[schnitzer79]

thanks for all the responses everyone.
i did end up ordering the 35mm due to its low price and since IQ difference from da40mm is not very significant.
will start saving some money then for the the FA43mm or FA77mm, probably the latter.

[TER-OR]

Indoors, and close, the 50mm and even 40mm might be too tight. Take your zoom and look at the view with these focal lengths. If you're going to take set pictures of small groups from a few feet away, you'll need wider.

I have a Sigma 28mm f1.8 macro which I like indoors. That 24-35 focal length is sort of the "normal" view - it's about what your eye sees.

The inexpensive 35mm is a definite temptation in this range, and may leave you some money for something even wider if necessary.

[stevebrot]

For sure a fast lens (say f/1.4) is great in low light with the proper equipment. However, be aware that with the stock focus screen:

• The viewfinder image will not be brighter
• Precision for manual focus will suck. Be prepared for missed focus much of the time.
• AF and Focus confirm will not be much better

The explanations for all three points are a little lengthy, but they are true and based on personal experience and good science. A quality aftermarket focus screen with split image and/or bright ground-glass field is pretty much required for manual focus. AF is pretty much a lost cause.*


Steve


* Effective aperture for the AF focus points on most Pentax dSLRs is f/5.6 and somewhat better (f/2.8) for the three center points on the K-3.

[mattb123]

I have the 50/1.8 and the 40 Limited. I have to say for the most part I prefer the FOV of the 40 and love the tiny size. I often have that lens on the camera when I'm not really sure what I'll be shooting because it's small, quick to focus (mostly), and I like the rendering. 50 is long for indoor shots a lot of the time so that lens gets used less for me. 35 is probably a better FOV for indoors.
Of those three and considering you already have a 50, I think the 35 or 40 would be better choices. If you really want it fast and 35mm, there is that Sigma 35/1.4 but it's not cheap or small.

[WaltKemo]

I think if forced, I'd rather keep my 43mm and use a generic zoom for other focal lengths than use a combination of lesser primes. It's invaluable to me. When I'm indoors with no light and no other lens is working, the 43mm still produces magic. It isn't good for all indoor shots obviously, but I always prefer the shot I take with it over other lenses that are wider/longer just because the 43mm photo always comes out better. And it's my go to walkaround lens.

In other words, once you get the 43mm, it's hard to go back.