[BigMackCam]

But my issue with the 20-40 is field curvature. I say "issue" - it's just an idiosyncrasy of the lens... in fact, it's one of the reasons some people find border performance even worse than it really is... but it can prove troublesome depending on the type of image you're shooting. I find it noticeable on the 20-40, even when stopped down.

When field curvature is not eliminated when stopping down, it is not field curvature because as you stop down, the depth of focus increases, masking the curved focal surface. Something else is at play here.

Without wanting to de-rail the OP's thread...

Field curvature doesn't disappear when you stop down. It's just that the depth of field all along that curve is increased. Roger Cicala has a helpful article on this, HERE.

@Mike: sorry, yes I was referring to geometric distortion. With that out of the equation, I haven't noticed any field curvature issues.

As with the FA43 that others have mentioned, I think it's one of those things you either notice and it bothers you, or you don't notice in which case there's no problem (or a third option - you recognise and embrace it ). I noticed the issue on my 20-40, especially at the long end, and from numerous shots determined it was field curvature. When I subsequently searched online, I found I wasn't the only one. That aside, for some people it will never be an issue, either because it doesn't impact in their day-to-day shooting, or they simply haven't noticed. For shots where the subject is in the centre of the frame, it's never going to be a problem.

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Last edited by BigMackCam; 01-02-2018 at 01:55 AM.

[Des]

I've only got three Limiteds: FA 43, FA 77 and (recently) DA 20-40. They all have something special about them, but for me the 77 is the real knockout. It can make the ordinary extraordinary like nothing else. The 3D effect, the rendering, the bokeh, the colours - it can be just breathtaking. You don't really get the full effect looking at small images on the web - even if you view them on Flickr. To get the full effect you need to see a full-size image on a large monitor or a large print. Still, you may get some idea from this stitched pano from 8 images taken with the 77 - somehow it still has the 3D effect (when viewed large anyway).


Can I add an honourable mention for a lens that is neither a * nor a Limited, but has some of the virtues of each (including beautiful all-metal construction and a relatively compact form)? The DFA 100 f2.8 Macro WR. Of course it's sharp - what macro isn't? But it also renders really really well.

[BigMackCam]

Can I add an honourable mention for a lens that is neither a * nor a Limited, but has some of the virtues of each (including beautiful all-metal construction and a relatively compact form)? The DFA 100 f2.8 Macro WR. Of course it's sharp - what macro isn't? But it also renders really really well.

Indeed - the DFA 100 f/2.8 WR is a Limited in all but name. A really lovely lens

[aslyfox]

I own the SMC DA 15 & 40, the HD DA 70, the HD DA 20-40, the FA 31, and the FA 77. I love them all.

Many said enough about the lenses but the most important question is what other lenses do you have and what do you want to accomplish that you can't now.

Also to run counter to the group think - you don't need even one of these to make stunning shots. There are images you may need these for, but most of your images won't require them.

It's easier to chase equipment than improve technique

improve technique,

hmm, that takes time, knowledge, consistency ( what did I do there and how do I repeat the good stuff and not the bad ) and

acceptance of constructive CRITICISM [ one of my big problems personally is that I tend not to recognize the term " constructive criticism " properly and be thankful when it is offered and I much prefer such help be offered through PMs rather than publicly posted ]

as far as my current stock of lenses, I've been able to get a lot in a short time:

PRIMES

Kino Precision Japan Kiron 28mm F2 MC P/KA
SMC Pentax-DA 40mm F2.8 XS
SMC Pentax-DA 50 mm F1.8
SMC Pentax-D FA 100 mm 2.8 macro

_________________________

ZOOMS

HD Pentax DA 16 - 85mm F3.5-5.6 wr
SMC Pentax DA 18-55mm al F3.5-5.6
SMC Pentax-DA L 55-300mm F4-5.8 ED
HD Pentax-D FA* 70-200mm F2.8 ED DC AW
HD Pentax-D FA 150-450mm F4.5 - 5.6 ED DC AW
___________________________

HD Pentax -DA af rear converter 1.4 AW

so as far as a " need " for more lenses, there isn't a tremendous amount of " hurry " to fill any gaps

this thread was an idea to gather information and knowledge for myself [ and perhaps others ( ? ) ] over and above the excellent reviews of the " limiteds " found elsewhere on the forums just in case I [ or someone else ] wins the lottery - I should buy a ticket some time if I hope to do that

more of a creation of a " bucket list "

