Tag Archives: Glass

How to tackle the problem of reflections and highlights with glass

• Photographing anything translucent requires treatment that defines the shape •

• Photographing anything translucent requires treatment that defines the shape •
Photograph by Phillip McCordall

Make the best of your resources.

Making the best of your resources is important. Expensive equipment is out of reach for many photographers. Using simple equipment and home resources helps. Glass presents particular problems. This tutorial will help you to tackle the problem with glass and learn more about using simple resources.

The problem with glass

By its nature, the translucence and reflectance of glass creates special problems for photographers. Translucence means that the definition of glass is lost against the background. Reflectance means that general highlights and specular highlights in particular can cause problems. Success in photographing glass is about learning to control those things. It is all a matter of using reflectance to define the glass and placing the light in the correct way for it to illuminate.

Using a simple house light and white and black cards, this tutorial helps you to control highlights to emphasise the glass and not create nasty highlights. You learn about good quality composition with a glass and a few tricks of the trade. Win:win I think.

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By Damon Guy (author and Photokonnexion editor)

Damon Guy - Netkonnexion

Damon Guy (Netkonnexion)

Damon is a writer-photog and editor of this site. He has run some major websites, a computing department and a digital image library. He started out as a trained teacher and now runs training for digital photogs.
See also: Editors ‘Bio’.
By Damon Guy see his profile on Google+.

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Finding lenses and buying to suit your needs

Finding lenses | A wide range of lenses makes choice difficult

The choice is wide. Finding lenses requires careful thought.

Finding lenses that are right for you can be hard

Knowing what lens to buy is a challenge. It can be made simple if you have a few ideas. It is all about understanding your needs and making sure you fit the lens to a budget. First, some general advice about buying lenses.

Are you happy with the camera brand you own?

After a line of different cameras SLRs and different brands, my first digital camera was a Canon. It was my first Canon too. I was impressed. Well, they told me that Canon lenses were the best in the world! So I stayed with Canon.

I know, I know… you don’t agree with me on the best lenses. Whatever the outcome of that argument, I am not going there. That’s the whole point. Buying lenses is a personal decision. It relates to a range of needs and understandings you have about your photography.

You need to be completely happy with your camera brand before you buy lenses. Otherwise you will be stuck with a camera brand you don’t like and lots of money invested in lenses. Love the brand first. Then look for the ‘glass’.

Finding lenses… Things to consider

Usually the budget is fairly clear. However, I have one word of advice. Make sure you look at the upper range of your budget where the quality will be better. Don’t cut corners. Quality lenses don’t come cheap. There are lots of cheap lenses around, but you get what you pay for with lenses. They are expensive, but they are also high precision instruments. If the lens is cheap it probably will not be very robust and the quality of the optics will tend to be low.

After budget the next most important thing is to define your needs. It may be lovely to have a 500mm behemoth of a lens weighing two kilos and costing thousands. But if you are only in a position to use it once a year then it will not be worth investing. Far better to buy a more general purpose lens of higher quality to benefit your general photography and will use often. Focus on your regular photography action and expand your lenses around those activities. If you need that behemoth one weekend, hire or borrow one.

Defining your ‘needs’ is often confused with defining your ‘wishes’. Try to be realistic. Finding lenses is about knowing what you need. Only go for a lens that will be of regular, practical use. Do not define your needs based on your wish to pursue a dream. Most types of photography can be performed with a non-specialist set of lenses. Get good with those. Only buy good quality lenses to replace them. Only buy lenses when you can afford it. And, when you have the mega-once-in-a-lifetime trip actually planned, then factor in the specialist lens (if you really need it for most of the trip). Finding lenses suited to your needs is about being realistic about what you can achieve and how you will use them.

Of course the focal length and how ‘fast’ the lens is are both important. Also important is the type of lens – zoom, telephoto, prime, normal, wide angle and so on… However, most of these will come out in your decision around why you need the lens.

There are other things that are a little less obvious when finding lenses…

  • Weight – Some people simply cannot hold up a big camera and a big lens. Be realistic about what you can handle.
  • Size – especially for travel purposes, big lenses are a complication and a problem.
  • Image stabilisation – Modern lenses usually have stabilisation – consider its weight, availability, cost and if you need it or not (large lenses are normally where there is an option).
  • Glass quality – with professional grade lenses the glass is usually of very high optical quality. However, it is also expensive. So consider the importance of glass quality and overall lens quality for your budget and use.
  • Brand name – Are you paying for a manufacturers reputation, or is the lens equalled by a third party manufacture – check the review websites. Ask around to see what other photographers think.
  • Suitability for purpose – does the lens you want to buy actually suit your intended use. Check on the manufactures website, review sites or on discussion forums to get more information about the best type of lens for your use.
  • Consider the insurance implications and cost. Covering several thousand pounds of lens for a foreign holiday is a significant extra cost.
Buying your lens

The sheer number of lenses available is bewildering. Finding lenses is best done with a finder tool. This tool for finding lenses on Amazon has made lens searches much easier.


