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09-01-2011, 10:00 AM   #1
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Fast lens opinions?

Hi all,

I recently updated my camera body to a K-5 and was looking to get a new fast lens (at least 1.8) w/ autofocus to go with it. I bought the DA40mm 2.8 ltd pancake lens, and while it takes awesome photos, it's just not as fast as I'd like it. So I was just wondering what some of your opinions were.

I was leaning towards the DA* 55mm 1.4, but the more I read reviews the more I wonder about it's price tag

The FA 50mm F1.4 is much cheaper, but all the reviews I've read have said its not great wide open which scares me (which is important to me, what's the point of have a 1.4 if you never get there due to image quality)

The FA 50mm F1.7 is cheaper than the DA 55mm, and has great reviews, but as it gets rarer the price goes up, and for a little more I think I might as well get the DA*

There is also the Sigma lenses, which I haven't read up as much on.

Any thoughts. Feel free to bring up any lens I didn't mention! I guess my primary concern is IQ below f2.

09-01-2011, 10:15 AM   #2
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QuoteOriginally posted by Codazzle Quote
The FA 50mm F1.7 is cheaper than the DA 55mm, and has great reviews, but as it gets rarer the price goes up
If you're leaning towards the f1,7, get the F50 version, it sells for about 200$ (that's the price I sold my two extras) and it's just as good as the Fa version, just more vintage-looking.

The DA*55 is clearly the sharpest but also the slowest to focus apparently. The 50s f1,4 are sharrp enough, and have a very nice bokeh (the 55 is probably better at this, though). The 50s f1,7 are the sharpest wide open *the DA*55 is probably close) and the fastest to focus.
09-01-2011, 10:26 AM   #3
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The 55/1.4 isn't great wide open either, although it is very good, and stopping down a half stop (f/1.8) makes a huge improvement to it.
The FA50/1.4 isn't great wide open either, it's not as good wide open as the 55 is, and it takes a bit more stopping down to hit it's stride, but by the time you hit f/2.8 with it, it's doing very well indeed, and is certainly improved greatly by ~f/2.
Most fast lenses aren't so good wide open, so this isn't unusual.
I had an F50/1.7 for a while, and though I didn't use it much, I was always happy with it's results. I don't recall how it did wide open though.
I just got myself a 43/1.9 and am finding it to be especially nice. It's decent wide open and spectacular by f/4.
It's also quite compact, which I like.
Something to remember with fast lenses, they may well be sharp enough wide open, but depth of field at open apertures can be slight enough that the lens will look unsharp, and AF really isn't reliably accurate with fast lenses wide open.
09-01-2011, 11:05 AM   #4
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Depends on how sharp you want it to be.

50 1.4 is fine wide open if you get the focus right, but is much sharper at f2. Most people who find it soft must have bad copies, autofocus problems, no lens hood, or some combination of the above.

The 50 1.7 is NOT sharper according to lens tests, so something else must be going on (although I do find it sharper in the corners and wide open at infinity).

55 1.4 is a better or equal lens in pretty much every way, It is also a better focal length for portraits.

Not sure about the sigma.

If you are on a budget the FA 50 1.4 for 250 used it pretty hard to beat.

The plethora of manual focus 50mm lenses available are dirt cheap and wonderful. If they at f1.4, they are generally good lenses (whether they are Pentax or otherwise).

Another option is the 35mm f2.4 or f2, but that is a compromise on speed for a more "normal" focal length.

09-01-2011, 11:20 AM   #5
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The Sigma 85mm F1.4 is a great performer, but it's also more expensive.

Sigma 85mm F1.4 HSM - Review
09-01-2011, 11:27 AM   #6
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Out of the Pentax 50s (I've tried) the DA* is the best

It's sharp at f1.4, very sharp from f2 and crazy sharp from f4!
Yes it focuses slower then other AF50s but has the best OOF out of AF Pentax 50s and by mile.
The only lens to beat it in OOF wide open is K/A50/1.2 but stopped down even these can't match the DA*55.
Add WR, quiet AF and the price is justyfied.

I'll try to post some shots at f 1.4 and crops later..

09-01-2011, 11:47 AM   #7
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The Sigma 30/1.4 is definitely very useable wide open. There's an active thread discussing it at the moment here with samples.
09-01-2011, 11:52 AM - 1 Like   #8
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One does not buy a f/1.2 or f/1.4 Fifty for wide-open edge-to-edge sharpness in closeups, but to GRAB LIGHT, or for DOF control. A f/1.4 Fifty may be edge-to-edge sharp when focused fairly close, but that sharpness exists in a razor-thin curved zone; you need very carefully-placed subjects to exploit that. A Fast Fifty is for capturing shots that would otherwise escape you, not for infinite detail wide-open. That's just the reality of optics.