All who have and will contribute are hereby awarded BONUS POINTS for sharing their knowledge and opinions

Bonus Points are accepted everywhere at your favorite " café " for the purchase of your favorite " beverage " when added to an adequate amount of the local $$

thank you

[Jonathan Mac]

I believe that the following Pentax lenses have great reputations:

SMC Pentax-FA 31mm F1.8 AL Limited

SMC Pentax-FA 43mm F1.9 Limited

SMC Pentax-FA 77mm F1.8 Limited

____________________

the following can be either HD or SMC

Pentax-DA 15mm F4 ED AL Limited

Pentax-DA 21mm F3.2 Limited

Pentax-DA 35mm F2.8 Limited Macro

Pentax-DA 40mm F2.8 Limited

Pentax-DA 70mm F2.4 Limited

1 are they worth their reputations

2 I notice that the older FAs are faster, is that because of the different focal lengths or other reasons

3 if only one can be chosen, [ excluding the 40 mm, I have the 40mm XS ] which one would be the best?

I own all the DA limited primes and I think they are slower than the FA limiteds purely to keep costs down. Someone will come along and say that large apertures are not necessary with digital, which is nonesense.

As for living up to their reputations, I would say:

15mm - no, it doesn't
21mm - yes
35mm - performace far exceeds even it's great reputation
40mm - yes
70mm - yes, maybe even exceeds it because it's often ignored as a fantastic telephoto landscape lens

[aslyfox]

Without wanting to de-rail the OP's thread...

Field curvature doesn't disappear when you stop down. It's just that the depth of field all along that curve is increased. Roger Cicala has a helpful article on this, HERE.



As with the FA43 that others have mentioned, I think it's one of those things you either notice and it bothers you, or you don't notice in which case there's no problem (or a third option - you recognise and embrace it ). I noticed the issue on my 20-40, especially at the long end, and from numerous shots determined it was field curvature. When I subsequently searched online, I found I wasn't the only one. That aside, for some people it will never be an issue, either because it doesn't impact in their day-to-day shooting, or they simply haven't noticed. For shots where the subject is in the centre of the frame, it's never going to be a problem.

IMHO

offering knowledge is never " derailing " a thread

at least none of the threads that I start


YMMV

[cyberjunkie]

I guess I'm going to ruffle some feathers but I think we all have the right to express our opinions, isn't it?
I have no experience about more recent Limiteds for APS-C, which I'm sure are different in many ways.
The Limiteds with FF coverage I've tried, and I still own and use, are tiny, well made, and AF.
These are huge merits, given the current panorama.
Though I wouldn't say that they excel optically, not in absolute terms at least.
All the hype about the 77mm is due to the two main reasons: 1) brand loyalty and cult status 2) very good rendition (reminding some great vintage lenses) in a compact all-metal AF package.
Don't get me wrong, I like it, but there are other cheaper MF lenses that have comparable sharpness and similar (very good) rendition.
Yes, it's AF. Yet it hunts a lot in low light (which is the kind of photography I usually do).
As most, if not all, photographic tools, it has its pros and cons.
I think the current prices of a second-hand example in good shape are high enough to suggest some caution. If you ask me, I'm not sure it's a must have. If you don't care that much about AF, a recent Samyang 1.4/85mm is probably slightly sharper at the same aperture, and can be found used for roughly one third of the price.
There are also better choices for portrait photography, but I'm not aware of any AF prime in the same range that is as practical and convenient (and has the same "character").
I've never used the 31mm, that is the other Limited with cult status, and the only one I never tried.
I had in mind to buy it, if it came at the right price, but I've never pulled the trigger, cause it's even more expensive, and AF is not as important at this focal. I couldn't justify the expense cause I have plenty of alternatives that are either sharper/faster (Samyang 1.4/35mm), have a great rendition at close range (Pentax/Zeiss 2/28mm), or are as practical (FA 2/35mm).
Of course I'm basing my considerations about the 31mm on full res images I found online. I'd prefer to compare in person but I don't think it will ever happen if I don't find a good bargain (let's say close to $500).
Which is an unmistakable symptom of serious LBA, all those affected know very well about that: I don't buy cause I don't need, but if I find a good deal, it's a damned good reason to buy just because I like...
But that's me, very fond of photographic lenses and their history, almost never selling, and buying a lot of them, for use or for collection, since the late seventies...
If I had to build a Pentax AF kit from scratch I'd go for a Sigma Art instead, bigger but also faster and sharper, and somewhat cheaper (especially second-hand).
Landscape enthusiasts who have to trek to remote locations would of course disagree. Personally I dislike any kind of unnecessary physical exercise, so I'm fine with a couple of huge primes most of the times, with my bike/car not too distant

