If you are not limiting yourself to natural light photography, at some point you may start to consider flashes or strobes and various light modifiers for them. Umbrella and softbox are two of the most commonly used light modifiers for portrait photography. People are quick to notice that umbrellas are typically much cheaper than softboxes. Does it mean you get what you paid for? Read More…
Windows 7 was officially released on Thursday October 22, 2009. I pre-ordered it from Amazon back in June when there was a promotion. Vista Home Premium to Windows 7 Home Premium cost only $50 back then. Now it is $120.
Amazon was nice enough to send me the upgrade Yesterday, the official release day. I started the upgrade process last night. First I ran the Windows 7 Upgrade Advisor to make sure I didn’t have hardware or driver issues. In a few minutes I was notified that I was all OK except that I should uninstall a couple of applications such as Apple iTunes and VMWare Player then reinstall them after the Windows 7 upgrade. I did that. The upgrade process took quite a while to preserve my 750K+ files so I went to bed. By the morning it was all done. During upgrade, the installer told me that my computer would need to restart a few times. It was all done without me acknowledging it with a click.
Just like what I heard all along, the new Windows is nice. It is uncluttered, snappy, and user friendly. My softwares all appear working. The only thing I found not working is Nikon Capture NX 2. Somehow the software thought my installed version was an expired trial version. Not a problem, I just had to re-enter the license key. If you don’t have the license key, you may be in trouble. Even if you have backed up the files, the key is likely hidden in the Windows registry.
I had little time to play with it before I had to go for work. Unfortunately things turned ugly by the time I got back from work. I saw an unresponsive dark monitor screen. I tried to power off the computer by holding on the power button. It did power off. But I was not able to power it on again.
This may not have anything to do with Windows 7 upgrade. It looks like the power supply is dead.
I really want to get the computer up running again. It contains all the photos I have ever taken. I have backup copies of them on an external drive. However they are in an archive format that I cannot easily access.
Update: The problem was indeed caused by a dead power supply. Replacing the power supply wasn’t a challenge but it did cost me $50 and a trip to BestBuy. At the end, I think the upgrade is well worth it.
A UK-based firm is launching a camera that you can hang from your neck and promises to capture every moment of your life.
The camera, called ViconRevue, can be configured to take photos every 30s. However it is not just a timer controlled point & shoot camera, it has multiple senses. It has a built-in accelerometer and light sensors to detect when a person enters a new environment and takes a photo automatically. An infrared sensor detects the body heat of a person in front of the wearer and the camera snaps an image of the person automatically. If you have seen an automatic toilet or urinal, you know how it works. Read More…
Nikon has not disappointed us when it comes to releasing new high end DSLR cameras. The new D3S is not an exception. The D3S redefines what is possible with a six-figure ISO sensitivity for stills and video capture while enhancing overall performance.
The D3S features a Nikon designed 12.1 megapixel FX-format CMOS sensor with 8.45 micron pixels. For image sensors, the pixel size does matter. Larger pixel offers better signal-to-noise ratio and larger dynamic range. The D3S has a standard ISO range of 200 – 12800, expendable downward to 100 and upward to an eye-popping 100400. The high ISO enables the D3S to capture images in darkness that is beyond the capability of human vision.
The 1280×720 24fps HD movie capture seems to be inferior to Canon’s 1080P offering but it is sufficient for the targeted professional users. The D-Movie mode supports full aperture control, exposure control, and contrast detection auto focus. The motion JPEG codec makes it easy to extract JPEG frames.
The in-camera post processing capability is a great feature. It is not about the silly art filters you can find on point-and-shoot cameras. D3S allows RAW editing. You can change JPEG compression, Size, White Balance, Exposure Compensation, Picture Control, Noise Reduction, Colour space and Vignette Control settings. Instead of downloading the images first then editing on the computer, the in-camera post processing capability allows the basic editing in the field before the images are transferred.
The D3S is speedy. It powers up in 12 ms with shutter lag 41 ms and mirror black-out 74 ms. It can shoot 9 fps in FX mode and 11 fps in DX crop mode. The buffer is expended to allow 48 frames in consecutive shooting.
