Questions about DSLR "Magnification"

Discussion in 'Beyond the Basics' started by MPerdomo, Jul 12, 2004.

  1. MPerdomo

    MPerdomo TPF Noob!

    Joined:
    Jun 27, 2004
    Messages:
    5
    Likes Received:
    0
    Given that the sensors in DSLR's are not full frame and magnify by 1.5x, is this good?

    I was thinking that it would be a good idea to get a DSLR, and for portraits, get a 50mm 1.8 lens, and then with the smaller sensor, it would be like a 75mm 1.8 lens, which would cost a lot more money. Or getting a 300mm f/4 lens, and then the magnification would raise it to 450mm f/4. The only downside is the wide angle end, but already, Nikon has made a ful frame fisheye for DSLR's.

    Can anyone elaborate or clear up any misconceptions. I know there has to be a catch somewhere.
     
  2. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

    Joined:
    Dec 16, 2003
    Messages:
    33,822
    Likes Received:
    1,811
    Location:
    Edmonton
    Can others edit my Photos:
    Photos NOT OK to edit
    I think you understand it pretty well. If you like telephoto...then the "magnification" factor is great. It's like a free teleconverter. Sports & wildlife photographers sure won't complain.

    If however you like to shoot with wide a angle lens...you will have to spend some money on some ultra wide lenses.

    Most people seem to think that affordable full frame DSLRs are just around the corner and will be available in a year or two. Lets hope so.
     
  3. MPerdomo

    MPerdomo TPF Noob!

    Joined:
    Jun 27, 2004
    Messages:
    5
    Likes Received:
    0
    But isn't the "magnification" not a true magnification?

    I thought I heard that it was merely a crop of the image, and that is different from a more powerful lens because a lens would change the field of view.
     
  4. danalec99

    danalec99 TPF Noob!

    Joined:
    Mar 14, 2004
    Messages:
    8,345
    Likes Received:
    68
    Can others edit my Photos:
    Photos NOT OK to edit
    So one should probably get a 14 or 15 lens to get a decent normal wide angled shot, right?
     
  5. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

    Joined:
    Dec 16, 2003
    Messages:
    33,822
    Likes Received:
    1,811
    Location:
    Edmonton
    Can others edit my Photos:
    Photos NOT OK to edit
    I'm not an expert on the subject but this is what I think it means.

    You're right, it's not a true "magnification" but more of a crop. I'm not sure but I think the field of view ends up being what it would be for the factored value compared to 35mm. So with a 50mm lens you get a field of view and zoom similar to what a 75mm lens would give on a 35mm film (or full frame D) camera.

    I think you may be asking if the perspective (if that's the right word) is different. I think that it is. If you shoot with a fish-eye lens on a "1.5 crop factor" DSLR you don't get the full perspective distortion that you would get with a full frame.

    I think this is only an issue with the widest lenses and not very noticeable on the long end.

    Of course I may be way off so check around. :roll:
     
  6. danalec99

    danalec99 TPF Noob!

    Joined:
    Mar 14, 2004
    Messages:
    8,345
    Likes Received:
    68
    Can others edit my Photos:
    Photos NOT OK to edit
    By a decent normal wide angled shot, I meant in the range of 22 - 28

    say if we are talking about a 18mm lens:
    18mm x 1.6 = 28.8mm on a DSLR

    Isn't that how the math works?
    Correct me if I'm wrong
     
  7. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

    Joined:
    Dec 16, 2003
    Messages:
    33,822
    Likes Received:
    1,811
    Location:
    Edmonton
    Can others edit my Photos:
    Photos NOT OK to edit
    I think that's right.
     
  8. danalec99

    danalec99 TPF Noob!

    Joined:
    Mar 14, 2004
    Messages:
    8,345
    Likes Received:
    68
    Can others edit my Photos:
    Photos NOT OK to edit
    Cool...thanks BM :)
     
  9. Slowboat

    Slowboat TPF Noob!

    Joined:
    Jun 30, 2004
    Messages:
    71
    Likes Received:
    0
    Location:
    Carnation, WA
  10. Digital Matt

    Digital Matt alter ego: Analog Matt

    Joined:
    Jan 30, 2004
    Messages:
    5,346
    Likes Received:
    65
    Location:
    Santa Barbara, CA
    Can others edit my Photos:
    Photos NOT OK to edit
    The "magnification" that you are speaking of is not a magnification at all. The actual term is Field of View Crop.

    Picture it like this. Lay a quarter down on a table, and say that is what you see through your lens with a film camera. Now lay a dime on top of it and that is what you see through a digital camera. Nothing is magnified. Everything is of the same size and distance. You are just seeing less of the frame. To me, it's a loss all around.

    Does that make sense?
     
  11. StvShoop

    StvShoop TPF Noob!

    Joined:
    Jun 9, 2004
    Messages:
    449
    Likes Received:
    0
    Location:
    Troy, NY
    gah, that article was painful to read through, slowboat. but i think i get it now

    so are there larger format digitals out there? the sense that i get from this thread and the article is that there are not... which just seems silly.
     
  12. Digital Matt

    Digital Matt alter ego: Analog Matt

    Joined:
    Jan 30, 2004
    Messages:
    5,346
    Likes Received:
    65
    Location:
    Santa Barbara, CA
    Can others edit my Photos:
    Photos NOT OK to edit
    Canon makes a full frame sensor digital camera, the Canon 1Ds. It's 11mp and suffers no FOV crop. It's also $7999. :)

    Several companies offer digital backs for medium format cameras, but they can costs upwards of $17k-20k.

    As with any technology, it will get cheaper as newer technology comes out, and eventually we'll be able to afford it :p
     

Share This Page