Some Tittle Reading from Forum (Just to Share)

I have read this article in one of the Photo Forum. So, just want to share it here.

1. What is exposure?
Exposure is measured, either manually or automatically, before you press the trigger on the camera to take a photo. You will need the right exposure for your photo to appear right.

When we take a photo, in order for the medium of capture, be it film or digital, to produce a similar scene as we see, we need to ensure that we give the right information to the camera. The information given is called exposure. If you give too much exposure (overexpose), your photo will come out blown; too little (underexpose), and it will turn out dark. Both of which will also result in loss of details in the photo. With most basic point and shoot cameras, the measurement and adjustment for the proper exposure is done for you automatically. However, with higher end cameras, like the SLR, you would have control over the exposure; hence allowing you more freedom of creativity. Exposure is determined by a simple equation, i.e. Exposure= amount of light x duration. The former is controlled by the aperture; while the latter by the shutter speed.

2. What is aperture?
Aperture controls the amount of light that enters the camera to reach the medium of capture. It is measured in terms of f-stop values.

Any opening that is placed in front of the medium of capture to control the amount of light reaching the medium is an aperture. The difference is whether it can be controlled or not. A fixed aperture point and shoot camera and a pinhole camera is two examples where the opening is fixed at a certain diameter. In such cases, the aperture value cannot be adjusted. SLR and certain high end point and shoot allow you to manually control the aperture values. The opening of the aperture and the amount of light allowed in with regards to the size of the medium is measured and denoted in f-stops. The f-stops is necessary to ensure standardisation among different mediums, i.e. A f/8 aperture on a 300mm lens and a 50mm lens will both let in the same amount of light on the medium of capture despite the difference in size and length. A larger f-stop value denotes a smaller opening, thus letting in less light; and vice versa. F-stops is measured in a linear fashion. Every time you double the f-stop value, you get +2 stops exposure. Some of the common f-stops value includes f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22 and f/32. The difference between f/2 and f/4 is two stops exposure, while f/2 and f/2.8 is one stop. Aperture opening also determines the depth of field of the photo.

3. What is shutter speed?
Shutter speed controls the amount of time the aperture opening is left opened for light to enter. It is measured in fractions, which doubles or halves the duration.

To control exposure, we not only need to control the amount of light that enters the medium of capture, but we also need to control the duration that amount is let in. This is where shutter speeds come in. Shutter speed is essentially the control that allows you to control the duration the aperture is opened. It is measured in fractions of seconds. The common shutter speeds available includes 30s, 15s, 8s, 4s, 2s, 1s, 1/2s, 1/4s, 1/8s, 1/15s, 1/30s, 1/60s, 1/125s, 1/250s, 1/500s, 1/1000s. As you can see, the values are either double or halve the amount of the previous speed. Each different speed gives you one stop difference in exposure.

4. What is ISO?
ISO is the sensitivity of the medium of captured to light.

ISO was originally designed for film, by compensating on the grain size, the films created need less light to achieve proper exposure but at the cost of blurred margins and large film grains. Digital took the same principle onto their sensors, but the end compensation is noise instead of film grains. Essentially, ISO value is how sensitive a medium of capture is to light. The lower the ISO, the finer the details are rendered in the end product. Common ISO values are 50, 100, 200, 400, 800, 1600, 3200 and 6400, with the last one more common for digital medium. Each ISO values are either double or halve of the previous value, just like shutter speeds; and with that, each difference of value also give you a one stop difference in exposure.

5. What is exposure value?
Exposure value or EV is the value given for an exposure. While knowing the exact value for a given exposure has little usage for your everyday photographer. It is useful to know that it exists. Each difference of value is one stop. So if you adjust your digital camera to +1EV, you are allowing more light into the camera and vice versa for -1EV. Each stop doubles the exposure of the medium of capture to the light, either by allowing more light in via aperture adjustments or allowing a longer duration for the light to enter via shutter speed adjustments.

6. What is push/pull?
Push/pull is only valid in films. The ISO for any given film is only a recommended value. You can shoot an ISO100 film at ISO400 if you are familiar. The technique of changing the ISO is call pushing or pulling. Pushing is when you rate the film at a higher ISO and pulling is for a lower ISO. Push/pull is important because you need to tell your developer about it if you decide to do pushing/pulling, so that he/she can do the necessary adjustments while developing.

