[CWyatt]

I'm going to be putting a decent amount of money into Pentax soon, for street photography I'm tossing up some of the Pentax limited primes.

My choice is the FA 31mm limited versus the 40 and 21mm pancake limiteds.

It's really speed versus size. I'd certainly like both. One of the main reasons I'm going prime is for less intrusive street photography, but I also want to be shooting street at dusk or night.

I have a couple of questions for things to take into consideration:
- What is the AF speed of the 31mm like? Does it come close to the super-quick 40mm pancake?
- The build quality of the 31mm sounds top-notch, but has anyone used it in the rain? Had any issues?

Thanks for the help.

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Last edited by CWyatt; 02-18-2010 at 04:11 PM.

[Bart]

...
I have a couple of other questions for things to take into consideration:
- What is the AF speed of the 31mm like? Does it come close to the super-quick 40mm pancake?
- The build quality of the 31mm sounds top-notch, but has anyone used it in the rain? Had any issues?

- I never found the 31 to be too slow. This is personal of course.
- I would never use the 31 in the rain: I have the 16-50 for that.

As for being less intrusive with a prime, I've never believed this: there is a dSLR in your hand after all. Apart form using a 70-200 2.8 zoom, I don't think it makes a lot of difference.
Again, just my opinion.

[CWyatt]

- I never found the 31 to be too slow. This is personal of course.
- I would never use the 31 in the rain: I have the 16-50 for that.

As for being less intrusive with a prime, I've never believed this: there is a dSLR in your hand after all. Apart form using a 70-200 2.8 zoom, I don't think it makes a lot of difference.
Again, just my opinion.

Hi Bart, unfortunately I can't also afford the 16-50. I'd like it, it's probably a better APS-C range than my Sigma 24-60, but optically not an improvement. Would love the sealing though!

One reason I'm continuing to buy into Pentax is the size of the K-7 versus the D300S/7D/similar. The K-7 also has a much quieter shutter. In my opinion, I certainly think a pancake lens would be less intrusive for street photography than a 77mm front-element 24-60 (or similar) zoom. The 24-60 is also pretty small for it's range - the (optically great) 24-70 Nikon is a beast.

[Urkeldaedalus]

- What is the AF speed of the 31mm like? Does it come close to the super-quick 40mm pancake?
- The build quality of the 31mm sounds top-notch, but has anyone used it in the rain? Had any issues?

Thanks for the help.

I've only tried the DA40 a little bit, but I would say the DA40 definitely has a noticeable AF speed advantage compared to the FA31. The FA31 isn't too shabby, though, especially when on the K-7.

I have not tried using my FA31 in the rain and would hesitate to do so (unless we're talking a sprinkling rain here)

I think you'll like the FA31 for street photography. If it was a little bit wider it would be about perfect, but if you keep this in mind and back up a few steps you can compensate for this.

As an alternative, you might want to try getting the DA15 f/4 and FA43 f/1.9 instead for about the price of the FA31. They are both more pocketable than the 31 so you could carry both, and the FA43 would give you the low light option you are looking for. I do love the FA31, though, so you won't go wrong there. It's a tough thing, these lens decisions

[axl]

as for the AF speed, 40 is noticable faster, especially in lower light or lower contrast. BUT! I found 40 to missfocus more often thatn 31 so it's like tossing up a coin...
As for the choice of 31 for streets, it's good choice but....
I don't know, I use it for streets only if I don't want to take 24 + 43.
Having said that, 31 can handle a lot of environment around the object and at the same time it's VERY cropable.
As for the rain, I haven't tried it with 31 but I shot 43 in quite "heavy" (for London standards anyway) snow, and it did perfectly fine.

[Gooshin]

mechanical lenses are unaffected by the rain

it will work even submerged in water..

id be worrieda bout your camera crapping out once the water gets past the mount.

[JeffJS]

as for the AF speed, 40 is noticable faster, especially in lower light or lower contrast. BUT! I found 40 to missfocus more often thatn 31 so it's like tossing up a coin...

So then what is faster about the AF on the DA40? I mean, if it's focus accuracy is less than the FA31 (missfocus more often than 31 so it's like tossing up a coin), then it really isn't faster.. Is it? Or is the focus throw shorter than the 31 so it moves front to back faster? When I decided I was going to buy limited primes, I also decided on one set only (there were only 3 DA limiteds at the time) and chose the FA lenses (with no regrets or afterthoght) so I've never even held a DA40..

