I had not (really) about the 1.5x, or 1.6x crop until today, that I may a 35 mm. lens

Discussion in 'Digital Photography' started by igmolinav, Sep 19, 2010.

  1. igmolinav macrumors 65816

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    Aug 15, 2005
    #1
    Hi,

    A person is selling some manual lenses. The price is atractive! Among the lenses I tried, there were a 35mm., a 50mm., and a 75mm. All of them from the manufacturer Carl Zeiss. The lens that attracted me the most was the 35mm. On my Nikon D50 is a 52mm, (on a Canon EOS dSLR it is a 55mm).

    Two things seemed a bit strange to me after doing a few shots with the 35 mm. lens, (but I have not shot with a normal lens in a while, so perhaps that is not that strange).

    One is, that I took a horizontal shot of a girl's face within two meters of focus range, and her face looks a little bit "expanded" or "too wide" for me. If it is allowed, I would gladly post the photos. (Perhaps my eyes don't usually notice a face that is a bit wider of what it seems to me. I also took a much closer vertical shot and her face looked a bit the same. This about a meter away from me).

    The other thing, while cool, I don't know if it may have a disadvantage. Being a lens with a 35mm. focal legth, a wide angle in full format the focusing distances for this lens are:

    0,24m., 1meter, 2meters, and then infinitum.

    with a regular or standard 50 mm. lens one has:
    0,45m, 0,8m., 1meter, 2meter, 3meter, 4meter, 5meter, and then it goes to infinitum. So your subjects can still be a couple meters farther away and one has the chance to "discriminate'?'" or tune a bit more the focusing distance. With the 35mm. lens one only has two meters and then infinitum!


    I would use this lens for two purposes:

    One, with the video capability of a dSLR, I
    would record the interviews of the people sitting (in front of me). (I am a sociologist). They would be no further away than 2 meters away from the camera. I just wouldn't like them to have a "tomato-sized" face due to the possible "wide angle effect" of this lens. The other use would be as a street documentary lens for photography.

    Some examples of interviews I found on youtube are the following,
    (I didn't even watch them completely, it is just to show how people sit
    while interviewed):
    1. http://www.youtube.com/watch?v=P9W_hI328FQ&feature=channel
    2. http://www.youtube.com/watch?v=mYjIsWNJGtw
    3. This other viedo is a bad video done with that lens on a 5ooD camera:
    http://www.youtube.com/watch?v=Q--6NQ9p6Ek

    What does the crop factor do, (either 1,5x, or 1,6x), with your image on a wide angle lens like the 35mm.?? Is it a "cut out" from what an image in full format would be, or the crop factor does have an influence on the image ?? Would a 50 mm. lens on full format have less "wide angle distorsion" than this "52 mm." on my Nikon ??

    With regard to focus with this lens. Suppose you have two people 4 meters away from you, and then a wall 7 meters away from you. What can you expect about sharpness, (being both, the two people and the wall), focused to infinity?? Will both be sharp or ..... mmmhh ??

    Thank you in advance, kind regards,

    igmolinav.
     
  2. acearchie macrumors 68040

    acearchie

    Joined:
    Jan 15, 2006
    #2
    Post the pictures! It would be much easier to see!

    The stretching your talking of though shouldn’t occur at the length of the lens you are talking about.
     
  3. igmolinav thread starter macrumors 65816

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    Aug 15, 2005
    #3
    Hi,

    I would post the .jpegs this evening, (in a few hours). I have never done this so I think one clicks on "Manage Attachments" and then adds the files, right ??
    I'll download the pics from my camera and then post them. I am expecting to post between two and four pictures is that ok ??

    Kind regards,

    igmolinav.
     
  4. igmolinav thread starter macrumors 65816

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    Aug 15, 2005
    #4
    Pics with the Carl Zeiss 35 mm. f/2 lens for Nikon.

    Hi,

    Here are some horizontal and vertical shots with the Carl Zeiss 35 mm. f/2
     

    Attached Files:

  5. igmolinav thread starter macrumors 65816

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    Aug 15, 2005
    #5
    Pics with the Carl Zeiss 50 mm. lens for Nikon.

    Hi,

    Pics. taken with the 50 mm. lens. Perhaps the face
    looks slightly different to the face taken with the
    35 mm.

    Kind regards,

    igmolinav.
     

