Something About Ultra-wide-angle lenses

1. Nikon AF Zoom-Nikkor 18-35mm f/3.5-4.5 D ED IF Aspherical
Nikon's lightest-weight ultrawide zoom, 11 elements in 8 groups, 93mm long, 82,5mm diameter, 77mm filters, 370g, one aspherical lense.
The close focus is 0.33m from the film plane, viewing angle of 100-62°.
The diaphragm has 7 rounded blades, stopping down to f/22, not quite regular in circular contraction.

2.Nikon 12-24mm f/4G IF-ED AF-S DX Zoom-Nikkor
Option for APS-C Nikon DSLRs,  11 elements in 7 groups, 90mm long, 82.5mm of diameter, 485g, 77mm filters, the close focus is 0.3m marked, magnification 1/8.3, on D100 viewing angle 99°-61°, largest aperture F4, Stops down to f/22.


3.Nikon 20mm f/2.8 AF
12 elements in 9 groups, 52mm long, 69mm of diameter, 270g, Stops down to f/22, it focuses as close as 0.25m, 94°of viewing angle, diaphragm has 7 blades.

 4.Nikon AI NIKKOR 24mm f/2s

This was the fastest 24mm lens ever made by Nikon up until 2010.  
11 elements in 10 groups, 51.5mm long, 63mm of diameter, 300g, close focus at 0.3m, max reproduction ratio 1/8.6, viewing angle 84°, 52mm filters, 7 straight blades, stops down to f/22

 5.Nikon AF-NIKKOR 24mm f/2.8 D

 9 elements in 9 groups, 46mm long, 64.5mm of diameter, 270g, 52mm filters, 7 straight blades.

stops down to f/22, close focus at 0.3m, viewing angle 84°.

 6.Canon EF 20-35mm f/3.5-4.5 USM

Canon´s first attempt to provide an ultra-wide lens to the masses.

 12 elements in 11 groups,  69mm long, 83.5mm of diameter, 340g, 77mm filters, close focus at 0.34m, 5 aperture blades, magnification of 1:7.7.

 7.Canon Zoom Lens EF 17-40mm f/4 L USM

12 elements in 9 groups,  96.8mm long, 83.5mm diameter, 475g, 77mm filters, 7 mostly straight blades stopping down to f/22, close focus at 0.28m from the image plane.

 8.Minolta AF 17-35/3.5 G

15 elements in 12 groups, close focus at 0.3m, 77mm filters, 90.5mm long, 82.5mm diameter, 600g, 7 aperture blades, circular, constant maximum aperture of f/3.5.

 9.Sigma 17-35 mm F2.8-F4.0 EX DG HSM

Covers a super-wide angle of view 104 degrees, 15 elements in 14 groups, 86mm long, 89mm diameter, 435g, 82mm filters, minimum focusing distance of 27cm at all focal lengths, maximum Magnification of 1:4.5.

10.Sigma AF 15-30mm f/3.5-4.5 EX DG

 17 elements in 13 groups, 130mm long, 87mm diameter, 615g, close focus at 0.3m, angle of view: 110.5-71.6°, 8 diaphragm blades, max magnification 1/6.

Panasonic Lumix DMC-GF2

Its body is smaller in every dimension than its predecessor's, making it very nearly as petite as the Sony NEX-5. In the process, though, it's shed a significant number of those external controls that until now have been the hallmark of the G series - most obviously the exposure mode dial, but also the drive-mode lever that sat beneath it, along with several of the buttons on the back.

GF2 gains Full HD movie recording capability (1080i at 60fps from 30p capture) that is supported by a stereo microphone on the top plate.On the photographic side the GF2 inherits the G2's ability to shoot at 2.6 fps while maintaining live view, along with its ISO 6400 maximum sensitivity, improved Auto ISO program and a dedicated iAuto button on the top plate. Meanwhile 3D fans will undoubtedly be delighted by its support for the H-FT012 lens.

Compared to the Panasonic DMC-GF1

The GF2 is, unusually for Panasonic's recent releases, substantially different in design from its predecessor. Here it is sporting the 14mm F2.5 pancake alongside the GF1 wearing the 20mm F1.7. The sleeker, simplified design is immediately apparent.