7. How do you measure the right exposure?
Exposure can be measured using a light meter. There are many types of light meters in the market, most them in-build into the camera. While the usage of these meters is up to your initiative to read the manual that comes with the equipment, it is good to know what types of light meters there are out there and how they function.

There are two types of light meters, an incident light meter and a reflective light meter. The incident light meter measures the light that is falling upon a surface; while the reflective light meter measures the light that is reflected off a surface. The latter would be more useful in photography as we are often capturing the light that is reflected and different surfaces might reflex different amount of light. Most modern cameras have multiple segment reflective light meters built into them. These cameras measure the reflected light at various points in the scene and average it out to give you the ideal exposure. However, as all things automatic, it is not foolproof. It is still better if you know how the meter in your camera works and be able to compensate for proper exposure in certain situations.

8. What is sunny-16 rule?
If you are stuck in a situation without a light meter, the sunny 16 rule is a rough guide for you to estimate the exposure of the scene. The rule is such: On a bright sunny scene, the exposure is 1/ISO used at f16. So, if your ISO is rated at 400, the correct exposure in a sunny scene is 1/500s at f16. Increase your exposure by one stop if it is slightly cloudy and two stops if it is heavily overcast.

9. What is 18% grey/ middle grey?
18% grey is a card issued by Kodak. The light reflected of it is said to give you the idea exposure for a scene. So if you place an 18% grey card in the middle of your scene, measure the reflected light off the card, and shoot the scene at that exposure; your photo would turn out as seen. In other words, an ideal exposure is the exposure value measured off an 18% grey card.

10. What is zone system?
A system created by Ansel Adams to make beautiful pictures.

The zone system was created by Ansel Adams back in the black and white days. It was originally created to be used to maximise the potential of black and white films and prints. However, it can still be used in today’s modern photography. To write about the zone system in detail required a whole book. I would suggest reading “the negative” by Ansel Adams if you want to know more about it. To describe the zone system briefly, the system is actually a series of 11 exposures, ranging from zone 0 to zone IX. In the middle, zone V is the exposure measured at 18% grey, and zone 0 gives pure black; zone IX pure white. Everything else falls within the other ranges. The idea of zone system is to visualise the end-photo before shooting it, and by using the zones as a guide, you can determine which part of the photo you want to be properly exposed and others really dark/bright. It’s a very useful technique that can help a photographer evaluate a scene in a methodological manner.

source from : www.photomalaysia.com

Pentax K20D On Show At PMA 2008

Pentax K20D is coming and according to sources will be on display at the PMA 2008 show. The announcement of the 14 megapixel dslr together with the K200 is expected at january 24 2008 in Beijing.

The Pentax k20D has a 14 megapixel Pentax proprietary cmos sensor, 2.7 inch screen with live view, revamped anti shake, and it also seems a new file format in addition to the PEF, DNG and jpeg presently in the K10D. We can only assume it may be a uncompressed raw format.

more info:

http://stock-photo.blogspot.com/2007/11/pentax-k20d-on-show-at-pma-2008.html

http://www.pentax-k20d.com/

Some leaked info of the cloned Samsung GX-20 by Aronsen - a Samsung branch in Noway:


Samsung GX-20
Avansert speilreflekskamera med Live View!

• 14,6 Megapiksler (CMOS sensor)
• Optisk billedstabilisering (Image sensor shift mechanism)
• Huset er motstandsdyktig mot regn, sand og støv
• Dobbel støvfjerning på billedbrikken
• Stor 2,7” LCD skjerm
• Søkerbilde på LCD (Live View)
• Ett- trykks RAW opptak
• Følsomhet inntil 3200 ISO
Veil pris ca. kr 9.995,-
Introduseres i januar

http://forums.dpreview.com/forums/read.asp?forum=1036&message=26361109

ny Alpha DSLR-A200

LAS VEGAS (CES BOOTH 14200), Jan. 6, 2008 – Sony is advancing the digital SLR category for mainstream photographers with today’s introduction of the new α (alpha) DSLR-A200 camera.

The DSLR-A200 model features upgrades influenced by the recently-introduced, enthusiast-class DSLR-A700 camera and replaces the former Sony DSLR-A100 model, which was Sony’s first in the DSLR class.


