Panasonic G7 crop factor question

Discussion in 'Panasonic Cameras' started by Jack2501, May 14, 2017.

  1. Jack2501

    Jack2501 Mu-43 Regular

    26
    May 14, 2017
    Hi there,

    I am really struggling with the crop factor concept on the G7 and could really use a simple explanation.

    If I buy a 12mm lens for the G7 it will perform like a 24mm lens and give the same field of view as a 24mm not 12mm on the G7 is that correct? I hear people say "full frame equivalent" a lot and that confuses me. I just need to know what field of view I should expect for lenses on the G7 M43 sensor.

    Many thanks!
     
  2. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    super easy..............multiply focal length written on lens by 2 and you have what it would be on a full frame camera.
     
  3. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    much easier then doing the same with an APSC camera, unless you good at math in your head.
     
  4. Jack2501

    Jack2501 Mu-43 Regular

    26
    May 14, 2017
    Thanks Phocal, the thing is thats where it get the most confusing. does that mean if I put my 12mm on a full frame camera that then it would act like a 24mm? Therefore if I use the lens on M43 it will be true 12mm?
     
  5. dwig

    dwig Mu-43 Top Veteran

    682
    Jun 26, 2010
    Key West FL
    Like a 24mm lens on what camera??

    Field of View (FoV) is not a factor of the lens FL, in and of itself. It is, instead, a factor of the relationship of the FL to the camera's image size, sensor of film. A 12mm lens on an m43 camera will give the same diagonal FoV as a 24mm lens on a full frame 35mm film camera or "full frame" digital. Since the two formats are not the same aspect ration (read: shape) the FoV comparison is not the same for the short-side FoV, the long side FoV, and the diagonal FoV. The long standing convention is to use the diagonal when listing the angular coverage of a lens and in such comparisons.

    Due to the long running popularity of 35mm full frame (AKA "double frame" in early years) it has become the reference standard for may comparisons. It is common to refer to a lens' FoV using its equivalent FL on a 35mm FF camera (e.g. "full frame equivalent" or "FL-e").
     
  6. dwig

    dwig Mu-43 Top Veteran

    682
    Jun 26, 2010
    Key West FL
    NO!!

    A 12mm lens is a 12mm lens, period. Moving it to a body with a different size sensor does not change the FL. If it was possible to use an m43 12mm lens on a FF body it would act just like a native full frame 12mm lens. In practice, the m43 lens wouldn't cover the whole FF sensor, but the image size of any subject in that area imaged would be the same size as if a native FF 12mm lens were used.
     
  7. Jack2501

    Jack2501 Mu-43 Regular

    26
    May 14, 2017
    I just don't understand how if i take a Panasonic M43 mount lens and put it on my Panasonic G7 M43 body it will be cropped by 2x but if I was to put that same Panasonic M43 lens on a full frame it would still be cropped. I would have thought M43 lenses were deigned to work with M43 sensors?
     
  8. Jack2501

    Jack2501 Mu-43 Regular

    26
    May 14, 2017
    Long sotry short I guess guys. If I buy a the Panasonic 12-35 for my G7 it will actually be a 24-70?
     
  9. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    They are designed to work on m4/3 cameras.......................

    The focal length of a lens is determined by the actually length of the lens. Well, with technology they have been able to reduce the length of the lens to some degree..........but we will keep it simple and say that the focal length of a lens is the actual length of a lens. People use that to represent the field of view a camera gives with a particular lens but it is actually not correct when dealing with today's different sized sensors. What people should really use when talking about a lens is the angle of view the lens provides. On a full frame camera a 50mm lens provides an angle of view of 46 degrees. When you put this lens on a m4/3 camera it will provide a 23 degree angle of view. But lens companies put the focal length and not angle of view on lenses so that is what everyone uses when discussing lenses and the angle of view they provide.
     
  10. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    no, it will still be a 12-35 lens...............it will just provide the same angle of view as a 24-70mm lens on a full frame camera.
     
  11. Jack2501

    Jack2501 Mu-43 Regular

    26
    May 14, 2017
    Im really sorry, thats where I get lost. I don't want to know what it would do if I put it on a FF. Everyone always says "on a full frame camera" im not putting it on a FF im putting it on my Panasonic G7.
     
  12. barry13

    barry13 Super Moderator; Photon Wrangler Subscribing Member

    Mar 7, 2014
    Southern California
    Barry
    What lenses do you have now?
     
  13. Jack2501

    Jack2501 Mu-43 Regular

    26
    May 14, 2017
    Just the 14-42 kit lens. But I'm looking at buying new glass and trying to understand the crop factor issue to try and get around it if needs be, with maybe a focal reducer.
     
  14. barry13

    barry13 Super Moderator; Photon Wrangler Subscribing Member

    Mar 7, 2014
    Southern California
    Barry
    The 12-35 would be over 10% wider than your current lens.
     
  15. Jack2501

    Jack2501 Mu-43 Regular

    26
    May 14, 2017

    with Only 4mm difference in the focal length? Im also thinking about getting the Rokinon cine lenses, for those I think I will need the focal reducer. If I buy the 85 for example I want the 85 not 170
     
  16. Hypilein

    Hypilein Mu-43 Top Veteran

    864
    Mar 18, 2015
    You don't have a crop factor issue. Just buy native lenses and stop thinking about these kind of things. They are there for people who change from a different system or run multiple systems. For mu43 this is what you need to know:

    7-14mm: Ultra Wide Angle --> used for extreme perspectives in Architecture/Landscapes
    14-25mm: Wide to Normal --> General Use
    25-45mm: Normal to Medium Telephoto --> Often used for portraits or other general use
    45-150mm: Telephoto --> portraits, indoor sports
    150-300mm: Super Telephoto --> wildlife

    Obviously other uses are possible and likely.
     
    • Agree Agree x 2
  17. Jack2501

    Jack2501 Mu-43 Regular

    26
    May 14, 2017

    So with the native lenses (Panasonic, Olympus) there is no crop factor? I have just been told differently in the past and thats why I am so confused.
     
    • Like Like x 1
  18. Hypilein

    Hypilein Mu-43 Top Veteran

    864
    Mar 18, 2015
    Lenses don't have crop factors. Cameras do. In case of all mu43 cameras the crop factor is 2, all APS-C cameras have 1.5 or 1.6, Full Frame cameras have 1. But the crop factor is not some inherently bad thing. As @Phocal@Phocal said, it is only a tool for photographers to compare lenses in different systems. If you ask people on here what lens you should buy for a given purpose (like the ones I stated in my post) they will recommend you native lenses to use. I would stay away from adapted glass for the moment, as they will not allow you to autofocus (way more important than crop factor).
     
    • Agree Agree x 1
  19. Jack2501

    Jack2501 Mu-43 Regular

    26
    May 14, 2017

    Thank you but that doesn't really answer my question. I just want to know if I buy a lens I'm getting the focal length written on it. Not 2x the focal length. I should mention I'm not a total beginner. I don't want auto focus for video thats why I'm considering cinema lenses.
     
  20. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    So why did you ask the question?