Pentax-F 50mm F1.7 vs Pentax-FA 50mm F1.4


appleric

New Member
Jul 15, 2010
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#1
Dear All,

I wanted to buy a 50mm primes lens, saw these two currently selling in the forum. But I don't really know what's the difference between the Pentax-F and Pentax-FA, how do I choose between these two, any user here using these two lens at the moment, can share some opinions?

Thank you.

Regards,
ERIC KOH
 

poppyer

New Member
Jun 24, 2009
217
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#2
Dear All,

I wanted to buy a 50mm primes lens, saw these two currently selling in the forum. But I don't really know what's the difference between the Pentax-F and Pentax-FA, how do I choose between these two, any user here using these two lens at the moment, can share some opinions?

Thank you.

Regards,
ERIC KOH
F is the old (first-gen) auto focus lens. FA is the newer version.
F is considered to be better built, with metal internal barrel. FA has more plastic parts.
But of course older lens might not be as "healthy" as newer ones, due to aging.
So it's tradeoff about personal choice. And both are good stuff. :thumbsup:

Also note there are some cheaper takumar-F (not SMC F) lens, which has no SMC coating.
But I don't think F50/1.7 has this problem.
 

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poseur

Senior Member
Jul 27, 2009
1,030
14
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#3
I own a FA50 1.4, my freind old a F 50mm F1.7.

in my own opinon

Pentax-F 50mm F1.7 sharper (wide open (f1.7) compare to FA50 shooting at f1.8)
Pentax-FA 50mm F1.4 bokeh nicer then F50 1.7 and of course with f1.4 u get to play more DOF choices....
 

appleric

New Member
Jul 15, 2010
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#4
Thanks poseur and poppyer.

I saw some reviews said that FA 50mm F1.4 got soft wide open problem. What does soft wide open means? Now I am hesitate to get F1.4 or F1.7?

Regards,
ERIC KOH
 

oceanpriest

Senior Member
Apr 24, 2010
3,455
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Ghim Moh
#5
Thanks poseur and poppyer.

I saw some reviews said that FA 50mm F1.4 got soft wide open problem. What does soft wide open means? Now I am hesitate to get F1.4 or F1.7?

Regards,
ERIC KOH
Get both and sell the one that you don't like :bsmilie:

When you use FA50mm f1.4 at f1.4, that's called wide open. Using a hood will help alot.
http://www.clubsnap.com/forums/showpost.php?p=6176438&postcount=32

Here is the resolution test for pentax 50mm lens, they don't have F 50mm f1.7, perhaps you can compare FA 50mm f1.4 with M 50mm f1.7. I believe F 50mm f1.7 shares the same design as M 50mm f1.7.
http://www.takinami.com/yoshihiko/photo/lens_test/pentax_normal.html

You can also see the MTF chart for FA 50mm f1.4 here and compare it with other lenses
http://www.photozone.de/pentax/126-pentax-smc-fa-50mm-f14-review--lab-test-report?start=1
 

detritus

Senior Member
Sep 12, 2009
2,922
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shootingbugs.blogspot.com
#6
Thanks poseur and poppyer.

I saw some reviews said that FA 50mm F1.4 got soft wide open problem. What does soft wide open means? Now I am hesitate to get F1.4 or F1.7?

Regards,
ERIC KOH
it means that its not very sharp a F1.4.

both lenses are ok lah... its a matter of personal preference and budget which one you choose.

i have the FA50 f1.4. no problems with it so far. bokeh is very nice at F1.4, but focus accuracy becomes very impt because DOF is very shallow at F1.4.

i only use F1.4 in dim lighting. most of the time, i step down to ~ F2.

another factor to consider is that the FA50 can be bought new from the shop so you'll have warranty.
 

poseur

Senior Member
Jul 27, 2009
1,030
14
38
#7
Thanks poseur and poppyer.

