18-200mm lens vs 2 separate lenses

[Cosmos_i7]

 

Hi guys,

I own a Samsung NX 1000 with 3 lenses. A 20mm "pancake" lens, a 20-55 "kit" lens and a 50-200mm zoom lens. I use all in lenses in various cases.

 

I noticed that there was a 18-200mm available as well, I was wondering what are the main differences between using 2 different lenses rather than one combined lens. I know that my 20mm has a wider aperture than the 20-50mm so takes better shots in low light and produces nice portraits too. But how does the 18-200mm compare. 

 

Here are the lenses in question:

 

18-200mm: http://www.amazon.co.uk/Samsung-18-200MM-F3-5-6-3-OIS-Lens/dp/B00513EMWI/ref=sr_1_1?ie=UTF8&qid=1377710112&sr=8-1&keywords=samsung+nx+18-200mm

 

20-50mm: http://www.amazon.co.uk/Samsung-20-50mm-F3-5-5-6-iFunction-Zoom/dp/B004CR4RRO/ref=sr_1_3?ie=UTF8&qid=1377710029&sr=8-3&keywords=samsung+nx+20-50mm

 

50-200mm: http://www.amazon.co.uk/Samsung-50-200mm-F4-5-6-OIS-lens/dp/B00513EN40/ref=sr_1_1?ie=UTF8&qid=1377710081&sr=8-1&keywords=samsung+nx+50-200mm

[Puppet]

I know next to nothing about Samsung lenses, but in general, with large range zooms you tend to lose some image quality due to the amount of elements required to make them work.

 

A lens element will not transfer 100% of the light through it, some will be reflected, diffracted etc so the more elements you have the harder it is to get the best quality possible. There are exceptions, better coatings and element design have improved things a lot so you may find that a higher end lens with lots of elements may have better IQ than a lens with a shorter range of focal lengths that is less complicated. Best to ask about specific lenses, sorry I can't answer that for you.

 

This is the reason why Primes generally have the best IQ, they are less complicated in terms of element design and therefore easier to prevent light loss as well as how well the image can be projected onto the sensor. So in theory with primes it's easier to achieve higher maximum apertures, less distortion, better color, contrast and sharpness. But again it all depends on how well the lens is designed.

 

Hopefully someone can answer for your specific lenses.

[Cosmos_i7]

I know next to nothing about Samsung lenses, but in general, with large range zooms you tend to lose some image quality due to the amount of elements required to make them work.

 

A lens element will not transfer 100% of the light through it, some will be reflected, diffracted etc so the more elements you have the harder it is to get the best quality possible. There are exceptions, better coatings and element design have improved things a lot so you may find that a higher end lens with lots of elements may have better IQ than a lens with a shorter range of focal lengths that is less complicated. Best to ask about specific lenses, sorry I can't answer that for you.

 

This is the reason why Primes generally have the best IQ, they are less complicated in terms of element design and therefore easier to prevent light loss as well as how well the image can be projected onto the sensor. So in theory with primes it's easier to achieve higher maximum apertures, less distortion, better color, contrast and sharpness. But again it all depends on how well the lens is designed.

 

Hopefully someone can answer for your specific lenses.

 

Actually that answered my question quite well. Its not really about the specific Samsung lenses I was curious as to what the differences mainly are. Also the 18-200mm is far more expensive than my two separate lenses so I guess I will be sticking with them, thanks for your help!