The tool for finding lenses allows you to enter the factors that you consider important. It will return you a list of the available lenses to suit that purpose. After years of buying lenses I find this tool invaluable for helping to me to find a range of lenses from which to choose my ideal purchase.

If you want advice on what to do once your new lens arrives, check out this post: Getting started with a new lens.

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Damon Guy - Netkonnexion

Damon Guy (Netkonnexion)

Damon is a writer-photographer and editor of this site. He has run some major websites, a computing department and a digital image library. He started out as a trained teacher and now runs training for digital photogs.
See also: Editors ‘Bio’.
By Damon Guy see his profile on Google+.

Skylight and UV filters

UV and skylight filters

• UV and skylight filters •
There is a debate about how useful they are…

What are UV and Skylight filters?

The keen starter in photography wants to protect their investment… Filters protect your lens – right? Or, is it that they stop damage from the sun? I want to clear up some myths and explain some half truths in this article. You may also save some money.

What are these filters for

Skylight and UV (UltraViolet) filters have a single purpose… to reduce ultraviolet light reaching film. The only difference between them is that skylight filters have a slight pink colour. Both filters prevent the slight tendency of some chemical films to acquire a slightly blue colour cast under some light conditions. (Yes, we are talking about film).

That was simple, wasn’t it?

Now the myths cleared up

UV and skylight filters have a number of myths surrounding them.

They prevent sunlight damaging my digital image sensor.
• No, they don’t. Sensors are UV insensitive or have built in filters (for both infra red and ultraviolet). UV (and IR) light has no effect on them.

They prevent the blue colour cast on sunny days.
• Not true. It is about 25 years since ultraviolet sensitive film was on sale. Even then, the film brands that were sensitive tended to only be sensitive in relatively few conditions; eg. when it was sunny at high elevations or beside the sea.

They provide more clarity in bright sunlight or at high elevations (over say, five thousand feet).
• Once upon a time… some colour film brands used a chemical that was sensitive to UV light. Around 30 years ago an ultraviolet inhibitor was developed that reduced the sensitivity of the film. Problem solved. The slight lack of clarity caused by the sensitivity went away.

They prevent lighter greys being over-bright when in black and white mode.
• Silver-based chemical black and white films were affected by UV. This is not a problem in digital cameras.

The skylight filter has slight pinkness that warms the picture up.
• No it doesn’t – pink is not a warming filter colour. Pink reduces blues in the image. Anyway, if you use auto-white balance any colour effect will be wiped out. If you use RAW there is no need for a filter as you can adjust in developing.

Actually these filters have problems

It turns out that UV and skylight filters can cause a few problems. Poor quality filters; inappropriate filter materials and lack of special coatings all take their toll…

Image effects…
Affects are created by using these filters. In particular over-exposure haze, flare and ghosting are created. The haze results from light bouncing between filter, lens elements and the sensor inside the body of the lens/camera. This creates a slight haze of over-exposure in very bright conditions. Flare, and therefore reduced contrast in the image, is sometimes caused by a beam of bright light being scattered by the filter. More expensive filters reduce this by having chemical coatings on (lens glass has coatings too). Ghosting is where spots of light appear in the image that were not in the scene. They originate from back reflection off the sensor onto the other lens elements or the filter. Usually this happens in low light situations stimulated by bright lights like car headlights.

Adding another glass (or resin/plastic) element…
Additional elements degrade the image. Cheaper filters can cause chromatic aerations, creating colour banding in an image. There may be additional light scattering. Some filters significantly reduce the light getting through (maybe as much as 1/3rd of a stop of light) leading to underexposure. Optical aberrations may be caused by poor alignment of the filter element (not flat/parallel) in its place. This causes loss of definition, particularly in some places where sharpness would be expected.

Are there any reasons to buy them?

Yes, but not many.

Protection:
UV and skylight filters do provide protection, creating a barrier against mechanical damage to your lens. The front elements glass or coatings on the surface are protected from dust, dirt, splashes and possible scratches or breakage from a bump, scrape or blow.
• Alternatively, consider a proper lens hood. They prevent angular light beams straying into the lens which can improve the image. They also greatly reduce the probability of damage to the lens too. Lens hoods are cheaper than filters, and don’t cause optical problems.

