[FantasticMrFox]

After having read through the whole thread, it looks like people are particularly unhappy with:

A range of older, film-era zooms
FA 50 f/1.4
DA* 16-50 f/2.8
DA 55-300 (various versions, not new PLM)

[Na Horuk]

After having read through the whole thread, it looks like people are particularly unhappy with:

A range of older, film-era zooms
FA 50 f/1.4
DA* 16-50 f/2.8
DA 55-300 (various versions, not new PLM)

I know the 16-50mm has been on the list for a while, mostly because of its high price and SDM problems. I'm a little surprised with the 55-300mm, maybe people just have too high expectations for it? Or its too difficult to use at 300mm? Its a "budget" telephoto zoom after all
But I am most surprised that people have problems with FA 50mm f1.4. Some people give it high praise! Really interesting. It doesn't have any obvious weaknesses - fast aperture, compact, no SDM to cause problems, not super expensive...

[FantasticMrFox]

I know the 16-50mm has been on the list for a while, mostly because of its high price and SDM problems. I'm a little surprised with the 55-300mm, maybe people just have too high expectations for it? Or its too difficult to use at 300mm? Its a "budget" telephoto zoom after all.

Same with me - I expected the DA* 16-50 (SDM, less than stellar reviews, high price) and in contrast to film-era primes film-era zooms have never had a good reputation, but the DA 55-300 is a great lens. Yes, I hate the AF on my HD DA 55-300 WR. Is is incredibly slow, loud and 'huntish' for a 2013 lens, but in terms of optical and build quality it's great. Thankfully Pentax have addressed the main issue with the successor, which is now as good value as it gets in a budget tele-zoom.

It doesn't have any obvious weaknesses - fast aperture, compact, no SDM to cause problems, not super expensive...

It seems most people here seem to be unhappy about what's most important in a lens - image quality. Low sharpness and contrast at larger apertures have been mentioned throughout.

[jddwoods]

That does suck. I really really like the DA 17-70 my dad bought and gave to my step brother's daughter. I think it is a superb lens but sadly underappreciated because of the SDM issues. Ours was a refurb and it just stuns me how good it is.

I bought a 17-70 when it first came out about 7 years ago. The main rule with this lens SDM is, use it or lose it. As long as I use it or at least exercise it about twice a month the SDM works fine and it is quite fast on my K-5 and K-3 bodies. IQ is quite good especially in near macro range and especially for a consumer zoom. I do not consider this lens a loser. In an earlier post in this thread I put the HD DA 40 Limited as my biggest disappointment since it is my only Pentax lens or camera to break down (frozen focus ring) After 2.5 months at precision, the lens is fixed so I hope I will get that feel good feeling again. The DA 21, 40 and the DA 17-70 are my most used lenses.

[Driline]

The most disappointing lens I've had over the 25 or so I've purchased in the last 5 years has been the Pentax DA 18-135. Soft at the long end and really almost identical to both my kit lenses. Maybe I got a bad lens? Who knows, but I've since sold it and moved on.

[audiobomber]

It seems most people here seem to be unhappy about what's most important in a lens - image quality. Low sharpness and contrast at larger apertures have been mentioned throughout.

It is rather absurd to criticise the FA 50mm f/1.4 for its wide open performance vs. other lenses which cannot even open to f/1.4.

[Jonathan Mac]

It is rather absurd to criticise the FA 50mm f/1.4 for its wide open performance vs. other lenses which cannot even open to f/1.4.

I don't think so, as people pay for a lens that opens to f/1.4 but if it's not usable there then then they aren't getting what they pay for. Given that there are other lenses around which are sharp enough with decent contrast at f/1.4 and Pentax hasn't bothered to update the lens to improve it, I think it's fair to criticise. Having said that, it's an old design and, while there are better old 50/1.4s, none of them performs really well wide open.

[normhead]

Anyone who has been through the lens charts at Photozone or a similar site will tell you, there are very few sub ƒ4 lenses that perform well wide open.

Nikon AF D 50mm 1.4


Nikkor AF-S 50mm f/1.4


Canon EF 50mm f/1.4 USM


Canon EF 50mm f/1.2 USM L


On APS_c
Pentax SMC-FA 50mm f/1.4


Pentax SMC DA* 55mm f/1.4 SDM




People don't apparently buy these lenses for wide open performance, regardless of brand, even if some folks would like to believe they do. People who want sharp edge edge wide open, buy a macro; Like anything, you have to know how to get what you want, and not assume that you can get everything in every lens. Ranting about what lens manufacturers "should" offer doesn't add anything to the conversation. At some point you have to deal with reality.

Notice, not one of 1.4 type lenses matches the 50 macro at ƒ2.8. The macro is excellent, centre and edge. SO, if you are looking for corner to corner sharpness at a wide aperture, that's the way to go.

[timo]

DA55-300 x 2
The first one (metal mount) was clearly, visibly, obviously defective. It was sent back to Pentax in Tokyo and came back worse. It was re-sent back, and declared to be 'within spec'. Well, if it was within spec, Pentax thoroughly deserved all the uncertainties that surrounded its fate at the time.
The second one I got as an act of misguided faith, with the plastic mount, is better, but noticeably decentred at various focal lengths.

So I gave up, and get much better results with my M manuals, notably 100/2.8, 150/3.6, and even the much despised 200/4. So to hell with the 55-300s, both of them.

