[Greenneck]

So I have the chance to pick up a used fa 31mm for under $500 at a local shop ( somewhat suspicious of the price but it’s a long drive to just inspect it with out being sure I’ll buy it). I currently have the 35mm limited macro that hasn’t actually gotten a lot of use. I feel like I have to get to close to macro subjects, I dislike the push in hood that always seems to slide back in and it’s the same f 2.8 as my da*16-50 walk around lens. I’ve read all the great things about the fa31 it’s probably fast enough to make it more viable for street shots (enjoy hanging out in the club district summer nights) and I like the fixed hood. Do I just have gas or is this too good of an opportunity to pass up? What can I hope to sell my 35 for? Then I’ll look into a budget macro replacement for the few times a year I use that.

[HYS]

Test the 31Ltd at first. And try to check the purple fringing. Otherwise this lens is marvelous.

[Greenneck]

Test the 31Ltd at first. And try to check the purple fringing. Otherwise this lens is marvelous.

Will I be able to zoom in enough to see that on the camera? I’m assuming that’s a known issue that lens can have from time to time?

[pakinjapan]

If I were you, I would already be on my way to get the 31.
and from what I learn, when I get a so call "budget" lens or whatever budget, I usually ended up sale it and go for what I really want... which... I feel like I pay more for something I don't really happy with. I should just save until I have enough and get what I really want and skip the "budget" things in the first place.
So, again, If I were you, I will go test the 31 ASAP. Buy it if it good enough, then sale the 35 ltd, and get DFA100WR or the 50 macro (F, FA or DFA version).
my 2 cents.

[Jonathan Mac]

A 31mm limited for under $500 is a steal. I love my DA 35mm macro (it's hood stays in place but I do wish it were faster) and I regard it as a lens I'd never, ever sell, but the 31mm has a great reputation and would get me the extra speed I yearn for.

Make the trip, test the 31mm and if you end up preferring it to the 35mm then sell the latter.

[mikeSF]

If the 31 is legit, by all means grab it. One of Pentax best lenses.

[twilhelm]

At that price I would have already been there checking it out. I paid a good bit more than that for mine used, but it was worth it, an amazing lens.

[Sandy Hancock]

Buy! Buy!! Buy!!!

[Kozlok]

All 31’s have some purple fringing. It’s not a copy-to-copy problem as far as I know. You could just look at examples on the internet to see if it bothers you. Lightroom can fix it, so to me it’s a non-issue.

[HYS]

All 31’s have some purple fringing. It’s not a copy-to-copy problem as far as I know. You could just look at examples on the internet to see if it bothers you. Lightroom can fix it, so to me it’s a non-issue.

My Lightroom can not fix it. Or I can not do it properly. I mention here this effect so often because this lens i all other "non contre-jour" situations is really more than fantastic. For me.

[Gianclaudio]

Just willing to add, the 35mm has its fair share of purple fringing, so I don't think the 31will be that much worse.

[RobA_Oz]

I have both, and intend to sell neither. Aside from the close FL, they have different characteristics. The DA35/2.8 Limited is sharper across the image than the FA31/1.8 Limited at wider apertures and, of course, focusses much closer than it. From what I understand, the FA31 has a curved image plane, which is what gives it the so-called "3D pop". I'm sure others will correct me if that's inaccurate.

Finally, and this won't affect anyone who stays with an APS-C body, the DA35 vignettes quite severely under some conditions on a 35FF body, though it doesn't actually mask in my experience, so the effect can be reduced in post-processing.

[neokind]

Those were the last two lenses I purchased. The 35mm pretty much lives on my K3ii now, but the 31mm is wonderful. $500 is a steal. I paid $200 more and bought used. As others have said, the purple fringing is an issue, but Lightroom takes care of it with no problems. I bought the 35mm for its focal length as much as for the macro capability. I also have the 100mm macro, and while it creates lovely images, it's a bit larger than I want on my camera most times, and the focal length is too long for a daily user.

[Sandy Hancock]

the DA35 vignettes quite severely under some conditions on a 35FF body, though it doesn't actually mask in my experience, so the effect can be reduced in post-processing.

It does mask at infinity focus. Even with the hood fully retracted the lens barrel takes significant nips out of the corners.
Even at close focus the image quality in the peripheries drops off dramatically beyond the APS-C image circle.

It's a great lens, but most certainly a crop lens.

[slivo]

The strong point of 35 limited is the nice background when shooting from close distances, and I use that quite often when shooting my daughter with it. It is very easy to get and repeat. I don't do any macro...
Bought the 31 limited recently, mainly for the sense of depth I've seen on so many photos taken with this lens. Made some nice pictures, but it is not even half way to what I've seen and what I want to get from it. Please note that i've taken only 300 shots, and have not tried to "calibrate" the af yet.

What i have noticed right away, is that 31 is much more difficult to focus correctly than 35. Giving me (only) some tip-top focused pictures at close focus distances, and almost none when daughter is more far away. So besides regular check, try the af thoroughlybefore buying.
Almost all the pentax lenses have CA to some extent, it does not bother me. And no you can not remove it in PP, you can just desaturate it.
Both lenses are build nicely. The 31 is cca 1.5cm (1/2") longer and a bit bigger. The cap on 31 is bulkier (2x depth of the 35's cap), and sometimes it is difficult to get off/put on. I have never had a problem with hood on hd 35, it always stays in its place.
I love shooting with da*16-50 stopped down, it has beautiful sun stars (prone to flare), but at 2.8 the 35 is way sharper and you can achieve nicer background with it too.
31 seems to me pretty sharp wide open, and has a really nice calm bokeh (but have not tried it with busy background yet)
Besides the macro, 31 can replace the 35 and for your low light shooting the 31 seems to be the better option. To answer the question, NO it is not a GAS :-)
Good Luck!