need for a "fast lens?"

Discussion in 'Photography Beginners' Forum' started by thereforeiamx, Nov 8, 2008.

  1. thereforeiamx

    thereforeiamx TPF Noob!

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    I'm interested in taking photos that capture the splash of a fruit/object into liquid, but for that, I'd need a fast lens. What MAKES a fast lens, and what type of requirements would a camera body need to capture these types of subjects? and what types of flash should I look into?
     
  2. Steph

    Steph No longer a newbie, moving up!

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    A fast lens describes a lens with a wide aperture, not necessarily what you are after for the type of pictures you describe. The pictures you described are usually taken complete darkness and the shutter is left open (B exposure), and the falling object will trigger a flash. You then close the shutter. You don't need a fast lens (as in wide aperture) to achieve this.
     
  3. epp_b

    epp_b No longer a newbie, moving up!

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    A "fast" lens is defined as a lens with a large aperture. For zooms, f/2.8 is considered fast (and it's as fast as zooms currently go). For a prime (fixed focal length lens), f/2 or larger is pretty fast.

    Not necessarily. All you need is enough light for a fast shutter. 1/500th is usually enough to freeze pretty much any motion. Even an f/1.2 lens isn't going to provide shutter speed to do that in normal indoor lighting.

    Any slow kit zoom and a flash should be enough if you can sync the flash high enough (use a fast enough shutter with the flash)
     
  4. K_Pugh

    K_Pugh No longer a newbie, moving up!

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    You don't really need a 'fast' lens for that type of photography. Generally strobes really are the best bet, plus you can use triggers to trigger strobes when the object makes the splash etc (audio trigger).

    A 'fast' lens just means one that lets in a lot of light, F2.8, F1.8, F1.4, etc.. they say fast because you have a wider aperture letting in more light which means faster shutter speeds for the same exposure, hence 'fast'.

    ^ah they beat me to it.. I ought to type faster.
     
  5. tkaat

    tkaat TPF Noob!

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    a "fast lens" is one that has a large apeture (large is considered to be under f.3 i.e 1.8). If your are working with a Dslr any one would be able to use a "fast lens" but some wouldn't be able to fully control it. Like with Nikon their entry level DSlr's do not have autofocusing motors in their bodies but instead in their lens (but only in a handful of lenses) and so if you were to use a let's say a 50mm f1.8 prime lens on a D40 you would be able to use it's largest aperture (f1.8) but you would have to manually focus the camera
     
  6. reg

    reg TPF Noob!

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    [ame="http://www.amazon.com/Olympus-35-100mm-Zuiko-Lens-Cameras/dp/B000BKP1JE/ref=pd_bbs_sr_1/178-2956268-2951604?ie=UTF8&s=electronics&qid=1226183271&sr=8-1"]Really?[/ame]
     
  7. Battou

    Battou No longer a newbie, moving up!

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    ...For that it is not a fast lens you are looking for but a fast camera. You are looking at shooting at 1/1000 or faster.

    Set your shutter speed to either 1/1000 or 1/2000 or even 1/4000 (if your body goes that high) and then set your aperture acordingly. Pending the size of your fruit you might need an aperture of roughly 4 or 5.6. If you can't get that aperture at 1/1000 then sacrifice some DOF and open it wider but don't go slower than 1/1000 if you want to be absolutely sure you stopped it.


    On a full frame SLR with 50mm lens 1/1000 will freeze frame most anything moving at a natural speed, the longer the lens the faster shutter speed is required to "freeze" the subject.

    I can accomplish these types of shots with my camera and any 50mm lens I own as well as my 85mm. This is one style of shot that is in the camera requirements and my camera only goes as high as 1/1000, so chances are likely you can do it with what you have provided there is enough light. If there isn't....grab some lamps if you need to.
     
  8. Steph

    Steph No longer a newbie, moving up!

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    The maximum shutter speed of the camera has nothing to do with the type of photography described by the OP. You would have a hard time to achieve the results she/he is after without lighting. The most important thing for these shots is lighting, not lens or camera speed. It requires a bit more than basic equipment to achieve good results. Here is a tutorial with some nice shots.
     
  9. Battou

    Battou No longer a newbie, moving up!

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    I know what the OP was talking about. Contrary to popular belief high speed photography can be done with basic equipment and improvised lighting, it just takes a little more time and effort. If I had a good tank I would do some of these, but I don't have one so it'll have to wait for me.

    Yes, shutter speed has a lot to do with it. Ok, so I did not make as big a deal as I prolly should have about the lighting, but that was my error when I got carried away trying to get the OP away from the fast lens ideaology.

    Trying to do shots like this using the fast lens for it's "fast application" is destined to fail, hell 4 or 5.6 might even be a little too open but still. I honestly feel it was the dark studio concept that put this perceved need for a fast lens into the OP's head in the first place.

    Judging by the OP's post, I have to assume that they are far from ready to be shooting in a blackout studio, They would be better served practicing on droplet pictures in the kitchen sink so they know what they are getting them self into, and then trying it under constant light.
     
  10. tsaraleksi

    tsaraleksi TPF Noob!

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    Don't forget that because of the differences in crop format, an Olympus lens is much smaller by nature, and it is therefore much easier to make a faster zoom lens for those cameras.
     
  11. roadkill

    roadkill TPF Noob!

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    You can capture those types of shots with many lenses that don't nessecarily have to be fast. Up your shutter speed. Use a flash. Keep your aperature low.
     
  12. Village Idiot

    Village Idiot No longer a newbie, moving up!

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    And that because of the small sensor, it takes a much smaller aperture to equal the DOF on a APS-C sensor...forget about a full frame sensor...
     

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