If you find that your focus is sharp when you are zoomed in but soft when zoomed out, your back focus needs adjusting. This normally only happens to cameras with detachable lenses — consumer-level camera users shouldn't have to worry about it.
Technical Note: Back focus refers to the "focal flange length". This is the distance between the rear lens element and the CCD.
You will need:
* A camera with a back focus ring. It will be located toward the rear of the lens housing.
* A back focus chart like the one pictured is helpful, but any object with sharp contrast will do
How to Adjust the Camera Back Focus
1. Set your camera on a tripod or stable mount, with your subject (back focus chart or other contrasting object) at least 20 metres/70 feet away (or as far as possible).
2. Your iris should be wide open, so it's better to perform this operation in low light. Alternatively, add some shutter speed or a ND filter.
3. If your lens has a 2X extender, switch it to 1X.
4. Zoom in on your subject.
5. Adjust the focus normally until the picture is sharp. If you're using a back focus chart, the centre of the chart will appear blurry - your focus is sharpest when the blurred circle is smallest. (You can simulate this effect by looking at the chart above and defocusing your eyes.)
6. Zoom out.
7. Loosen the back-focus ring's locking screw, and adjust the ring until the picture is sharp.
8. Repeat steps 3-6 until the focus is consistently sharp.
9. Tighten the back-focus locking screw.
source : http://www.mediacollege.com/video/camera/focus/back-focus.html
3/21/2008
Back Focus
Video Camera Focus
First of all, locate the focus control. Professional cameras usually have a manual focus ring near the front of the lens housing. Consumer-level cameras usually have a small dial (Note: you may need to select "manual focus" from the menu).
1. Make sure the camera is set to manual focus.
2. Zoom in as tight as you can on the subject you wish to focus on.
3. Adjust the focus ring until the picture is sharp. Turn the ring clockwise for closer focus, anti-clockwise for more distant focus.
4. Zoom out to the required framing — the picture should stay nice and sharp.
5. If the picture loses focus when zoomed out, check the back-focus and make sure the macro focus is not engaged.
If you need to adjust your focus on the fly (for example, you're in the middle of shooting the Prime Minister's speech when you realise her face is soft), it helps to know which way to turn the focus ring. If you go the wrong way and defocus more, even if you correct yourself quickly you've drawn attention to your camera work. Try comparing the background and foreground focus. If the background is sharper than the subject, then you need to pull focus to a closer point (and vice versa).
Note: You will usually find the sharpest focus occurs at about the middle iris position.
Difficult Focus Conditions
You'll notice that focusing is more difficult in certain conditions. Basically, the more light coming through the lens, the easier it is to focus (this is related to depth of field). Obviously it will be more difficult to focus in very low light. If you're really struggling with low-light focus, and you can't add more lighting, try these things:
* Make sure your shutter is turned off.
* If your camera has a filter wheel, make sure you're using the correct low-light filter. Remove any add-on filters.
* If your camera has a digital gain function, try adding a little gain (note: this compromises picture quality).
* Stay zoomed as wide as possible. If your lens has a 2X extender, make sure it's on 1X.
source : source : http://www.mediacollege.com
Camera Angles
The term camera angle means slightly different things to different people but it always refers to the way a shot is composed. Some people use it to include all camera shot types, others use it to specifically mean the angle between the camera and the subject. We will concentrate on the literal interpretation of camera angles, that is, the angle of the camera relative to the subject.
Eye-Level
This is the most common view, being the real-world angle that we are all used to. It shows subjects as we would expect to see them in real life. It is a fairly neutral shot.
High Angle
A high angle shows the subject from above, i.e. the camera is angled down towards the subject. This has the effect of diminishing the subject, making them appear less powerful, less significant or even submissive.
Low Angle
This shows the subject from below, giving them the impression of being more powerful or dominant.
Bird's Eye
The scene is shown from directly above. This is a completely different and somewhat unnatural point of view which can be used for dramatic effect or for showing a different spatial perspective.
In drama it can be used to show the positions and motions of different characters and objects, enabling the viewer to see things the characters can't.
The bird's-eye view is also very useful in sports, documentaries, etc.
Slanted
Also known as a dutch tilt, this is where the camera is purposely tilted to one side so the horizon is on an angle. This creates an interesting and dramatic effect. Famous examples include Carol Reed's The Third Man, Orson Welles' Citizen Kane and the Batman series.
Dutch tilts are also popular in MTV-style video production, where unusual angles and lots of camera movement play a big part.
source : http://www.mediacollege.com/video/camera/angles/
Make Your Amateur Photos More Professional
With everyone and their grandmother having a digital camera you can make almost anybody look like a professional photographer, well, better-than-amateur at least. You can use this simple process on almost any photo you take.
