JPW Photography

With SLR cameras and interchangeable lenses, you have a wide range of possibilities for setting the aperture of your lens, along with the lighting, sensor sensitivity and shutter speed. When I’m taking most of my photographs, I use my aperture-priority setting so that I don’t have to worry about the shutter speed, and I also try to shoot at the lowest possible ISO setting (usually in the 100 to 400 range) so thatI get good, sharp photographs.  And, as mentioned in another post, I try to make sure that I shoot so that my shutter speed is at least as fast as the reciprocal of my lens’ focal length.

If I’m shooting for fun, then I’ll typically set my aperture at f/5.6 because then I usually don’t have to worry about my shutter speed being too slow (again, depending upon my lens focal length and other factors).  So, this is my fun & carefree setting.

But, when I’m seriously shooting, for example, portraits, then I set my aperture at what I feel is my lens’ sharpest setting and I’m using a tripod.  Since I’ve shot thousands of photographs with my camera and lenses, I have a good sense of what lenses to use in what situations. But, I also need to know how to use these lenses in these situations.

Your lens’ sharpest setting at the focus point will often be at the middle of the range of possible apertures.

The lens that I frequently use for portraits has an aperture range from f/1.4 to f/22.  Therefore, the lens will be at its sharpest in the f/5.6 to f/11 range.  If I want the background to be sharper, then I’ll tend towards f/11.  Or, if the available light isn’t quite enough, then I’ll open up to f/5.6.

Photographers will frequently refer to this aperture range of maximum sharpness as the lens’ “sweet spot.”
With another of my favorite lenses, it’s aperture ranges from f/4 to f/32.  When I’m seeking my sharpest photographs, then I’ll set the aperture on this lens in the f/8 to f/16 range.  Also, depending upon the lighting conditions and other factors, I may choose this lens particular lens over my faster lens, just because I can get sharp photographs in brighter conditions with this lens than with my other great lens.

Remember that shooting at smaller apertures can sometimes detract from photo quality

As you’re likely aware, opening the aperture to let in more light can often leave the background out of focus.  Conversely, the more that you stop down the aperture, the more that the whole scene will be in focus (although this can come at a cost).

I’ll explore “depth of field” and sharpness in a different posting, but for now, suffice it to say that while your photographs may very well be “sharp” when you stop down to your smallest aperture, you’llstart to run into issues involving how the lens diffracts light.

At these smallest apertures, most lenses suffer diffraction issues that cause the different wavelengths of light to be not quite coherent, so that you’ll see more “color fringing” at the edges of distinct objects, detracting from your photographic quality.

Faster lens usually have a faster sweet spot

If you’ve been following along, you might now have a better sense of why professional photographers often want to have as fast a lens as possible (with a wide aperture).  Yes, these fast lenses work well with fast-moving objects (sports) and in low light.  But, more importantly, with a fast lens, the lens’ “sweet spot” lets in more light than a slower lens (and thus, a faster shutter speed), so that it’s easier to get a good, sharp photograph at these middle aperture ranges in poorer lighting.

So, having a “fast” lens when it’s wide open is nice, but having a lens with a “fast sweet spot” is even nicer!  So, try to buy the fastest lenses that you can afford for this reason.

When not working for Brilliant Prints (The United Kingdoms Best Trade Canvas Printing Company) Tim Barnes is a passionate wedding photographer and has shot more than 200 brides (…in a nice photographic way).

The rise in the popularity of digital photography has resulted in a sharing of photographic work on a scale never seen before. Before the internet, photography was really just limited to the sharing family albums with close friends and family, and mainstream media photography as seen in the press. Photography as art was not something that was readily available to the average person, not without searching for galleries dedicated to photography, or joining a local camera club.

Now there are a plethora of ways to share your photography online, whether you are sharing pictures with family, or showcasing your finest amateur photography, or selling your work online as a professional photographer.

Few people realise how easy it is to share their photos online today. I have used several different online photo sharing tools / sites, but the three that I have found most impressive are Jalbum, Flickr and Fotopic. Each of these has advantages over the others. They are all very good ways of sharing photos online.

