Camera lens help

[Ccarver80]

So I'm new to this fourm and photography in general, I have a nikon D5000 with a basic 18-35mm nikor lens that came with it. Im Looking online because I want a all around versital lens i like shooting landscapes and wildlife I found on ebay a 18-200mm lens for $119 I think it might be factory refurbished but I cant afford a $1,200 lens.

If having the range of 18-200 mm why do some photographers have 20 differnt lens?

 

[Derrel]

Nikon's original 18-200mm zoom was replaced by a later, better model, as the category (called "superzoom" category) grew in popularity, and as Nikon cameras themselves went higher in megapixels. The 18-200mm Nikon lenses worked pretty well on the 6-Megapixel generation cameras, like the Nikon D70 and D70s and so on, and were also "okay" on the next generation, which was composed of cameras with sensors in the 10- and 12-Megapixel range, and which then shifted to 16-Megapixels, and then to 24-Megapixels. As the Megapixel counts have gone higher and higher, lens faults have become more obvious to more users, and the need for ever-better lens designs has become an issue for the camera and the independent, third-party lens makers like Sigma, Tokina, Tamron,and Rokinon and Samyang, and so on. YES, you probably can buy a first-gen 18-200 Nikon, or third-party 18-200 lens for $119.

Many people want specialized lenses that are really, really GOOD lenses, while others want the convenience of wide,wide zoom ranges, like 18-200mm, or 18-270mm, or even 18-300mm. Specialized lenses,like macro lenses, are also a thing many people like. Same with fast, prime lenses like 85mm f/1.4 or 135mm f/2 lenses, or 24mm f/1.4 or f/1.8 primes; specialty tools for the highest possible image quality, or for use in the most difficult circumstances, like poor light, or at night for star photography, etc.

 

[FotosbyMike]

Welcome to the forum, most of the lenses that cover a large focal range are very cheaply made which means:
- Soft looking images
- Slow F-stops and variable f-stops like 3.5-5.6 Less light gets in the lens as you zoom
- Higher chromatic aberration (discoloration in high contrast scenes)

It is worth spending good money on lenses, it is also going to be a little hard to pick one lens to do both landscapes and wildlife since this are two different animals. Landscapes need a wide angle of view (10mm-50mm-ish) while wildlife needs a narrow angle100mm-600mm to really fill the frame.