The new model is designed to be faster, lighter and easier to use. Upgraded features include a wider, 2.7-inch Clear Photo LCDTM screen for easy playback viewing; a more compact body and an easily-accessible mode dial; an easy-to-use function menu (camera function display); improved noise control for higher quality images; an auto focus speed 1.7x faster than the previous model; improved predictive control performance; quieter shutter sound; automatic pop-up flash; and a battery life indicator that displays the percentage of battery life remaining so you know exactly when to recharge.

As seen in all α (alpha) camera bodies, the DSLR-A200 camera incorporates Super SteadyShot® image stabilization in the body to allow shooting at shutter speeds of 2.5 to 3.5 steps slower than otherwise possible – a benefit realized with every compatible lens attached to the camera. Compatible lenses encompass all Minolta Maxxum® mount lenses, in addition to Sony α (alpha) lens lineup - including Carl Zeiss® lenses.

“With the DSLR-A200, we are helping consumers capture high-quality images with advanced technology that’s practical and easy to use,” said Phil Lubell, director of marketing for digital cameras at Sony Electronics. “This model is an ideal step-up for point-and-shoot users who are looking for a camera that can capture virtually all of the photographs they want.”

High-Quality Images

With its 10.2-megapixel (effective) APS CCD image sensor, the DSLR-A200 camera continues to offer high-quality images by allowing more light to pass through to each pixel – increasing sensitivity, reducing noise, and providing greater detail.

Clean, reduced-noise signals are sent from the image sensor to Sony’s BIONZ™ processing engine, which processes data-rich picture information at high speeds and reduces picture noise in the RAW data stage before image JPEG conversion. The results are high-resolution, detailed images with rich tonal reproduction.

The DSLR-A200 model supports JPEG and RAW file format support. It has a slot for CompactFlash™ Type I/II media cards. An adaptor for Memory Stick Duo™ media cards is sold separately as an accessory.

Get The Photo Results You Want
In addition to Super SteadyShot image stabilization for virtually blur-free photos, the new model incorporates Sony’s D-Range Optimizer (DRO). It helps you capture well-exposed images, especially when shooting high-contrast or backlit scenes that often lead to loss of highlight and shadow detail. Sony’s DRO modifies the range from highlights to shadows, including gain and contrast, through its in-camera hardware processing to produce more natural, evenly exposed pictures. The camera’s image analysis technology studies the captured image data and instantly determines the best exposure and color tonality for the image before JPEG compression.

The BIONZ image processing engine powers the camera up immediately and the eye-start autofocus starts the focusing system before you even press the shutter. The camera can shoot up to three continuous frames per second at 10.2-megapixels at the finest JPEG compression level.

As seen in previous α (alpha) models, the new model carries a static-free anti-dust coating on the CCD filter which is gently vibrated to dislodge any dust that might have collected each time the camera is powered off.
Additionally, the DSLR-A200 camera’s supplied lithium ion battery offers up to 750 shots per full charge.

Bright and Easy Playback
The camera’s smaller, more compact body along with its wider, 2.7-inch Clear Photo LCD TM screen and a new on-screen navigation interface make it easier to carry and to use. The vibrant, easy-to-view screen features 230K-pixel resolution, an anti-reflection coating and glare-reducing layer assures vivid, accurate colors with a wide viewing angle, even in daylight. The on-screen navigation display shows camera settings and key shooting information in large, easy-to-read text. The display’s orientation automatically switches from landscape to portrait position when the camera is turned on its side.

Accessories Expand Creative Possibilities


Sony is providing a full line of accessories for the model, including flashes, rechargeable battery packs and several carrying cases. An interesting addition is the VG-B30AM ergonomic vertical grip equipped with the most essential controls for portrait orientation shooting. It also allows for the use of two InfoLITHIUM® batteries (sold separately) for up to 1,500 shots on a single, full charge.

The DSLR-A200K kit includes the camera body and a DT 18-70mm f3.5-5.6 3.9x zoom lens for about $700. The DSLR-A200W kit includes the camera body, the DT 18-70mm lens and a 75–300mm f4.5-5.6 lens for about $900. Both will ship in February and will be available at sonystyle.com, Sony Style® retail stores (www.sonystyle.com/retail), military base exchanges, and authorized dealers nationwide. Pre-orders begin online on Jan. 7 at www.sonystyle.com/dslr.