The D3S offers great flexibility. D3S offers several different crop modes (up to 1.2x) for different lenses or for convenience so no useless pixels are recorded. Picture Control allows pre-defined picture styles. Coupled with Nikon’s RAW editing software such as Capture NX, the users can quickly get the desired output image without extensive post processing. Live View and Quiet Shutter modes make it easier or possible to shoot in certain situations. Dual card slots allows users many options in saving their images and videos. Users can record two full CF cards of data sequentially, record the same data onto two cards for backup, record RAW and JPEG simultaneously onto separate cards, transfer data from one card to another, and use one slot for stills and one slot for D-Movie recording. Read More…
The mysterious smoke fascinates many photographers. If you are one of them, you may be tempted to take your own smoke photos. It is not difficult at all. The following video tutorial shows you how to setup the equipments, take the photos, then edit them in Adobe Photoshop to achieve some cool effects.
The popular Apple iPhone has a very crude camera application and there is no way to edit the photos on the phone after you take them without third party applications. There are quite a few good photo editing applications available at Apple App Store that are not very expensive. But why not use a free application from the big name software company Adobe if you have only the most common editing needs? It gets even better than just editing: by signing up for a free photoshop.com account, you get 2GB of free storage for online photo sharing and storage. Read More…
Have you ever wondered why wide angle lenses such as Sigma 10-20mm f/4-5.6 EX DC HSM doesn’t have the problem with its rear element getting too close to the image sensor of your DSLR camera?
Well, this is a reasonable question if your understanding of optics is not much beyond the simple thin lens model you learned in high school. Photographic lenses are not thin lenses. Even the simplest prime lenses are constructed with multiple lenses in multiple groups. These are called “thick lenses”. The effective focal length of the thick lenses are no longer the distance between the last optical element to the rear focal point (called back focal length). To make the wide angle length work on SLR cameras, the back focal length of the lens needs to be longer than the effective focal length so the mirror doesn’t hit the lens when the shutter is release. On the opposite, for telephoto lenses the back focal length needs to be shorter than the effective focal length. This is typically achieved by putting a concave lens (or negative lens group) or convex (or positive lens group) at the front for wide angle and telephoto lenses, respectively.
The modern day wide angle lenses were mostly inspired by the old but clever design called retrofocus lens design pioneered by a French engineer (a little more history can be found here). If you compare the original retrofocus lens and the aforementioned Sigma wide angle lens, you can notice the similarity. The Sigma lens used a group of concave lenses instead of single concave lens for the front element in the original design.
If you are interested in digging into lens design, there are many good books, for example, Applied Photographic Optics by Sidney Ray. However you can learn quite a lot without spending a dime from free online resources by using search engines.
People who are familiar with flash photography know the inverse square law, which states that illumination from any light source falls off with distance. For a point light source, the intensity of light is inversely proportional to the square of the distance from the source.
This is a law based on physics principles, specifically in this case, energy conservation. As energy radiates from a point source, it spreads out to an area that is proportional to the square of the distance from the source. Hence, the radiation passing through any unit area is inversely proportional to the square of the distance from the source.
Like any physics law, there is a specific set of conditions the inverse square law can be applied. One of the key phase here is “point light source”, which typically means something infinitesimally small in mathematical term.
The flash head cannot be a point light source, right? Well, the bare flash head is quite small. It can be a good approximation if the subject is far away from the flash. If you put the flash behind a softbox or umbrella, the light source is essentially the entire surface of the softbox or umbrella. We typically do not use the softbox or umbrella very far away from the subject. So you cannot consider the softbox or umbrella as a point source. Will the inverse square law fail then?
Yes and No. If you blindly apply the inverse square law using the distance between the subject and the softbox (or umbrella), the law fails especially when the distance to the subject is short compared to the dimension of the softbox. However if you think the surface of the softbox as a collection of tiny point light sources, the law continue to apply and the intensity of the light at the subject is result of being illuminated by the collection of point light sources that have various distances from the subject.
Someone tried to bust the inverse square law myth and failed. The tests contained numerous errors, such as measuring the light intensity off the axis, using the pixel values as intensities, ignoring the gamma correction done by the camera, etc. When the experiment was done right, the myth was un-busted.