Let's start with our regular, old, point-and-shoot photo. This one was taken with a little higher-end camera, but it can still use a lot of work.
First, we're going to sharpen our image a bit using the Unsharp Mask Filter > Sharpen > Unsharp Mask. We don't want anything too drastic, so I used some low settings. Amount: 40%; Radius: 0.9 pixels; Threshold: 1 level. You basically want enough to make a difference, but you don't want any glowing or hard edges.
source : http://www.photoshoplab.com/tips/
Lighting
Lighting your Subject
The lighting possibilities are virtually limitless in photography, but the amount of control you have over the lighting conditions depends on your location and your resources. If you are shooting indoors, you likely have the choice of shooting with or without a flash, near a window, lamp, or overhead light, or you may have access to specialized lamps and reflectors. Outdoor lighting is more dependent on the weather conditions (i.e. sunny, overcast, dawn, high noon, dusk, etc.), but you still have the option of shooting in the shade or in the open, or towards or away from the sun.
The best time of day for outdoor photography is in the early morning or late afternoon. The morning light is softer, casting longer shadows, and enhancing your subjects with a warm, rosy glow. Just after sunset the colors will be intensified by the sunlight shining up at the sky. Midday is less pleasing, when the strong sun casts harsh shadows, increasing contrast.
No matter the time of day or the location, you can dramatically change the tone of the photograph simply by shifting the illumination of your subject. Frontlighting the subject will provide even lighting, while lighting from the side will enhance the three dimensional qualities of the subject. Backlighting can produce a pleasing effect, but may require some practice to get the result you want. When not done properly, the subject may appear too dark as the camera sets the exposure to match the surrounding light. To correct this, approach the subject and take an exposure reading with the camera. Next, "lock" the exposure setting values (you may need to place your SLR in manual mode for this). Step back from the subject, and take the photograph using the exposure settings obtained from the reading. If you do not follow this procedure, the subject will appear as a dark silhouette, which in itself can be a very pleasing effect.
Don't be reluctant to photograph outdoors if it is not a sunny day. The even, soft light of an overcast sky is ideal for portraits, producing soft shadow that can flatten your subject. This type of lighting can give a cool blue cast to your photos.
Using a flash
Very fast film (such as ISO 1000) may be used without a flash even in low light conditions, although the prints may look grainy. In low light conditions with a slower film speed, it is necessary to use a flash for correct exposure. However, photographs taken with a built in flash can sometimes look harsh if there is no other light source. This effect can be seen in passport photos, or outdoor night shots. If other light sources are available, such as a living room lamp, they can soften the flash effect.
Some flash attachments for SLR's have adjustable aim, where you can bounce the light off a ceiling or wall. This results in a more natural light appearance. In cases such as this, the light has further to travel than if it were aimed directly at the subject. The aperture should therefore be opened to compensate for the reduced amount of light reaching the subject. Using this flash technique can eliminate the risk of 'red-eye' in your subject.
'Red eye' is a common problem with flash photography. It is caused by light from the flash reflecting off the blood vessels in the subject's retina. Because their pupil will be larger in a room with dim light, the subject's eyes will reflect more of the bright light from the flash. Some cameras feature a red eye reduction mode, whereby a prelight or multi-flash is activated, to reduce the size of the subject's pupil in preparation for the regular flash and exposure an instant later.
Remember that the light from a flash will reflect off shiny surfaces such as water or glass. When shooting through a window, try shooting the subject from an angle to reduce the amount of direct reflected light. Otherwise, the reflected glare may ruin what might have been a good photo.
When taking multiple flash photographs, wait for the flash to recycle and the red 'flash ready' light to go on before you take another photo.
source : http://www.timebanditphoto.com/lighting.htm
Composition
Contrast
When trying to emphasize a subject, it is best not to photograph it against a cluttered background. Compare a photo of someone taken at an amusement park, with dozens of people in the background, with a portrait. The portrait has a very subdued background that lets the observer concentrate on the subject. This is not to say that you should try to make the background as plain as possible. Other people and objects in the background can make the photo more interesting, but taking a moment to think of how the photo will look will give you the chance to improve its composition. Even in the amusement park example, the photographer can try to find a less cluttered background to improve the contrast of the photo. Another method would be to 'crop' the photo, so that the subject fills more of the frame. The subject can also be emphasized using an exposure control such as selective focus (depth of field).