If you want flatfield edge-to-edge sharpness, use a macro lens -- but it won't be anywhere near f/1.4, and it won't be cheap. If you want wide-open sharpness and speed, use a lens much wider than a Fifty, with much thicker DOF, like a 30/1.4, whose DOF is rather like 55/2.8. If you want an affordable AF Fast Fifty, get the FA50/1.4.

If you can skip AF, there are zillions of affordable 50/1.4 and 55/1.4 MFLs available pretty cheap, and some superb 50/1.2 and 55/1.2 MFLs costing less than the FA50/1.4 -- my K50/1.2 was market rate at US$250 a few months ago. If you can skip blazing speed and don't mind using an adapter, the SuperTak and Petri CC and Rikenon 55/1.8's in M42 are exquisitely sharp and quite inexpensive. If adapters are out, the A50/1.7 is well-liked and nicely sharp.

Ain't no magic, ain't no free lunch. Fast lenses are what they are.

09-01-2011, 12:03 PM   #9
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They're all usable wide open and yes, some are better than others. I have to wonder though, Why, with a camera like the K5, you believe the DA40 is not Fast enough? If you just want a new toy, I can appreciate and understand that. Be aware that the 50 f1.7 options are out of production so your only choice there is Used. To get one at a reasonable price, you may have to hunt around a little bit. I'll guarantee (almost) that the people who bought Berts lenses, won't be reselling them for $200, IF they resell them.

All of these faster than f2.8 lenses are likely to have a few issues on the more modern cameras because the cameras just aren't set up for them. The typical digital Pentax lens tops out at f2.8 (or f2.4 in the case of the DA35). The exception to that in the Pentax lineup is the DA*55.

The FA50 f1.4 is a nice lens. I can't take away from the optical quality but I've never cared for the Build of the FA primes. They feel cheap to me and I hate the focus rings but that may just Be me.

The DA*55, I never had issues with the focus speed. I don't know what you are after in that respect but mine performs just fine. If I missed a shot, it is because I wasn't prepared at all for it. The lens completes your weather sealed camera, is quiet, has an AF/MF switch that I find quite handy. It Is bigger and heavier than the FA counterpart though.

If that range is what suits you, and the DA*55 is in your consideration, also consider the FA43mm f1.9 Limited. Or if you want to go a little longer, the FA77mm f1.8 Limited. Both can be had, used for DA*55 money.

I would consider though before spending a bunch of cash, answering the question I opened my response with.

Last edited by JeffJS; 09-01-2011 at 12:51 PM.
09-01-2011, 12:11 PM   #10
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QuoteOriginally posted by paperbag846 Quote
50 1.4 is fine wide open if you get the focus right, but is much sharper at f2. Most people who find it soft must have bad copies, autofocus problems, no lens hood, or some combination of the above.
I agree fully with paperbag here. My FA50 1.4 is just fine wide open. But from f2 it gets VERY sharp. Very reliable lens.
09-01-2011, 12:25 PM   #11
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Sigma 50mm f/1.4 - Best option. Very good wide open. Fastest AF of the bunch. $200.00 cheaper than the DA* 55mm.
09-01-2011, 12:27 PM   #12
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I can whole-heartedly recommend the FA43/1.9. I absolutely love the images I get from this lens. The difference between 1.9 and 1.8 is negligible. It's very compact and a very good performer.
09-01-2011, 01:05 PM   #13
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QuoteOriginally posted by RioRico Quote
If you can skip AF, there are zillions of affordable 50/1.4 and 55/1.4 MFLs available pretty cheap, and some superb 50/1.2 and 55/1.2 MFLs
If you do not need AF, there are some outstanding fast prime MF lenses, including Zeiss 50mm f1.4, Voigtlander Nokton 58m f1.4, ... These high-quality fast primes costs less than the DA*55mm and the IQ is truly oustands. Thye all come in Pentax bayonnet mount and do not need an adapter.

If you are after outstading IQ, you shoud consider seriously the Zeiss 50(1.4) and VL 58(1.4).

Food for thoughts...

Last edited by hcc; 09-01-2011 at 03:59 PM.
09-01-2011, 01:09 PM   #14
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Just for fun: if you really want fast get a Leica to Pentax adapter and put it on a 50 Noctolux F1.0....
09-01-2011, 03:08 PM   #15
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The DA*55 is hugely under-rated, and reviews have left it with a bad rep of slow AF, sure its not a speed demon but its not as slow as everyone makes out it to be, but it is deadly accurate and ive never seen it hunt, even in almost complete darkness it will get a focus lock.

As for the sharpness, wide open it is very sharp and very very usable.

a few examples wide open:



Last edited by TOUGEFC; 09-01-2011 at 10:32 PM.

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