Canon EOS-1D Mark III AF: Canon Europe Issues Statement

Canon Europe today released an official statement on the AF problems experienced by some users of its EOS-1D Mark III DSLR. It seems the sub-mirror assembly is to blame for focus and tracking inaccuracy in AI servo continuous mode particularly when working in high ambient temperatures. Bodies with serial numbers 501001 through 546561 are said to be affected, and Canon are preparing to offer free repairs from late November.

This statement is available in alternative languages via the link below. Choose your country then perform a search for case ID 72525.


Canon's statement:

Title: Why do I experience inconsistent Auto Focus (AF) behaviour with my EOS-1D Mark III?

Phenomenon:
The focus or AF tracking is inconsistent when using the Artificial Intelligent (AI) servo continuous shooting mode under high temperatures in particular.

Cause:
In the digital SLR camera, EOS-1D Mark III that was launched in May this year, Canon has found that some cameras have an adjustment problem with the mirror for AF. The adjustment problem means for the affected products that the focus is not stable or that the Auto Focus tracking is not right when using the AI servo continuous shooting under high temperatures in particular.

Affected products:
The products that could have this problem can be identified as explained below.
If the serial number on the bottom of the camera is between 501001 and 546561, it could contain one of the AF mirrors with the adjustment problem.

source : dpreview.com

New Canon Superteles Under Development

CANON U.S.A. TO EXHIBIT TWO NEW TELEPHOTO LENSES UNDER DEVELOPMENT AT PHOTOPLUS EXPO

Canon has given the world a glimpse of its lens development program, unveiling two all-new super telephotos. First up we have the EF200mm f/2L IS USM - aimed at portrait and indoor sports photographers and the seeming successor to the legendary 200 f1.8L USM (discontinued in 2004). The EF800mm f/5.6L IS USM meanwhile slots above the current 600mm f/4L, whose performance it is said to surpass. Further details on the lenses are scant but they are due to be shown at the PhotoPlus Expo in New York City from October 18-20.

LAKE SUCCESS, N.Y., October 15, 2007 – Canon U.S.A., Inc., a leader in digital imaging, today announced the development of two all-new telephoto lenses for use with its EOS SLR cameras: the EF200mm f/2L IS USM*/** and the EF800mm f/5.6L IS USM*/**. The Company will exhibit prototypes of the new lenses at PhotoPlus Expo (booth #318), taking place at the Jacob K. Javits Convention Center in New York City, October 18 to 20.

The new Canon EF200mm f/2L IS USM and EF800mm f/5.6L IS USM, both of which are L (luxury)-series lenses incorporating a high-performance Image Stabilizer, feature optical systems utilizing special optical materials such as fluorite to correct chromatic aberrations, making possible high-resolution, high-contrast shooting performance.


The Canon EF200mm f/2L IS USM, targeting users who seek a brighter lens for portraiture and indoor sports photography, realizes a large aperture of f/2. The EF800mm f/5.6L IS USM, expected to deliver telephoto performance surpassing the current top-of-the-line EF600mm f/4L IS USM super telephoto lens, is being developed in response to requests from users working in the fields of sports and news photography who are looking for a high-performance lens that offers a longer focal length.


"These new lenses demonstrate that Canon is continuing to respond actively and flexibly to the wide-ranging needs of professional and advanced amateur users, with the aim of contributing to the expansion of photographic possibilities for SLR cameras," said Yuichi Ishizuka, senior vice president and general manager, Consumer Imaging Group, Canon U.S.A. "Canon's EOS System is the premier brand of Digital SLR cameras, and we take great pride in offering the world's largest selection of interchangeable autofocus lenses." ***

As these new lenses are currently under development, pricing and availability information is not yet available.

* This device has not been authorized as required by the rules of the Federal Communications Commission. This device is not, and may not be offered for sale or lease, or sold or leased, until authorization is obtained.
** A Product Report required by 21.C.F.R.§ 1002.10 has not been submitted to the United States Food and Drug Administration for this product. This product is not, and may note be, offered for sale or lease, or sold or leased, until the required report has been submitted.
*** As of October 15, 2007

source : dpreview.com