Rule of thirds
When framing your photo, it is usually best not to have the subject exactly in the center of the frame. A subject that is off-center encourages the eye to explore the photograph. Following the rule of thirds can help you compose a more artistic looking photo.
Mentally divide the scene into a grid, like a tic-tac-toe pattern. This will consist of two vertical and two horizontal lines. For photographing the horizon, align the horizon along the top or bottom line, depending on whether you want more of the sky or ground in the photo. You should end up with a photo that is proportioned with two-thirds sky or land (depending on the one you wish to emphasize), which is much more pleasing to the eye than having the scene split evenly.
With vertical subjects such as a people, trees, buildings, and monuments, align them with the left or right imaginary line. When photographing people, have the person face slightly inward, towards the center of the scene.
Experiment with placing the subject at the intersection point of the lines, which are strong positions for your center of interest. With some compositions, you can utilize both the vertical and horizontal lines and intersection points.
Framing your Subject
A subject is framed if the photographer is able to include and crop surrounding objects so that the resulting lines and shapes lead to the subject. For example, you could take a photograph through a wooden fence overlooking a horse in a farmer's field. The fence will be cropped, so that not much of it is visible, because its role in the photo is to frame the horse in the field. You can follow the rule of thirds here as well, having the horse slightly offset from the center of the frame.
Lines and Curves
Lines and curves present in your photo, whether in the subject itself or in the area leading to the subject, lend a pleasing aesthetic quality to the scene. As in the rule of thirds, the eye is naturally drawn to asymmetry, following the lines and curves to examine the scene. This can add interest to an otherwise simple image and can emphasize a particular feel in the subject.
Point of view
When you look up at a large object such as a building or statue, the object conveys a message of dominance and power. Conversely, when looking down upon a subject, such as small children or pets, the message is more deferential or humble. Try taking photographs of these subjects at their eye level for a different, perhaps more realistic perspective. You will notice a difference.
Experiment by shooting buildings from a distance using a telephoto lens, and then shooting upwards from the structure's base. Each view will give you a vastly different perspective.
source : http://www.timebanditphoto.com/composition.htm
How to Take Bad Pictures
Simple formula for poor pictures: put a building in the shot, then don't aim level. You end up with what is called "converging lines." The left and right side of the building seem to meet somewhere above the picture. If that's what you wanted, fine.
If not, get it under control.
The Band-Aid
Level off. You need to have the lens (and film plane) parallel to the edges that you don't want converging. (You don't actually have to be parallel to a side of the building, just an edge.) For most buildings this means vertical. You probably have zero height compared to a building, so for practical purposes this means aiming at the base of the building. But, when you do this, you are probably cutting off the top. So, you will back up quite a ways to get it to fit in. This makes it small.
You'll notice now that the building is only using the top half of the film. My example image shows beautiful green meadow, but you've got parking lots and hot dog stands. At the very least, you will have to crop half the shot away, and enlarge your grain twice as much as needed. Is there a better way?
Film Geometry
Before looking at the real answer to this stumper, look at the numbers in image 2. "35mm" film has images 36mm wide by 24mm tall. The "centerline" of each shot is exactly half that: 12mm down for horizontal compositions and 18mm down for vertical compositions.
Shift Lenses
Shift lenses do a few tricks but perhaps the main professional gimmick is letting you control that centerline. Within limits, you can put it where you want it, without changing the angle of your camera (and screwing up the perspective).
Shift lens documentation should tell you how much they shift. Let's look at the Canon TS-E 24mm/3.5L. Like the other TS-E lenses, it shifts up to 11mm. This is the distance the lens elements move up, but that also means the image moves exactly that much on the film. Since film images are upside-down, moving the lens up moves the image down. This means... fewer parking lots and hot dog stands. And you can go back to your original vantage point and get a bigger image.
How Close?
How far from your target do you need to be to get the desired shot without twisting the perspective? Believe it or not, no trigonometry is needed. It depends on the height of the target above your eye level, the height of the film above the centerline (red, above), and the lens' focal length.
Distance / TargetHeight = FocalLength / HeightAboveCenterline
Using that, solve for anything if you know the other three. In practice, you know the focal length and height-above-centerline numbers exactly, or can dial in the height-above-centerline you need with a shift lens. Distance may be harder to estimate, and height can be tricky. With buildings, you can usually guess 5 meters or 15 feet per story for commercial structures.
For now, this can help you picture what shots a given shift lens lets you take. For instance, since the height-above-centerline is 12mm for a normal lens and twice that (well, 23mm) for the TS-E lenses with maximum shift... we can get twice as close to our target. Or, shoot a target twice as tall. Or use twice the focal length (say, the TS-E 45mm instead of a normal EF 24mm).
