[no694terry]

get the plastic fantastics and turn ISO up to 3200

[The Squirrel Mafia]

Like already mentioned, get some fast lenses. From .85 to 2.8. The only problem at times will be the extremely shallow depth of field & focusing on the correct plane. It might be a challenge.

I take it that the K-50 & the K-5 put out similar image quality. If so, shooting up to ISO 3200 is not a problem if you post process the RAW file. I shoot up to ISO 3200 on my K-50 with no issues at all. The post processed image regains a ton of fine details & looks far more amazing than the OOC jpeg.

At ISO 6400, the noise starts getting grainer & harsher, but it's still usable. The K-50 RAW files are 12 bit, though. I did an 11x14 print out of a processed ISO 6400 RAW file & it looked pretty good. I could probably get a decent looking 16x20 from the same file. I highly doubt that an ISO 6400 OOC jpeg could give me a large print like that. If the K-5 has 14 bit RAW files, they should look slightly better at ISO 6400. That might be the usable limit for you.

[DeadJohn]

Try using the 16-45 f4 a little more in low light. Use the wide end because wide angles can tolerate slower shutter speeds before showing camera shake. Boost the ISO as needed. If high ISO gives too much noise, consider B&W instead of color.

If you conclude the 16-45 can't cut it, lenses that are f2.0 or better will give 2 full stops compared to the 16-45 f4.0. Here's what I can find at 50mm and below in the lens database. Sigma has additional options.
SMC Pentax-DA 50mm F1.8 Reviews - DA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA* 24mm F2 AL [IF] Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 31mm F1.8 AL Limited Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 35mm F2 AL Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 43mm F1.9 Limited Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 50mm F1.4 Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 50mm F1.7 Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database

[sabzijoon]

Try using the 16-45 f4 a little more in low light. Use the wide end because wide angles can tolerate slower shutter speeds before showing camera shake. Boost the ISO as needed. If high ISO gives too much noise, consider B&W instead of color.

If you conclude the 16-45 can't cut it, lenses that are f2.0 or better will give 2 full stops compared to the 16-45 f4.0. Here's what I can find at 50mm and below in the lens database. Sigma has additional options.
SMC Pentax-DA 50mm F1.8 Reviews - DA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA* 24mm F2 AL [IF] Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 31mm F1.8 AL Limited Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 35mm F2 AL Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 43mm F1.9 Limited Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 50mm F1.4 Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database
SMC Pentax-FA 50mm F1.7 Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database

I did do some tests of the 16-45mm in low light even with ISO 3200 and it seemed to do fine. So, it might be the case that I'll just stick with it.

[Nicolas06]

Hi everyone,

I'm currently in the process of acquiring new camera equipment. I generally shoot landscapes and macros. Besides this, some wild life and a few portraits and general family style shots. Currently, I own a Pentax K-5 with a Pentax 16-45/4 and Pentax 55-300 WR.

Sometimes, I end up taking shots in low-light or at night. For landscapes and subjects that are still, a tripod works really well. What kind of glass do you recommend for low-light or night shots where the subject isn't still? I'm not big on using the built-in or an external flash, which is why I'm asking about this. I was looking at the DA 35/2.4 to experiment with, but it doesn't seem like it's all that faster than what I currently have, which works well in most circumstances.

Thanks

The best shoots are often taken with flash (a bunch of flash indeed). It is not only the quantity of light but also the quality... But that's not always usable.

Now if you need to get good pictures in low light without flash and of moving subjects (so SR isn't going to help) then there no much substitute for large sensor and very fast lenses.

When I say fast, I mean it, should be f/2 or faster... WIth autofocus and affordable that would be Sigma 30mm f/1.4 or DA50 f/1.8. Beware that you'll need likely a K3 or at least a K5-II to have an AF that work well in low light. More expensive but quite interresting lenses would be FA31 f/1.8, FA43 f/1.9, DA55 f/1.4 or FA77 f/1.8 from Pentax and sigma 35mm Art f/1.4 or sigma 50mm f/1.4

The 18-35 f/1.8 zoom is quite an interresting compromize too.

In cheap manual lenses you should give a try to some samyang lenses.

Beware that user wider apperture mean there almost no deph of field and that not necessarily match all subjects.

I tend to think 18-35 f/1.8 or 30mm f1.4 from sigma would maybe give the best compromizes overall with a very good price.