Many new digital SLR cameras now come with a feature called Auto ISO, which automatically adjusts the ISO sensitivity of the camera based on pre-programed algorithms and user preferences such as maximum allowed ISO and minimum shutter speed.

Is this feature useful?

The typical support argument for the Auto ISO feature goes like this: Camera lenses have the maximum aperture limitation. At a given ISO,  the required shutter speed to achieve proper exposure may be too slow to stop motion or avoid camera shake even when the aperture is at its maximum setting. In this case, the ISO setting of the camera needs to be raised until a usable shutter speed can be obtained. This previously human-involved process can be automated by the Auto ISO feature.

Still need to see some more convincing arguments or have some questions answered about the usefulness of the Auto ISO feature? Professional photographer Steve Simon shared his thoughts on the Auto ISO feature in Nikon DSLR camera in two discussion threads on Flickr:

Posted in Online Resources, Tips and Techniques on December 30th, 2009. No Comments.

Small flashes such as the Nikon SB-600 can emit quite some energy in a short time, enough to scorch vinyl table top. The story goes like this:

I was shooting tonight with my D90, wirelessly triggering my SB-600. At one point, I left my SB-600 flash tube facing down on a vinyl covered card table. When I released the shutter, the SB-600 obediently fired, probably at full power. A whisp of smoke appeared and a scortch mark 0.25″ by 1.25″ was left in the table top. No damage done to the SB-600, but I was quite surprised at the smoke and burn mark.

Can this be true? I don’t have a vinyl surface anywhere in my house so I tried the following: I set the flash to manual mode, 1/1 (full power) output, covered the flash head with my palm then hit the test button… I felt a sharp burning sensation in my hand that almost made me drop the flash.

Before you actually try something like this, read the title of the post again. That’s your last warning. 😉

Posted in Miscellaneous on December 29th, 2009. No Comments.

In the article titled Understanding Flash Sync Speed, I discussed in details how focal plane shutter works and what maximum sync speed is. What was left out was the two different flash sync modes: front-curtain vs. rear-curtain sync.

In front-curtain sync, the flash fires immediately after the first (front) curtain opens completely; in rear-curtain sync, the flash fires just before the second (rear) curtain starts to close.  To understand the differences they make, let’s use a simple two-image model.

The image sensor continuously capture the image formed by the lens on the sensor surface when the shutter is open. There is one image captured by the camera in each exposure but you can imagine the sensor captures two images: one image formed by ambient light and one image formed by the flash. The two images are then superimposed together. In front-curtain sync, the flash image is captured first followed by the image of the ambient light; while in rear-curtain sync, the flash image is captured after the image sensor captures the ambient image. Read More…

Posted in Photography Lighting, Tips and Techniques on December 28th, 2009. No Comments.

Starblitz Flash, front

It is not the safety of the photographer but the safety of the camera at stake here. Some flashes use very high voltages in the trigger circuit that may be high enough to fry your camera’s circuit board. If you are temped to buy cheap flashes from garage sale or off eBay to expand your strobist arsenal, check this site first to make sure it is safe to use on your camera or other triggering devices’ hotshoe.

If the flash you are interested in is not listed, you can follow the instructions (scroll down until you see How to Check the Trigger Voltage) to measure it yourself. My Starblitz 200 DNX isn’t listed in there. The voltage on the sync terminal is ~11 volts. I put it on my Nikon D200 and it works just fine. According to Nikon D200 manual, the accessory shoe on the camera can support up to 250 volts.

Posted in Online Resources, Photography Lighting on December 24th, 2009. No Comments.

If you are not afraid of wiring up an AC circuit, this constant lighting kit may be a good project for you. All the parts can be obtained from home improvement store. The set built by the author cost him $46.07 including 4 100W equivalent daylight compact fluorescent bulbs (but not the umbrella).

Why do you want constant lighting when you already have strobes or flashes? The nice thing about constant lighting is what-you-see-is-what-you-get, which makes adjustments easy. This is particularly helpful for still life photography when there will be no complaints from subject about a constant bright light making the subject uncomfortable. This will also be a good setup for people who make videos.

Source: Nikonian Forum

Posted in DIY Photography on December 23rd, 2009. No Comments.

According to this Financial Times article titled Camera makers focus on functionality, camera makers are no longer engaged in pixel wars but rather focusing on functionality.

Even though the market is reaching maturity, the digital camera technology is still far from perfection. Camera makers are offering various new things and consumers are showing interests in upgrades. New technology will continuously expand the existing limits and make what was impossible possible.

Currently one of the biggest trends is the transition from digital compact cameras to DSLR cameras, which offer changeable lenses, much better image quality due to larger image sensors and quicker responses. Many people I know have bought DSLR cameras even though quite a few of them use their DSLRs as an expensive point-and-shoot by leaving the mode dial in Auto.

DSLR camera likely isn’t the end of digital camera revolution. Jin Nakayama, head of Casio’s camera business, predicted that new technology will eventually make SLR camera disappear because “… digital camera will have an image sensor so precise and processing so powerful that optical zoom lenses and flash will become unnecessary.”

Posted in News on December 22nd, 2009. No Comments.

In this CBC article, Steven Sasson, the Kodak engineer who invented digital photography 35 years ago, discusses how he did it and the impact it has had. It is fascinating to know the first digital camera had a 100×100 pixel (0.01 megapixels) CCD sensor and the size of a toaster. It took an unimpressive 23 seconds to record an image and another 30s to display it.

Read more – Digital cameras: a decade of revolutionary pictures

Posted in Miscellaneous on December 22nd, 2009. No Comments.

Nikon USA Learn & Explore learning site has posted some really nice video tutorials in which Joe McNally brings you on location and shows you how to control the color in flash photography. The video tutorial has two parts:

In this set of video tutorials, Joe brings you to Good Springs, Neveda, a ghost town. You will learn from Joe as he steps in a historical place called Pioneer Salon and goes through location assessment and the actual shooting process. The success criteria of location photography is that the photos should be able to capture the mood of the environment and invoke feelings in people who sees the photos even though he/she may be millions of miles away. The focus of the tutorial is about achieving such goals by the choice of color and control of color. Read More…

Posted in Photography Lighting, Tips and Techniques on December 20th, 2009. No Comments.
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