Later, on a shoot, this can avoid a certain amount of trial-and-error. For instance, say you have a 24mm lens with 11mm of shift, and a four story building on a city street. You can back up to 65 feet away from your 60 foot target. The formula says 65/60 = 24/X. X is about 22mm. You know that's right at the limit of your shifting and the corners may darken somewhat. On the other hand, you not to even bother getting your 1.4x TC out unless a vertical composition would work (vertically, 65/60 = 36/X, X would be 33.3mm, and a you could get a maximum height-above-centerline of 18mm + 11mm x 1.4, or 33.4mm).
Drawbacks
When maximum shift is employed, shift lenses (with their unnaturally wide field of view) can show some light falloff in the corners, due to basic optical properties. In addition, even the widest filters may be visible in the corners of the shot. Smaller apertures typically fix the first problem but accentuate the second. Hopefully you have the option of backing away from your target and reducing shift slightly. If not, consider using an auxiliary filter holder instead of screw-on filters.
There are not yet any auto-focus shift lenses, even the Canon TS-E lenses with the auto-focus mount. Some shift lenses are a bit more primitive, making you stop down manually before shooting. This will be true for any "old" mount with manual aperture control, because it would take Rube Goldberg hardware to translate the mechanical movement at the mount to movement at the aperture, when half the lens moves up and down.
You will be paying quite a bit extra, both for the optics that make a larger, shift-able image, and the hardware on the lens that let you move the glass up and down. Even then, the lens will probably have a smaller maximum aperture than you'd expect. For instance, a Canon 24mm/2.8 is about $500 while the shifting 24mm/3.5 is more like $1200 on the street. If its any consolation, the makers are probably losing money on every one they make due to the low volume of production. You'll see all three Canon TS-E lenses for the same price, even with their vastly different optics, because Canon is offering them to complete its lineup, and not attempting to price them to recoup their cost.
Tele-Converters
A tele-converter (TC) is a lens group that attaches between your objective lens and camera body. They typically magnify the image size by a factor of 1.4x, 1.5x, 2x, or 3x. TC's also (sadly) increase your f-stop by the same factor. Generally any older TC or 2x TC with less than seven elements will be crap.
On shift lenses, a TC will also (for practical purposes) increase the amount of your shift. The Canon TS-E lenses go from 11mm shift to 15.4mm (1.4x) or 22mm shift (2x). Looking at image #3, guess where you can now place your ground level. The horizontal format can suddenly lose the bottom third of your building, when the centerline moves to 10mm below the bottom of the frame with a 2x. The vertical format can move the centerline to 4mm below too. (Just as lens specs are not exact, teleconverter specs can be pretty loose. A nominally 2x converter may be 1.8x or 1.9x. Never seem to be better than advertised, even for Leitz and Zeiss.)
Now, compare the Canon TS-E 45mm/2.8 vs. the TS-E 90mm/2.8. With a 2x TC, the 45mm/2.8 turns into a 90mm/5.6... but with 22mm shift possible instead of 11mm. Which sounds like more fun?
Since TC's in effect take their picture from the center of the objective lens' image, they avoid problems that tend to arise in the corners of the objective.
But Wait! That's not All!
Any Shot with Lines!
The example buildings can be replaced with trees. Show those forest canopies while avoiding the "acid trip trees" look. Or any other shot where there are two parallel lines... and if that sounds like "most shots" you get the picture. Back before rolls of film were invented, there was a time when all camera lenses shifted, and truing perspective was considered as important as focus and selecting shutter speed and aperture. (Back then, they also used a variety of terms for shift: rise was shift up, etc. Archaic people still do so today 8-)
With the first professional-use "box" cameras (as opposed to bellows cameras), a generation of photographers - and photograph viewers - grew up not having this advantage.
As time went on, all the serious 35mm camera marques issued "perspective correction" lenses. Or perhaps I should say, lens, usually with a focal length of 35mm. Zeiss does a 35mm for Contax, Leitz does a 35mm for Leica. Olympus and Pentax have one too. Minolta made a 35mm for the old manual lens mount, but doesn't have one for the auto-focus cameras. Nikon made (and makes) the 28mm and 35mm. Canon had the TS 24mm and 35mm for the manual mount, and the TS-E 24mm, 45mm, and 90mm for the current electronic mount.
Distortion!
Besides fixing perspective, you can use the same feature to screw up normal perspective. I took a band's CD cover picture, where the guitars are the size of battleships and the guitarists' heads are the size of gnats. Art is Truth.
