Len speed, Why are all f/4.0-5.6, even expensive ones, I want to go to F11

Discussion in 'Photography Equipment & Products' started by Treymac, Jun 12, 2007.

  1. Treymac

    Treymac TPF Noob!

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    Hey guys. With my camera today came lenses that are around 3.5 - 5.6 or something like that. I don't like to be limited to only using apertures between that, so I went to look at expensive lenses, and I found a lot of them still only go 4.0-5.6. Are there any lenses that go to F11 or higher?

    Also, is it possible to take a shallow depth of field shot with f/4.0? I know it needs to be a small aperture for a shallow shot, but I'm not sure at what size.

    And, is there such a lens that goes from something like 2.6 to 11? My dads Lumix FZ30 goes from 2.6 to 11, and goes from 35mm to 400mm. I want a lens that can do everything. I want a lens that allows for very shallow depth of field, but also is very wide but can also go to 35mm, and can go to a very high numbered aperture. Is this a pipe dream?
     
  2. Steph

    Steph No longer a newbie, moving up!

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    The 3.5-5.6 range is the maximum aperuture range of a zoom lens. At the short end the maximum aperture will be f/3.5 and it will be f/5.6 at the long end. The minimum aperture (highest number) will probably be f/22 across the zoom range. Read the manual that came with your camera/lens to see how to set a smaller aperture (bigger number).
     
  3. Groupcaptainbonzo

    Groupcaptainbonzo TPF Noob!

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    The apertures that appear in the name (f4 -5.6 etc) are the widest apertures that the lens will open to through its zoom length. So the 17 - 85mm f4 - 5.6 will open to f4 at 17mm and opent to f5.6 at 85mm. It will colse down to f22 or f32 if required as will most lenses. But that is not recorded in the name (Don't know why).

    The depth of field (DOF) will vary with aperture. The wider the aperture the smaller the f number and the shallower the DOF. Also this becomes shallower the closer you get. So focusing at infinity you will have a greater distance in DOF than at close / macro ranges. Lastly the wider the angle of the lens the greater the DOF. So a 17 or 35mm lens focused on an object 800 yards away at f22. will have a great DOF. while a 500mm lens focused on an object 5 feet away at f2.8 will be VERY shallow.

    There is a reason why people carry several lenses as opposed to just one. The wider the zoom range, the more difficult it is to get quality. So MOST 50mm lens should give good quality at a reasonable price. While it will probably go from f1. something. it will almost undoubtedly perform best at about f8 or so. a 10 - 1000mm f2.8 zoom would , if it existed be a VERY expensive lens indeed. It would be VERY big, Very Heavy, and probably not very clear.
    It is much easier and therefore cheaper, to manfacture lenses with smaller zooms. or no zoom at all (Prime lenses).
    Most manufacturers these days do a "Good alrounder". and Canon are no exception. They also do "Super Zooms with better than 10X zoom range. But the best quality is in prime lenses and the most convienience is in super zooms. You need to strike a balance which suits you.
    My own choice is the EFs 17-85mm f4-5.6 IS USM, for a general working lens. and the EF 70-300mm f4-5.6 IS USM. with optional teleconverter to pull in the long shots. For Macro I use the Sigma 105 f2.8 EX DG Macro. and for speed either that or the 50mm f1.4. These suit my needs and just about my pocket. You will have to find out what you want to use as you go.
    Hope that this helps. Any other questions please feel free to ask again.
     
  4. EOS_JD

    EOS_JD TPF Noob!

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    You are not limited. if you think f4-5.6 lenses are expensive look at f2.8 lenses! These figures are as decribed above as Maximum Apertures - the widest the lens will open. Al lenses will likely close down to around f22 and you can choose any aperture in between.

    Yes it is. get close to your subject and use a long dfocal length. I'd suggest you also buy a book on photrography to help you understand. You are wrong that it's a smaller aperturew for a shallow shot. What is best is a large aperture like f2.8 or larger (look at the 50mm f1.4). Large apertures have smaller numbers.

    Most of my lenses go from their max apertures to f22 or f32. So my 70-200 f2.8L IS goes f2.8-f32. My Tamron 28-75 f2.8 goes f2.8-f22 I think. All lenses will be roughly the same.

    Focal length however is another matter and to make a lens like a 35-400 the quality would suffer and to make that f2.8 it would probably need to be the size of a small car!!!
     
  5. JIP

    JIP No longer a newbie, moving up!

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    Well that about covers it.
     
  6. kaboom

    kaboom TPF Noob!

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    they don't tell you the minimun aperture number because what sells is speed.
    the fact that a lens can stop down to f/22 or f/28 doesn't mean much because even the crappiest 50 dollar zoom can do it.
     

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