Any Rumors About Upcoming DX Lenses?

Discussion in 'Lens Lust' started by Vandyu, Jun 24, 2005.

  1. Vandyu

    Vandyu

    175
    May 14, 2005
    Richmond, VA
    I know they just released the DX18-55 and 55-200 basically to accompany the new D50, which I have purchased. Anyone heard rumors about anything in the 70-300 range specifically for digital cameras, aka DX series?
    Also, how important is it to have a DX series lens on the D50?

    Newbie questions from a newbie who is still seeking information about how to maximize a few precious dollars. Several people have suggested that a non-DX lens will mean a lost of digital functionality and quality. Other folks who know quite a bit about the D70 and D50 say that a DX isn't that big of a deal and a non-DX Nikkor 70-300 ED will do fine.
     
  2. jfrancis

    jfrancis

    May 8, 2005
    Orlando, FL
    I don't think that non-DX lenses per se lose functionality. The do tend to be lighter and cheaper than their "designed for 35 mm" counterparts, but that's about it IMO. There is no particular reason to use DX lenses on the D50, other than the weight issue. The non DX 70-300 does very well on a DSLR (mainly because it effectively becomes 105-450 mm).
     
  3. I take it you did not find anything to suit you. You may want to PM Gale per her response on your other post. She is a SUPER lady and will probably work something out for you on hers.
    I enjoyed talking with you this afternoon.
     
  4. Vandyu

    Vandyu

    175
    May 14, 2005
    Richmond, VA
    As it turned out, I didn't go lens shopping today. Ritz at CTC only had the 55-200. Ritz at Stoney Point has both and I plan to visit them tomorrow. The salesman there was telling me the 70-300 would work but I would lose some clarity (?) at the edges of my shots because it wasn't specifically designed for digital cameras. That's what got me wondering. I enjoyed talking with you as well, Dave, and I'm glad there are some more Richmonders here in the Cafe.
     
  5. faenix

    faenix

    98
    Jun 21, 2005
    Bayside, NY
    What the salesman told you is wrong. All Nikon lens without the DX tag are still 100% functional with your D50. If he wasn't talking about the 70-300 being slightly soft at the 300mm focal length, he either didn't know what he was talking about or was pulling your leg into buying the DX 55-200 lens.
     
  6. jfrancis

    jfrancis

    May 8, 2005
    Orlando, FL
    It's actually the opposite. The digital sensors don't receive light from the extreme edges of non-DX lenses and therefore often work BETTER with these than the 35 mm cameras.
     
  7. Vandyu

    Vandyu

    175
    May 14, 2005
    Richmond, VA
    John, this is what he was talking about, or something close to it. Could you elaborate a bit more and perhaps give an example of this situation--what would be lost or gained? I'm still confused.
     
  8. Chris101

    Chris101

    Feb 2, 2005
    Arizona
    Hi Ann, there are two main effects that occur when you take a lens that was designed for 35mm film and use it on a smaller, digital sensor.

    First is the 'angle of acceptance' factor. This term refers to the fact that a digital sensor element works best when the light hits it directly square on, as opposed to coming in at an angle.

    So light hitting the center pixels of a sensor will look brighter because it's hitting straight on. Light hitting pixels in the corners, where it is coming in at an angle (because the center of the lens is above the center of the sensor) will be dimmer.

    Practically this only adversely affects some wide angle and normal lenses. The point where the light appears to come from, relative to the sensor is called the exit pupil. Large exit pupil distances work better then small exit pupil distances. You can look up exit pupils for many lenses on Joe Wisniewski's page.

    The second factor can be called the 'center of the image circle' factor. All lenses cast their images in a circle. Lenses designed for 35mm film must have an image circle at least 43mm in diameter (the diagonal of a 35mm exposure.)

    The diagonal of a Nikon DX format sensor is about 29mm, so DX lenses need only make a circle 29mm in diameter. Thus, with a lens that covers a 35mm frame, you are only using the central 46% of the image circle cast by lens with a digital sensor.

    The advantage here is that certain lens faults such as coma, chromatic aberation, field curvature and linear distortion are more pronounced in the outer portions of the image circle. By using only the inner portion of the circle, a digital sensor eliminates (or greatly reduce0 these problems.

    So it depends on the which lens, if it will work better on a digital body or not. Most telephotos will favor the center of the image circle effect and work better. Some wide angles will be more affected by the angle of acceptance factor and do worse.
     
  9. Vandyu

    Vandyu

    175
    May 14, 2005
    Richmond, VA
    Well, Chris, what can I say. I'm impressed and also thinking there was merit to owning a Brownie Hawkeye and pushing one button. Now I see why my high school geometry teacher kept saying that I would need that someday :wink:

    Truthfully, after printing out your explanation and going to the website you linked to, I'm thinking that all of this is very technical, but I have somewhat of a better understanding. I appreciate your taking the time to explain and now I'm going to find that copy of "Digital Photography for Dummies" that I thought I could by-pass :lol:
     
  10. Chris101

    Chris101

    Feb 2, 2005
    Arizona
    Well remember - it's all about making pictures and not the underlying technology. If you have a lens and it makes good pictures, then it is a good lens. And that's all you really need in order to use it well.

    ;) The rest is just something to think about at 2:30 in the morning. ;)
     
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