Panoramas!
Look at the example vertical image #3. Assuming your shift lens shifts left and right (Canon TS-E's do), you can take the left half and right half of a panorama on separate frames, and combine the images in the darkroom or a photo touch-up program. There will be some overlap to help you assemble the halves into the final image. This overlap can be nominal if you use a TC.
You can end up with a scene that uses about 70mm width and 24mm height. This will give you strictly higher image quality that you'd get with a 6x6 medium format camera and cropping to get a panoramic slice - merely 55mm x 20mm. If anyone cares, that’s 1.5x larger negative... advantage 35mm.
The Canon TS-E lenses will shift in any direction, and have clicks every 30 degrees. You can thus also get a shift somewhat up or down at the same time you shift hard left to get one half, and reproduce the exact shift amount and angle to take the second half.
Unsightly Blemishes!
Normally you can change your viewing angle to select the foreground and background that surround your actual subject. You may have artistic conflict, however, if there is a strong rectangular element in the subject that you want to render squarely. Examples are mirrors, railings, and windows.
If you face a mirror head on, you will be in the shot. If you move to the side, it turns into a parallelogram. With a shift lens mounted, move the camera to the side, turn the film and lens parallel to the mirror, then use shift to get the original composition back (more or less).
Sometimes you have limited access to a fixed display, especially in tight interiors. There might be a ceiling support exactly where you'd like to stand. Set up to one side and shift horizontally to reframe.
Depth of Field!
Besides shifting in any direction, the Canon TS-E lenses also tilt. Actually, this has nothing to do with the above shift stuff, except that the only lenses that tilt are the Canon TS-E's. What does tilt do for you?
Normally, everything in a plane a set distance from, and perpendicular to your lens will be in focus. When you use lens tilt, you forego the "perpendicular" constraint. You can tilt that plane quite severely if desired. The plane of the back element of the lens, the film plane, and the focus plane will all intersect.
The classic example is for landscapes. You have wildflowers at your feet and Alps at infinity. f/22 won't give you the depth of field you need (well, it would at 24mm but at the sacrifice of sharpness). As its just after sunset there's not much light, and there is also a wind moving the flowers so a long exposure won't work. Fast shutter dictates big aperture, which means lousy depth-of-field... normally.
As you tilt the lens, you make the focus plane tilt. However, a small tilt of the lens creates a huge tilt in the focus plane. Just 10 degrees of lens tilt can rotate the focus plane to the point that wild flowers a meter away, at the bottom of the frame, are perfectly focused as are distant alps.
There are very mathematical explanations to calculate all the exact effect, but I don't know how you could use them accurately in the field. It would be nice if there was a focusing screen with a half-prism focusing aid at both the top and bottom of the frame. But there's not. The camera could also calculate this information for you and display it.
The other tilt trick is just the opposite. Say you want everything out of focus except for the subject. Say there is a row of columns ahead of you, running left to right. Tilt like mad, focus one column, and the equally distant neighbors to the left and right will be fuzzy.
Why You Can't Get a Good Exposure
Wide angle lenses get darker the further from center you get. This is called "cos^4 vignetting" and is due to the light hitting the film at an angle. This is a problem when the lens->film distance is small compared to the image width.
On SLR's, wide angle cameras use a "reverse telephoto" group at the back, so the rear of the lens is far enough away to leave room for the mirror. This extra glass hurts quality, but means that even a EF14mm/2.8L is about 40mm from the film, which is 36mm wide... which means "cos^4" is NOT visible on SLR wide-angles. Rangefinders like Leica M and Contax G and Mamiya 7 have no telephoto group, so their images are sharper - but the back of the lens is VERY close to the film, and the corners are much darker.
So what does this have to do with your shift lens? Everything! Shift lenses make a picture much wider than a normal lens, but the distance from lens to film is still about 40mm. Your lens shifts 11mm, so the image is 36mm (film) + 11mm * 2 = 58mm or so. Unshifted, only the center 24mmx36mm of the image hits the film, and has no more cos^4 vignetting than a normal 35mm. However, as you shift, the darker part of the total image hits the film.
If you externally meter, then a meter reading good for a centered shot will be too short an exposure for a shifted shot. How much too short? Who knows, bracket! 8-) On the other hand, the camera meter depends on taking readings of light off of partial reflections, and depend on the angle the light hits the sensors. When you shift, the light comes from a different direction and the sensors may see none of it (or too much), so they will suggest a bad exposure.
