Pentax 50mm vs 100mm Macro: Minimum Focusing Distance

Hi.

I am considering a new 50mm f2.8 SMC-FA Macro from BandH versus a used
100mm f2.8 SMC-F Macro
The used 100 SMC-F is $75 more, but as I understand is a highly regarded
lens.

Pros of the 50mm: I already have 52mm UV filter, polarizer etc, which
reduces costs. 50mm would be brand new vs used 100mm
Pros of the 100mm: It would be nice to have a fast 100mm , plus the added
distance between the subject when in Macro mode.

When reading the specs of B&H (maybe should double check at Pentax.com), the
min focusing distance of the 50mm is 20cm vs 30cm for the 100mm.

Everyone seems to make such a big deal about the min focusing distance diff.
between these two lenses, but 10cm does not seem that significant to affect
how you work with a close up subject (ie - youre still damn close either
way). Not having any experience with them though, I dont really know.

Any comments about min. focusing difference, or what would you choose?

Thanks

Jeremy

 

I have the F-100/2.8 macro and can testify that it's a *very* good lens
indeed. Boz's Pentax page gives the minimum focusing distances for the
50mm and 100mm as 19cm and 31cm, respectively. I suppose the difference
isn't that great but it could be significant in some circumstances,
especially when using flash. Also a lot easier to work around plants and
such. That extra 12cm can be a godsend - I wouldn't want to have to work
any closer than the 100mm lens gets me. YMMV.

 

x-no-archive: yes

I suppose the difference
One other consideration that comes to mind is that there may be less
perspective distortion when shooting three-dimensional objects with the
100mm, because your lens isn't quite as close to the subject as is the 50mm.

Analogous to shooting portraits with a normal lens vs. a short tele--the
nose and ears may appear too big when using the normal lens (especially if
the camera is relatively close to the subject's face), but the use of a
short to medium telephoto compresses the perspective, flattening out the
protruding parts and making them appear more natural.

I own both the SMC TAkumar 50mm and the SMC Takumar 100mm macros (in the
older screw mount) and I find that I rarely use the 50mm--the 100mm's larger
magnification is really welcome.