Supporting your dealer:
Filters are expensive to buy, but are profitable to sell. In these hard economic times you will be providing a rich return for your dealer and helping him survive a tough market.

A mistake to clear up

Somebody told me recently, “I always have this polarising filter on the front of my lens”. Wow! (It was actually a skylight filter when I looked). Polarising filters are great for reducing some reflections from some surfaces and may darken skies in some light conditions. Some people mix them up with UV and skylight filters. Just let me say for now, don’t keep a polarising filter on your camera.

By Damon Guy (author and Photokonnexion editor)

Damon Guy - Netkonnexion

Damon Guy (Netkonnexion)

Damon is a writer-photog and editor of this site. He has run some major websites, a computing department and a digital image library. He started out as a trained teacher and now runs training for digital photogs.
See also: Editors ‘Bio’.
By Damon Guy see his profile on Google+.

Tips for doing wide angle shots

Retired aeroplane - wide angle photography really brings out certain features of a shot.

• Retired aeroplane •
Wide angle photography really brings out certain features of a shot.

You can do wide angle photography with most zoom lenses

I am surprised how little the wide end of the zoom focal lengths are used. Keen starters often forget wide! We are going to look at what you get for going wide angle photography work.

But I don’t have a wide angle lens?

No? Have a look. Most people buy their first lens as a kit lens with their first DSLR. Very often these lenses are in the focal length range of 18mm to 70mm. With a bridge or compact camera they are built-in. To benefit from this article you just need to set the focal length to the wider end. Any lens which can open up below 35mm will be working on the wider end. Wide angle photography is available to nearly everyone. Read on!

What is a wide angle lens?

A wide angle lens is considered to have a focal length considerably less than a ‘normal’ lens. Lenses are measured against the old SLR standard of 35mm film. Today we have 35mm digital sensors. These are used in “full-frame” cameras (as against the smaller ‘cropped sensor’ or ‘APS-C’ camera of most DSLRs). A ‘normal’ lens for a ‘full frame’ is a 50mm lens. A 35mm focal length or less is considered to be great for wide angle photography. Many wide angle lenses are around 24 – 35mm. For APS-C sensors, focal lengths wider than around 25mm are considered to be getting into the wide angle photography range.

Below 24mm there is a class of lenses called an “ultra-wide angle” lenses. These are around 24mm to around 18mm. In this case, depending on the camera they are built for, they would show some distortion and a tendency to create fish-eye shots or actually be a fish-eye lens. Some lenses, like a 16mm lens for a DSLR will be a fish-eye on a full-frame sensor. However, the same lens mount on a camera with a cropped sensor would use the lens as for ultra-wide angle photography. The fish-eye distortion would not be seen at all.

Many smaller focal lengths exist. Some digital cameras with very small sensors (compact cameras for example and some point-and-shoot models) have wide angle capability of around 8mm, possibly 6mm. These focal lengths are not practical for a DSLR. There are special design features involved to use them at this short focal length which are not feasible in larger cameras.

With all that in mind… here’s my first tip. If you are looking for a lens for wide angle photography, know your sensor size. Look at the manufacturers specification carefully to see that the lens is suitable for what you want on the camera you’ll be using. If you buy the wrong lens/sensor mix you may not get what you expect – although you will get a perfectly good lens!

What is wide angle photography?

In general wide angle photography tends to emphasise a difference of size and distance between a photographic subject in the foreground and one in the background. The result is an optically distorted view magnifying distance between objects, but allows a greater depth of field than a normal lens. This creates a pleasingly large foreground object and by comparison a tiny background one even though the distance between them is quite short.

The exaggeration of the size of foreground objects provides opportunities for composition that really emphasise the expanse of the background. In the picture above the large relative size of the Spitfire wing emphasises the shape and prominence of the aircraft in the foreground. Meanwhile the foreshortening of the foreground-to-background distance has really given the clouds a powerful strength in this shot. They appear to be trending toward the centre-distance. Appropriate for an aircraft don’t you think? At the same time the expanse of the airfield itself is also felt because of the relative smallness of the buildings and the width of the scene captured by the wide angle.

Find ways to exaggerate the relative sizes of foreground and background objects. For example, Spitfire vs. buidings. Where you can use perspective lines (eg. receding clouds) through the scene. This will help you develop a strong composition in your wide angle photography.
More after this…

Interior shots

Wide angle photography works best with focal lengths of around 24 to 30mm on most DSLRs. These lenses are great for use in the interior of buildings. This type of lens lets you see more of the scene without having to move a long way back. In a small room that is very useful as you are unable to move back very far anyway. Personally, I love rooms taken on the diagonal from the corner. These shots with a wide angle lens give you the perspectives of the room angles to help provide depth and still get everything in the shot. Do be careful to get the camera straight. If the level is off and you are using the lines of the room to frame the shot it becomes almost sickeningly wrong with a wide angle and there is little you can do to retrieve it! wide angle lenses are very good at bringing out perspective lines in your composition. With some lenses there is some curvature (spherical) distortion. So in a room watch out to correct for that when the lines curve.

