What lenses do you have and why?

Canon 10-22 - Got it for Christmas and use it for landscapes.
Canon 28-135 - came with the 7D.
Canon 55-250 - bought it on the cheap to get more reach at the zoo over the kit lens.
Canon 50mm (nifty fifty) - bought it on the cheap for indoor get togethers and low light.
Sigma 150-500 - bought it for nature and wildlife photography.
Sigma 600 f/8 mirror lens - bought it on the cheap for reach but quickly replaced it with the 150-500. Looking to sell it.

I mainly use wide aperture primes now. I love shooting street candids in low light.

I've pretty much followed the standard path for crop cameras:

18-55 IS - Kit Lens, came with camera
55-250 - first lens bought, telephoto
50 1.8 - first creative play lens, low light
17-55 IS - ok, time to replace the kit lens with something better performing
10-22 - ultrawide for creative reasons and nice play lens too

Next up will be replacing the relatively slow 55-250 with a 70-200, probably the F4 IS, and then after that maybe getting the 85 1.8 or maybe a 50 1.4 if Canon ever make a new version...

Won't really need anything other than those. A 70-200 2.8 IS would be amazing but realistically is out of my budget...

See my signature but I can cover the focal lengths from 10mm to 300mm pretty well with this collection. Since I am crop sensor Rebel owning fool I use the 60mm for macro, primarily while underwater. The 10-17 Tokina serves as a great UWA underwater. I still use the kit lens quite a bit for walking around and the nifty for night shooting around town. The Tamron is a fine, inexpensive long lens with good IS. If I was going to add to the collection it would be a longer lens, a better walkaround lens, and a 14mm L fisheye for underwater work.

I have some of my lenses because they popped up for sale used at crazy low prices and I couldn't resist. They are all in perfect condition, so why not give them a go. Can always resell for a profit.

1.) Canon 28-105 USM - From Film days...still have it.
2.) Sigma 18-125mm - bought with my 20D. I sold it because I just don't use it much.
3.) Canon 50mm f/1.8 - Bought it from film days. Sold it because I bought the Canon 50mm f/1.4
4.) Canon 85mm f/1.8 - Sold this as I just don't use it much after I bought the 135L.
5.) Canon 50mm f/1.4 - Sold because it wasn't very sharp from 1.4-2.0 on my 20D.
6.) Canon 135mm f/2L - Awesome portrait lens and may never sell.
7.) Canon 100mm f/2.8L - Bought it to try out macro but I just don't use it enough and prefer my 135L for portrait. I traded for Zeiss 50MP.
7.) Canon 17-40mm f/4L - Bought it and like it very much but is on the trading or sale block because I like the 24-70mm f/2.8L I bought recently a lot more.
8.) Canon 24-70mm f/2.8L - Got a great deal and bought it even though I didn't need it. I found out I like it so much so I'm selling my 17-40mm f/4. Great lens for wedding!
9.) Canon 200mm f/2.8L - Love this lens but it's a bit long for portrait and a bit short for most sport so I may sell it.
10.) Canon 300mm f/4L IS - Bought it a few weeks ago for sport.
11.) Zeiss 50MP - Got this a few weeks ago via trade. Love the lens and may never sell it. I love the rendering of this lens and color for portrait. Take a little more work to use it but well worth it.
12.) Canon 1.4X II - I just didn't use it very much and sold it. 1.4X is just not very much enlargement for me.
13.) Canon 35mm f/1.4L - Love this lens. I use it for portrait, landscape, and low-light photography.

Some day I may be able to justify the Canon 85mm f/1.2L and Zeiss 21m Distagon. Last of the two remaining lens that I want.

Very often I first buy a lens, and afterwards see what their good and bad sides are:

Minolta Rokkor 58mm f/1.2 (converted): Super fast - good for low light and for small DOF. Little "glowing" gives special images I like for my art of photography. Good optical quality, even with extension tubes. Some say the lens is better than the EF 50mm L lenses - dont know. I like that the lens has no aspheric elements - no onion rings in bokeh. Very high mechanical quality. Even like the fact to DIY converted it to Canon EOS with infinity.

Meyer Goerlitz Trioplan 100mm f/2.8: Very special bokeh when used wide open.

Samyang 14mm f/2.8: Super wide angle for low price. Very good optical quality, nearly no problem with sun in the image - good flare resistance. Not for film users and not good for video users because of heavy moustache (!) distortion. Very low mechanical quality - at the moment out of order, plan to make own mechanics for that lens.

Zeiss 25mm f/2.8 (C/Y): Good optical quality and perfect mechanics.

Canon FD 85mm f/1.2L converted: High optical quality - even in close up work with extension tubes. Super fast. Very good mechanical build quality.

Zeiss 18mm f/4 (C/Y): Good optical quality and super mechanical quality. Have to test more to find the edge of its performance.

Helios 44-2 58mm/2.0: Good quality for price. Sturdy mechanics. Flare prone - usable for effects. Good quality with extension tubes. Love these lenses and its sibblings for experimentation - super cheap, got them for ~ 10 USD each.

Zeiss 85mm f/1.4 (C/Y): Great lens for people. But even good for reproduction like work stopped down. 3D pop in the way without small DOF. But small DOF pop is no problem tough. Fine mechanics too - no wonder for Zeiss lenses for Contax.

Canon FD 300mm f/2.8L: Good optical and mechanical performance. Even good with extension tubes. Super fast focussing with its IF.

17-40L - Landscapes. One of my favorite lenses. I love 17mm on a FF camera and really want to get a 17mm TS-E lens. I doubt it'd replace the 17-40L though. AF makes the 17-40L too usefull for me.