[Gooshin]

what he ment was that you will take a photo faster, ie, the lens/camera will "lock" focus quicker but in the end you may not have an actuall in focus shot.

thats generally the problem when you combine short-throw lenses with a finicky AF module.

[jsherman999]

So, what is that new avatar?

[Gooshin]

So, what is that new avatar?

check the "67 y.o. knocks out black kid" thread in the general section

[axl]

what he ment was that you will take a photo faster, ie, the lens/camera will "lock" focus quicker but in the end you may not have an actuall in focus shot.

thats generally the problem when you combine short-throw lenses with a finicky AF module.

spot on....

[redpigeons]

The 31mm is the 31mm it is one of the greatest lenses ever made

And would be the perfect lens for street on a 35mm camera . on digital the 31mm is more like a normal lens.
meaning harder to create dynamic composition or get a group shot of people . (in my opinion)

on digital I find the 20mm focal length to be a perfect focal length .

for other stuff like sharpness ,3D effects , portraits and other stuff the 31mm is the king of lenses .

in general what I learned in the hard way is that a street photographer is a snap shooter, we don't need an expansive gear ,what we need is to always have a camera with us

today after I got my own technique I would buy a K-7 with a 21mm LTD if I would go for an SLR , small enough to take everywhere and strong enough not to worry about it

[JeffJS]

what he ment was that you will take a photo faster, ie, the lens/camera will "lock" focus quicker but in the end you may not have an actuall in focus shot.

thats generally the problem when you combine short-throw lenses with a finicky AF module.

Which is why I've sold every FA50 f1.4 I've ever owned.

spot on....

That, I understood. What I meant was, if it fails to actually achieve focus, then it isn't really faster. I assume we're talking low light situations here, I've yet to grab a Pentax AF lens that didn't lock on in good light, reasonably fast and reliably accurate every time.

[axl]

Which is why I've sold every FA50 f1.4 I've ever owned.



That, I understood. What I meant was, if it fails to actually achieve focus, then it isn't really faster. I assume we're talking low light situations here, I've yet to grab a Pentax AF lens that didn't lock on in good light, reasonably fast and reliably accurate every time.

Well, it depends.
Every now and than it happened to my DA40 that it would be off focus. But I mostly blamed my technique.
Anyway, what I meant in my original post was. With DA40 I would describe the AF as:
zzzzzzzzzzzzzz. done, lens is locked, and
with 31:
zzzzzzzzz....zz..zz..z. and it's locked.
Now you can see it as good or bad. 31 (or at least mine) likes to make sure it's spot on.
40 on the other hand is overconfident, and stays put on the first time. And sometimes the AF sensor just picks wrong thing.....
In good light though, 40 is just faster.
In lower light, well 40 would still win, in speed but from my experience it would either fail to focus or lock focus on wrong thing more often than 31.

my 2p

[CWyatt]

The 31mm is the 31mm it is one of the greatest lenses ever made

And would be the perfect lens for street on a 35mm camera . on digital the 31mm is more like a normal lens.
meaning harder to create dynamic composition or get a group shot of people . (in my opinion)

on digital I find the 20mm focal length to be a perfect focal length .

for other stuff like sharpness ,3D effects , portraits and other stuff the 31mm is the king of lenses .

in general what I learned in the hard way is that a street photographer is a snap shooter, we don't need an expansive gear ,what we need is to always have a camera with us

today after I got my own technique I would buy a K-7 with a 21mm LTD if I would go for an SLR , small enough to take everywhere and strong enough not to worry about it

The 21mm/40mm combination is tempting, covering slightly-wider-than-classically-wide and slightly-longer-then-classically-standard focal lengths. I personally shoot a lot at around 30mm, standard length, although I use all the focal lengths of my 24-60 a bit. Most of my street stuff isn't 'snap' type stuff, some is, but mostly it's setting up a geometrically pleasing composition and observing people in it.

The 21mm would certainly be a great 'snap' lens and make you get close, the 24-60 is quite noticeable and often does the little AF hunt like the 31mm might do, which can be pretty annoying.

Considering the 21 and 40 together are still cheaper than the 31mm, they're a tempting combination. As I said before, it's really a toss up between speed and size. The IQ of the DA limiteds sound just fine, even if they don't match the 31mm. I'd love f/1.8, but it's not a deal breaker. As I'm going for unobtrusiveness, I really need fast AF, any hunting can mean a missed shot (although it's interesting to read that maybe the 40mm isn't the most accurate AF lens).