# Why is the 50mm f2.5 macro so cheap?



## mreco99 (Nov 2, 2011)

Why is the canon 50mm f2.5 macro so cheap?

Checking the iso charts, its one of the sharpest lenses. CA looks very well controlled.

Sure at 50mm, macro is very close and would scare bugs, but otherewise, am i missing somthing as to why this is a bargin?

thanks


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## Old Shooter (Nov 2, 2011)

Well, it's an old design. I bought mine nearly 20 years ago to use on an EOS 10s body. It doesn't have USM so it is a little noisy. That being said, it is still one of the sharpest lenses I own. Stop it down to f/5.6 or smaller and it is tack sharp. On a crop body it's effectively an 80mm so it can do double-duty as a portrait lens. The filter size is 52mm so they're cheap. I have a collapsible lens shade on mine to reduce any possibility of flare. I think it is a bargain; if mine broke today I would order another one to replace it...


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## mreco99 (Nov 2, 2011)

really? 20 years old!!! wow

Hows the AF on it? slow?


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## torger (Nov 2, 2011)

mreco99 said:


> Why is the canon 50mm f2.5 macro so cheap?
> 
> Checking the iso charts, its one of the sharpest lenses. CA looks very well controlled.



Some focal lengths are easier to design than others, they require less lens elements. If there are few and small glass elements the lens can be cheap, and those simple symmetric designs can perform very well concerning CA. 50mm is such a focal length, and this is where you can find great price/performance. Some 50mm lenses are expensive anyway, if you need to have the best bokeh and very large aperture you need larger glass and price goes up, but those lenses can actually be less sharp at say f/8 than the low cost designs, so if you shoot landscape with large DoF and you want maximum detail the cheaper lens can give you better pictures.

Other focal lengths are more difficult to design, such as 24mm, there you need lots of elements and the price goes up.

What decides which focal lengths are easy to design is the flange distance and image circle size. Since EF needs to fit a mirror short focal lengths must be retrofocal designs which make them more complex. So it is impossible to make a 24mm lens as good as a 50mm lens at similar price.

This article presents more detail about the subject http://www.canonrumors.com/tech-articles/lens-genealogy/


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## dr croubie (Nov 2, 2011)

For the same apertures, the 50/1.8 ii is a tiny bit sharper, and that's a lot cheaper. Add a full 68mm set of Kenko extension tubes and the 50/1.8 can get to 1.35x magnification, for cheaper than the 50/2.5 macro.
But then, the niftyfifty bokeh is nice and pentagonal, and it's not the sturdiest made lens (and changing to add in extension tubes can get tedious)
Pretty much all 50mm lenses are going to be cheap compared to other lengths, they're called 'normal' for a reason...


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## thejoyofsobe (Nov 2, 2011)

it's cheap because it's an old, slow focusing, macro lens with a native maximum magnification of .5X. Canon wants you to shell out an addition $290 for life-size converter to get the lens to 1X.


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## iaind (Nov 2, 2011)

thejoyofsobe said:


> it's cheap because it's an old, slow focusing, macro lens with a native maximum magnification of .5X. Canon wants you to shell out an addition $290 for life-size converter to get the lens to 1X.



By the time you have bought both, you have paid the equivalent of 100mm 2.8 non IS.


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## Old Shooter (Nov 3, 2011)

mreco99 said:


> really? 20 years old!!! wow
> 
> Hows the AF on it? slow?



LOL! LOUD and SLOW! Years before the USM lenses... I used it for police forensic photography; so the fingerprints and dead bodies didn't seem to mind too much...


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