recommend me a cheap prime lens?


Oct 17, 2010
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#1
Hi all,

im looking for a budget portrait/nature lens mainly on still subjects, posed pictures, flowers etc. Was reading up on the pentax M and A series which offer a cheap alternative to big apature lenses, with the trade of MF and the need of step down metering (for M series).

I have a budget of around $100, and hence i am looking at the pentax 50mm M f/1.7 vs the pentax 50mm A f/2. Both cost around $100 i presume, based on previous sales in B&S,

anybody would comment on the two lenses? my main concern is whether the A 50mm f2 is able to maintain sharp wide open as i would actually prefer the A series (im abit lazy to control the metering haha)

given a choice, which of the two would you recommned? both have mostly excellent reviews and i cant decide haha
 

Aug 5, 2009
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#2
I'd go with the 50/2 SMC-A, for the simple reason that metering is predictable (and program modes work!)

With the M-lenses (no "A" on the aperture ring) the metering with the green button is wildly off the mark depending on aperture selected (the offset is not consistent).

Yes the 50/1.7 would be sharper wide-open than the 50/2 (and obviously would also be sharper at f/2 than the 50/2 wide-open). However in my experience, you won't be using wide-open. Well, I have the 50/1.4 FA and wide-open it has aberrations galore and paper-thin DOF, even a few inches of subject movement at portrait distances will spoil all your sharpness. The problem gets even worse with MF lenses.

For portraits I generally stick around f/2.8 at which both of your lens choices would do fine. The convenience of the A lens would become more and more apparent the more photos you take. :)
 

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oceanpriest

Senior Member
Apr 24, 2010
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Ghim Moh
#3
You may want to consider SMC 55mm f1.8 also. It's as sharp as 50 1.7 but with slightly better color/bokeh imo.
 

snapnut

New Member
Oct 1, 2004
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#4
I have both lenses.
Both lenses are optically very good, and both are pretty sharp wide open.
Personally I feel the M f1.7 is slightly sharper.

The A f2.0 lens is easier to use as you can use all modes (Av, Tv etc), lighter and better for flash photography.

The M f1.7 lens is better build, more beautiful and very sentimental :cry:. Very smooth focusing and feels great to use. And it takes great and super sharp pics ;p
 

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pinholecam

Moderator
Staff member
Jul 23, 2007
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#5
I'd go with the 50/2 SMC-A, for the simple reason that metering is predictable (and program modes work!)

With the M-lenses (no "A" on the aperture ring) the metering with the green button is wildly off the mark depending on aperture selected (the offset is not consistent).

Yes the 50/1.7 would be sharper wide-open than the 50/2 (and obviously would also be sharper at f/2 than the 50/2 wide-open). However in my experience, you won't be using wide-open. Well, I have the 50/1.4 FA and wide-open it has aberrations galore and paper-thin DOF, even a few inches of subject movement at portrait distances will spoil all your sharpness. The problem gets even worse with MF lenses.

For portraits I generally stick around f/2.8 at which both of your lens choices would do fine. The convenience of the A lens would become more and more apparent the more photos you take. :)

Great advice!
Certainly sums up everything I would have typed :)
 

Oct 17, 2010
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#6
haha thanks all, actually i was wondering, if i get the A 50mm f/2, looking at the lens pics, it seems that the next stop after f/2 is f/2.8, but if set auto mode can i get it to step down a half stop? maybe like f/2.5 or f/2.4? because if i have to set it to f/2.8 to get a sharp picture it might not be that worth it anymore because i already have a pretty sharp copy of the tamron 17-50 f/2.8 but i was thinking maybe the prime lens could produce higher IQ and bokeh
 

pinholecam

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Jul 23, 2007
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#7
haha thanks all, actually i was wondering, if i get the A 50mm f/2, looking at the lens pics, it seems that the next stop after f/2 is f/2.8, but if set auto mode can i get it to step down a half stop? maybe like f/2.5 or f/2.4? because if i have to set it to f/2.8 to get a sharp picture it might not be that worth it anymore because i already have a pretty sharp copy of the tamron 17-50 f/2.8 but i was thinking maybe the prime lens could produce higher IQ and bokeh
On Av mode, you can change by 1/3 stops :)
As long as you use a hood to get good contrast and get focus right, I don't see why a 50/2 won't give you sharp enough pictures. Not to mention that the shallower DOF will give you more 'apparent' sharpness as the regions around the point of focus will be more OOF.
 

hotwork77

New Member
Jun 21, 2009
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#8
Hi all,

im looking for a budget portrait/nature lens mainly on still subjects, posed pictures, flowers etc. Was reading up on the pentax M and A series which offer a cheap alternative to big apature lenses, with the trade of MF and the need of step down metering (for M series).