Jokes aside, the only humble advice I have is a very simple one. Use some common sense, don't fall for web generated hype excesses, use the incredible amount of available informations and make up your own mind (possibly taking a close look to non resized online photos).
There are no magic bullets, but there many different points of view, and an almost infinite number of nuances and subtleties that are not so obvious to an uneducated eye. Looking at great pictures made with great (and often not so great) lenses helps a lot in finding what we like and what we don't, which lenses would help our creativity and which would serve no purpose, at the same time providing us with plenty of tricks and suggestions that help us explore different paths or do better what we already do.
Fashionable and expensive are not synonymous terms of useful and convenient. Following the hype is an easy shortcut, it just takes enough money!
I don't mean to be judgemental, just thinking of some prices skyrocketing because of collective Internet-induced mania.
Trioplan's are a good example. I really love them but I also think that current prices are unreasonable, and people should know better... leaving the heavily overpriced ones in the hands of opportunistic vendors.
FA Limited's should be appreciated in regard to their merits, not as status-defining items. We all fall for that, more or less, starting with myself. Being aware is at least a little step in the right direction.
Knowledge is the best antidote, unfortunately it does not come fast nor cheap.

To better clarify my point, a simple example.
I like my 40mm Limited, but I'm not sure I would be able to identify its pictures from others shot with the other old pancakes I have (the old M, two Cosina-made f/2.8 and f/2.5, plus a wonderful Konica f/1.8 that I keep with the fantasy of converting to PK). Of course the Limited is AF, light and pretty, but the performance on FF most likely won't be affected by all that...

Cheers

Paolo

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Last edited by cyberjunkie; 01-02-2018 at 04:09 AM.

[Sandy Hancock]

PRIMES

Kino Precision Japan Kiron 28mm F2 MC P/KA
SMC Pentax-DA 40mm F2.8 XS
SMC Pentax-DA 50 mm F1.8
SMC Pentax-D FA 100 mm 2.8 macro

_________________________

ZOOMS

HD Pentax DA 16 - 85mm F3.5-5.6 wr
SMC Pentax DA 18-55mm al F3.5-5.6
SMC Pentax-DA L 55-300mm F4-5.8 ED
HD Pentax-D FA* 70-200mm F2.8 ED DC AW
HD Pentax-D FA 150-450mm F4.5 - 5.6 ED DC AW

So now we get to it.

You have a macro, and you have two very capable portrait lenses (DA50/1.8 and DFA*70-200/2.8). You have a fastish normal prime in the Kiron 28/2.0. You have two wide-to-normal zooms, one of which is highly regarded.

I'd say, if you are looking at one limited prime only, you *need* the DA15. Just do it

[aslyfox]

So now we get to it.

You have a macro, and you have two very capable portrait lenses (DA50/1.8 and DFA*70-200/2.8). You have a fastish normal prime in the Kiron 28/2.0. You have two wide-to-normal zooms, one of which is highly regarded.

I'd say, if you are looking at one limited prime only, you *need* the DA15. Just do it

" ah, there's the rub "

all are DA, so not designed for full frame if I ever go that route and

the 15 is a F 4

and the 21 is a F 3.2

and my 16 -- 85 is a F 3.5 ish

so is there enough difference between it and either the 15 and/or 21 to make it worth the $$$

or am I too hung up on the aperture

[Sandy Hancock]

Yes, you are too hung up about the aperture

The DA15 is tiny, almost totally immune to flare, and renders skies like it has a built-in polariser. Then there are the starbursts (with the older SMC version at least).

It is a landscape lens, and is generally most used from f/8.0 to f/16, so its maximum aperture is largely academic. The extra 1mm makes quite a significant difference to the field of view.

If you don't like it you should be able to re-sell it at no or minimal loss, so don't sweat the cost too much.

From a recent trip to Italy:

[BigMackCam]

or am I too hung up on the aperture

That depends.