I saw some reviews said that FA 50mm F1.4 got soft wide open problem. What does soft wide open means? Now I am hesitate to get F1.4 or F1.7?

Regards,
ERIC KOH
Both are good enough. "Softness" for some people is undesirable, but for me i think there is a use for it. For example if u take portraiture, i like it softer so it can hide some of the blemish of the person.. if it is too sharp..then a small pimple will look like a volcano...;)
 

detritus

Senior Member
Sep 12, 2009
2,922
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#8
Both are good enough. "Softness" for some people is undesirable, but for me i think there is a use for it. For example if u take portraiture, i like it softer so it can hide some of the blemish of the person.. if it is too sharp..then a small pimple will look like a volcano...;)
not really lah :) if its sharp, u can PP out the flaws. a pimple can be easily cloned off ;)

if u want the pic to have a "soft" feel, it can also be achieved in PP.

but if the original pic is soft to begin with, there's very little you can do in PP.
 

poseur

Senior Member
Jul 27, 2009
1,030
14
38
#9
not really lah :)
but if the original pic is soft to begin with, there's very little you can do in PP.
well said, i think it is a valid point. as a beginner in pp i still have many things to learn....
 

hamustar

New Member
May 23, 2007
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0
SengKang
www.flickr.com
#11
Oops I didn't notice this thread was concurrent with my sale. But anyway the lens is sold to a nice chap already so I have no conflict of interest in my reply.

All the 50 1.4s have the same optical formula (7 elements in 6 groups), just like all the 50 1.7s share the same (6 Elements in 5 groups).
More isn't necessarily better, just like a 14megapixels camera may not be better than 12megapixels one.
On another note, the 50 1.4s have 8 blade aperture openings, while the 1.7s have 6. This could explain the difference in bokeh when stopped down. Wide open, I don't think this has any bearing.

I have owned both before, 2 times FA50 1.4, and once the F50 1.7.

Given if one wants to buy new, there is no better choice than the FA50 1.4.
However for used lenses, if say to compare a A-50 f1.7 vs a A-50 f1.4, my opinion is to get the 1.7 version for the fact that it is generally a sharper lens with decent bokeh.


For those considering, best is to borrow(or buy??) 2 versions and see which one suits your style of photography more.

Cheers.
 

pinholecam

Moderator
Staff member
Jul 23, 2007
10,934
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#12
Just get the FA50/1.4.
I have the whole series of M and A 50mm (1.4/1.7/2.0) and have done center point focus comparisons with all of them.
IMHO, the f1.4 lenses for both series are sharp and a match to the 1.7 and f2.0 lenses. I did not observe what is often touted as the 1.7 being better than the 1.4. In fact I believe this hearsay came from some comments in PentaxForums. The problem most ppl face is the shallower DOF at f1.4 that can easily affect focus accuracy. A use of a hood will also help increase contrast and therefore perceived sharpness.
I won't discount the fact that there will be sample to sample variations though, so these are based on what I have and my own tests.

Furthermore, you can't beat that the FA50/1.4 is new (so less wear and tear) and not too expensive vs the F50/1.7 which has been pushed up in price over the years (mainly due to vintage; 'so said' performance at f1.7; FA50/1.4 price increases). You will also get warranty.
 

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detritus

Senior Member
Sep 12, 2009
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#13
The problem most ppl face is the shallower DOF at f1.4 that can easily affect focus accuracy. A use of a hood will also help increase contrast and therefore perceived sharpness.
totally agree with this point.

i myself succumbed to this silly misconception when i got my FA50. as it was my first fast lens, i was happily shooting away at F1.4 all the time and wondering to myself if i got a bad copy when i reviewed the pix :bsmilie:

in the end, after lots of shooting, experimenting and reviewing, i realised that the pix were not "soft"... they were OOF :embrass:

now i shoot at F2 ;)
 

sircam

New Member
May 21, 2007
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#15
Yeah... that's all okay... but it is the FA 50 f1.4 that is THE CHAMPION in the Auto Focus category... all the other contenders from Final onwards are Manual lenses only! :)

One can lose a lot of photo opportunities with the slow focusing of a manual focus lens... not worth it unless you are doing serious studio work or are photographing still objects/subjects most of the time.

