Different lens focus?

Discussion in 'Photography Beginners' Forum' started by Fred Kim, Apr 27, 2008.

  1. Fred Kim

    Fred Kim TPF Noob!

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    Ok so i was lurking around a bit and i was wondering something.

    How would you go about taking a picture like this?

    I mean focus and detail wise. I think the person i got this from said it was a 10-20mm lens.

    But how in the hell would you get such a large view in such great detail?

    I took this picture with my d80 with 18-135mm lens and all i can get is a small area of focus and a surrounding blur, and I most likely took this photo with a non extreme aperture.
     
  2. ScottS

    ScottS TPF Noob!

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    Well the two shots you poster are way different in subject matter.
    The way the person who shot the first one got most of it in focus is because they used a tripod and a long exposure, along with a small aperture. Like f/22 or f/36

    To get more depth of field in your photos, you need to make your aperture smaller. ( the bigger the number, the smaller the aperture.)
     
  3. Night shot: Tri-pod to hold it steady. Low ISO (100, or even 50). Small aperture, meaning a higher number such as f/8 or f/11 or even f/16 pending on the lens. A long exposure, possibly as long as 30 seconds.

    The smaller aperture means greater Depth of Field (DOF) which means a lot more is in focus. It's calculation based on aperture size and relative distance to the subject. Your dog is so close to the lens that the relative distance to the ground is so big that it is already out of focus again - I bet your lens was wide open for that shot. Also, the elements too close to the lens are out of focus. In the night shot that slimy looking ballustrade in the front of the shot (which I find highly distracting) is out of focus. So is the dog's nose in your shot.

    Hopefully some of the other members here are will add to this thread. Some of them are really good at explaining DOF. I know it well, but am not good at explaining it... at least not on Sunday morning after a big bender, followed by the kids waking me at 7.20 AM.
     
  4. Ah, ScottS got to it before I did.
     
  5. Fred Kim

    Fred Kim TPF Noob!

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    I understand the whole aperture deal for sure, but I just cannot achieve such a photo as the first link even with low ISO and high f-number.

    If i got a 50mm lens, would the detail be a lot greater than a 18-135mm at the same aperture?
     
  6. Fred Kim

    Fred Kim TPF Noob!

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  7. ScottS

    ScottS TPF Noob!

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    I think you did a fine job of explaining it!
    Heh, well I'm off to bed. :greenpbl:
     
  8. ScottS

    ScottS TPF Noob!

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    The detail would be a little sharper perhaps, but unless you can close down the aperture on the 50mm more than the zoom, the photos DOP will remain about the same.
     
  9. Fred Kim

    Fred Kim TPF Noob!

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    Ok i guess the lens wont matter too much.

    This photo was shot with the exact same camera and lens setup as I have. I'm not going to compare with any of my photos, but simply ask how i would achieve this photo.

    Edit:

    I was wrong. Sigma 10-20mm lens have some INTENSE depth of field.

    http://www.flickr.com/photos/90001203@N00/582396891/sizes/l/in/set-72157600310736311/
    http://www.flickr.com/photos/jeffclow/1110140856/
    http://www.flickr.com/photos/erroba/2380163253/sizes/l/

    So basically a smaller focal length has a greater depth of field?

    Does that mean I would need a lens with a shorter focal length to get results like those three pictures i just linked?
     
  10. Garbz

    Garbz No longer a newbie, moving up!

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    Go back into the original thread and look at the example at the bottom. It should explain everything.

    Yes aperture has a lot to do with depth of field, but in this case it was all about the field of view.

    Before people go and recommend f/22 or some other high aperture it would help to look at the EXIF data. That image was taken at f/5.6 ONLY.

    The wider the angle of view on the lens, the wider the depth of field at a given aperture. Again I posted examples back in the thread it came from.
     
  11. Rogan

    Rogan TPF Noob!

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    is the first picture in the OP disney land :S ? looks like it :D
     
  12. Early

    Early TPF Noob!

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    Your pic was shot close up, giving you very narrow depth of field where the first pic was most probably shot at infinity giving the photog more depth.
     

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