Flickr is now possibly the largest photo sharing site on the internet. It is run by Yahoo, and is currently undergoing further change and growth as Yahoo are encouraging its Yahoo Photos account holders to transfer over to Flickr. Flickr has two membership levels – a standard free membership that allows you to have three albums / sets of photos, and a Pro membership that allows more albums, and has additional features. One of the main strengths of Flickr is that you can set up photo blogs, and comment on photos. There are also many groups, so that you can share your photos with like-minded photographers – whether it be a macro photography group, or a group for people that enjoy photographing trains! There is something for everyone on Flickr. Flickr is a great way to learn from other photographers, to share knowledge and ideas. As Flickr is also aimed at making photo sharing easier, you can add other photographers to your “friends” lists, and then be updated when they update their albums. Flickr is a great photographers community. An example of a Flickr account: http://www.flickr.com/photos/jonwade/

The first site that I used was Fotopic. When I was first looking for a place to share my photos, I looked at Flickr but was not impressed as the upload facilities seemed a little poor at the time, and it also seemed hard to organise photos easily. Much has changed since then, however at the time (a couple of years ago) I opted for Fotopic. Fotopic is again free, and gives 250MB storage, your own web address. The upload process is easy, as you can upload entire directories of photos if you wish.

Fotopic allows you to set up many collections, so makes sharing a family and friends album much easier than with Flickr. Whereas Flickr is the tool for amateur photographers, and photo bloggers, Fotopic is the tool for sharing holiday snaps and parties as albums.

With Fotopic you can make the page more your own, as you can add site headers and footers, with HTML code, and add links to other websites, plus a site desciption and narrative. Fotopic also allows users to leave comments, but there is less of a community feel to Fotopic than with Flickr. For someone that just wishes to load up a new set of photos for friends and family to view, then Fotopic is probably still the better choice of Flickr. Both allow people to order prints, although only Flickr provides HTML code to allow viewers to show the photos on their own blogs. An example of a Fotopic account: http://jonwade220.fotopic.net/

Finally, there is Jalbum (I am only familiar with version 7.1. ). Jalbum is different, in that rather than being a website, it is a piece of free software that allows users to generate albums to be uploaded onto the internet. In fact, you can use Jalbum to build albums to be shown just on your pc if you wish, but the real purpose is for online publishing. For this users have to have their own domain and web host, and their web host details are entered into the publishing section of Jalbum. Jalbum is a far superior way of showing off photo collections online. For a start, the site is your own, so there is no advertising. There are also a large selection of “skins”, which means that you can chose one of many album styles to suit your photographs. For example there are wedding album skins, plus prefessional photographer skins. Also, each skin, or template, can be edited, so that you can design your album exactly as you please. With each photograph you can show the camera settings, so with each photograph are all the details of how it was taken, i.e. Camera model, Resolution, ISO settings, shutter speed, aperture, date and time, focal length, flash and exposure mode. Jalbum does now have a comments field (you need to be able to change the permissions for this on the web server, i.e. chmod 777, to allow comments to be saved. I failed to et this working myself, admittedly I did not try very hard though).

Some people may be put off by Jalbum as they require their own domain, but some domains are very cheap. Uk domains (.co.uk) are typically GBP3.00 per year, and .com’s are usually around GBP10.00 per year. This is a small price to pay for your own website. Cheap web hosting can be found, Jalbum does not require an expensive hosting platform to run. For example, you can host up to 20 websites with hosting providers such as Jumpline.com for less than GBP10.00 per month. This means that if you team up with other family members, friends, or photo clubs members, you can share the hosting costs, and it becomes very cheap to have your own albums online. Example of a Jalbum generated album: http://www.jpwphotography.co.uk/photos/index.html

Really there is no reason not to share your photos online. With Flickr and Fotopic, sharing is free and can also be educational in the process. With Jalbum you can make a professional looking album and take more control over the look and style of the website. All three options are very low cost. Flickr and Fotopic generate their revenue through advertising and photo printing. With Jalbum, you can build a site with your own adverts, or start to sell photos online, and generate your own revenue from your photography. Whether you are looking for a simple way to share photos with friends, to learn by joining photographer groups, or set up a small online business, there is an online album tool for you.

Creating nude portraits has long been an element of art – instead of capturing these portraits with the brush on canvas; today they are captured with the pixel.

Since the invention of photography the naked human body has been a natural subject for photographers and there has always been a large audience there for it.

