[nj1975]

I am struggling to make a decision on a lens for taking indoor pictures of young kids - fast movers, low light scenario!! - I was just wondering if any Pentax users have any experience of either of the Pentax 31mm f/1.8 FA AL Limited or Sigma 35mm f1.4 DG HSM Lenses for this purpose? Thank you

[nicoprod]

They are both excellent lenses. For indoor I would go with the 31 because it's wider. Also the 31 has something very special about transition and bokeh. It's an expensive lens though.

[mtux]

If you can live with the size and weight of sigma I think go for it, faster and silent focus!
but for most of the time speed of 31 is just enough if no too much, and it's smaller and lighter which I prefer.

[hcc]

Both lenses are good based upon all PF reports. I do not have the Sigma and I will not get it because it is too heavy and bulky. I moved to Pentax for a number of reasons. One of them, the camera and lenses are petite compared to some Canokon.

If weight and bulk would be an issue, go for the FA31mm.

Otherwise you cannot go wrong with either.

My 5 cents.

[yusuf]

This has been discussed plenty of time here. SIgma is faster. Although I never used Sigma, the general perception is that Sigma is slightly sharper. However, FA31 has tremendous size advantage.

Another good (or better) option is Sigma 30 f1.4.

[Paul the Sunman]

My Sigma 35mm f1.4 is certainly very sharp, but exposure is hit-and-miss on both my K3 and K5. In certain common situations, it overexposes by 1 to 1.7ev, though in other circumstances it's fine. Whenever I use it I'm sure to check the shot immediately after on the screen to see whether I need to apply exposure compensation, which is a bit of a pain. It is also big and heavy.

I am using it a lot nevertheless, partly because of its excellent sharpness and bokeh, but also because I am trying to figure out its quirks. Because of its weight though, I won't take it with me to Europe early next year. The DA 40 pancake is a much more agreeable travelling companion.

[Apapukas]

I've used both of these lenses and it is really hard to say which is better.

I will try to explain why.

Image quality:

Even though, sharpness is very good on both lenses, bokeh is better on Sigma.
Color rendition. Well, both lenses render colors really nice, but I prefer the colder look that Sigma produces that the warmer from 31.
CA - Sigma is miles away, 31 suffers from CA pretty badly.

I give a point to Sigma here.

Build quality:

31 is all metal, looks like a jewel. Even though usually suffers from wobbly front element which isn't acceptable for such an expensive lens. Also, there is a little movement in the focus ring when camera is in AF mode (no QS for the 31). Yes, these are small things, but for 1.3K $ lens, they are hardly acceptable (IMO).
Sigma is metal/plastic, has a metal mount. No wobble or anything, feels very solid. Features internal focusing, quick-shift which makes the lens feel high quality and very well build.

Hard to say which is better. I'd say it is a draw.

Auto focus:

31 is screwdrive, Sigma - HSM. Both focuses very fast and both lenses didn't need any AF adjustments (on K5IIs). Sigma needed +3 on K3.

Win for Sigma (for silent focus)

Joy of use:

Sigma is a very large lens compared to Pentax. Heavy too. Grip is necessary for comfortable use (IMO). So, it is a little tiring to use it for two or more hours. The biggest drawback for the Sigma is that you may not have it when you need it.
Pentax 31 is small and light. It will fit in any camera bag, there is really no problem having it always with you.

Win for Pentax. Quite subjective, but I enjoyed using the 31Ltd a bit more.

Conclusion:

So, even though the overall score is Sigma 3, Pentax - 2, I'd say there is no real winner here. Both lenses are very good and you should get the one that suits your priorities better

Hope it helps

P.S. information written above is 100% subjective, based on my semi-pro use and it is absolutely normal if it varies from yours

[bossa]

They are both excellent lenses. For indoor I would go with the 31 because it's wider. Also the 31 has something very special about transition and bokeh. It's an expensive lens though.

The Sigma isn't a real 35mm.. more like 33-34. I sold my Nikon 35/1.4 last week because I bought a Sigma - the focal lengths were quite a bit different, the Sigma being wider.

Wide open the Sigma kills the FA31 but at around f/4 the 31 is god.

[FantasticMrFox]

Another good (or better) option is Sigma 30 f1.4.

Do you have that one? I've been drooling over the 35 f/1.4 for some time, but the size and price have been putting me off. Also, I think 5 mm more wide-angle would suit me well.

