[pathdoc]

So I've been playing around with an old manual focus 28mm Vivitar lens that was gifted to me, and a very fine lens it is too. But I missed quite a few shots with it because of not being able to manual-focus or green-button it quickly enough, and naturally the question of what to replace or supplement it with now arises. My preference is for a prime over a zoom. The camera is a K-5.

The first thing that comes to mind is the 21mm DA limited, which I'd be happy to have in the original SMC version in the name of low cost. I am aware this will be significantly wider and is also a little over a half stop (2.8 vs. 3.2) slower. The small size is, however, a strong attractant.

The 15mm Limited is a theoretical possibility, but is a full stop slower than the Vivitar... and quite frankly, given the experience I've had so far with the 28mm FOV on the K-5, I consider the Vivitar quite wide enough and 15mm would be WAY too wide. I accept that it's probably the best landscape lens in existence for its size, weight and price, but I don't anticipate operating in close-enough quarters that I'd need it for "people" shots.

The 31mm f/1.8 isn't that far off in terms of focal length. It's a wonderful lens, and one day I will almost certainly add it to my collection, BUT... I've had it on my camera for a try-out and my impression is that it's quite a weighty piece and not one I'd feel comfortable swinging around in a hurry or one-handed the way I do the Vivitar, my 40mm Pancake, or my 50mm f/1.8 DA. Not that the extra stops of light wouldn't be handy!!!

The rationale behind the 20-40mm f/2.8-4 Limited Zoom at last makes itself clear, BUT... at what point does the shift from f/2.8 to f/3.5 or f/4.0 occur?

As far as IQ specifications go, I'm not the sort to pixel-peep. If it can turn out desktop-size screen images on large laptops or 5 x 7 glossies as well as a Limited prime can, that's fine by me.

But are there any contemporary AF offerings from reliable third parties that might fall into consideration? Size, weight, price and handling are prime considerations here. I would be willing to consider the 30mm Sigma Art in this context IF those considerations make it competitive with the Pentax Limited primes and IF it's true (as has bee suggested elsewhere) that its focus issues can be mitigated or eliminated by selecting the centre-focus point.

Default choice if (hypothetically) I had to cough up the cash right this instant would be the 21mm DA Limited, but if anyone can point a clear path to something else with good reason (preferably backed up with comparative experience), I'll throw that into the mix and swing the harsh glare of internet research some more in that direction.

[alamo5000]

Pentax F28 f2.8

Done. Enough said.

It focuses great on a K5 or any other body and it's sharp.

With over 30 reviews in the database and to have it score a 9.4 out of 10 thus putting it right up there with many if not most DA Limited lenses.

SMC Pentax-F 28mm F2.8 Reviews - F Prime Lenses - Pentax Lens Reviews & Lens Database

[K57XR]

For the same FL have you considered either the F or FA (non-Soft) 28/F2.8? I found my shots lately clustering between 28mm and 30mm range and though of getting a prime at this range. I'd also consider either the older version Sigma 30mm/f1.4 or 28mm/f1.8. I would love to the have the FA 31 Limited (who wouldn't) but it's nowhere near my price range.

Edit: Alamo5000 beat me to it

[robthebloke]

DA21. It kicks the crap out of the FA28. The FA28 is sharp, but it's focal length is a bit bland on apsc, it's build quality is a bit meh, and the bokeh is a bit meh as well. The only reason why you'd get it is for FF.

[alamo5000]

DA21. It kicks the crap out of the FA28. The FA28 is sharp, but it's focal length is a bit bland on apsc, it's build quality is a bit meh, and the bokeh is a bit meh as well. The only reason why you'd get it is for FF.

I've never owned the FA version but the F series is pretty darn good. I wouldn't use the term 'kick the crap out of' for my two lenses. I have the 21mm and pretty much every Limited lens and for sure I will say they are different. On the short end like that though 7mm is huge. It's an apples and oranges comparison if you are talking about that aspect.

If you are talking about the pixel peeping sharpness the F series is not a limited lens but it certainly ain't no slouch.It definitely has a different 'character' to it's rendering.

[Edgar_in_Indy]

Maybe this would be a good time to think outside the box if you really enjoy that focal length.

Panasonic has a fantastic little 20mm f/1.7 for m43 mount. With the Four Thirds 2x crop factor, it's equivalent to a 40mm, whereas your 28mm is equivalent to 42mm. So very close there. It's a tiny little pancake lens, and it has a great reputation. The larger aperture should help makeup for the smaller sensor size, in terms of depth of field and SNR. but I don't know how it exactly calculates out.