What is glamour photography? Glamour photography covers a wide range – from the partial nude body, which you may see an a billboard advertising ladies underwear to the erotic images or the full nude body you may see on Page 3 of some papers or adult magazines.

There are no special elements to photographing glamour; all the standard photography techniques remain the same. Care should be taken when photographing models, nude or partially nude because some may find a sexual element attached to it.

Finding a market: Glamour photography remains one of the most lucrative areas of freelance photography. For a student trying to break into the glamour photography market, he would be well advised to use a film camera over digital. Film will give you warmer skin tones and give you a greater chance of being published.

When trying to find suitable markets for your glamour photography, the same principles apply as in any other photography field. You must study “Glamour Photography Publications” to find out what sort of material they use.

Where to shoot: If you don’t have your own studio, don’t worry. Most of the great glamour images are shot on location. Shooting in the natural environment will be rewarding – use the early morning light to give extra warmth to the skin. Try different places – your neighbours hay barn can make an effective setting for a glamour image or if you have an attractive garden – perfect.

Choosing a model: One of the basic elements of glamour photography is a willing model. If you are having trouble finding one try your local art classes. People with an ambition to be a model may let you do test work. But if you are serious about being a glamour photographer you should work with a professional model.

Glamour images don’t always need to be sharp. Many of the great glamour photographers defuse their image with a filter to add mood to their nude portraits. The best way to get good is plenty of practise and sharpen your eye by looking at glamour publications.

There should be greater emphasis on controlling light contrast to ensure that the human body isn’t lost in heavy shadows or bright highlights. Controlling exposure is very important to get the perfect body tones.

While many may find this type of photography offensive, the glamour photographer is an artist and should be respected as one. It’s not for me to comment on whether the use of glamour material is good or bad, but to explain the art of this competitive and lucrative market.

About the Author:

TJ Tierney is an award winning Irish Landscape photographer and a freelance writer. He frequently writes for the photography directory http://www.goldprints.com and the shopping directory http://www.shop-4us.com To view or buy some of his images visit his on line gallery @ http://www.goldenirishlight.com

Here are some simple tips for photographing babies.

Babies can be the most challenging and rewarding portraits to take, but can also be the most frustrating. Babies tend to sleep, eat and cry a lot and won’t pose in front of the camera but don’t let that put you off photographing them. Creating the perfect baby portrait, when done right, will certainly be rewarding.

One of the most important factors in photographing babies is patience and the way you apply child psychology when relating to the baby. Babies over six months may be shy and won’t react well to a complete stranger. This is where child psychology comes in – you must try to play with the baby, or even become a child yourself while taking the photograph. The keys of your car can be very effective. But remember, your job is to take a baby portrait; you must be able to react quickly when the infant responds to your entertainment.

Shooting a portrait of a newborn baby can be difficult. At this age the baby will not be active, so it’s better to focus on close-up headshots. Try using natural light from a bedroom window to add mood to the portrait.

Babies over a few months of age will be more alert and will have a lot more movement in them. Shooting fast is a necessity, the infant will tire quickly. Babies seven months or older can be very tricky to shoot. The baby will bore quickly and will not want to stay in the same position.

If you are serious about baby photography and you tend to shoot from your own studio make sure you have a lot of toys to amuse the infants. A light colour background will work best and shoot the portraits in colour and black and white.

Parents may be worried about the affect of studio lights on their baby. Point out that strobe lights have no effect on kids. Try to point this out before the parent asks. Don’t ever handle a baby without the parents consent. Most parents will be very protective and won’t react well to a stranger lifting the infant.

Watch out for the fingers – fingers in the mouth can be attractive but on most occasions they will obscure the face.

If you plan to resell the baby photograph to an agency make sure you get a release form signed from the parents. There is a large market out there for baby pictures but agencies or magazines won’t touch them without the parents consent. For baby portraits to be sellable they must be technically perfect, but the picture must illustrate the baby being active or some form of child care.

About the Author:

TJ Tierney is an award winning Irish Landscape photographer and a freelance writer. He frequently writes for the shopping directory http://www.shop-4us.com and the photography directory http://www.goldprints.com To view or buy some of his images visit his on line gallery @ http://www.goldenirishlight.com

The world of photography is an amazing one. It’s been with us for quite a while now but it is constantly changing. Cameras are changing and improving. Methods of developing are changing and improving as well. We have digital cameras that allow people to take a view of their pictures immediately without traditional developing. Another change in the world of photography is underwater photography.

