# canon 100mm macro usm vs non usm?



## SHaller (Jan 26, 2011)

I'm wondering what the difference be between these two lenses. I know there is going to be a difference in focusing speed, but is there anything else that is worth mentioning. Do they use the same optics at?


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## reznap (Jan 26, 2011)

I've actually heard people say the optical quality of the old one and new one are identical.  The non-usm one doesn't work with tripod rings though, from what I've heard.


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## Dao (Jan 27, 2011)

I have the non-usm version.  
- Yup, no tripod mount on the old one. 
- The new one use internal focusing mechanism, so it will not extend while focusing while the older version will.
- The old version front lens element is recess in the lens, so no need to use a lens hood.
- The optics design between the 2 are different, but the result is about the same (from what I read from the net)
- According to Darrel here in TPF, the older version has a creamer out of focus look than the new version.
- The older version use a smaller size filter.


This photo is taken with the old non-usm Canon EF 100 macro lens


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## SHaller (Jan 27, 2011)

Dao said:


> I have the non-usm version.
> - Yup, no tripod mount on the old one.
> - The new one use internal focusing mechanism, so it will not extend while focusing while the older version will.
> - The old version front lens element is recess in the lens, so no need to use a lens hood.
> ...



Thats an amazing photo! I feel that i would never really need the usm for macro shoots, but was there ever times where you felt you needed the extra speed?


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## Dao (Jan 27, 2011)

Do I need USM for the macro shots?  In fact, most of the time (over 95%) I use MF for the macro shots.  So it really does not matter if the AF speed is fast or not.

Like the skipper butterfly photo shown above, it was taken with manual focus. And it is actually easier to use MF than AF if I like to maintain the 1:1 ratio.

If someone want to use the 100mm lens for some other type of photography such as portrait, than the AF with USM comes in handy.  But I already have the 85mm prime lens for that.


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