Lenses

[CapiluisPanay]

I have a EOS 7D with a 18-200 EFS lens, I would like to enhance my photographic capabilities purchasing another lens for close and long range. What lenses could I add to my equipment....off course within reasonable expense.

Thanks

[Skirball]

What do you want to shoot?  You’re not going to get one lens that does it all (the best).  That’s kind of the point of the SLR, to allow you to swap out lenses for a specific purpose.  In general, shooting close and far are opposite ends of the spectrum.  Technically you could get a long tele macro, like the Canon 180, that would allow you to shoot close and far.  But I don’t know what you mean by close.   Like, an insect close, or just wide angle like for a group shot?  Tell us what you’d like to shoot and we could probably help you more.

[CapiluisPanay]

Thanks for a fast response.....to give you and Idea, I am a ships pilot in the Panama Canal and there are circumstances on which I would like to take a shot at a friend pilotong a submarine at a distance of lets say 500 ft. Furthermore the watershed is full of wildlife, that is another aspect....and you put it, lets say an insect......

I was overviewing the lenses in the web and it is difficult to choose the wright one or the ones....that is the purpose of my inquiry.

Thanks

[TCampbell]

The dimension field of view for a 400mm focal length shooting a subject 500 ft away is about 28' (horizontal) by just shy of 19' (vertical).  Submarines are, of course, much larger than wildlife.  

If I were shooting primarily wildlife, I'd probably want a 400mm lens.  If I were shooting anotther boat, then 300mm is probably sufficient.

Canon makes an EF 100-400mm f/4.5-5.6L IS USM - about $1700

There's also an EF 70-300mm f/4-5.6L IS USM - about $1600

And then for a much lower price point, there's the EF 70-300mm f/4-5.6 IS USM (without the "L") for about $650.

Most (but not all) "L" series lenses are weather sealed (not water-proof though).  They're usually higher performing, better optical quality, etc.  Sometime sthe difference is huge... sometimes it's subtle.

As for the lens to take something as small as an insect... that's what macro lenses do.  These lenses allow extremely close focusing distances and the true macros allow for a 1:1 image scale on the sensor.  That means the size of an object on the camera sensor is as large as it would appear in real life.  To give you an example, a US penny has a diameter of roughly 19mm.  The sensor on your camera has dimensions which are roughly 14 x 21mm.  That means if you took a photo of a penny at closest possible focusing distance, the penny would fit in the frame the "long" way (e.g. horizontally) but would not fit in the frame the "short" way (e.g. the vertical dimension) -- it would be slightly clipped.  So that's pretty close.

There are other ways to get close-up shots as well.  Some zoom lenses have a "macro" mode, but these are never 1:1 scale macros... usually 1:3 or 1:4.  

You can use "extension tubes" -- hollow tubes that go between the camera body and lens and extend the position of the lens out a bit.  This has the effect of shortening the entire focusing range for the lens so that you can focus on closer subjects.    These are actually fairly inexpensive.

There are even close-up diopters that screw onto the end of the lens -- inexpensive but also the lowest in image quality.

Canon makes a number of true macro lenses in different focal lengths.  I use the EF 100mm f/2.8L IS USM Macro.  

There is also a non-L version of the 100mm Macro and a 180mm f/3.5L Macro USM.  

The longer focal length on the macro lens allows you to be farther away from your subject which provides two advantages:  

#1  the greater distance means you hopefully don't scare away a skittish critter

#2  since focusing distances are often very close with macro lenses, you, the camera body and lens can often block some of the light you were hoping to use to light up your subject.  By using a longer lens, both you and your gear are able to be far enough away that you hopefully don't block the light.

As lens focal lengths start to get long, the price tags REALLY go up (as do the physical dimensions of the lens).