[Merts]

I'm thinking about getting a (relatively) fast lens mainly for taking photos at family functions etc without a flash. My 18-135WR is terrific in good light, but is a bit slow at anything other than 18mm which means pushing the ISO to a point where the quality suffers. My 50 A 1.7 gives great results, but it's a bit too long for lots of indoor shots and the lack of auto focus can be problematic too. The Sigma mini-wide is soft wide open and no auto apperture or auto focus means it's pretty useless for the purpose.

The two lenses I'm thinking about are currently available through CR Kennedy in Aus at very reasonable costs.
Sigma 24-60mm 2.8 AF EX DG - $AU 249
Pentax DA SMC 35mm F2.4 - $AU 194

The reviews I've seen regarding the DA35 have been very positive.
The zoom would be usefull, but I'm wondering if the quality would match that produced by the prime.

Does anyone have experience with these lenses and/or an opinion on which would be better?

[nicoprod]

I would go with the 35mm 2.4 and use my legs. It's a good lens.

[hcc]

FA31mm f1.8. Great lens which will give you great results. I know that it is not what to hear, but f2.8 or even f2.4 might not be aperture large enough.

[Merts]

FA31mm f1.8. Great lens which will give you great results. I know that it is not what to hear, but f2.8 or even f2.4 might not be aperture large enough.

Yep, and only 5x the price of the DA35......

[MadMathMind]

There aren't many options for Pentax, sadly. There's a real dearth of fast lenses at the wide end (say, under 30mm). You can find plenty at f/2.8, but Pentax has no autofocus primes aside from the FA*24 that are f/2 or below. There's the A 28mm f/2 as well, but it's manual only.

I can't recommend the DA35 for indoors--it's just not wide enough. "Using legs" only works outdoors, really, as if you can't simply take steps back in crowded museums or small rooms and get the photo you want. I find that indoors, I am parked below 24mm mostly and rarely come near 35mm.

Your options are 3rd party:
1) Sigma 18-35 f/1.8. It's absolutely wonderful when it works; I've been lucky that mine has performed awesomely. Others report severe problems with the autofocus.
2) Sigma 24mm f/1.8
3) Sigma 28mm f/1.8

That's probably about it for wide, fast primes.

[Sandy Hancock]

Although I have not used it myself, you really have very little to lose with the DA35/2.4
If you still feel limited by it, then shelling out for the FA31/1.8 or Sigma 18-35/1.8 might be the best option.
Then there's the FA*24/2.0; I'll report back on it when mine arrives in a day or so

[Merts]

There aren't many options for Pentax, sadly. There's a real dearth of fast lenses at the wide end (say, under 30mm). You can find plenty at f/2.8, but Pentax has no autofocus primes aside from the FA*24 that are f/2 or below. There's the A 28mm f/2 as well, but it's manual only.

I can't recommend the DA35 for indoors--it's just not wide enough. "Using legs" only works outdoors, really, as if you can't simply take steps back in crowded museums or small rooms and get the photo you want. I find that indoors, I am parked below 24mm mostly and rarely come near 35mm.

Your options are 3rd party:
1) Sigma 18-35 f/1.8. It's absolutely wonderful when it works; I've been lucky that mine has performed awesomely. Others report severe problems with the autofocus.
2) Sigma 24mm f/1.8
3) Sigma 28mm f/1.8

That's probably about it for wide, fast primes.

Yeah, you are probably right about 35 still being a bit long.
I had considered the Sigma 18-35/1.8 and if I decide to spend that sort of money it would probably suit me better than a prime.

[dms]

If the point is to get a low light lens, I would suggest getting a prime lens, and at least f/2 (and possibly f/1.4), and likely something in the range 28 to 35mm. That will let you shoot at about f/2.4 to 2.8 which will minimize lens aberrations (i.e., not full open), and give you a little more DOF.

I happen to use both the Pentax (K) 35mm f/2 and the Vivitar Series1 28mm f/1.9 (and the Pentax M 50mm f1.7) a lot in relatively low light (mostly theatre and dance, and some night time functions/party)--and can recommend them all (and for me the best is the VS1). But that does not help you as they are not AF.

I do not use AF, but if I was looking for an AF, from what I have heard I think I would get the FA 35mm f/2.

[clackers]

At 2.8 or below, there are 14mm from Samyang and Pentax. Normal zooms from Sigma, Pentax and Tamron. Sigma and Samyang 35mm f1.4 primes. Sigma 20mm, 24mm, 28mm f1.8 primes.

Choose your poison, but DoF for a portrait needs about f4, and people sitting together maybe f5.6 or 8.

No substitute really for well-done additional lighting.

[psychdoc]

For a [relatively] low cost option Tamron 17-50 f2.8 lens, its pretty good. However for family functions etc indoors, why would you not use flash?

[Merts]

Mmm, clackers and psychdoc, you blokes may be right.
I could just use the 18-135 and bounce the flash off the ceiling.

[clackers]

Mmm, clackers and psychdoc, you blokes may be right.
I could just use the 18-135 and bounce the flash off the ceiling.

Absolutely, Merts.You can even use apertures sharpest for your glass, which may be f5.6 or f8 even for a fast lens. Give yourself aperture and shutter speed.

[Nimble]

The two lenses I'm thinking about are currently available through CR Kennedy in Aus at very reasonable costs.
Sigma 24-60mm 2.8 AF EX DG - $AU 249
Pentax DA SMC 35mm F2.4 - $AU 194

The reviews I've seen regarding the DA35 have been very positive.
The zoom would be usefull, but I'm wondering if the quality would match that produced by the prime.

Does anyone have experience with these lenses and/or an opinion on which would be better?

I have experience with the mentioned lenses for similar purposes. 35/2.4 I tried comparing to 40/2.8 Lim. The price was almost equal (about 30 usd). I chose 40/2.8 Lim - it's a bit slower, but gives much more interesting picture. I suppose, one should use 35 instead of 40 only in very cramped conditions.

Considering Sigma 24-60/2.8 - a bit useless lens for indoors action - It's great on wide angels, but aperture 2.8 over 50mm is practically useless. It should be at least 2.0. This lens as all Sigma EX series - very sharp, quite fast screwdriver AF, but dull, imho. Portraits are worse than on most pentax prime lenses.

[Merts]

So, I had a play around this evening.

I find the inbuilt flash produces fairly harsh and unnatural looking photos, but when I set the camera on X, 400 ISO and F8, it gives me a range of 1 to 7.5 metres using my old faithful sun auto thyristor flash. Some testing bouncing it of the ceiling produced well lit and natural looking results with the 18-135 lens.

Thanks for the suggestions everyone.

[infra4801]

Yes, while reading the original post and the responses, I kept thinking "Why not use a flash?" I bought the Metz 52 AF-1 when it first came out, and even though I still don't know how to synch it to the camera, and use it fully manual, the results have been quite great. Indoors I always bounce off the cieling, and got myself a diffuser as well. Then you can use your "Slow" wide angle lenses.
I have had the problem mentioned before: Use a fast lens without flash, pretty open, and get some people focused and some not, specially in group shots.
I am glad you are using the flash gun.