Actually the worst lens I EVER had was the cheapo Sigma 18-50, available a decade or so ago. That really was a stinker, although hailed at the time as a worthy alternative to the mediocre FAJ 18-35 that Pentax were offering as a kit lens for the *istD. Oddly the Sigma 50-200 that went with it was quite good, albeit a bit heavy.

---------- Post added 12-12-2016 at 08:31 PM ----------

I don't think so, as people pay for a lens that opens to f/1.4 but if it's not usable there then then they aren't getting what they pay for. Given that there are other lenses around which are sharp enough with decent contrast at f/1.4 and Pentax hasn't bothered to update the lens to improve it, I think it's fair to criticise. Having said that, it's an old design and, while there are better old 50/1.4s, none of them performs really well wide open.

I don't think the 1.4 is as bad wide open as some say - the key is to get the focus right. The 1.7 has a bit more contrast wide open, but the difference is not night-and-day. Once stopped down a bit, I find the 1.4 superior, certainly at the edges.

This is all quibbling. They are both excellent for what one would use them for - and I use the M 50 1.7 regularly with an adaptor on my M4/3 GX7. Very nice.

[cyberjunkie]

Another of my pet hates is the A 35-105. A clunky heavy abomination which is anything but a 'stack of primes'.

Strange.
On film it was one of my preferred lenses, together with the Pentax-A 70-210mm f/4, which has been already bashed


EDIT:
I already wrote my post, and i'm still reading this thread with great interest.
While i'm at it, let's write a few lines about my own experience
I value rendition more than absolute sharpness, so i often buy old lenses after i read a favorable post or i see pictures that meet my aesthetic taste.
I've read many favorable opinions about the Meyer Lydith 30mm. Well, the one i tried didn't impress me at all!

I collect, and actually use, Soligor branded lenses, made by various lensmakers.
Many are long tele's. I have many of them, from 85mm to 800mm. I've been very positively impressed by some, even old preset objectives, while others lacked resolution.
Low contrast can be easily pumped up in PP, resolution can't.
What surprises me is the very similar look of the lenses. Some really have a very similar look, but were made by a different maker, and perform in a radically different way.

About recent, expensive lenses, i have an horror story.
I bought a Sigma 24-70mm f/2.8 zoom, knowing that i would sooner or later buy a K-1.
I found it on Ebay. The lens came, immaculate, in its original case, without a minimal sign of damage.
I tried it quickly, on my K-5 II. The lens correctly focused in AF, and it zoomed.
I released a positive feedback, and the lens went in hybernation waiting for the K-1.
Months later i bought the camera, and foud that probably the zoom had to be serviced by Sigma, for compatibility issues.
I sent it to Sigma Italy service, together with a 120-400mm that needed a bayonet exchange and a software update.
Immediately i learned that my 24-70mm was the penultimate version (of at least four!), and that it didn't need any upgrade.
It was tested, though. They found out that past a certain focal the lens couldn't be focused to infinity.
Now i have it back, probably better than new: tested, with software updated, and with two new parts... but it didn't come cheap: 250 euros!
At least i had it sent back free together with the other lens that was serviced in warranty.
I always had the impression that most modern lenses, especially zooms, are of very weak construction.
Now i have a practical confirmation!
With no external signs of damage, the lens had a bent guide and another damaged part!
I have old lenses, with badly bent front rims, that still perform at 100%, with very good image quality.
I hope the Sigma zoom won't disappoint me, performance wise, but i will always be scared to knock it against something.
It is fragile, very fragile, and important parts are too thin or made of plastic.
Doing mostly travel photography, thinking that a single knock that leaves no external traces could mess up the lens isn't very reassuring

cheers

P

[RightOnTime]

Sigms 30mm 1.4 ART. I hated that thing, had about a 40% chance of getting your shot remotely in focus (we're not talking microadjustment here, I mean getting a nice blinking confirmation light and then reviewing the image to find it focused an olympic-swimming-pool's-worth of distance in front of your subject for no obvious reason). And even when you did, the purple fringing was terrible and the distortion mildly irritating. The optics are really stellar for certain subjects but for my use I found it no better than the Tamron 17-50, so back to the shop it went.

[cgchang]

FA* 24mm f2. Sort of.

I wouldn't say it's a full on "disappointment", but the biggest gripes I have of it is the softness at f2 and the weight. Weight I can justify for the fast aperature, but my DA 50 f1.8 is sharper/clearer wide open. Still love the focal length and the image quality when it sharpens up stopped down past f2.8-3.5. Should I have gone with the DA 21? Maybe.

[Gedeon]

150-450mm
Because it's not going under 180mm after 1 year. Just a mess.

[stevebrot]

I have had worse lenses on the shelf, but the most disappointing was a Super Takumar 50/1.4 purchased off eBay. The lens was in good cosmetic shape but distinctly soft at all apertures. It went back to the seller with me picking up the cost of postage.


Steve

[FantasticMrFox]

I can't say I have any disappointing lenses. I started with the DA L 18-55 kit lens, and for what it is, it is a very good lens. Took many of my favourite images with it. Then got the SMC-A 50 f/1.7 - what can I say, just great. Then the DA 35 f/2.4, another great lens. HD DA 55-300 WR, really good image quality. Finally the Sigma 17-50 f/2.8 HSM, my standard lens now.

Each and every one of this lenses has weaknesses (manual focus on the SMC-A, slow aperture and noisy focus on the DA 35, slow and noisy AF on the 55-300, and instances of misfocusing on the Sigma), but none I am really disappointed it.