Most Accurate 50mm for the K3

shutter_count · 03-03-2017, 01:37 PM

Hi, all. I posted the other day seeking advice on a new walkaround lens for my K3. Thanks so much for all the thoughtful suggestions. Yesterday, I spent an inordinate amount of time testing every camera/lens combination in my collection and came to the conclusion that 50mm is my sweet spot, especially on either the K3 (better bokeh) or K110d (an old flame which, in perfect light, looks like Portra film on a K1000).

Now the question becomes: which autofocus 50mm plays best with the K3? Which one has the most accurate AF most of the time?

My ancient SMC-M 50mm 1.4 is my go-to, and I'm 100% happy with the IQ, bokeh, etc. (It's a legendary lens for a reason!) The only problem is that I'm not getting younger and my eyes tire faster with MF. I would really like to invest in an AF equivalent ... but which one? There are so many on both the new and used markets, and most of the reviews and posted images are from older bodies. It's true that the K3 weeds out lenses.

I'm most interested in shooting "things" in daily life (restaurants, friends, nature, curiosities). I have focal lengths at other ends of the spectrum to fill in where necessary, but the 50 will stay on the K3 about 80% of the time.

Any advice would be greatly appreciated.

TL/DR: I need a new or used accurate, artful 50 for the K3.

**BigMackCam** · 03-03-2017, 01:42 PM

I don't know why AF lenses should perform differently, as I thought all of the AF logic was built in to camera firmware. That said, I find that my DA50 f/1.8 is not all that consistent in lower light. Not bad by any means, just not always spot on. By comparison, my FA50 f/1.4 always seems to nail the focus reliably. I haven't used it as much as the DA50, though, so maybe I'd notice more inaccuracies over time. You can pick up an FA50 f/1.4 in very good used condition for sensible money. People seem quite polarised on it. I love mine, and since you like the M50 f/1.4, I suspect you'd be happy with it too.

Again, I don't understand why one screw-drive AF lens would be more consistently accurate than another... maybe it's to do with tolerances in the screw-drive mechanism?

shutter_count · 03-03-2017, 01:51 PM

I have a hunch I would prefer an F or FA as well, Mike. Based on a random sampling of posted samples I've studied here and at Flickr, the film-era lenses consistently outperform the newer glass.

**TwoUptons** · 03-03-2017, 01:55 PM

I bought a F 50mm f1.7 for not a lot that was quick and precise once it got back from the shop...

And my DA 50mm macro is remarkably sharp.

But if you like the artistic look of the M lens, the FA 1.4 is probably the right choice...

-Eric

**pres589** · 03-03-2017, 01:58 PM

F 50 1.4 is probably going to render closer to your existing M 50 1.4. I'd probably look for a good condition version of that. Should save a bit of money over an FA as well due to age and external styling (I know, shouldn't matter, but I think it does have a slight effect on pricing).

A lens that seems interesting to me is the Sigma 50 EX 2.8 Macro. I like that lens in concept (never held or used one) because the extension to reach to infinity focus is much reduced vs. the Pentax F, FA, and DFA 50 Macro's. So for walking out with the camera with this lens attached, it would be easier I think vs. the Pentax's.

**TER-OR** · 03-03-2017, 02:01 PM

I'd also consider the DA40mm pancake. There's a lot of fun in those little lenses, and it gives you just a bit wider image.

**BigMackCam** · 03-03-2017, 02:01 PM

Originally posted by shutter_count

I have a hunch I would prefer an F or FA as well, Mike. Based on a random sampling of posted samples I've studied here and at Flickr, the film-era lenses consistently outperform the newer glass.

I reckon you might get some robust responses on that last comment

That said, I do think many of the film-era lenses have somewhat different rendering than you get from much more recent models. There seems to be a lot of demand these days for lenses that are pin sharp edge to edge and corner to corner, with very strong contrast and rich colours, but otherwise quite sterile rendering. Whether one lens is better than another is highly subjective, but I'll admit to a weakness for older glass

**pepperberry farm** · 03-03-2017, 02:04 PM

I have several 50's (or close to 50) and my favorites are the K55/2 and the Helios 44K-4 - I have the DA 50/1.8 and an SMC A 50/1.7, but the rendering, handling, and IQ of the older two seal the deal for me....

**UncleVanya** · 03-03-2017, 02:21 PM

The AF modules on modern DSLR cameras are really not optimized for faster than f2.8 lenses so there is some bias perhaps towards the DFA 50 macro which is a stunning lens by all accounts.