What do you think brings us those great shots of saltwater fish and movies that film in the ocean and under the sea? What about shots taken in swimming pools? You see those in the movies a lot but may not have thought about how they take those pictures and videos.

You probably never thought about it because for a long time underwater photography was not really an option for everyday people. But now it is not just an option, it’s really easy to achieve.

What is Underwater Photography?

Underwater photography is as the name implies photos that are taken under water. This is pretty interesting since early cameras could not function if wet. But as people started discovering the wonders under the sea, they wanted to be able to share that with others or even just to prove what they actuallysaw. So we began creating cameras that could work under water.

It is no surprise that underwater photography is a favorite pastime for scuba divers. The idea could have come from those few people that were able to experience the joys and beauty of underwater life and a desire to share that beauty with others.

There are many different occasions where people use underwater photography. As we mentioned earlier, underwater photography is used in Hollywood for movies. You have probably also seen it used on documentaries and national geographic type programs about underwater life.

But it is still most commonly used by divers. There are many websites dedicated to all the ins and outs of underwater photography; which cameras and lenses are best, which film to use, and much more can be found on these sites.

How to Take Underwater Photography

Equipment is an important factor in taking great underwater photography. Of course you will need an underwater camera but there is more than just that.

You can take some amazing pictures using underwater photography. There are now even disposable use underwater cameras and you can take them on vacation with you and get that great underwater look. Even an amateur can do it. Disposable underwater cameras can typically be developed at your local Wal-Mart or other film developing center. You can also purchase underwater cameras for more of a price but they last whenever you need one. Some people find this more economical than disposables, especially if they want to take these pictures often.

Just like other venues of photography, you will probably start off with a cheaper and less advanced camera and work your way up if you continue underwater photography for a long time. There are two basics kinds of cameras; the underwater or waterproof camera and the encased camera which is inside a housing that protects it.

When taking pictures, you are going to need to be familiar with:

• Your camera
• Your lens
• Your film
• Your flash

There are different things in your environment that will affect the quality of your underwater photography.

Such as:

• Depth of water and transparency of water
• Light
• The angle of the sunlight on the top of the water
• The backscatter
• Water has a magnifying effect

These are some things to help you get started in the world of underwater photography. If you are lucky enough to be swimming in the sea, you should get some proof to share with others.

About the Author:
Looking for information about Photography? Go to: http://www.asaphotography.com ‘ASA Photography’ is published by Colin Hartness – An excellent resource for Photography! Check out more Photography articles at: http://www.asaphotography.com/archive

By Dora Wysocki

A Top Competitor

The Canon PowerShot Digital Camera series offers 23 different cameras with features ranging from professional SLR quality to one of the easiest to use point-and-shoot cameras available. The PowerShot digital camera series last year helped push Canon into second place, behind Kodak and ahead of Sony, in the US digital camera market. (It is estimated that over 90 million digital cameras were sold worldwide in 2005.)

Canon cameras were first introduced in Japan in 1936. The name reportedly means “standard for judgment,” a goal the company constantly strives to achieve. In 2004, the Canon PowerShot digital camera series was named “America’s Choice” by sources within the industry.

Why a PowerShot?

The PowerShot digital camera line starts with the “flagship” model, PowerShot Pro 1, and continues through to the very affordable PowerShot A410. In between, are digital cameras designed to fit the needs of all photographers – both professional and amateur. Canon PowerShot digital cameras are used in a wide array of applications, everywhere from forensic labs to baby showers. PowerShot users include famous news photographers and six year old, first timers.

Of Canon’s many available PowerShot models, these five best describe the versatility of the line:

• PowerShot Pro 1: This Canon PowerShot digital camera is the leader in its class with 8 megapixel images, a standard 7x zoom lens and dozens of other professional level capabilities.

• PowerShot S70: High performance, ease of use, lightweight, built-in wide angle lens. One of the most popular in the line of Canon’s PowerShot digital cameras.

• PowerShot SD500: 7.1 megapixel digital ELPH with 3x optical zoom; “My Colors” feature; curved, metallic body.

• PowerShot SD30: Comes in four different body colors to assure a “fashion statement. With 5.0 megapixels and a 2.4 optical zoom, the PowerShot SD30 delivers high quality photos.