I have a budget of around $100, and hence i am looking at the pentax 50mm M f/1.7 vs the pentax 50mm A f/2. Both cost around $100 i presume, based on previous sales in B&S,

anybody would comment on the two lenses? my main concern is whether the A 50mm f2 is able to maintain sharp wide open as i would actually prefer the A series (im abit lazy to control the metering haha)

given a choice, which of the two would you recommned? both have mostly excellent reviews and i cant decide haha
Buy both and try. I'm also a bit lazy to decide for you. :cool:
 

Oct 17, 2010
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#9
On Av mode, you can change by 1/3 stops :)
As long as you use a hood to get good contrast and get focus right, I don't see why a 50/2 won't give you sharp enough pictures. Not to mention that the shallower DOF will give you more 'apparent' sharpness as the regions around the point of focus will be more OOF.
well thats nice lol, so i could get it to stop down at f/2.2 and f/2.5? sounds nice to me,

about the sharpness part, im afraid that wide open there might be that "tad softness" when taking pictures, which always happens to me on zoom lenses - that 99% of my pictures are unable to get the "crisp sharp" feel (although this may be due to my poor skills)

i tried to find the MTF chart for the lenses but to no avail, but looking at the FA 50 1.4 and 1.7, seems that there is quite a bit of softness wide open which they put in the bad region (red)
 

Aug 5, 2009
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#10
Well you've got a point there.. if you have the 17-50/2.8 then a 50 @ 2.8 might seem redundant.

But the 50 @ 2.8 will be sharper than the 17-50 wide-open at its long end. Plus the 50 @ 2.8 will be much much lighter.

I only have the 16-45/4 and many times I wish I had the DA 21 Limited as an all-around lens (the 15/4 is a better "travel" focal length but somewhat larger.. come to think of it the 15/4 is "perfect" except it costs too much!). The DA 35 Macro is also a nice form factor (a bit bigger than a 50/2) but it's too long for general photography.

Regarding the SMC 55/1.8 -- yes it does have nice bokeh, but being a screw-mount lens, you don't have automatic stop-down of the aperture, and you still have the wild and wacky metering problems (even worse than on an M-lens).
 

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oceanpriest

Senior Member
Apr 24, 2010
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Ghim Moh
#11
Well you've got a point there.. if you have the 17-50/2.8 then a 50 @ 2.8 might seem redundant.

But the 50 @ 2.8 will be sharper than the 17-50 wide-open at its long end. Plus the 50 @ 2.8 will be much much lighter.

I only have the 16-45/4 and many times I wish I had the DA 21 Limited as an all-around lens (the 15/4 is a better "travel" focal length but it's larger). The DA 35 Macro is also a nice form factor (a bit bigger than a 50/2) but it's too long for general photography.

Regarding the SMC 55/1.8 -- yes it does have nice bokeh, but being a screw-mount lens, you don't have automatic stop-down of the aperture, and you still have the wild and wacky metering problems (even worse than on an M-lens).
Sorry, I mean SMC K 55mm f1.8, if I'm not wrong, there's one on bns. I have M 50 1.7 and K 55 1.8, in the end I decided to sell M 50 1.7.
 

pinholecam

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Staff member
Jul 23, 2007
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#12
well thats nice lol, so i could get it to stop down at f/2.2 and f/2.5? sounds nice to me,

about the sharpness part, im afraid that wide open there might be that "tad softness" when taking pictures, which always happens to me on zoom lenses - that 99% of my pictures are unable to get the "crisp sharp" feel (although this may be due to my poor skills)

i tried to find the MTF chart for the lenses but to no avail, but looking at the FA 50 1.4 and 1.7, seems that there is quite a bit of softness wide open which they put in the bad region (red)
IMO, this is where a lot of the MTF figures fail the potential buyer. They fail to show that in actual photos, the sharpness is sharp enough for normal viewing and the apparent sharpness due to the shallow DOF of the surrounding area.
YMMV
 

Aug 5, 2009
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#13
Actually a lot of the time the lack of that "crisp" look is because of mis-focusing.