I would wager however that any of the autofocus 50mm (or 55 for that matter) will meet your needs. I'd read the review section for these lenses:

DFA 50 2.8
DA 50 1.8
F/FA 50 1.4 & 1.7
F/FA 50 macro 2.8
DA* 55 1.4 (SDM: no af on k110d)

You could also include the following 40mm's:

DA 40 HD or SMC limited 2.8
DA 40 XS

All said and done I'd suspect the F/FA 50 f1.4 will fit your needs since it mimics what you have and works on both bodies. The runner up would be the macro lenses (any) because I am partial to them and because the f2.8 max aperture is aligned to the af system best. The faster lenses can be less accurate since the sensors for focusing are designed for f2.8 lenses.

I love my DA 40 (SMC) and use it more often than my F 50 f1.7 - but you expressed a preference for 50mm.

shutter_count · 03-03-2017, 02:42 PM

"Showing my work" here with my forum research:

M 50mm 1.4 (7 elements; ~8.2 oz); 9.25 rating <== Already Have

F 50mm 1.4 (7 elements; 8.1 oz); 9.47 rating
F 50mm 1.7 (6 elements; 7.2 oz); 9.19 rating
FA 50mm 1.4 (7 elements; better bokeh; softer focus; AF hunts indoors; 7.8 oz); 8.86 rating
FA 50mm 1.7 (6 elements; sharper focus; busier bokeh; 6 oz); 9.61 rating
DA 50mm 1.8 (6 elements; inaccurate AF; annoying mf focus ring; loud AF; only 4 oz; avail on Amazon Prime and easy to return if I hate it); 9.31 rating

All of these are in the same neighborhood price-wise. Decisions, decisions.

** No pancakes for me. I've always braced my left hand under the lens, especially on the K3 where there's not much to the left side to grip!

mholford · 03-03-2017, 05:31 PM

one other thought.... unless you're in a *big* hurry, you could wait a bit and see if the upcoming DFA* 50 f1.4 is worth saving for.

awscreo · 03-03-2017, 06:42 PM

I got the da 50 1.8 and never been satisfied with its af. It would miss in bright day light sometimes, something that my other af lenses do much less often (and DFA 28-105 misses even less). Not scientific in any way, just my observation after using it quite a bit on my trip and after getting back.

**suraswami** · 03-03-2017, 08:48 PM

Originally posted by TER-OR

I'd also consider the DA40mm pancake. There's a lot of fun in those little lenses, and it gives you just a bit wider image.

Like the above and few others suggested I have the DA40mm XS pancake lens. None of the lens that I have comes close to its sharpness and low light rendering.

Recently bought DA 50mm 1.8 and A 50mm F2 both are pretty good in terms of sharpness and color rendering but I feel A 50mm is sharper at comparable F values.

I have tried F 50 1.7 lens and its pretty sharp and colors are very good too. If you like the special color rendering of the F and FA then should consider F 50 1.7 lens too.

Here are some pics for comparison:
Taken with DA 50mm F1.8

Taken with A 50mm F2.0.

I did some color correction on the DA photo but then when I saw the A 50 mm I liked the actual color and left it alone, no correction. Both was done with same lighting.

Hope it helps.

leekil · 03-03-2017, 10:20 PM

This might be too far from the 50, both in FOV and price, but there is also the FA 43.

emalvick · 03-03-2017, 10:40 PM

I've got an M 50 1.7 that I love. I've also got the DA, which I don't like, and I've not tried another 50.

Part of that reason is the FA 43 is the one lens that gives me as much joy as the 1.7 with respect to performance and image quality at a similar fov.

If I had to get a 50, I'd probably get the F 1.7 as I think it would compare with the M I already have.

1.4 seems tempting, but given the iso on modern cameras, the extra stop of speed doesn't seem necessary for the money. And the 1.7s usually perform as well at 1.7 as the 1.4s do at 1.7.

03-03-2017, 01:37 PM	#1
shutter_count New Member Join Date: Feb 2017 Location: Ohio Posts: 9	Most Accurate 50mm for the K3 Hi, all. I posted the other day seeking advice on a new walkaround lens for my K3. Thanks so much for all the thoughtful suggestions. Yesterday, I spent an inordinate amount of time testing every camera/lens combination in my collection and came to the conclusion that 50mm is my sweet spot, especially on either the K3 (better bokeh) or K110d (an old flame which, in perfect light, looks like Portra film on a K1000). Now the question becomes: which autofocus 50mm plays best with the K3? Which one has the most accurate AF most of the time? My ancient SMC-M 50mm 1.4 is my go-to, and I'm 100% happy with the IQ, bokeh, etc. (It's a legendary lens for a reason!) The only problem is that I'm not getting younger and my eyes tire faster with MF. I would really like to invest in an AF equivalent ... but which one? There are so many on both the new and used markets, and most of the reviews and posted images are from older bodies. It's true that the K3 weeds out lenses. I'm most interested in shooting "things" in daily life (restaurants, friends, nature, curiosities). I have focal lengths at other ends of the spectrum to fill in where necessary, but the 50 will stay on the K3 about 80% of the time. Any advice would be greatly appreciated. TL/DR: I need a new or used accurate, artful 50 for the K3.

