Tag Archives: Lens glass

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+.

Using a wide angle lens

Using a wide-angle lens.

Unless you have seen the effects of the distortion created by a wide-angle lens or a fish-eye lens it is difficult to imagine how the image is a impacted. In this post we look closely at the actual distortion and impact of the characteristics of these lenses.

In Tips for doing wide angle shots we looked at the type of subject in which you can use a wide angle lens. I pointed out the characteristics and ways the lens affects the image. In this video we look more closely at the impact of the lens on the image/eye. The commentator shows the effect of various types of moves and perspectives the lens affects. A simple and informative examination of the wide angle lens.


Photography tutorial: How to use wide-angle lenses | lynda.com – A Lyndapodcast