So, practically speaking, for the generic photographer, its is the FA 50 f1.4 that is THE CHAMPION. There is no other prime lens in this category that is such great value for money and also available brand new with warranty (for those who value it.)

Last year I had most of the manual lenses in the 50mm category because I acquired them for a great price. After a comparison test, I sold most of them. Any guesses which one gets used the most for everyday photography because it gives me the most razor sharp keepers?!!
 

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Jun 10, 2005
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#16
Just get the FA50/1.4.
I have the whole series of M and A 50mm (1.4/1.7/2.0) and have done center point focus comparisons with all of them.
IMHO, the f1.4 lenses for both series are sharp and a match to the 1.7 and f2.0 lenses. I did not observe what is often touted as the 1.7 being better than the 1.4. In fact I believe this hearsay came from some comments in PentaxForums. The problem most ppl face is the shallower DOF at f1.4 that can easily affect focus accuracy. A use of a hood will also help increase contrast and therefore perceived sharpness.
I won't discount the fact that there will be sample to sample variations though, so these are based on what I have and my own tests.

Furthermore, you can't beat that the FA50/1.4 is new (so less wear and tear) and not too expensive vs the F50/1.7 which has been pushed up in price over the years (mainly due to vintage; 'so said' performance at f1.7; FA50/1.4 price increases). You will also get warranty.
I've made just that point about the 1,4 several times on forums - i have, or have had, the FA1.4, FA1.7, M1.4 and M1.7 and while the 1.4s may lack a bit of contrast wide open, the key thing is to focus them properly, which is not easy. Overall I find the 1.4s better, both the FAs and the Ms. Mine are certainly sharper in the corners.
 

astroseal

New Member
Dec 4, 2009
13
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#17
can all the experts share with a noob like me on the cost of the various lenses. still a bit confused by all the different series. Only know kit lens DAL, DA, and got the * one.

the FA50 like cost 500+-. am not prepared to spurge on such lens for half-pass-six skills of mine. so looking for affordable lens. see some like M lens cheap cheap nia. M=manual??


any significant diff if got AF ot not especially for noob.

appreciate the sharing, thanks
 

detritus

Senior Member
Sep 12, 2009
2,922
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shootingbugs.blogspot.com
#18
can all the experts share with a noob like me on the cost of the various lenses. still a bit confused by all the different series. Only know kit lens DAL, DA, and got the * one.

the FA50 like cost 500+-. am not prepared to spurge on such lens for half-pass-six skills of mine. so looking for affordable lens. see some like M lens cheap cheap nia. M=manual??

any significant diff if got AF ot not especially for noob.

appreciate the sharing, thanks
u can consider the new DA35 instead. is more affordable and its a very sharp lens.
http://www.clubsnap.com/forums/showthread.php?t=781683

if u have "half-past-six" skills, then u better get the newer DA lenses, or at least the A series lens. i don't see a problem spending money on good lenses if u can afford it cos i'm sure u won't want to stay "half-past-six" forever right? :bsmilie:

M series lenses doesn't have the electronic contacts for the body to detect the aperture so the auto modes (including P, AV, TV, SV and TAV) won't work. if u use a flash, P-TTL won't work also. you can only use it in M mode and set the aperture from the aperture ring.

some of the M (or even the earlier K and Takumar) series lenses are awesome, but i wouldn't recommend it if u're very new to DSLR and not comfortable to use M mode.

focusing obviously, is manual also. depending on what kind of pictures you take, it may or may not matter. but better know all the facts before you jump in to buy an M lens and know what to expect.
 

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astroseal

New Member
Dec 4, 2009
13
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#19
thanks bro detritus. will go read the link u posted first =)
 

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