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01-28-2009, 07:02 PM   #1
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FA 50mm F1.7 vs F 50mm F1.7


I'm just curious as to what the difference is between the F and FA version of the 50mm f/1.7 lens? FA I'm assuming is newer, but is there any differences in auto-focusing noise, sharpness, etc?
I'm about to purchase a used F version for $120. Is this a good price or should I wait til I come across an FA version?


01-28-2009, 07:48 PM   #2
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Optically identical - in fact all 50mm f1.7 lenses are the same optical formula. The only differences are exterior styling and the chip in the lens stores more info about the lens. AFAIK the only documented extra information is MTF data. The lens can tell the camera its sharpest aperture. Some cameras have an MTF program line so you can optimize sharpness.
01-28-2009, 07:50 PM   #3
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Bought the F version 50mm f/1.7 last year for AU$200 in absolutely mint condition.
By far the best low light, indoor without flash, portrait lens I have ever used.
Autofocus is fast and accurate even under dim lighting.
Works great on my K20D @ ISO1600 and wide open.
DOF wide open is quite narrow (as expected) but subject is razor sharp with good soft background.
Have heard reports that the FA version is just as good.
Go for it.
01-29-2009, 12:52 AM   #4
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go for a F lens ;-)

01-29-2009, 03:19 PM   #5
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Original Poster
When looking at the lens database on pentax forums I noticed a lot of people praising the FA version since it was supposedly sharper than the f/1.4 50mm.... does this sharpness also apply to the F version since it's optically identical to the FA version?
01-29-2009, 03:55 PM   #6
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The F is a great little lens - super sharp wide-open. See This Link.
01-30-2009, 01:08 AM   #7
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never had FA version but I own F50/1.7 and can only recommend it.
Great lens, and can be bought for very cheap money.
You can't really go wrong with it..
05-08-2009, 01:12 PM   #8
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Underrated ?

Edit: double post, deleted


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