Which is aggravated at large apertures.

We all know the "accuracy" (cough cough) of Pentax bodies, right? :confused: even a few mm of front- or back-focus at portrait distances will rob you of sharpness.

If you want to use MF primes a lot, you'll want to replace your focusing screen.

I have a "jinfinance" screen in my K20D that is slightly off. I need them shims!!! but nowhere to get them. I think I'll just put 3M Magic Tape on the existing shims..

Generally you'll get more crispness by stopping down to f/2.8 to f/4 on the primes.
 

Oct 17, 2010
163
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#14
Actually a lot of the time the lack of that "crisp" look is because of mis-focusing.

Which is aggravated at large apertures.

We all know the "accuracy" (cough cough) of Pentax bodies, right? :confused: even a few mm of front- or back-focus at portrait distances will rob you of sharpness.

If you want to use MF primes a lot, you'll want to replace your focusing screen.

I have a "jinfinance" screen in my K20D that is slightly off. I need them shims!!! but nowhere to get them. I think I'll just put 3M Magic Tape on the existing shims..

Generally you'll get more crispness by stopping down to f/2.8 to f/4 on the primes.
yup, reading from the pentaxforums, this lens is know to be soft wide open... actually im really forcing myself to stop considering the A 50 f1.7 due to its much higher price.. (if im not wrong its about $170) :dunno:
 

Aug 5, 2009
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#15
Actually (to make your life more complicated...) ;)

If "manual focus" and "not too expensive" were the criteria for a 50mm f/2 (or f/1.8) lens, my personal favorite would be the Zeiss Jena Pancolar 50/1.8. I haven't had the chance to try any of those Leica-R lenses or the Zeiss Contax (W. Germany) ones.

Another inexplicably nice and cheap 50mm is the Made-in-Singapore Rollei Planar 50/1.8 for Rollei Bayonet mount. It has this amazing color that I can't explain... problem is, it can't focus to infinity on Pentax bodies (I destroyed one such lens trying to mod it to reach infinity).
 

Oct 17, 2010
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#16
oh well, after considering all the choices i have, i think for now ill go in this order of lens choice

50mm A f1.7 (if i can find one real cheap like $140 lol)
50mm A f2
50mm M f1.7

PS: how come in sg the 2nd hand pricing for vintage lenses like these are noticably higher than in US or other countries? i saw the pentaxforums many of them got their copies for like $30USD (pentax A f2) compared to SG ($100-120++)
 

Aug 5, 2009
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#17
Glen: regarding resale price.

Yeah I notice that local prices are higher. Don't know why. That's why I buy on ebay. Shipping is a hassle though (a small item like a 50mm lens, shipped via USPS International Small Flat Rate Box, is $15 USD right away.. so if you got it for $30 USD.. + $15 USD international shipping.. well you get the drift).
 

Oct 17, 2010
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#18
Glen: regarding resale price.

Yeah I notice that local prices are higher. Don't know why. That's why I buy on ebay. Shipping is a hassle though (a small item like a 50mm lens, shipped via USPS International Small Flat Rate Box, is $15 USD right away.. so if you got it for $30 USD.. + $15 USD international shipping.. well you get the drift).
oo... but some sellers give free international shipping if im not wrong, although i bet it will wont be by air mail,

guess the main reason why pentax lenses cost more in sg is due to lack of supply in the resale market lol, fewer pentax users in a relatively small population (compared to us and uk)

ps: i was looking at a random AF lens (FA 35 f2) and realised it costs as much as a FA 50 1.4, anyone care to explain why a shorter focal range + smaller apature would cost more? i thought it would be cheaper cus of the smaller build/glass and the shorter the focal length (except for the UWAs of course)
 

reyreina

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Dec 26, 2008
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#19
no flea market = no $30 lo

thieves market and peninsular sell old lenses to earn money. clubsnap is ur best bet.
 

reyreina

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Dec 26, 2008
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#20
apparently 50mm is the easiest FL to make on apsc dslr, so its the cheapest. other factors like the built and glass quality play all part too. anyway don't read too much into the price. i also used to wonder why one lens cost $100 while another cost $2000 when R&D costs have long been amortised. in the end u realised it's just a way to make money. i also dont like the fact singtel charge $50/mth when they used to charge $5 for my pod lite plan.
 

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