The loss of the mode dial (replaced by a stereo microphone on the top plate),the remolded grip and the closer integration of the hot shoe into the overall design all adds up to a cleaner, less boxy look. The GF2's 'Full HD' label signals the presence of its 1080i video mode.

The wealth of buttons that adorned the GF1's back has been simplified right down, and the restyled four-way controller gives a more 'compact-like' appearance. The blue tinge to the GF2's LCD screen signifies a small, but welcome change - the addition of an anti-reflective coating to aid shooting in bright sunlight.   

 

  Some major changes:

·                     Smaller and lighter body

·                     LCD screen now touch-sensitive, with added anti-reflective coating

·                     Fewer external controls (mode dial, drive mode lever, AEL and DOF preview buttons removed)

·                     Completely revamped, fully-customizable Quick Menu designed for touchscreen operation

·                     Built-in stereo microphone

·                     1080i 60fps full HD video (from 25p sensor output)

·                     Continuous shooting at 2.6fps with Live View

·                     Increased maximum sensitivity (ISO 6400)

·                     iAuto button on top plate

·                     Variable 'Defocus Control' in iAuto and 'My Color' modes, with live preview

·                     Full support for F-FT012 3D lens

·                     No remote release socket

·                     2nd curtain sync and flash exposure compensation no longer available

·                     New smaller DMW-BLD10 battery with slightly lower capacity (7.3Wh vs 9 Wh)

 Compared to the Olympus E-PL2

The GF2 is smaller than the E-PL2 in every dimension, but not by all that much. Olympus incorporates in-body image stabilization that works with all lenses. 

 Compared to the Sony NEX-5 and Samsung NX-100

Here it is with the 14mm F2.5 lens sitting between two of its direct competitors each kitted out with their respective wideangle pancakes, the Sony NEX-5 + 16mm F2.8 and Samsung NX100 + 20mm F2.8.

The GF2 is now one of the smallest cameras of its type, although it's still not as tiny as the NEX-5 despite having a smaller sensor than the Sony's APS-C chip. The key difference is in the body height, though, which reflects the GF2's hot shoe and built-in flash: features which are missing from the NEX. The NX100 doesn't have a flash either.  

 

Unpack + Review -----EP1

Since I bought the SLR camera, I have used it no more than 3 times a year. It's too big and too heavy...
I've always wanted to buy a smaller and better picture quality camera. At the beginning, I wanted to buy SIGMA DP1, but the reviews said that it has a SLOW response, and same thing happens for DP2. Then I decided to look for another cam because even the pic quality is awesome, I am afraid that the slow response will drive me crazy.

After all, I saw the 4/3 system and I definitely love it. Before I buy EP1, there's LEICA X1 coming out. It was amazing, unable to critic on its look nor its pic quality. The most important, it's LEICA!!!But at the same time, it's a little bit expensive for me, and it cannot change lenses.
While I was hesitating which one to buy, I saw a post on the cam fan forum, and it mentions that we can use EP1 to connect with LEICA 50MM to take pictures. What a good news...I bought EP1 the next day with a 17MM fixed focus KIT.

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The cam itself is upgraded to 1.3, and the lenses to 1.2, also changed the EXTREME SDHC card

  Some pics...

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To conclude, I'm pretty satisfied with this cam, but the the aperture of that lenses is too small, ok for everyday use.
Can set to the 16:9 mode, all pictures above are widescreen display.

Can record video 720P. 

Unpack Casio Exilim EX-TR100~~~~~

The HOTTEST self portrait cam Casio Exilim EX-TR100, auto exfoliating, 360degree rotation, girls gonna LOVE it.....
Already sold because personally, I don't often take pictures of myself, so it's useless for me...
However, it is still a good choice for those who are self portrait addictive.

Something About The Depth of Field

First, I have to introduce you a few concepts before move on the calculation of the depth of field.

1.Focus
A point toward which light rays are made to converge after passing through a convex lens.

2. Circle of confusion
Optical spot caused by a cone of light rays from a lens not coming to a perfect focus when imaging a point source.It is the largest blur spot that will still be perceived by the human eye as a point.

3.Depth of Field 
Distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. Changes by changing the focus, aperture value or the distance between the subject and the camera.  

