Re: To Tamron or not to Tamron


"Alan Browne" <alan.browne@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:mPadnfjg1uDgx3LUnZ2dnUVZ_jli4p2d@xxxxxxxxxxxxxxx
Neil Harrington wrote:
"Mark Sieving" <Mark_Sieving@xxxxxxxxx> wrote in message
news:khjqu4hrg4h6rva0kjjj6vgtrhh0ohkajg@xxxxxxxxxx
On Mon, 20 Apr 2009 22:30:16 -0400, Alan Browne
<alan.browne@xxxxxxxxxxxxxxxxxxxxx> wrote:

2.5" sounds very short (so does 3.5") as focus distance is measured
from
the film/sensor plane to the subject...
Yes, focus distance is measured from the sensor plane. Minimum focus
distance for the 90mm F/2.8 is 11.4", and for the 60mm F/2.0, it's
9.1". But minimum working distance is measured from the front of the
lens to the subject.

Or more specifically from the front of the lens barrel to the subject,
and the 90mm Tamron has a very deep set front element. That may be one
reason why its working distance is shorter than this new 60mm lens.

At 1:1 I would guess the lens element protrudes completely (minus the lens
shade). That is the case with my Minolta 100 f/2.8 @ 1:1.

Not with the Tamron 90 -- the barrel moves forward as you go to 1:1 and the
front element remains just as far back from the front end as ever; that
distance never changes.

The Tokina 100mm macro (which also has a deep-set front element, though not
as deep set as the Tamron) is the same way. The barrel moves forward on
close focusing and the front element keeps the same relationship to it.

Both lenses come with generous-sized lens hoods, but neither seems at all
necessary except to keep stray light away from a filter if you're using one.


.

Relevant Pages

  • Re: To Tamron or not to Tamron
    ... the film/sensor plane to the subject... ... focus distance is measured from the sensor plane. ... But minimum working distance is measured from the front of the ... That may be one reason why its working distance is shorter than this new 60mm lens. ...
    (rec.photo.digital.slr-systems)
  • Re: To Tamron or not to Tamron
    ... the film/sensor plane to the subject... ... focus distance is measured from the sensor plane. ... But minimum working distance is measured from the front of the ...
    (rec.photo.digital.slr-systems)
  • Re: New Tamron 60mm macro for APS-C cameras
    ... Is there something I'm missing? ... It's smart to make a macro lens with smooth bokeh which is also usable as ... Working distance of 100mm, the longest distance among lenses in this ...
    (rec.photo.digital.slr-systems)
  • Re: Short macro bellows lens recommendation for 35mm, beyond 1:1
    ... Working distance is not as much of an issue for this, ... I picked up an old Spiratone 35mm f/3.5 bellows lens, ... up to extreme magnifications like 1:8 shown here: ... Enlarger Lens for extreme macro work. ...
    (alt.photography)
  • Re: WTB Long Working Distance Micro/macroscope
    ... Gordon Couger wrote: ... >>>The lens I am looking for is a macroscopic lens for SLR and ... >>>applications, not a microscope lens. ... > 100mm working distance and 12.5 mm Leitz Photar that belonged to ...
    (sci.techniques.microscopy)
Loading