated to Hercules. The name Agia Dimamis derives from the power of the Virgin Mary.
Below the altar of the church there is a secret cave 15 meters deep. It has Ancient Greek ruines. During the greek revolution against ottomans it was a secret depot for holy relics, documents and ammunitions. It is said that from there begins a tunnel that leads to the Kesariani district of Athens.
The true is that Athens has many underground secret passages.
The small bell structure was built in 1963. The neighborhood of the church was named Rodakio. The church is believed to help pregnant women. The little church had also some nearby small structures which were demolished during the creation of Mitropoleos street.
The building above the church used to be the ministry of education and religions. Maybe it has the tallest first floor in Athens.
Many of the roads in Athens used to be river, streams or torrents. After the liberation from Ottomans and the expansion of the city this rivers were conveniently converted into wide streets. The benefits were huge. Less exposed waters prevented citizens from using foul water. Also mosquitoes couldn’t find proper ground to multiple. So mosquito and water related diseases were diminished. However the cityscape was becoming less attractive. And the use of cars demanded the covering of every picturesque river or stream.
Until 1945 there were 1280 km of small rivers in Athens. The landfill of rivers have led to great disasters during thunderstorms. The waters don’t have any exit except the major roads in Athens.
Stadiou street was a river and was named with the rude name Chezopotamos because it was used as a sewer. From the Lycabetus the Voidopniktis river was following the Voukourestiou street and split into two parts. The first followed the Akadimias street and the second the Stadiou street until the Omonoia square. The photos proves that under Stadiou street a river still flows. The Stadiou street was one of the major urban works in the mid 19th century. If you watch carefully the tarmac of Stadiou street isn’t flat. It creates a slight arc. Underneath is a tunnel for the covered river.
Omonoia metro station have water leakage problems and many deep basements of the buildings in Stadiou use water pumps during winter.
What I like most in the photos is that nature persist to the human manipulation of earth. The collapse is not more than two years and small trees has appeared in the pavement from nowhere.
The central building of the University of Athens was occupied for several days by anti authoritarian and students of the university.
It was the first major activity in the university sector since the election of the the left wing Syriza party. As it is usual the area was covered with banner. Except the typical graffitis the interior of this old neoclassical building was respected.
The building is a part of an architectural trilogy. It was designed by the Danish architect Hansen. It courtyard has some important statues. Rigas Feraios statue was places in 1871, the statue of Patriarch Grigorios in 1872, the statue of Korai in 1875, the statue of british prime minister Gladstone and last but not least the statue of the first governor of Greece Kapodistria in 1928.
The trilogy of the Academy, Univercity, Library was a part of an effort to convert the village of Athens into a respected capital city in Europe. It was built the same period with the Royal Palace (parliament) the metropolitan cathedral church, the Arsakeio and Zappeion. Even today this buildings are the most impressive in Athens.
The area around the academy and the university is considered asylum. So police can’t intervene without special permit and order. During Sundays and late Staturdays drug trafficking and usage is occurred. During working hours everything is safe except some used syringes on the cobblestones.
Today the amateur cycling tour of Athens took place. It was a small tour of around 8 kilometers in the center of Athens. There was one small and a big route. The big route was from Amalias avenue to Vasilisis Olga’s avenue, Vasileos Konstantinou avenue, Kifisias street, Alexandra’s avenue, 28is Octomvriou street, Stadiou street, Philelinon street and back to Amalias avenue.
The start was at Zappeion gardens and nearly 8.000 cyclists of all ages participated. The weather was perfect sunny and cool.
Greece is not a cycling country and neither Athens. The last years a movement for cycling in Athens made that activity friendly. It was fueled by the Facebook and Friday nights cycling gatherings. Many biking shops have opened and it is usual to see bikers at the streets of Athens.
The cycling in Athens is a little dangerous for many reasons. The obvious one is the very bad tarmac, full of patches and holes. Another one is the traditional rudeness of car driver and especially taxi drivers against cyclists. Also during night the roads in Athens are very badly lighted.
On the other hand many cyclist are rude to the pedestrians. They prefer the more secure pavements and pedestrianized streets and anoy pedestrians if they block their path.
Unfortunately all plans for bicycling lanes have failed. The illegal car parking has bigger priority than a healthy activity. The recent crisis and the sudden rise of the public transportation cost has led many to the more economic use of a bicycle.
What I really dislike from some bikers is the total disrespect of road rules. The don’t obey traffic lights, one way streets and I doubt if most of them have a driving license. The road education in school in Greece is no existent.
Athens and Greece in general is a mountainous country. Athens is a pit surounded by four mountains. Egaleo at the north-west, Parnitha at the north, Penteli at the north-east, Hymettus at east. Is not a flat city and that is very tiresome for the ordinary biker. Also only a few months ago the municipality of Athens decided to create proper bicycle parkings. The pety crime is high in the city, so an expensive bicycle is prime target for desperate thieves.