What real advantages are there when spending extra money on an expensive lens over its cheaper counterpart?
When comparing pro lenses to the ‘cheaper’ lenses, the higher priced lenses deliver better quality for the most part. Depending on the lens you might also get expedited auto-focus, sharper images and less chromatic aberration.‚ Perhaps the biggest advantage though is with regard to aperture. More expensive lenses are often faster. This means that their largest F-stop (smallest number eg. F1.8, F2.0, F2.8 etc) is usually larger than cheaper lenses. Remember, the larger the aperture, the more room you have to use a faster shutter speed. In addition, the larger the lens’s aperture, the easier it is to shoot in lower light because when you look through the viewfinder you are looking at a scene through the lens’s largest aperture. If a lens has a max aperture of F2.8, any scene you look at through your viewfinder will look BRIGHTER than if the lens’s widest aperture was F4.0. It makes no difference what F-stop you use during the actual exposure. This doesn’t make a difference in bright sunlight, but in makes a huge difference in low light where it is easier to focus if the viewfinder is brighter. On the negative side, higher priced lenses with larger apertures will often‚ buy you significantly more ‘weight’ as well.
When comparing the results of pro lenses to the ‘mid-range’ priced lenses (pro-consumer level), there doesn’t seem to be a noticeable difference to many advanced photographers so long as the images are kept small. This is especially true if the images are for Internet use only.
If you’re still skeptical and want to test the waters yourself, you can always take the same picture using two different lenses to prove a point. Or, an easier route is to search the web for someone who’s already taken the time to do it — much easier!
As a final point, when people (photography newbies/hobbyists) ask me what camera to buy, they never ask about lenses which is a monster mistake. I ALWAYS council newbies/hobbyists to spend MORE on the lenses than the camera, especially the first ‘expensive’ camera. This is because the camera is just a box with a flap to let light in. The LENS does all the focusing so a poor lens on an expensive camera will give you a poor result. A great lens on an average camera will give you a great result (in the right hands of course )
When you’re just learning though you can easily learn on a used or lower end DSLR that you’ll surely replace as technology changes. The lenses though, you can keep those for decades. Trust me, spend the dough on the lenses.
Check out the link in our photography forum for more info.
Matthew kinda mentioned it in the forum, but it bears repeating: Depending on your shooting style, the bokeh can also be an important quality of the lens.