How to Get a Good Exposure
If you don't want to bracket, you need to build up some base-line cos^4 data for your lens. Perhaps the following might be agreeable:
1. Build comparison series: on slide film, photograph a grey card metered with 0 shift and no exposure compensation, then -1/3, -2/3, -1, -1 1/3 stop. (either internal meter or external is fine)
2. Find worst-case dropoff: shift maximum (horizontally if you can shift sideways), and use the same shutter and aperture as the first shot of your comparison series.
3. Develop these shots.
4. Using the center of the series shots, determine whether the maximum shift is -2/3 darker or whatever. That maximum shift is 36mm(width)/2+11mm(shift)= 29mm from image center. If you want, measure the falloff at other distances.
Then: after metering a scene with a handheld meter or unshifted lens, set the exposure manually but with the test-result compensation. This should be perfectly accurate with one caveat: Because the darkening is progressive, the maximally-shifted side will always be somewhat darker. For arrchitecture, this is perfect - it saves you from using an actual graduated filter to bring the sky and ground brightness closer.
Since you may not be able to see this difference in the viewfinder, your probably still want to bracket, but bracket from the external/unshifted exposure to your test-result maximum compensation. Some picture in that range should be ok.
Wish List
The only return I get on writing an article like this is the right to voice my own opinions - and hopefully Canon's listening!
New Lens
More than anything in the world, I want a 35mm tilt-shift lens. The gap between the 24mm and 45mm is just too great. And, the 24mm is not sharp enough to have its images cropped 50% without pain. This lens physically works with the Extender EF 1.4x teleconverter (TC), but resolution seems to suffer somewhat. In effect, the TC creates a very expensive, 35mm f/4.9 lens with less than ideal sharpness. Instead, a one-piece TS-E 35mm F/2.8 or 3.5 lens should have much better optical quality (no TC), as well as being cheaper (no TC), lighter (no TC), and brighter (no TC).
It would be nice if the TS-E lenses became TS-EF - autofocus. I firmly believe that everyone's 24mm (and 35mm...) lens should have tilt and shift, for when they are needed, but autofocus when they aren't. Canon, with their great all-electronic mount, could easily allow this.
New Focusing Screens
We need a new focusing screen for shifted composition. Canon makes a screen with a grid, for verifying perspective. This is great, except the TS-E lenses are all manual focus, and the grid screen doesn't have a focus aid. There is a perfectly good screen with the usual split-circle, but no grid lines of any sort. So, we are left estimating ranges and looking at the distance scale on the focus ring.
For tilted composition, the situation is even worse - the distance scale only tells us what is happening at the image center. The scale might say 3 meters when the lens is actually focused at infinity on one edge and 50cm at the other. Calculating lens tilt mathematically is practically a black art. I only know a couple people that even know how, and they don't do it in their head on the scene. They guess a tilt, then squint at the viewfinder trying to guess if it is sharp enough. This is hard at f/3.5 (the Canon 24mm lens) or f/4.9 (same with 1.4x TC). I'd like a focusing screen with the normal split-circle focus aid, but instead of merely the image center, have a circle (or major portion thereof) at each corner or perhaps centered on each of four sides.
More Advanced Camera Electronics
An second alternative would be a camera that tells us what focus we're at, at the extreme edges of the camera. This would involve the camera asking the lens 1) focus distance, 2) tilt, 3) rotation of tilt, and 4) a constant or two related to focal length. The camera then calculates the focus distance extremes and displays them on the LCD. A photographer who could estimate ranges accurately could adjust the lens until the readout matches his estimates.
A third alternative would have two focusing rings for near and far focus. It would use Canon "E-M". (This means that the focusing ring is just an electronic input sensed by the computer, that drives a motor to change focus.) We would get a focus motor, and a second motor that tilts the lens appropriately. The focus rings would be right next to each other, so normal operation would involve grabbing both simultaneously.
If this two-ring lens had autofocus (in untilted mode), Canon wouldn't mark distances on the focus rings, making the split focus screen mandatory. If the lens was manual focus only, the rings would have full markings, and ranges would be estimated by the photographer. I don't even postulate a camera with AF sensors at the frame's extreme corners, that attempted to tilt, rotate, and focus, simultaneously 8-)
Adding electric control of the current tilt probably would be awful. Hopefully, just as many lenses are now internal or rear focus, the tilt effect could be accomplished simply by tilting one internal group.
Conclusion
source : http://photo.net/equipment/canon/tilt-shift
by Frank Sheeran; created 1997
Tips for Using a Point & Shoot Camera
Do you feel inadequate because you have a puny Canon SD900 or Fuji F30 in your pocket while your friend is lugging around a digital SLR?