Record shots and wide angle photography

If you are taking a record shot, for example, to capture an objects uniqueness, then wide angle photography is useful. The lens emphasises the foreground object, background objects lose prominence. By isolating the foreground object, which is what your record is about, you can make is really stand out with no background distractions. This technique is useful for statues, vehicles, buildings… well you can see the point. Again, be careful. Some wide angle lenses can badly distort in the vertical plane if you are too close, say, to a building. So experiment. Particularly with a record shot, you are trying not to distort as you want the image to be a record of the object as it is.

The artist in you

As an exact opposite to the record shot you can exercise quite a lot of creative licence with wide angle photography. The superb exaggeration of length is great for really long perspective lines or long objects. It’s great fun to take pictures of people with a portrait view. Small people look large and loom over the shot when done close up. Buildings, columns, trees and other tall objects can really be made to loom large. So if you want to really to emphasise certain features a wide angle shot can be really fun.

Portraits and wide angle photography

A current favourite format for portraits is the ‘environmental portrait’. Sounds grand. Actually its about taking pictures of your subject outside in the open air. The wide end of the focal lengths are particularly good for capturing a lot of scene while making it look like your subject is close. And yet it can be a really freeing way to tackle portraits – you can really use the environment to say something about your subject. Picture the proverbial pretty girl in a field of flowers… a lovely wide shot pulls in the expanse of flowers and yet the foreground emphasis is on the subject. Nice. Equally, the right sort of urban environment can be great for emphasising maleness… Again, let your creative juices flow. Study some wide angle photography work of other portraiture artists. It is important to see how the body can be distorted by the lens to artistic effect or emphasis.

Landscape shots and wide angle photography

The landscape shot is one of the popular pursuits for photographers. Yet, as many good photographers have pointed out, they are difficult to carry off well. Wide angle photography can fail miserably with landscapes. Particularly if there is something big like mountains in the distance. The relativity of a wide angle shot is not good with massive background objects. It tends to take the awesomeness out of such a shot. On the other hand, wide angle photography with a foreground is great. It emphasises the lateral extent of the shot. Think beaches and wide landscape vistas. The horizon makes a good marker for the depth of the shot with wide angles (as long as it is straight!). Remember, if you are going to emphasis the foreground and lateral extent of a view have a prominent foreground object to focus upon.

Actually this is an opportunity. Often photographers forget the human element in a landscape. Sometimes you can make your focus the well placed family or an interesting personality, whatever. The human interest is often stronger than people think in a landscape. Wide angle lenses give you a chance to do something others forget!

What now!

Get out there and do it! If you have a wide angle lens, or if you have a zoom that gets you down to those focal lengths, try experimenting with wide angle photography. We often hear people saying ‘get in close’, well here is an opportunity to go out wide.

Damon Guy - Netkonnexion

Damon Guy (Netkonnexion)

Damon is a writer-photographer and editor of this site. He has run some major websites, a computing department and a digital image library. He started out as a trained teacher and now runs training for digital photogs.
See also: Editors ‘Bio’.
By Damon Guy see his profile on Google+.

How do you make a camera lens?

A lens is a high-tech piece of equipment

We don’t see what goes into their production and we also see straight through them. So it is easy to see why lenses are not appreciated as high-tech components. So when I saw these three videos I was suddenly intrigued. They are produced by Canon to show what goes into making lenses. Considering how much work and manufacturing technology is involved we should not be surprised by the cost.

The first video in the series especially fascinated me. I had no idea that creating the glass in lenses was such an involved process. It is not just glass, it is high-quality, high-technology, high production work all in one.

More after the jump…

The grinding of the lenses is also a very precise and time-intensive process. The coatings applied to lenses are high-tech processes too.

In the final video we see how a lens is actually constructed. There is a lot of very detailed and skilled work done by hand. The use use of a whole range of special tools and adhesives makes it inadvisable to take lenes apart!

A personal recommendation…
This little lens cloth is a very handy item. It hangs on any ring or strap right next to your camera. It’s completely out of the way until you need it and then it is right on hand. It is a quality cloth and because if is always near at hand reminds you to keep your lenses clean. Clean lenses have a longer life and your images will be free of dirt smudges.
Lenses are expensive. Protect them for the long-run. Buy now while you remember!