You get two key benefits from a "fast" aperture... the ability to capture more light (therefore allowing a lower ISO setting in low light) whilst simultaneously achieving shallow depth of field. In reality, though, very shallow depth of field is only of practical use in a limited range of situations... you usually want *some* depth of a scene to be sharp, which means you'll need to stop down a little (or a lot) - and then you've lost the light gathering advantage. Furthermore, many fast lenses just aren't that great wide open... Often, they're somewhat soft, and need to be stopped down a bit to get really usable results.

The DA Limited primes may not be all that fast, but they're sharp in the centre from wide open, while the borders and corners improve quickly by stopping down just a little bit, and contrast is always excellent. So you can actually shoot the DA21 at f/3.2 or the DA70 at f/2.4 all day long and get very decent results. Shoot the FA50 f/1.4 wide open, for example, and you'd need to accept some softness and lower contrast. You'd have to bring it down a stop or more to get really usable performance.

So... if you feel you need to achieve extremely shallow depth of field for creative reasons, then yes - fast aperture lenses may be important for you. Otherwise, slightly slower lenses - especially those that perform well even wide open - will suit you (and most of us) very nicely

[Alex645]

" ah, there's the rub "

all are DA, so not designed for full frame if I ever go that route and

the 15 is a F 4

and the 21 is a F 3.2

and my 16 -- 85 is a F 3.5 ish

so is there enough difference between it and either the 15 and/or 21 to make it worth the $$$

or am I too hung up on the aperture

On the ultra wide end, aperture IMO is not important. It adds bulk and price but depth of field is inherently large, so you're not going to get much bokeh anyway and focusing is forgiving. You can also get away with much slower shutter speeds (i.e. 1/15" handheld without SR with 15mm vs. 1/30" with a 30mm).

Unless you're planning on getting FF in the near future, I would deal with that when the time comes. Currently, there are no Pentax branded UWA FF primes, although many are satisfied with 14 or 15mm Irix or the 20mm Rokinon (manual focus) wide FF primes.

For APS-C, yes, there is a dramatic/significant difference between the 15mm and the 21mm. My second favorite lens is the 645 A 35mm prime, which has an approximate equivalence to 21mm for FF and 14mm for APS-C. So for APS-C, I'd say the 15mm Limited is worth it. For FF, Pentaxians wanting AF are waiting on Ricoh for a 20mm prime.

[lytrytyr]

With all this talk about the apertures of the DA Limited non-macro primes,
it's worth remembering their design philosophy.

Why do we have a 70/2.4, 40/2.8. 21/3.2, and 15/4?

If the minimum hand-held shutter speed in seconds is 1/(focal length in mm),
then the maximum apertures roughly match equal exposure values (EV).

(And if you're going to use a tripod, you don't need the compactness of the DA Limited lenses.)

[jddwoods]

Yes, you are too hung up about the aperture

The DA15 is tiny, almost totally immune to flare, and renders skies like it has a built-in polariser. Then there are the starbursts (with the older SMC version at least).

It is a landscape lens, and is generally most used from f/8.0 to f/16, so its maximum aperture is largely academic. The extra 1mm makes quite a significant difference to the field of view.

If you don't like it you should be able to re-sell it at no or minimal loss, so don't sweat the cost too much.

From a recent trip to Italy:

Beautiful pictures. Shows what the DA 15 Limited is capable of. Even with wide angle capability in my 16-85, my DA 15 Limited expands what I can get with my K-3. I have the SMC version and it comes with me, even when I am using the zoom.

[Gimbeley]

There are a lot of things we say when comparing our Pentax to Canikon cameras about weather sealing, in body image stabilization, dial customization, pentaprism viewfinder, pixel shift image processing, dynamic range and so forth, and that's all true, but in my opinion, the Limiteds are THE reason to own a Pentax, particularly a Pentax APS-C camera. A lot of people like the DA* lenses and the DA16-85 is also popular. The new D FA zooms are supposed to be quite good. I've used some of them and found them to be very nice lenses, but I can get equivalent lenses to most in the Canikon inventories - some better optically, some not, but all quite large, heavy affairs. If you want a DSLR that has a fully fleshed out system of compact, high quality primes (and one zoom, hopefully more will follow), then there aren't really a lot of options. In my opinion, a K-3 with any of the DA Limited lenses is a better compact package than any mirrorless camera.