But the reason I was so excited about the 35 f/1.4 is the tremendous IQ and I was now wondering how the 30 f/1.4 compares? Obviously it's not quite as good, but would it be a significant improvement over my DA 35 f/2.4 in terms of sharpness, contrast, colour rendition etc.?

[yusuf]

Do you have that one? I've been drooling over the 35 f/1.4 for some time, but the size and price have been putting me off. Also, I think 5 mm more wide-angle would suit me well.

But the reason I was so excited about the 35 f/1.4 is the tremendous IQ and I was now wondering how the 30 f/1.4 compares? Obviously it's not quite as good, but would it be a significant improvement over my DA 35 f/2.4 in terms of sharpness, contrast, colour rendition etc.?

Regarding Sigma 30/1.4, I posted a comparison sometime back, it's here https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/237093-wide...nt-brands.html

Regarding Sigma 35/1.4, I don't have any personal experience. Heard nothing but pretty good things about it. However, size and weight is not of my liking. I also passed over Samyang 35/1.4 because of the same reason which is another excellent choice if you are okay with manual lenses and weight.

DA35 is a good lens. I personally like to shoot a bit more wide open at that focal length, f1.4 & f2 is fun for kind of photography I do but I think you should be happy with your DA 35 unless you want something faster. You should be able to find examples in excellent 30 f1.4 thread (search) and a few in my previous posts.

[Hattifnatt]

I agree with Apapukas review above. I have been using the Sigma 35mm f1.4 Art for some time, and I can say it's one tricky pony. It does not constantly get good shots, but when it does, it's a killer. Might be because of my lack of skills, I've started with photography from zero less than 1.5 years ago. I have the feeling I'm very far away from using this lens at full potential. Also, as others mentioned, it's quite bulky, but this did not bothered me so far. It also has the tendency to backfocus, especially in low light. One of those days I'll get my copy to benefit from the free calibration that I got from my local dealer. Or I might buy the Sigma USB calibration tool.

Some samples at various aperture and ISO settings (I'm too lazy to write off the setting but you can find them on Flickr):





















Perhaps it would be wise not to jump on this lens before you hear some more opinions from more experienced photographers. If you need any kind of help from my side (as original RAW files or whatever) please let me know. Hope that helps.

[JustinThomason]

I have not used the Sigma, but I own the 31 Ltd. It hardly leaves the body - I think it is an absolute joy to use, and it seems like anything I point it at comes out looking fabulous. I end up shooting quite a bit indoors, and it is plenty fast and wide for my purposes.

From the reviews it appears that the Sigma is also a winner. My guess is that you really cannot go wrong with either of these lenses.

[emalvick]

I have the Sigma 30/1.4 and it has kept me from buying the 31mm (the only limited I don't own). The Sigma is pretty good, and I haven't been able to justify the cost to get the 31 mm. The only problem with the 30 mm is that it tends to be softer at the corners vs. the center when it is wide open. That would really only be a factor if you were going to try and use it as a landscape lens, and even then you'd likely shoot stopped down.

I purchased the 30 for indoor photos of family, and it's perfect. It's not a bad size either. I think it's roughly the same weight as the 31 mm lens and about the same size.

[Paul the Sunman]

I agree with Apapukas review above. I have been using the Sigma 35mm f1.4 Art for some time, and I can say it's one tricky pony. It does not constantly get good shots, but when it does, it's a killer.

I agree totally! For no other lens that I own do I have to think so much about what the lens will do to the exclusion of the composition of the image.

[nj1975]

I agree with Apapukas review above. I have been using the Sigma 35mm f1.4 Art for some time, and I can say it's one tricky pony. It does not constantly get good shots, but when it does, it's a killer. Might be because of my lack of skills, I've started with photography from zero less than 1.5 years ago. I have the feeling I'm very far away from using this lens at full potential. Also, as others mentioned, it's quite bulky, but this did not bothered me so far. It also has the tendency to backfocus, especially in low light. One of those days I'll get my copy to benefit from the free calibration that I got from my local dealer. Or I might buy the Sigma USB calibration tool.

Some samples at various aperture and ISO settings (I'm too lazy to write off the setting but you can find them on Flickr):





















Perhaps it would be wise not to jump on this lens before you hear some more opinions from more experienced photographers. If you need any kind of help from my side (as original RAW files or whatever) please let me know. Hope that helps.

Thank you for adding all those images