Don't.
You can get a better picture than he can, for the following reasons:
* Your camera is light and compact enough that you have it with you at all times.
* You have about as good a lens as he does; like most first-time SLR owners, he hasn't bothered to upgrade from the cheap low-contrast zoom lens that was included in a kit with his camera body.
* He is using the pop-up flash on his camera as his primary light. You would never be that uncreative (at least not after reading the rest of this article).
* Your camera has a better system for combining light from the flash with ambient light ("fill-flash").
MIT Graduation 1998 A professional photographer with a pile of $1500 lenses and a tripod is going to be able to do many things that you aren't. But rest assured that he carries a P&S camera in his pocket as well.
The photo at left shows Bill Clinton handing out a diploma at MIT's 1998 graduation ceremony. I was in the press box with a Canon EOS-5 (film!), 70-200/2.8L lens, and 1.4X teleconverter ($2500 total). In the upper right of the frame is a woman with a point and shoot camera. I would venture to guess that her pictures of Clinton are better than mine.
Think about Light
"He spoke with the wisdom that can only come from experience, like a guy who went blind because he looked at a solar eclipse without one of those boxes with a pinhole in it and now goes around the country speaking at high schools about the dangers of looking at a solar eclipse without one of those boxes with a pinhole in it."
-- Joseph Romm
My personal definition of photography is "the recording of light rays." It is therefore difficult to take a decent picture if you have not chosen the lighting carefully. Read the photo.net tutorial chapter on light.
Just say no
Amy, Philip, Paula, at Aspects of Love in Minneapolis Just say "no" to on-camera flash. Your eye needs shadows to make out shapes. When the light is coming from the same position as the lens, there are no shadows to "model" faces. Light from a point source like the on-camera flash falls off as the square of the distance from the source. That means things close to the camera will be washed-out, the subject on which you focussed will be properly exposed, and the background will be nearly black.
We're at a theater. Can't you tell from the background? That's me in the middle. The guy with the flat face and big washed-out white areas of skin. Part of the problem here is that the camera was loaded with ISO 50 film and therefore doesn't capture much ambient light (i.e., the theater background).
Virtually all point and shoot cameras allow you to control the on-camera flash. What you want to do most of the time is press the tiny lightning bolt button until the "no flash" symbol is displayed. The "no flash" symbol is usually a lightning bolt with a circle around it and line through it. Now the camera will never strobe the flash and will leave the shutter open long enough to capture enough ambient light to make an exposure.
A good point and shoot camera will have a longest shutter speed of at least 1 second. You can probably only hold the camera steady for 1/30th of a second. Your subjects may not hold still for a full second either. So you must start looking for ways to keep the camera still and to complete the exposure in less time. You can:
* look for some light. Move your subjects underneath whatever light sources are handy and see how they look with your eyes.
* set a higher ISO sensitivity, e.g., ISO 400 or ISO 800 (currently only Fuji F30 and rather expensive compact digicams are designed to give good quality at higher ISO settings; the rest just give you a lot of digital "noise")
* steady the camera against a tree/rock/chair/whatever as you press the shutter release
* leave the camera on a tree/rock/chair/whatever and use the self-timer so that the jostling of pressing the shutter release isn't reflected on film. This works well for photographing decorated ceilings in Europe. Just leave the camera on the floor, self-timer on, flash off.
* use a little plastic tripod, monopod, or some other purpose-built camera support
Yes it was dark in Bar 89. But I steadied the camera against a stair railing and captured the scene with a Minolta Freedom Zoom 28-70 (current eBay value $5?). Note that not using flash preserves the lighting of the bar.
Just say yes
Just say "yes" to on-camera flash. Hey, "consistency is the hobgoblin of little minds" (Emerson; slightly out of context).
The on-camera flash on a compact digital camera is useful. It just isn't useful for what you'd think. As noted above, it is not useful for lighting up a dark room. However, it is useful outdoors when you have both shaded and sunlit objects in the same scene. A JPEG photo or a print cannot handle the same range of contrast as your eyes. A picture that is correctly exposed for the sunlight object will render the shaded portrait subject as solid black. A picture that is correctly exposed for the shaded portrait subject will render the sunlit background object as solid white.
