Yes. It's my second copy. I sold my first one so I could try the 24-70, didn't really care for it so I sold it and picked up another tammy 28-75.
I have this lens too and was skeptical at first because many people said it doesn't do well on the 5D, but I like it a lot. It's nice and sharp, even if it is a little soft in the corners. Although it seems to sit in the bag mostly now since I'm using my primes more.
S-Man23 wrote:
I have this lens too and was skeptical at first because many people said it doesn't do well on the 5D, but I like it a lot. It's nice and sharp, even if it is a little soft in the corners. Although it seems to sit in the bag mostly now since I'm using my primes more.
I find that I am using my tammy more and more, especially towards the end of the reception when I don't want to carry two cameras and primes.
First of all, one has to recognize a number of facts:
1. The nominal focal length of a lens applies ONLY when the lens is focused at infinity. Otherwise, all bets are off. Depending on how the lens is designed, focusing at close range can result in the lens changing its effective focal length. This is especially common in zoom lenses, but it is also observable in various prime lenses. This phenomenon is colloquially known as "focus breathing," and lenses for cinematography are typically designed to avoid it.
2. DOF is a model that describes the range of distances for which objects are in reasonably sharp focus. It says nothing about the imaging behavior of objects outside this region. Two lenses can have the exact same DOF, yet one lens can show larger blur circles at infinity than the other. Thus, it is imprecise and/or inadvisable to use the term "DOF" as a way to describe extent of blur for out-of-focus objects.
3. Optical aberrations may complicate the measurement of DOF, but for most reasonably designed lenses at the image center, this should not be an issue. The presence of field curvature makes measuring DOF in the frame periphery questionable, especially for wide-angle designs.
4. More elements absolutely do NOT affect the DOF, nor the extent of blur of OOF points. The number of elements affects only the transmission of the lens, and indirectly at that. A well-designed lens with many elements can still have excellent transmission characteristics, provided that the choice of materials, construction, and optical formula are proper.
To explain why a "35/2.8" prime might have a different extent of blur than a "35/2.8" zoom, then, I propose one or more of the following explanations, among others not mentioned below:
* One lens is (or both lenses are) not actually 35mm and/or f/2.8 at the chosen subject magnification, due to differences in focusing design and/or pupil ratio.
* The lenses may actually have identical DOF (or nearly so), but the extent of background blur is slightly different due to subtleties of optical construction not pertaining to the number of elements used, but rather, the symmetry of the lens design (again, pupil ratio).
* Error in testing methodology.
* Curvature of field or presence of other optical aberrations are not taken into account.