03-03-2017, 08:48 PM	#13
suraswami Site Supporter Join Date: Jun 2015 Photos: Gallery \| Albums Posts: 419	Originally posted by TER-OR I'd also consider the DA40mm pancake. There's a lot of fun in those little lenses, and it gives you just a bit wider image. Like the above and few others suggested I have the DA40mm XS pancake lens. None of the lens that I have comes close to its sharpness and low light rendering. Recently bought DA 50mm 1.8 and A 50mm F2 both are pretty good in terms of sharpness and color rendering but I feel A 50mm is sharper at comparable F values. I have tried F 50 1.7 lens and its pretty sharp and colors are very good too. If you like the special color rendering of the F and FA then should consider F 50 1.7 lens too. Here are some pics for comparison: Taken with DA 50mm F1.8 Taken with A 50mm F2.0. I did some color correction on the DA photo but then when I saw the A 50 mm I liked the actual color and left it alone, no correction. Both was done with same lighting. Hope it helps. Last edited by suraswami; 03-03-2017 at 09:01 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
The Most wanted feature -K3 2 Successor	sumitkar1971	Pentax DSLR Discussion	20	08-20-2016 04:05 PM
Which DSLR has most accurate exposure	K-9	Pentax DSLR Discussion	28	09-20-2015 12:45 PM
Is K3 AF more accurate than K5II	Shanti	Pentax K-3 & K-3 II	28	04-10-2015 06:31 PM
What's the best accurate Pentax TTL Flash for weddings for bouncing?	crossover37	Pentax DSLR Discussion	18	03-25-2011 12:55 PM
Is the electronic level accurate for you?	m8o	Pentax K-5 & K-5 II	25	11-30-2010 10:19 AM

03-03-2017, 01:42 PM	#2
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,661	I don't know why AF lenses should perform differently, as I thought all of the AF logic was built in to camera firmware. That said, I find that my DA50 f/1.8 is not all that consistent in lower light. Not bad by any means, just not always spot on. By comparison, my FA50 f/1.4 always seems to nail the focus reliably. I haven't used it as much as the DA50, though, so maybe I'd notice more inaccuracies over time. You can pick up an FA50 f/1.4 in very good used condition for sensible money. People seem quite polarised on it. I love mine, and since you like the M50 f/1.4, I suspect you'd be happy with it too. Again, I don't understand why one screw-drive AF lens would be more consistently accurate than another... maybe it's to do with tolerances in the screw-drive mechanism?

03-03-2017, 01:51 PM	#3
shutter_count New Member Join Date: Feb 2017 Location: Ohio Posts: 9 Original Poster	I have a hunch I would prefer an F or FA as well, Mike. Based on a random sampling of posted samples I've studied here and at Flickr, the film-era lenses consistently outperform the newer glass.

03-03-2017, 01:55 PM	#4
TwoUptons Loyal Site Supporter Join Date: Nov 2015 Photos: Albums Posts: 4,210	I bought a F 50mm f1.7 for not a lot that was quick and precise once it got back from the shop... And my DA 50mm macro is remarkably sharp. But if you like the artistic look of the M lens, the FA 1.4 is probably the right choice... -Eric

03-03-2017, 01:58 PM	#5
pres589 Site Supporter Join Date: Jan 2014 Location: Wichita, KS Photos: Albums Posts: 4,529	F 50 1.4 is probably going to render closer to your existing M 50 1.4. I'd probably look for a good condition version of that. Should save a bit of money over an FA as well due to age and external styling (I know, shouldn't matter, but I think it does have a slight effect on pricing). A lens that seems interesting to me is the Sigma 50 EX 2.8 Macro. I like that lens in concept (never held or used one) because the extension to reach to infinity focus is much reduced vs. the Pentax F, FA, and DFA 50 Macro's. So for walking out with the camera with this lens attached, it would be easier I think vs. the Pentax's.

03-03-2017, 02:01 PM	#6
TER-OR Site Supporter Join Date: Apr 2009 Location: Dundee, IL Photos: Gallery \| Albums Posts: 6,699	I'd also consider the DA40mm pancake. There's a lot of fun in those little lenses, and it gives you just a bit wider image.