Manhattan 1995. Here the chess players are being shaded by some overhead screens while the background foliage is not. The on-camera flash makes sure that the foreground players are bright. In fact they are a bit brighter than they probably should be and note the washed-out highlight on the leading edge of the table, which is close to the camera. This picture was taken by prefocusing on the shirtless player on the right, then moving the camera with the shutter release half-depressed to the final composition. Without the prefocusing the camera would have latched onto one of the chess tables in the center of the picture, quite far away. The foreground men would have been out of focus and also tremendously overexposed since an amount of flash adequate to illuminate a far away subject would have been used. [Note that many $1000 SLR cameras would not have been capable of making this picture except in a completely manual mode. Their flash metering systems look for light reaching the central area of the image rather than computing appropriate flash power from the focussed distance.]
Pressing the little buttons on a P&S camera until a single solid lightning bolt appears in the LCD display will keep the flash on at all times. Note that a side-effect of the "flash on" mode is that you also get the same long shutter speeds for capturing ambient light that you would with "flash off" mode. The standard illustrative picture for this has an illuminated building at night as the background with a group of people in the foreground who've been correctly exposed by the flash.
Sunglasses & ferris wheel. Coney Island. Sometimes it all comes together, as it did here in Coney Island. Without fill-flash, the ride operator would have been a silhouette. Prefocussed on the human subject's face. "Flash on" mode.
Prefocus
Market Street, San Francisco The best-composed photographs don't usually have their subject dead center. However, that's where the focusing sensor on a P&S camera is. Since the best photographs usually do have their subject in sharp focus, what you want to do is point the center sensor at your main subject, hold the shutter release halfway down, then move the camera until you like the composition.
Virtually all P&S cameras work this way but not everyone knows it because not everyone is willing to read the owner's manual.
A side effect of prefocusing is that most P&S cameras will preset exposure as well. Ideal exposure with a reflected light meter is obtained when the subject reflectance is 18% gray (a medium gray). If you don't want to wade into the exposure compensation menus, try to prefocus on something that is the correct distance from the camera and a reasonable mid-tone. I.e., avoid focusing on something that is pure white or black.
Burn Memory
Stockholm airport, hopskotch If a memory card is lasting for months, something is wrong. You aren't experimenting enough. An ideal memory card for has 50 pictures of the same subject, all of them bad. These prove that you're not afraid to experiment. And then one good picture. This proves that you're not completely incompetent.
It takes at least 10 frames to get one good picture of one person. To have everyone in a group photo looking good requires holding down that shutter release button. You should have pictures from different angles, different heights, flash on, flash off, etc.
Buy a stack of 2 GB SD cards and challenge yourself to fill them up!
Try to Buy a Decent P&S Camera
You can read our buyer's guide. My personal ideal point and shoot camera would have one of the following lenses:
* 24-50 zoom (35mm film equivalent; zooms out wide enough to capture a subject and the background context)
* 24-70 zoom
* a single focal length (non-zoom) because it is one fewer decision to make at exposure time
Sadly, the marketplace doesn't agree with me and compact cameras with these lenses aren't available. Almost always you get a zoom lens, which would be more useful on a full-sized SLR camera because the user interface is better/quicker (i.e., you can turn the ring on the lens instead of pushing little buttons to drive a motor)
http://photo.net/learn/point-and-shoot-tips
by Philip Greenspun; created 1997
Blink 182
Blink-182 was an American trio that played pop punk[1][2][3] and punk rock[4][5] music. The band was originally formed in 1992 in Poway, California[6] (a northern suburb of San Diego) by Tom DeLonge (Vocals and Guitar) and Scott Raynor (Drums)[7] who quickly recruited Mark Hoppus (Vocals and Bass). Originally, the band's official name was "Blink" with the numerical three digit suffix being appended early in their career following an objection from an Irish band with the same name. In 1998, midway through a U.S. tour, Raynor announced that he was leaving the band, due to undisclosed reasons. Drummer Travis Barker, who was touring with The Aquabats on the same bill as Blink-182, joined the band permanently. DeLonge left the group in early 2005, with the band portraying it as an "indefinite hiatus". DeLonge went on to play alternative rock in a band called Angels & Airwaves, while Hoppus and Barker continued in a similar genre with their band +44.
Blink-182 were known for their catchy, simple melodies, teen angst and lyrical toilet humor. They have sold almost 40 million records worldwide and have gained a strong cult following since their establishment during the mid-90's and especially during the start of their "indefinite hiatus". Songwriters Hoppus and DeLonge cite punk rock bands such as NOFX, The Descendents, Unwritten Law, and Screeching Weasel[8] as their early influences although the band's songwriting and production was driven by a pop sensibility and they were primarily known for popular hits such as "All the Small Things", "Feeling This", "Adam's Song", "What's My Age Again", "The Rock Show", "Dammit", "I Miss You", and "Stay Together for the Kids".
source : www.wikipedia.org
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