    Attached Files:

  6. H2Ockey macrumors regular

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    Aug 25, 2008
    #6
    The "crop factor" and "effective" focal length are in regards to field of view and not perspective.

    So a 35mm lens on a crop sensor will give near the same field of view as a 50mm on a full frame or film camera but the perspectives are different due to the way the light is actually focused through the lens.

    A 50mm lens is still normal and a 35mm lens is still wider angle, meaning that portrait type shots will tend to be flatter and wider with the 35mm. The typical distortions associated with a wide angle lens is minimized because a crop sensor is more or less using the center of what could be a larger frame and the distortion is more noticable on the outside or near the edges of the frame.

    So, for portraits on a crop sensor for the same appearance you will need to step back a little.
     
  7. joelypolly macrumors 6502

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    Melbourne & Shanghai
    #7
  8. igmolinav thread starter macrumors 65816

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    Aug 15, 2005
    #8
    Hi,

    Would two meters be enough ?? Right after two meters, the next focusing distance is infinitum.

    Kind regards,

    igmolinav.
     
  9. igmolinav thread starter macrumors 65816

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    Aug 15, 2005
    #9
    P.S. I'll try to use the lens tomorrow and focus at 2 meters.
     
  10. H2Ockey macrumors regular

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    Aug 25, 2008
    #10
    I think you missed my point. Regardless of sensor size for portrait type shots you will want to use the same lens you normally would. Just because a 35mm on a crop sensor has a similar field of view as a 50mm on a full frame, the distortion and perspective does not change. A 35mm lens will have the same drawbacks; therefore you will want a 50mm – 105mm for this type of work. The drawback (to some) is that with the crop sensor you will need to be further from your subject. Stepping back with a 35mm lens may actually increase the effect you are wanting to avoid.
     
  11. scottkifnw macrumors regular

    scottkifnw

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    Trophy Club, TX
    #11
    barrell distortion

    Try a longer lens for portraits.

    sek

     
  12. Edge100 macrumors 68000

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    #12
    You're quite right in saying that no matter which camera you mount a given lens to (FF, 1.6x, 1.3x, etc), the perspective does not change, per se.

    But keep in mind that perspective is dependent on subject to lens distance, not focal length. So...

    If you put a 50mm lens on a 1.6x camera, you have a field of view equivalent to an 80mm lens on a FF camera. That is, you can stand in the same place and get the same perspective and field of view with a 1.6x camera and a 50mm lens as you can with a FF camera and an 80mm lens.

    Now, lets say you only have that 80mm lens. To get the same field of view on the 1.6x camera as you get on your FF camera, you'll have to move back 1.6x further from the subject. Now your perspective has changed.

    This is why "zooming with your feet" is not a substitute for zoom lenses; having a range of prime lenses is the correct substitute.

    So, if you're doing portraits on a 1.6x camera, you want to choose focal lengths that allow you to get the same field of view AND perspective as you get on a FF camera. So if your regular FF portrait length is 85mm, then you'll need (roughly) a 50mm lens to give you an equivalent. If you slap that 85mm lens on your 1.6x camera, you're going to have to move back quite a bit vs. FF, and thus your perspective changes.

    The same principle works in reverse. If you like the look of 50mm on FF, you can get the same field of view and perspective with a 30mm lens on 1.6x crop (because the angle of view AND the subject to lens distance is the same in both cases).
     
  13. igmolinav thread starter macrumors 65816

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    #13
    Hi,

    My main worry is if the lens will have a lot of distorsion. My camera, a Nikon, has a 1.5x crop factor. I would be about two meters away from my subject.

    H2Ockey mentions that distortion will stay the same, or will increase:
    Kind regards,

    igmolinav.
     
  14. Edge100 macrumors 68000

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    The "distortion" is a function of subject to lens distance. That's all you need to concern yourself with. Standard portrait focal lengths are generally in the 85-135mm length; on a 1.5x crop, that equates to 56-90mm. Lenses in that range will give you the "proper" perspective for portraits on a 1.5x crop body.
     
  15. igmolinav thread starter macrumors 65816

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    Aug 15, 2005
    #15
    Hi,

    Thank you again for your answers !!!

    I'll take some pics today with the 35 mm. and with the 50 mm. from the distances I'll be using them the most !!!

    Kind regards,

    igmolinav.
     

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