[RyanS]

I currently have the 18-135WR on a K30. So far it has been good. I'd like something faster for indoor/low light situations so that I don't need to use the flash as much. I'm looking at the DA 35mm f2.4. Has anyone used both side-by-side? Is the 18-135 just as sharp in the 35mm range? Is the difference in speed enough to warrant the purchase price? Is there a better lens around the same price range I should consider?

[Docrwm]

I've got both and have kept the 35/2.4 over other lenses. It's a step up in both light gathering and slightly-IQ over the 18-135 at 35mm IMHO. It's also smaller and lighter and therefore less obtrusive for intimate shots.

[carrrlangas]

Equally important as Maximum aperture, is how good the lens is wide open (I´ve read the DA35 is quite good). I can recommend the DA40 XS which has a maximum aperture of f/2.8 and is very good wide open. (Audiobomber has one on the marketplace for U$D 150 right now).
Most likely, your DA18-135 is f/4 at 35mm so if you are getting speeds arround 1/30, with a 35/2.8 lens you´ll get 1/60.
Another important thing is how much depth of field do you need. Perhaps a 28mm/2.8 would be more useful indoors. The F28/2.8 is really good but hard to find.

[Docrwm]

Equally important as Maximum aperture, is how good the lens is wide open (I´ve read the DA35 is quite good). I can recommend the DA40 XS which has a maximum aperture of f/2.8 and is very good wide open. (Audiobomber has one on the marketplace for U$D 150 right now).
Most likely, your DA18-135 is f/4 at 35mm so if you are getting speeds arround 1/30, with a 35/2.8 lens you´ll get 1/60.
Another important thing is how much depth of field do you need. Perhaps a 28mm/2.8 would be more useful indoors. The F28/2.8 is really good but hard to find.

The 35/2.4 is pretty good at 2.4, the 18-135 at f4 needs a bit more stopping down as I recall. So you are going to compare 2.4 vs 5.8 in practical terms for the two lenses. Minimum focus distance on the 35/2.4 is slightly less than 1 ft and reviews indicate that color rendition is actually better than the DA*16-50.

[RyanS]

I appreciate the responses! Looks like the 35mm f2.4 is a good choice for my situation.

[Docrwm]

I appreciate the responses! Looks like the 35mm f2.4 is a good choice for my situation.

The DA50/1.8 is faster, better IQ, but far tighter on an APS-C camera. If you want something that long then its actually a better lens IMHO.

[RyanS]

The DA50/1.8 is faster, better IQ, but far tighter on an APS-C camera. If you want something that long then its actually a better lens IMHO.

I think 35mm would be better for inside a home, which is where it would get used the most.

[Docrwm]

I think 35mm would be better for inside a home, which is where it would get used the most.

Yes, absolutely. Just wanted to throw that out there, but the 35 is much more suited to inside the house use.

[Na Horuk]

The three high quality primes in that price range are DA 35mm f2.4, DA 40mm f2.8 XS, and DA 50mm f1.8.
For low light and portraiture, the 50mm f1.8 is your best choice. For general purpose with a slightly wider angle, like group photos or in tight spaces - the 35mm. The 40mm is very sharp with fast AF and great IQ overall, but not so great for low light.
I have the 35mm and 40mm XS and would probably choose the 40mm over the 35mm, unless I need that extra 5mm wideness (and it is noticeable). I have a manual M 50mm f1.7 that I really enjoy using. I usually use the 40mm XS as my main AF lens for casual photography.
Each of these lenses will give you better IQ than the 18-55mm or 18-135mm. They are brighter, give sharper images, should render colours better, etc. They will also change how you take photos, because they have a fixed focal length. A lot of people say that a prime lens improves your photography exactly for that reason, because it makes you more conscious of your framing of the photo.
Any of these three will give you a lot of bang per buck and I doubt you would regret getting any of these.

[carrrlangas]

The 40mm is very sharp with fast AF and great IQ overall, but not so great for low light.

why not?

[Na Horuk]

why not?

Because f2.8 is relatively dark for a prime lens. f1.8 or f2.0 is significantly brighter. But for most uses, daylight photography, studio photography, if you have a flash, or even in well-lit interiors, its great.

[carrrlangas]

Because f2.8 is relatively dark for a prime lens. f1.8 or f2.0 is significantly brighter. But for most uses, daylight photography, studio photography, even well-lit interiors, its great.

True, but f/2.4 is only half a stop faster.... With today´s sensors any f/4 lens (good wide open) is fairly usable in low light, hend held photography. This is not the case with variable aperture zooms, but constant aperture zooms or primes certainly do. The quantity of aperture blades and light sources rendering (don´t know how this is called, I think is ghosting?) is more important for low light IMO.

[Kozlok]

I still like my Sigma 30/1.4 for when light is precious indoors. A great FL and I can get ~1 2/3 stops lower ISO compared to the 35/2.4.

[Docrwm]

I still like my Sigma 30/1.4 for when light is precious indoors. A great FL and I can get ~1 2/3 stops lower ISO compared to the 35/2.4.

I have both and agree, but then the 30/1.4 is also HUGE in comparison and cost around 2x what the 35/2.4 cost.

[RyanS]

I have both and agree, but then the 30/1.4 is also HUGE in comparison and cost around 2x what the 35/2.4 cost.

Would you say it is worth the extra cost?