Understanding Evaluative Metering on Your EOS Camera Photo by Flickr user MiNe By Andrew S. Gibson – the author of Understanding Exposure: Perfect Exposure on Your EOS Camera (currently 36% off at SnapnDeals). Imagine that it is early 1959. The Flex (pictured above) was so basic by today’s standards that it didn’t even have a built-in light meter. The first Canon camera with through-the-lens (TTL) metering came in 1965. Centre-weighted averaging came along later and served photographers well until the evaluative metering system we are familiar with today was invented in the late eighties. Evaluative metering arrives The first Canon camera to feature evaluative metering was the EOS 650, released in March 1987. The EOS 650 had a six zone evaluative metering mode. The auto exposure sensor from the EOS 60D. Understanding evaluative metering Evaluative metering is the most sophisticated metering mode on your EOS camera. Other metering modes This is fine if, as in the photo above, that’s where your main subject is. iFCL evaluative metering
Lidar to DEM Introduction Geographic Information Systems (GIS) often store representations of continuous surfaces representing physical properties such as elevation, temperature, water depth, etc., which can be approximated to a reasonable level of accuracy by smooth, single valued functions of the form z=F(x,y). Often such a surface is stored as a regular grid—or raster—of data values. When physically measuring the value of the surface, it is often impossible to collect data for every point on the surface. We are particularly interested in data sets collected using lidar—a remote sensing method that collects highly accurate and dense point samples that measure the height of a terrain. Input lidar points shown in red (left) and corresponding DEM (right) with color representing height. Issues Many sophisticated point interpolation routines have been developed that solve a system of N linear equations given N input points. Our Approach Our Results Publication P. Links
Fonctionnement des détecteurs CCD Aujourd’hui, les meilleurs détecteurs de photons sont des dispositifs dits CCD (Charged Coupled Device). Elle permet la détection d’une grande fraction (en général >50%) de photons depuis les rayons X jusqu’au proche infrarouge. En comparaison, la plupart des appareils photographiques classiques (argentiques) arrivent seulement à permettre la détection de l’ordre de 2 à 3 % de photons entrants en y ajoutant le fait qu’ils ont une plus petite gamme de longueurs d’onde. La manière dont fonctionne un CCD est très simple dans son principe. Une très belle analogie est souvent utilisée (voir la figure ci-dessous) : On peut imaginer un réseau de seaux distribués régulièrement sur une grande surface. Pour produire une image on doit donc : generer des photoelectrons collecter les electrons transferer les electrons lire les charges La première étape est basée sur l’effet photoélectrique.
Create a Photo-Realistic Orange from Scratch - Photoshop Tutorial Step 1 Create a circle using the ellipse tool. Orange should not have a smooth spherical shape. So we need to make it irregular. Add anchor points as in the figure and create and make the circle irregular. Step 2 2. coloring and shading Hit Ctrl+ Enter, then the shape will turn into selection. We need one more layer. I used a hard brush for the basic shading Brush opacity 20 and flow 60. Step 3 Create the texture brush for Orange. 1. Step 4 Open the brush menu from the windows. Step 5 Use a hard rounded brush and blend the shades together. Step 6 Create a new layer and set the blend mode to screen. Step 7 Follow the steps as shown in the figure to make the portion of calyx Step 8 I have added a simple background to the image. Step 9 I hope my tutorial was helpful. suggestions and critiques are always welcome.. thanks for reading...
Imperfect Sound Forever his article started life as a Soulseeking column about my new headphones, a rather delicious-sounding pair of Grado SR60s. The original opening line was meant to be as follows: "You’d think I’d know Spirit Of Eden pretty well by now. And I was going to go on to detail how much, well, detail my wonderful new cans had rung out of this fantastic record, about how I'd noticed the sound of rain against the window of the building they recorded in during a few seconds of what I had previously considered to be near-silence at the start of "The Rainbow." So, this new article starts like this: Imperfect Sound Forever The new Flaming Lips CD is the kind of cod-metaphysical psychedelia (there’s a reason actual philosophers don’t take acid—it stops them from thinking properly) that’s bound to garner glowing reviews from broadsheet critics to whom all music blends into a homogenous morass and to whom cosmic platitudes equal great spiritual insight. Don’t get me wrong; music sounds better loud.
15 Tips for Successful Fireworks Photography With the summer coming up and different celebrations you may have the opportunity to photograph some fireworks. If you’re in the USA you have the 4th of July, in Canada July 1st. In many other places you can find fireworks festivals or competitions even, or special occasions when fireworks may be set off including weddings, New Years Day or course and of course at Disneyland! So here’s a few tips to help you photograph fireworks. Please remember that if you’ve never tried fireworks before it’s all trial and error and I’ve made a lot of mistakes myself before I got any images that I was happy to show anyone. 15 tips for fireworks photography #1 Use the right equipment: use a sturdy tripod and remote to fire the camera and bring an extra battery as long exposures tend to use them up quickly. This image was actually purchased by the company that put on the fireworks show in Portland. #2 Set your ISO low like 100 or 200, for a couple reasons. #3 Turn OFF long exposure noise reduction. Summary
Image Scale Math Image Scale Math Educator Guide Audience: EducatorsGrades: 6-8 Image Scaling is an important first step that all astronomers perform in understanding image-type data produced by satellites and telescopes. Each activity in this booklet has an image. The physical size of the object shown in the image is listed in the activity. Students measure the size of the image and divide the physical size by the image size to determine the scale factor. Image Scale Math [7MB PDF file] More booklets in this series:Space Math ISpace Math IISpace Math IIISpace Math IVSpace Math VSpace Math VISpace Math VIIAdventures in Space Science MathematicsAlgebra 2 With Space Science ApplicationsAstrobiology MathBlack Hole MathEarth MathElectromagnetic MathExploring Planetary MoonsExploring Stars in the Milky WayExploring the Lunar SurfaceExploring the Milky WayLunar MathMagnetic MathMars MathRadiation MathRemote Sensing MathSolar MathSpace Weather MathTransit Math
Micro trends: Graphic design aesthetics We’re not interested in trends for their own sake. For many designers, the very word ‘trend’ is something of a taboo, conjuring up images of blind imitation of whatever’s hot at any given time, rather than encouraging genuine innovation and independent creative thought. Rest assured, you won’t find any of that here. Rather than looking at seasonal, fleeting trends, FranklinTill focuses on longer-lasting movements that have genuine impact on creative professionals. “This is a visual run-down of seven major visual directions currently manifesting within graphic design,” explains FranklinTill’s co-founder Kate Franklin. “It’s also an identification and celebration of the key designers and studios responsible for driving these emerging visual landscapes.” 01. As a reaction to our participatory culture, in which we are always switched on, connected and increasingly overloaded with data, designers are exploring new and simplified ways of refining and simplifying visual information. 02. 03. 04.
Wiener filter Application of the Wiener filter for noise suppression. Left: original image; middle: image with added noise; right: filtered image Description The goal of the Wiener filter is to filter out noise that has corrupted a signal. Typical filters are designed for a desired frequency response. Assumption: signal and (additive) noise are stationary linear stochastic processes with known spectral characteristics or known autocorrelation and cross-correlationRequirement: the filter must be physically realizable/causal (this requirement can be dropped, resulting in a non-causal solution)Performance criterion: minimum mean-square error (MMSE) This filter is frequently used in the process of deconvolution; for this application, see Wiener deconvolution. Wiener filter problem setup The input to the Wiener filter is assumed to be a signal, , corrupted by additive noise, . , is calculated by means of a filter, , using the following convolution: where is the noise, ), and The error is defined as and
Street Photography an eBook by Alex Coghe