Camera flash pulses are typically very fast. It is fast enough to freeze motion even if you use a very slow shutter speed as long as the light from flash dominates the exposure.
Most camera flashes have xenon flashtubes. It lights up when the charge stored in a capacitor is discharged through xenon gas. The xenon gas is not very conductive in its normal state but its resistance can be greatly reduced when the xenon gas molecules are ionized, ignited by a high voltage pulse. The charges stored in the capacitor start to flow through the tube, giving out a very bright light. As the charge stored in capacitor discharges, the light intensity decreases.
The light intensity during a flash pulse isn’t constant. The light intensity emitted from the flash tube rises to a maximum quickly then fall off. If the charges stored in the capacitor are allowed to completely discharge, the light intensity will show a graduate reduction tail. Since we don’t want full power flash for each shot but rather just the right amount of light for proper exposure, the flash unit cuts off the discharge circuit at different times to control the amount of light emitted. Lower flash output power means shorter flash duration. Read More…
The flash output level of a Nikon SB-600 Speedlight Flash can only be set to the minimal of 1/64 in manual mode. That leads many people to speculate the minimal output from the flash is 1/64. If you have used the Nikon Creative Lighting System (CLS) Advanced Wireless Lighting (AWL), you will know that you can use 1/128 output setting on the wireless commander unit. The wireless commander can be the built-in flash of your camera, or SU-800 commander, or SB-800/SB-900 Speedlight flashes. The question is what happens when the remote flash is a SB-600. Will it actually output 1/64 or 1/128 of light when the commander tells it to do 1/128?
To answer this question, I ran a test with a flash light meter to measure the output of the SB-600. Read More…
Before I got my first true Macro lens, a Sigma 105mm f/2.8 EX DG, I had a cheap way of getting macro shots: Mounting a Nikkor 50mm f/1.8D AF reversed using a reverse ring (Nikon BR-2A or the cheaper clone). The picture of that setup and sample image can be found here. Basically it worked OK. On my D200, the camera maintains auto-exposure but no more auto-focus. The images are quite sharp. The magnification is not high through.
Recently I acquired the 35mm f/1.8G AF-S DX, which is a nice prime lens for DX format Nikkon DSLR cameras that gives you a “normal” field of view. When I stumbled across the reverse adapter ring I purchased long time ago on a dusty shelf, I decided to try it with the Nikkor AF-S 35mm f/1.8G lens. Read More…
Kodak had its glorious Kodak Moment days but now it is struggling to survive. Obviously that means it will go after any possible revenue source. Even though Kodak falls behind in today’s digital camera market, it did invest quite a lot in digital photography technology and accumulated a large portfolio of more than 1000 patents, which is generating hundreds of million dollars royalties annually.
One of the patents at the center of the dispute covers the function that almost all digital cameras have: a real time preview of the scene before the shutter is pressed (US patent 6,292,218). Apparently many other companies have paid Kodak to use the technology but Apple and RIM refused.
Kodak probably isn’t one of the hated patent trolls. The patent seems obvious now but it most likely wasn’t when Kodak started to develop digital photography technology. First digital camera was invented by Steven Sasson of Kodak in 1975, which looked more like a toaster than a modern digital camera.
Photography is about image quality but not just pixel quality. The quality of the image content is also important. The camera on the iPhone doesn’t produce noise-free images like a PRO DSLR camera but it still offers endless ways of creative photography, especially with the help of more than two thousand photography-related Apps you can find in the App Store.
If you are an aspiring iPhone photographer, this contest offered by Adorama is a great opportunity to display your talent and win some cool prizes. It is easy to get started, just follow the simple steps:
A panel of celebrity judges (big names in photography such as Scott Kelby, Joe McNally, Syl Arena, Moose Peterson, etc) will pick the winners but it is you who will select the best iPhone Apps.
Check out the details at contest.adorama.com.
The technique is simple but the result is amazing!
It is amazing how creative people can be when it comes to DIY photography lighting equipment. This Gary Fong style flash diffuser costs only a few dollars to make: just a piece of plastic food packaging (where the name comes from) and an elastic band. We don’t know how well it performs against the real deal that costs ~$50 and the durability may be questionable but the results aren’t bad at all.