The 20mm is running $329 new right now, and goes used on eBay for $200-$230. And there are all kinds of nice used m43 bodies you can pick up for $100-$200. So for $300-$450 you could have a great new toy. And you could even go out with the 20mm on your m43 camera, and another lens on your DSLR, and not have to change lenses back and forth.



And in case you don't already have a lightweight alternative to your DSLR, you would be set.

And once you already had the m43 body, there are a lot of other fun and affordable m43 prime lenses in that same range. The Panasonic Lumix 14mm f/2.5 and the Panasonic Leica Summilux 25mm f/1.4. The Olympus 12mm f/2 , 17mm f/1.8, 17mm f/2.8, and 25mm 1.8. The Sigma 19mm f/2.8. And maybe there's some I'm forgetting?

You know, I think I've almost talked myself into getting a m43 camera again! I sure loved my Pen E-P1.

[aleonx3]

I have the DA 20-40 f2.8-4 and IMHO is a gem as if you are mounting a stack of prime lenses all at the same time. There is little distortion at 20mm and little slower at 40mm, which understandably is a bit of compromise, but it is well worth it, especially that the price is quite attractive recently for a fraction more than a single prime lens itself (21, 28, 30, 35 and 40).

The max aperture at each focal length range are as follows from my lens (someone please correct if I made a mistake).
20-24 2.8
25-33 3.5
34-40 4.0

I strongly suggest that you read the last 3 reviews in the lens database. If you are looking for a wide, fast lens, this is probably not for you. But if you are looking for a lens that will give you life-like color, nice flare control and bokeh, I believe this lens will not disappoint you.

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Last edited by aleonx3; 05-24-2015 at 07:30 PM.

[pathdoc]

In reply to you all:

1) I've gone and had a look at the reviews for the F and FA 28mm autofocus lenses, and they're currently vying for first position at the top of the ladder as an apples-for-apples substitute. The fact that either could be used on a FF or film camera doesn't hurt them at all in my estimation, even though I fully expect I'll be staying with crop for the foreseeable future.

2) In reply to Edgar, I've thought on and off about micro 4/3 since my last trip abroad, when I got to handle one of the new digital Olympus Pen ILC's in the duty-free store. I agree it has its definite advantages as regards the size and variety of lenses one could take in a kit of limited space and weight, but I'm heavily invested in DSLR and I don't think I'm ready to take the plunge into a completely separate system right now.

3) To Aleonx3, a wide, fast lens is indeed a higher priority. This hasn't stopped me from considering the 20-40, but the loss of speed toward the tight end still bothers me a bit.

4)

it's focal length is a bit bland on apsc,

Perhaps, but this is a very individual thing and what I'm seeing through the lens suits me just fine.

5) K57XR, I'd considered the slightly older Sigma, but I'm aware that Sigma had its "bad old days" and then a point beyond which it pulled its finger out of a dark place and got on with producing some really good lenses - perhaps not the level of optical perfection they've achieved with the Art series, but at least worthy of comparison with the OEMs. If the 30mm f/1.4 you speak of is after that cutoff, we've got something to talk about; the extra speed would be wonderful, and a couple of millimetres toward the narrow end wouldn't hurt much. Have you got one, and what's it like for size, weight and handle-ability? (Remember it might have to compete for space in the bag with a bunch of other primes at some stage, so size and weight are an issue for more than just on-camera handling!

My main concern about getting the fast 30mm Sigmas is that it would kill any justification I later had for acquiring the glorious FA 31mm, whereas if I went for the 21mm DA Limited as was my original intention, there is significant enough size and speed discrepancy that the 31 becomes justifiable at some future time.

Nevertheless it is all useful food for thought, for which I am grateful, and I shall continue to consider my various options accordingly (and take any further advice others have to give).

[osv]

So I've been playing around with an old manual focus 28mm Vivitar lens that was gifted to me, and a very fine lens it is too. But I missed quite a few shots with it because of not being able to manual-focus .

the only fix for that is to get a camera with a good evf display, that has magnification capability... sony a7 series, sony a-mount, how about that xlnt fuji evf, if you can deal with the baby-sized sensor, etc.

not being able to use manual focus accurately because of the ovf isn't the end of the world, but it eliminates the ability to use some of the best lenses that have ever been made.

imho, 28mm on crop isn't wide enough, how about 24mm, like the af version of the sigma superwide II, if you can find a copy that isn't decentered.