50mm f/1.4 - bokeh, although I'm not very impressed with the lens. My friend has one and loves it so I figured I'd give it a go. FL and f/1.4 is fun to play with, but I'm just not impressed with its performance. Everyone seems to rave about it and love it, but I'm thinking I may sell

100mm f/2.8L IS Macro - had the non L/IS and upgraded because I wanted IS and weather sealing. IQ is pretty much the same with a very slight edge to the L for colors and contrast.

70-200mm f/2.8L IS mk2 - Perfect FL for me for general walkaround use. I mainly bought it for indoor sports shooting, but it will probably become my most used lens.

300mm f/4L IS - Bought for wildlife and just to get my foot into the super tele range. After getting the 70-200 I'm thinking I won't need the 300mm anymore and will probably sell it.

2x mk3 extender - for getting 600mm and playing around. Also used on the 70-200 with great sucess IMO for a 140-400mm.


Other lenses I've owned
18-55mm IS - Upgraded to 28-135
55-250mm IS - Upgrade to 70-200
50mm f/1.8 - broke after 2 days of ownership, bought brand new.
100mm f/2.8 Macro - upgraded to the L/IS version for IS and weather sealing
28-105mm USM - first USM lens, wanted to see what all the fuss was about
28-135mm IS USM - better range than the 28-105, has IS, and better IQ
24-105mm f/4L IS - came with 5D2 kit. Don't really NEED it, and I found myself using other lenses less.
70-200mm f/4L - bought the Sigma 18-250mm OS HSM and didn't want to swap lenses all the time, so I sold it even though IQ was much better
Sigma 28-80mm macro - it was $50 and had good macro ability... What do you expect? Upgraded to the 100mm f/2.8 Macro
Sigma 18-250mm OS HSM - Bought a 1D mk2 and couldn't use the lens on it. Sold and bought another 28-135mm
Tamron 400mm f/5.6 APO - Gave to a friend as a Christmas gift after getting the 300mm f/4L IS

I will/might have at some point
17mm f/4L TS-E - I will have one. It's next on my to buy list. I really want to get started in the world of tilt/shift and 17mm is the perfect focal length for me.
24mm f/1.4L mk2 - I will have one. I love wide angle, and f/1.4 just can't be passed up. I really feel like just using the 24mm will push/challenge my photography.
24-70mm f/2.8L - probably, still unsure if I want to buy. Used a friend's and liked it, but I don't see why I'd want this around since I sold the 24-105mm. Seems like overlap.
24mm f/3.5L mk2 TS-E - possibly. Not sure if I want to buy this lens yet, but it's not out of the question.
300mm f/2.8L IS - Simply stunning lens and with the mk2 out now, the mk1 will become cheaper and within my price range.
500mm f/4L IS - MAYBE in a long time, if/when I can afford it. Trips to Australia for shooting wildlife in the bush would be awesome, or BIF at Midway, or even just a whale watching tour in the Puget Sound...
8-15mm f/4L - I'm a sucker for UWA lenses. It's so much fun. Plus the fisheye would be awesome.
135mm f/2L - possible for indoor sports, but unsure because of the 70-200mm f/2.8L IS mk2 I already own. I doubt I'd need the 135L

I have a 500d, 7D and a 5DII.

My first lens was he 18-55 kit lens on the 500d. Was good to play with.

Then I decided to buy a 70-300 USM in hindsite I should have bought a 70-200 F4 but I didnt really know what I was doing at that point.

Next lens was another 4 months on and its was the 17-40 as I wanted to do wide shots. This became my main lens and it lived on the camera.

I then started reading about the nifty fifty and treated myself just before xmas 2010. Love this lens.

Jump forward to May 2011 and I decided I wanted a 7D which came with the 18-135mm kit lens. Though I found generally I only use the nifty and then 17-40.

Then in July 2011 I decided that I wanted a 5D, the nifty became a proper super lens then...and the 17-40 a proper wide angle lens.

Then for xmas Ive got myself a 35mm F2 which gives me a nice wide-ish angle on the 5d and nice 50mm(ish) prime on the 7D.

Love my prime lenses but cant really justfy an L prime. Would like a 24-70 as my walk around lens next but suspect thats a bit of a pipedream now due to funds.

See my signature. Wanted to be able to shoot it all!

i have below lens all of them used only with 550d :
- 18-55 is kit: i want to upgrade with tamron 17-50 2.8
- 50 1.8: is my first prime. wanted it due to fast aperture and low price. excelent image quality for the money. i use it for events, products and portrait
- tokina 100 2.8 macro- because i wanted to shot macro and was the best option for the money

next: a tele 70-200 f4 or tamron 70-300 VC

24-105L - First L lens and primary walk around lens. Works out great for my needs.

10-22 - Love taking wide angle shots and this one is great for that on my crop

8mm Fisheye - simply got this one as it's a bit wider than the 10-22 and it's a nice lens when you want to take some "irregular" shots.

ALWAYS 1 less than I want

I've got a 7D and a 5D2 camera for a start, no use for the lenses without them. Then I have some Canon lenses.
50 f1.8 II,
MP-E65 Macro,
100 f2.8 L Macro,
24-105 f4 L IS,
70-200 f4 L non IS,
and a 100-400 f4-5.6 L IS
and I've just ordered a Sigma 150-500 OS.
On top of those the wife has a 550D, an 18-55 IS II and a 55-250 IS. I've also had and sold an 18-55 MkI and a 75-300 MkIII, a Tamron 28-300 VC and a couple of others that I can't remember.

What I have is listed in my sig. Basically, I have what I have because I don't specialize. I do mostly landscape and nature, but I do just enough other stuff to need the general spread. I bought what I felt were the best available for my body and needs, as well as for my wallet. I have a 100mm f2.8 L IS on order. I don't know if I will sell the 60mm when I get the new one or not.