Working with the Macro lens.

This year I'm using a  Tamron AF 90mm f/2.8 Di SP AF/MF 1:1 Macro Lens and I am quite impressed with it.  It's better than any other macro I've owned and it's been a joy to work with.  I have used it on a wide variety of subjects in varied situations and have yet to be disappointed.  It's very easy to work with this lens.

  One aspect of working with macro lenses which was new to me was the "effective aperture" which is reported in camera when using the lens.  In the past, my cameras and lenses have either not been of a superior quality or of the type that I am using now, so I was not exposed to this phenomena.   I have often seen apertures reported as high as f67 with this lens.  I was a bit confused at first, as I had never heard of apertures this small.  It would seem amazing that any light whatever could reach the sensor through such a small opening.  However, a bit of research revealed that  "Macro lenses change their 'effective aperture' as you focus closer. This effective aperture gets smaller as most macro lenses actually change focal length too, as you focus close. Some lenses do not report this, but all Nikon brand macro lenses and some 3rd party ones like your Tamron do."*  It might be hard to comprehend how and why this occurs but once you have a grip on the concept, it makes sense.  Basically, the closer you get, the less light is allowed into the lens and, even though we are using an fixed aperture f2.8 lens, the amount of light entering is "effectively" the same as an aperture of f51, for instance.  The camera is then relaying that information to you in your viewfinder.

More information than you ever wanted to know and a good starting point for further research concerning this subject can be found in the photomacrography.net forums.  There are also discussions about the relationship between effective aperture and diffraction blur.



*Harrison - photographyreview.com

Spring Flowers and Close Up Photography

I'm working with a new lens this year.  I'd shopped around for awhile and finally decided on the Tamron 90mm f2.8 Macro.  This lens is super sharp and has a fast auto focus.  It's a great lens for doing macro work, and though it's not my choice for an every day walking around lens, it doesn't do such a bad job at that, either.  As long as you remember you are at a fixed focal length, it works fine.  Love the lens.

I was pretty much chomping at the bit to get busy with this lens and have had a pretty good time working with it this spring.  From bugs to flowers, I've been impressed with this lens.  It's capabilities are awesome. The depth of field is excellent and I experimented with it recently on a nature walk.  Here are a couple of shots.  The first is wide open at f3.5 and 1/250, and the second is at f29 and 1/6.

 You can see the difference in the depth of field.  It is pretty spectacular and the clarity is impressive as well.  Both images were processed identically.

While in the woods, where the above shots were photographed, I ran across a couple of other nice wildflowers, but was somewhat disappointed at not finding any Jack in the Pulpit, which is what I went there to find.

At any rate, it was a nice walk, and my first real opportunity to spend some time with the lens in a real time shooting environment.  I've always liked shallow depth of field shots for the fine backgrounds they can create, but in some circumstances I'm looking for more detail and a deeper area of clarity and the depth of field on my new lens is outstanding for that purpose.