• PowerShot A410: Affordable, compact, 14 shooting modes using 3.2 megapixels and a 3.2 optical lens.

For more information please go to:http://cannondigitalcamerainfosite.com/

Source: Free Articles from ArticlesBase.com

By Bruce Whittaker

So you’ve booked your once in a lifetime safari trip to Africa and now your thoughts turn towards photographing all the wildlife you are going to encounter on your adventure.

It would be a great shame to come across your first African pride of lions and not have some decent pictures of the memorable event to show your friends and family back home.

Unfortunately many people who go on safari don’t realize that the camera lens you take with you will be the deciding factor between getting wildlife photos where the subject is an unrecognizable blob in a sea of vegetation compared to a crisp, tightly framed image of that black maned leader of the lion pride.

I’ve been practicing wildlife photography on safari for over twenty years now and I’ve learnt which are the best lenses to arm yourself with when you go into the African bush to capture lasting, quality images you will be proud to display to anyone.

My recommendations here are for the occasional wildlife photographer such as someone going on an African safari and not for professional wildlife photographers as they have different needs when it comes to camera lenses because they take photographs for a living.

To help you choose a lens to take with you on safari, here is a list of the factors you need to take into account before putting your money down…

1. Size Of The Lens

Anything less than a 300mm lens for the big game you will encounter on safari like lion, rhino, elephant etc will be too small. A 400mm lens will allow you to get good pictures of the smaller animals like bushbuck, vervet monkey and the like. If you are aiming for bird photographs then a 600 mm lens will do the trick.

2. Your Budget

It’s very easy to find lenses that cost thousands of dollars but if you are primarily going to be using it for your safari trip and maybe a smattering of wildlife photography after that, you shouldn’t be spending more than a few hundred dollars. It is possible to get a lens of high enough quality for your purpose in that price range.

3. Image Stabilization

It’s not imperative but if you can get a lens with an image stabilizer it’s a huge advantage on a safari because you can handhold the lens without too much fear of blurring in good light which is especially useful if you are not next to a window in the safari vehicle or don’t have enough space to position your beanbag or tripod.

4. Zoom Ability

On safari one lens is better than two because of the nature of your subject. When you come across a leopard you won’t have time to switch lenses on your camera body because they tend not to stick around for too long so one lens with a good zoom is a big advantage to capture the very shy wildlife you will encounter. Another reason not to change lenses is that dust that is prevalent on an African safari can cause the camera mechanisms to clog up.

So keep these four factors in mind before you make your purchase and if you can find a lens that conforms to all the above requirements than you have a winner.

A photographic lens (also known as objective lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.

While in principle a simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct the many optical aberrations that arise.

There is no difference in principle between a lens used for a camera, a telescope, a microscope, or other apparatus, but the detailed design and construction are different.

A lens may be permanently fixed to a camera, or it may be interchangeable with lenses of different focal lengths and other properties.

Aperture and focal length

The maximum usable aperture of a lens is usually specified as the focal ratio or f-number, which is equal to the focal length divided by the effective aperture (or entrance pupil) diameter in the same units. The lower the number, the more light per unit area is delivered to the focal plane. Practical lens assemblies may also contain mechanisms to deal with measuring light, to hold the aperture open until the instant of exposure to allow SLR cameras to focus with a bright image, etc.

The two main optical parameters of a photographic lens are the focal length and the maximum aperture. The focal length determines the angle of view, and the size of the image relative to that of the object; the maximum aperture limits the brightness of the image and the fastest shutter speed usable.

Focal lengths are usually specifed in millimetres (mm), but older lenses marked in centimetres (cm) and inches are still to be found. For a given film or sensor size, specifed by the length of the diagonal, a lens may be classified as

* Normal lens: angle of view of the diagonal about 50°: a focal length approximately equal to the diagonal produces this angle.
* Wide-angle lens: focal length shorter than normal, and angle of view wider.
* Long-focus or telephoto lens: focal length longer than normal, and angle of view narrower. A distinction is sometimes made between a long-focus lens and a true telephoto lens: the telephoto lens uses a telephoto group to be physically shorter than its focal length.