The bigger the lens aperture, the smaller the depth field and vice versa.

The longer the lens focus, the smaller the depth of field, and vice versa.

The farther the distance, the bigger the depth of field. 

4.How to calculate the depth of field 
δ: diameter of circle of confusion
f: focal lengh
F: aperture value of the lens
L: focus distance
ΔL1: front depth of the field
ΔL2: back depth of the field  
ΔL: depth of the field

                FδL²  
ΔL1= ——————    (1) 
            f² + FδL  

                FδL²
ΔL2=  ——————    (2)
             f² - FδL 

                                         2f²FδL²

ΔL =	ΔL2 + ΔL2  = ———————

                                      f⁴ - F²δ²L² 

 The back depth of th field > front depth of field  

Some thing about telelens DC

A telelens is a  long-focus lens in which the physical length of the lens is shorter than the focal length.
Although telelens DC has many advantages, it will require more skills, higher quality of big zoom lens and higher ability to resist dispersion.

I will introduce some well known model.

1.Sony Cyber-shot H1

Cyber-shot H1 is Sony's attempt to win a share of one of the fastest growing digital camera market sectors, the 5 megapixel 'super zoom'. Although Sony has produced big zoom cameras before, the H1 is the electronics giant's first foray into compact, big zoom image-stabilized cameras. As well as a huge 12x optical zoom the H1 is a real treasure chest of photographic control, offering a wealth of automatic, semi automatic and manual exposure modes, a big 2.5" screen and captures VGA/30fps movies in space-efficient MPEG format.

·                     5.1 effective megapixels

·                     36-432mm equivalent (12x optical) F2.8-3.7 zoom lens

·                     2.5” LCD (115,200 pixels)

·                     Full photographic control

·                     Optional wide and tele lens converters

·                     Scene selection (7 modes)

·                     32MB internal memory, plus a Memory Stick/PRO slot

 2.Canon PowerShot S2 IS

 S2 is no 'minor upgrade' - almost every aspect of the S1's specification and performance has been improved or refined, the body is entirely new and some of the most serious problems found on the original model have been addressed.

·                     12x optical zoom (36-432mm equiv.)

·                     5.0 million effective pixels

·                     1.8-inch tilt-and-swivel LCD monitor

·                     Color electronic viewfinder

·                     Optical Image Stabilizer (3 modes)

·                     Ultrasonic motor (USM)

·                     Extra-long movie mode with enhanced VGA resolution and stereo sound

·                     Canon DIGIC II processor with iSAPS

·                     PictBridge and Canon Direct Print compatible – no PC required

·                     Six new 'special scene' shooting modes 

3.Panasonic Lumix DMC-FZ5

FZ5 has a range of relatively minor changes over the FZ3, including longer battery life, a repositioned shutter release and improved grip design, larger LCD screen, orientation sensor and a new fast focus mode, which Panasonic claims gives a 30% improvement on the previous model.

·                     5.0 million effective pixels

·                     36 - 432mm (equiv.) F2.8-3.3, 12x Leica DC VARIO-ELMARIT Zoom Lens

·                     Mega O.I.S (optical image stabilisation)

·                     New orientation sensor

·                     Venus II image processing engine

·                     9 scene modes and full photographic control

·                     TIFF mode

·                     Ultra-fast startup, focus, shutter lag and shot-to-shot time

·                     'Simple' mode for novice photographers

4.Konica Minolta DiMAGE Z5

 Latest addition to the big-zoom DiMAGE Z range to feature the CCD-shifting Anti-Shake system seen on the A2/A200 and Maxxum 7D Digital SLR. Aside from a 5MP sensor and a couple of minor specification tweaks, the DiMAGE Z5 is almost identical to the Z3.

·                     12x optical Mega Zoom and 4x digital zoom

·                     CCD-shift Anti-Shake System

·                     Fastest-in-class*1 Rapid AF with Predictive Focus Control

·                     5.0-megapixel CCD

·                     CxProcess III image processing technology

·                     High-resolution, shake-free VGA movies

·                     Large 2.0-inch LCD, compact body, and fast response

·                     Super Macro mode for shooting subjects as close as 1 cm from the lens