lens difference?

[Dave L]

Can any of you knowledgeable people tell a complete novice (me) what make a certain lens £100 and another £5,000 just what do you get for your money?

cheers Dave.

 

[Alastair]

Quality of build and quality of results.

With most things in life you can have high quality of build, high quality of performance and low cost to purchase.. it's just that you can only pick two out of three in one product..

 

[StewartR]

Well, £5000 lenses tend to be very very big, specialised bits of kit. A lot of the cost is because they are big and made in small quantities.

But there are very interesting comparisons to be made between £100 and £1,000 lenses.

For example: the Nikon AF-S DX 18-55mm f/3.5-5.6 G VR "kit" lens is about £100.

But the Nikon AF-S DX 17-55mm f/2.8 G IF-ED professional lens is about £1,000.

So what do you get for your money? Three things mainly:

• Build quality. The 17-55 is built like a tank and will take any amount of punishment. The 18-55 is flimsy and plasticky by comparison - even its mount is plastic.
• Big aperture. The 17-55 opens up to f/2.8 throughout its zoom range. That places big demands on the optical design because the rays which have to be focussed to form the image are coming in from more different angles.
• Optical quality. The 17-55 is sharp, even wide open, even into the corners of the frame. The 18-55 needs to be stopped down a bit to be really sharp, and the corners won't be as good.

The reason why build quality affects the price should be obvious. The reason why the other factors affect the price may be less obvious, but they are real. For example the professional lens uses extra-low-dispersion glass, which is expensive. It utilises aspherical elements, which are expensive to design and manufacture. It needs big bits of glass in order to achieve that f/2.8 aperture - the front element is 77mm compared wth 52 mm for the kit lens, so it has twice the area. And there are a whole host of other subtle design features which add to the cost too: 9-bladed diaphragm, non-rotating front element, evenly spaced zoom mechanism, and so on.

 

[Dave L]

thanks for the quick and detailed replies, better get some overtime in

Dave.

 

[classcams]

Here is another example. I have a Nikon 55-200 lens purchased at Currys very cheap. Recently I purchased a Nikon 55-300 priced at £299.95. On test for resolution, the former is far superior. The latter quite frankly is piddlin` poor. Both have the same speed.