03-03-2017, 02:01 PM	#7
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,661	Originally posted by shutter_count I have a hunch I would prefer an F or FA as well, Mike. Based on a random sampling of posted samples I've studied here and at Flickr, the film-era lenses consistently outperform the newer glass. I reckon you might get some robust responses on that last comment That said, I do think many of the film-era lenses have somewhat different rendering than you get from much more recent models. There seems to be a lot of demand these days for lenses that are pin sharp edge to edge and corner to corner, with very strong contrast and rich colours, but otherwise quite sterile rendering. Whether one lens is better than another is highly subjective, but I'll admit to a weakness for older glass

03-03-2017, 02:04 PM	#8
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,656	I have several 50's (or close to 50) and my favorites are the K55/2 and the Helios 44K-4 - I have the DA 50/1.8 and an SMC A 50/1.7, but the rendering, handling, and IQ of the older two seal the deal for me....

03-03-2017, 02:21 PM	#9
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,398	The AF modules on modern DSLR cameras are really not optimized for faster than f2.8 lenses so there is some bias perhaps towards the DFA 50 macro which is a stunning lens by all accounts. I would wager however that any of the autofocus 50mm (or 55 for that matter) will meet your needs. I'd read the review section for these lenses: DFA 50 2.8 DA 50 1.8 F/FA 50 1.4 & 1.7 F/FA 50 macro 2.8 DA* 55 1.4 (SDM: no af on k110d) You could also include the following 40mm's: DA 40 HD or SMC limited 2.8 DA 40 XS All said and done I'd suspect the F/FA 50 f1.4 will fit your needs since it mimics what you have and works on both bodies. The runner up would be the macro lenses (any) because I am partial to them and because the f2.8 max aperture is aligned to the af system best. The faster lenses can be less accurate since the sensors for focusing are designed for f2.8 lenses. I love my DA 40 (SMC) and use it more often than my F 50 f1.7 - but you expressed a preference for 50mm.

03-03-2017, 02:42 PM	#10
shutter_count New Member Join Date: Feb 2017 Location: Ohio Posts: 9 Original Poster	"Showing my work" here with my forum research: M 50mm 1.4 (7 elements; ~8.2 oz); 9.25 rating <== Already Have F 50mm 1.4 (7 elements; 8.1 oz); 9.47 rating F 50mm 1.7 (6 elements; 7.2 oz); 9.19 rating FA 50mm 1.4 (7 elements; better bokeh; softer focus; AF hunts indoors; 7.8 oz); 8.86 rating FA 50mm 1.7 (6 elements; sharper focus; busier bokeh; 6 oz); 9.61 rating DA 50mm 1.8 (6 elements; inaccurate AF; annoying mf focus ring; loud AF; only 4 oz; avail on Amazon Prime and easy to return if I hate it); 9.31 rating All of these are in the same neighborhood price-wise. Decisions, decisions. ** No pancakes for me. I've always braced my left hand under the lens, especially on the K3 where there's not much to the left side to grip!

03-03-2017, 05:31 PM	#11
mholford Senior Member Join Date: Dec 2012 Location: Vancouver Island, BC Photos: Albums Posts: 238	one other thought.... unless you're in a big hurry, you could wait a bit and see if the upcoming DFA* 50 f1.4 is worth saving for.

Thread Tools	Search this Thread
	Search this Thread: Advanced Search

03-03-2017, 06:42 PM	#12
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722	I got the da 50 1.8 and never been satisfied with its af. It would miss in bright day light sometimes, something that my other af lenses do much less often (and DFA 28-105 misses even less). Not scientific in any way, just my observation after using it quite a bit on my trip and after getting back.

03-03-2017, 10:20 PM	#14
leekil Pentaxian Join Date: May 2016 Photos: Albums Posts: 2,003	This might be too far from the 50, both in FOV and price, but there is also the FA 43.

03-03-2017, 10:40 PM	#15
emalvick Veteran Member Join Date: Feb 2008 Location: Davis, CA Photos: Gallery Posts: 1,642	I've got an M 50 1.7 that I love. I've also got the DA, which I don't like, and I've not tried another 50. Part of that reason is the FA 43 is the one lens that gives me as much joy as the 1.7 with respect to performance and image quality at a similar fov. If I had to get a 50, I'd probably get the F 1.7 as I think it would compare with the M I already have. 1.4 seems tempting, but given the iso on modern cameras, the extra stop of speed doesn't seem necessary for the money. And the 1.7s usually perform as well at 1.7 as the 1.4s do at 1.7.