[Kerrowdown]

See, THIS is the kind of advice I DON'T need. I can't afford a divorce!

Just saying is all.

[stevebrot]

between K/M/A lens quality are quite contentious and I haven't seen a clear consensus regarding which is best.

I own the K 55/1.8, M 50/1.7, and A 50/1.7:

• Pentax-K 55/1.8 is the best optically and has great build quality, but is also the bulkiest of the three. It is the best "fast 50" out of the many I own.
• Pentax-M 50/1.7 shares the K-series lens' great build, is the most compact of the three and is optically equivalent to the A-series lens
• Pentax-A 50/1.7 is similar to the M-series lens above except for being a little larger and a little lighter due to its largely plastic construction. When new the plastic may not have been an issue, but most representatives have developed issues with the aperture ring due to a broken plastic part in the detent mechanism. As a result, the aperture rings on many of these lenses operate so poorly that they cannot be moved off the "A" setting or if moved, may not work well enough to return!*

All three are optically excellent lenses and all three are worth owning. The A 50/1.7 has the benefit of allowing full metering and flash functionality with current-model Pentax dSLRs. The other two (sadly) require stop-down (green button) metering and manual flash technique.


Steve

* lenses with non-functional aperture rings should be priced accordingly

[Fat Albert]

Any thoughts on the Voigtlander Nokton 58mm f/1.4?

[SpartanD63]

Any thoughts on the Voigtlander Nokton 58mm f/1.4?

I have no experience with it, but I quite like the "look" from it. And I haven't heard much, if anything, bad about it. Aside from price of course.

[DSims]

It's true, but I always interpreted this statement as that 1.4 isn't so good, so the major selling point of the 1.4 over the 1.7 is kinda pointless. The question then becomes how do the two compare at 1.7/1.8? No one ever seems to do that comparison.

I compared, but it turned out none of the f/1.4 and f/1.7 50's I tried are that good at less than f/2. You may want to go <f/2 to get certain effects, but sharpness and overall IQ are generally lacking. The one that's really good at f/1.8 is the DA*55 - hence the higher price.

It is an open secret that most f/1.4 and f/1.2 lenses are not really superior in any way other than letting more light in and having narrower DOF.

Except for the quality of the OOF backgrounds with the f/1.2s, especially with the K. Not just the amount of blur, but also the appearance. It's difficult to get a harsh looking background on these lenses. IMO these lenses have a real purpose, while the f/1.4s just have overall degraded IQ near wide-open that doesn't serve a purpose.

[jeffshaddix]

Any thoughts on the Voigtlander Nokton 58mm f/1.4?

I owned it for about 4 years and used it a lot. It's quite good, but barely usable at f/1.4. Really dreamy at that setting, even at distance IMO. It got stolen about a year back, and I've been trying to replace it with something ever since. The only other issue I had with it was the nervous bokeh wide open, but stopped down to about f/2.2 and beyond and it was top class.

Now I use an A50/1.2, and I recommend it over the Nokton. It's dreamy 1.2-1.4 up close, but at portrait distance can be sharper than the Nokton. I also like the bokeh a bit better, and find f/2 to be a great setting, in which the aperture blades form a closed nonagon (no jaggies) and a good degree of sharpness.

...so I guess I agree with Kerrowdown on this one.

[AquaDome]

You list the DA35 and the FA43 in your signature. Those plus your A-50 1.7 should be just fine. Especially on a digital camera.
I have never had an f 1.2 anything, but I've had most of the other 50s. The K-55/1.8 is my favorite with seemingly glassy-wet color rendition. Goes great with Ektar in sunlight.
Everybody wants to know what's down there in the forbidden f-stops. You would have a hard time finding out, even with Live-View. I can't focus to find DOF at f1.4 without split-screen, micro-prisms, and a dioptric-corrected viewfinder-magnifier. And plenty of light.

If you really wanted to get an odd-ball 50 to try out, the M-50/f4 Macro is good enough to make it worth the extra hassle.

[Fat Albert]

I found a beautiful K 55 f/1.8 for peanuts, so I picked it up. Although I vowed never to go back to the green button after buying my first A-series lens, if this K is as good as you all say it is, I suppose I can make an exception.

You list the DA35 and the FA43 in your signature. Those plus your A-50 1.7 should be just fine.

Let's be clear: this was never about a thoughtful, rational approach, which is what your statement is. This is about indulging the whims and obsessions of LBA, which has begun to consume me

[tvfd911]

I don't think you'll be upset. I have the M50 f1.7, the SMC 55 f1.8, DA40. I had an FA50 f1.4, which came before all of those other lenses, which was my first lens after the kit lens. Taught me the value of a fast lens, but the rest spoke to me more and the FA appreciated in value from what I paid for it new, so it funded other LBA.

[SpartanD63]

I found a beautiful K 55 f/1.8 for peanuts, so I picked it up. Although I vowed never to go back to the green button after buying my first A-series lens, if this K is as good as you all say it is, I suppose I can make an exception.

I too don't care much for the metering limitations, but I'm fairly certain you'll like the lens. It sees far more time out of my house than any other lens, despite the limitations it has.

Everybody wants to know what's down there in the forbidden f-stops. You would have a hard time finding out, even with Live-View. I can't focus to find DOF at f1.4 without split-screen, micro-prisms, and a dioptric-corrected viewfinder-magnifier. And plenty of light.

Yup, that's the biggest problem with 1.2 and even the 1.4 lenses. They can be fantastic lenses, but a pain to focus.

[jeffshaddix]

Yup, that's the biggest problem with 1.2 and even the 1.4 lenses. They can be fantastic lenses, but a pain to focus.

Not to mention focus shift between f/1.2/1.4 and f/2.8...I find that more frustrating than the thin DOF.

Congrats on the K55/1.8, those are gems.

[AquaDome]

Let's be clear: this was never about a thoughtful, rational approach, which is what your statement is. This is about indulging the whims and obsessions of LBA, which has begun to consume me

Here's what my kind of "Thoughtful & Rational" will get you:

[kiwi_jono]

Here's what my kind of "Thoughtful & Rational" will get you:

Wow! That would probably be me if I had a bigger budget and didn't have a financial controller. If I was to be honest (which I have not intention of being) I'm not all that unhappy to budget restrictions - it could get out of control.