The 35mm film format is so prevalent that a 90mm lens, for example, is sometimes assumed to be a moderate telephoto; but for the 7×5cm format it is normal, while on the large 5×4 inch format it is a wide-angle.

A side effect of using lenses of different focal lengths is the different distances from which a subject can be framed, resulting in a different perspective. Photographs can be taken of a person stretching out a hand with a wideangle, a normal lens, and a telephoto, which contain exactly the same image size by changing the distance from the subject. But the perspective will be different. With the wideangle, the hands will be exaggeratedly large relative to the head. As the focal length increases, the emphasis on the outstretched hand decreases. However, if pictures are taken from the same distance, and enlarged and cropped to contain the same view, the pictures will have identical perspective. A moderate long-focus (telephoto) lens is often recommended for portraiture because the flatter perspective corresponding to the longer shooting distance is considered to look more flattering.

Number of elements

The complexity of a lens—the number of elements and their degree of asphericity—depends upon the angle of view and the maximum aperture, among other things. An extreme wideangle lens of large aperture must be of very complex construction to correct for optical aberrations, which are worse at the edge of the field and when the edge of a large lens is used for image-forming. A long-focus lens of small aperture can be of very simple construction to attain comparable image quality; a doublet (with two elements) will often suffice. Some older cameras were fitted with “convertible” lenses of normal focal length; the front element could be unscrewed, leaving a lens of twice the focal length and angle of view, and half the aperture. The simpler half-lens was of adequate quality for the narrow angle of view and small relative aperture. Obviously the bellows had to extend to twice the normal length.

Good-quality lenses with maximum aperture no greater than f/2.8 and fixed, normal, focal length need three (triplet) or four elements (the trade name “Tessar” derives from the Greek tessera, meaning “four”). The widest-range zooms often have fifteen or more. The reflection of light at each of the many interfaces between different optical media (air, glass, plastic) seriously degraded the contrast and color saturation of early lenses, zoom lenses in particular, especially where the lens was directly illuminated by a light source. The introduction many years ago of optical coatings, and advances in coating technology over the years, have resulted in major improvements, and modern high-quality zoom lenses give images of quite acceptable contrast.

Zoom lenses

Some lenses, called zoom lenses, have a focal length that varies as internal elements are moved, typically by rotating the barrel or pressing a button which activates an electric motor. Commonly, the lens may zoom from moderate wide-angle, through normal, to moderate telephoto; or from normal to extreme telephoto. The zoom range is limited by manufacturing constraints; the ideal of a lens of large maximum aperture which will zoom from extreme wideangle to extreme telephoto is not attainable. Zoom lenses are widely used for small-format cameras of all types: still and cine cameras with fixed or interchangeable lenses. Bulk and price limit their use for larger film sizes.

Lens mounts

Most Single-lens reflex cameras, and some rangefinder cameras have detachable lenses. The lenses attach to the camera using a lens mount, which often also contains mechanical or electrical linkages between the lens and camera body. The lens mount is an important issue for compatibility between cameras and lenses; each major camera manufacturer generally has their own lens mount which is incompatible with others.

Special-purpose photographic lenses

* Macro lenses are designed for good performance at close distances, e.g., for images of the same size as the object.

The world’s first perspective correction lens for 35mm cameras, Nikon’s 35mm f/3/5 PC-Nikkor
The world’s first perspective correction lens for 35mm cameras, Nikon’s 35mm f/3/5 PC-Nikkor

* Apochromat (APO) lenses have extreme correction for chromatic aberration.
* Process lenses have extreme correction for aberrations of geometry (pincushion distortion, barrel distortion).

Process and apochromat lenses are normally of small aperture, and are used for extremely accurate photographs of static objects.

* Enlarger lenses are made to be used with photographic enlargers (specialised projectors), rather than cameras.
* Lenses for aerial photography
* Fisheye lenses: extreme wide-angle lenses with an angle of view of up to 180 degrees or more, with very noticeable distortion.
* Stereoscopic lenses, to produce pairs of photographs which give a 3-dimensional effect when viewed with an appropriate viewer.
* Soft-focus lenses which give a soft, but not out-of-focus, image and have an imperfection-removing effect popular among portrait and fashion photographers.
* Infrared lenses
* Ultraviolet lenses
* Perspective correction lenses (also called “tilt and shift lenses”), mainly used in architectural photography to mitigate the effects of perspective

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article