[pathdoc]

osv, you've both misunderstood and quoted me out of context here. The issue was one of not being able to adjust exposure or focus with sufficient rapidity - the subject or subjects were moving fast, and opportunities were fleeting. Autofocus and some degree of auto-exposure (even AP or SP) would have nailed it. When I have time to be careful about my focus and exposure with this lens, the results are beautiful.

the only fix for that is to get a camera with a good evf display, that has magnification capability... sony a7 series, sony a-mount, how about that xlnt fuji evf, if you can deal with the baby-sized sensor, etc.

If I had any interest at all in changing systems, I'd have taken my question to a general photographic forum. I'm here at Pentaxforums because I'm invested in Pentax to the eyeballs, deliriously happy with it, and have no reason or justification either to plunge headlong into a separate system or to throw it all in and start again. And if I were, I would want to go with a company with which I was familiar and which I felt knew photographers. If Pentax and all its works disappeared off the face of the earth tomorrow as if they'd never been, my first call would be to Olympus for a decently-featured Micro 4/3 camera and the widest-range zoom lens available.

[osv]

osv, you've both misunderstood and quoted me out of context here. The issue was one of not being able to adjust exposure or focus with sufficient rapidity - the subject or subjects were moving fast, and opportunities were fleeting. Autofocus and some degree of auto-exposure (even AP or SP) would have nailed it..

except when it doesn't nail it, as shown by the k3 autofocus failure in this thread: https://www.pentaxforums.com/forums/76-non-pentax-cameras-canon-nikon-etc/270...n-d750-32.html

both normhead and parallax claimed that the normhead dog running sequence was in focus, but you see how that worked out later in the thread.

both myself and edgar are offering you alternatives, if you don't want to listen, that's fine.

[Edgar_in_Indy]

2) In reply to Edgar, I've thought on and off about micro 4/3 since my last trip abroad...I don't think I'm ready to take the plunge into a completely separate system right now.

Well, I didn't mean to imply that you need to go full-bore m43. I'm just looking at the 28mm focal length you're after, and there aren't too many viable options out there.

With the 20mm 1.7 you could get a great camera AND great lens for a little more than $300, and the two together weigh less than some of my APSC lenses do by themselves. Not much of a commitment, and your DSLR would have a little buddy!

But it's your money, so nobody else can tell you how to spend it, least of all me! (AKA some random guy on the internet) But now that I think about it, I do have somebody that tells me how I CAN'T spend my money...

[kh1234567890]

The first thing that comes to mind is the 21mm DA limited, which I'd be happy to have in the original SMC version in the name of low cost. I am aware this will be significantly wider and is also a little over a half stop (2.8 vs. 3.2) slower. The small size is, however, a strong attractant.

+1 for the DA21Ltd, but you may find it a bit too wide compared to your manual 28mm Vivitar. You could always get the plastic DA 35mm F2.4 AL ?

As for zooms - I'd recently picked up the DA16-45 f4 cheap and although big and heavy compared to say the DA21 it is growing on me - Flickriver: kh1234567890's photos tagged with smcpda1645mmf40edal

[pathdoc]

You could always get the plastic DA 35mm F2.4 AL ?

A good suggestion, and if I didn't already have this focal length covered in prime I'd probably buy it, but I already have the 35mm DA Limited Macro (for work), and I really can't justify buying a second AF lens in this focal length just to keep one at home. If it were an f/1.4 I could justify it on the basis of speed alone (two extra stops), but 2.8 to 2.4 isn't enough of a speed gain.

It's a pity so many of the FA series lenses are now out of production. I think people would snap them up if they were brought back as non-Limited DA - the optical development work has already been done, after all, and all they'd need to do is design new DA-style outer shells for them (and most of THAT work seems also to have been done already; how dissimilar are the 35 and 50 Plastics, after all?).

Other things have come up in the last 24 hours, meaning there may be other major fun purchases that will be taking priority over this one, but I shall keep all of this in mind. Shall let you know how it all works out, though.

[TER-OR]

I have a Sigma 28mm f1.8 macro, it's big but it's nice. I also have a DA21mm, and it's among my favorites. It's wider but it's not super wide. If you keep an eye out, you can get a used copy for a very good price.