View Full Version : Pentax FA31mm

23-08-2011, 11:34pm
i am thinking f buying a Pent

23-08-2011, 11:41pm
Sorry, had a hic cup before I finished entering. I am new to photography and have a lot to learn, I have read a lot about the FA 31mm 1.8 lens and I am thinking of buying one. Some of the reviews mention that it is not an easy lens to use. Am I being too ambitious if I buy this lens.

JM Tran
24-08-2011, 12:06am
every lens has its quirks and strengths and weaknesses, the FA31 Limited is considered to be one of the best 3 primes ever made for SLRs and those who know about it, speak very highly of it. Even Canon owners have modified their cameras to fit the K mount lens on them.

just buy it, you are not ambitious at all - and will kick yourself later on if you dont do it.

I have owned a few Limiteds in the past but never had the chance to grab an FA31.......

24-08-2011, 9:34am
Don't have the 31 Ltd, but have the 15 and the 40 Ltd's.

All the Ltd lens are absolutely top shelf.

38 reviewers on the Pentax forum, and read that as 'togs like yourself, rated the 31 Ltd @ 9.71/10, and they are a hard lot to please. See the review here... http://www.pentaxforums.com/lensreviews/SMC-Pentax-FA-31mm-F1.8-Limited-Len

You don't mention what camera you have or what use you expect from the lens. If you have an entry level DSLR this lens will probably out resolve it, but if you intend to upgrade your body you will be delighted with the improvement.

If the focal length suits your needs (46.5mm on the Pentax sensor with the 1.5 crop factor) and the price is right, I'd be grabbing it in a flash.

Lance B
24-08-2011, 12:13pm
The FA31 is considered one of the best auto focus lenses ever according to some highly regarded photogs. Here is a good link:


Since this aritcle was written, the other manufacturers have produced lenses that can possibly equal or surpass these little gems as far as outright IQ and build quality, but they are generally bigger and heavier and costlier.

When I used Pentax I had this lens and it was a real gem. However, being a "standard" focal length lens on APS C DSLR's it is a focal length I do no not use very much and hence it didn't get much use. In fact, I have very few sample photos from it at all!

Personally, my favourite Pentax lens for APS C DSLR's was the FA43 f1.9 Limited as it's bokeh was better than the FA31, sharpness better also when stopped down, was slight tele lens and therefore could be used as a portraiture lens as well as a general purpose walk about lens, and could give was a 3d look to some images. The other FA Limited favourite was the FA77 f1.8 as it is perfect for portraiture, which also has beautigul smooth boken and was very sharp with beautiful colour rendering.

A few samples of the other FA Limited lenses from Pentax:

FA77 f1.8 Limited:


FA43 f1.9 Limited:



FA31 f1.8 Limited:


24-08-2011, 6:30pm
I own a FA 31 Ltd and have no complaints. Grab one, you will enjoy it immensely.

29-08-2011, 11:50am
Im thinking of getting one for my K5. Dou you think I would get enough use as I have a FA*28-70 and a FA*80-200.as well as a SMC 100 macro f/2.8. I want to do a bit more portrait work and a little less weight to lug around.

31-08-2011, 12:03pm
I dont know that its a hard lens to use - its a prime, but minimum focus distance of about 30cm

Even unprocessed images come out with a good colour render and good contrast, and at F1.8 its pretty fast. Its also a full frame lens so will be usable IF and when Pentax finally put out a full frame sensor DSLR.
Bokeh is very nice, and I'll go against Lance above in saying that its bokeh is softer than the FA43 Ltd - from the examples i'd seen elsewhere and general consensus on the other Pentax web forummy places.

Its probably my most used prime lens.

31-08-2011, 12:06pm
Im thinking of getting one for my K5. Dou you think I would get enough use as I have a FA*28-70 and a FA*80-200.as well as a SMC 100 macro f/2.8. I want to do a bit more portrait work and a little less weight to lug around.

Yes, but it is heavyish for a Pentax prime lens, but even against my DA* zooms, I still like its quality better.
Cant compare with the FA* as Ive never used them (though I know they are huge and heavy!)

05-09-2011, 10:26pm
Thank you for all of your responses re the FA 31. I have been off iine for for a while. Del

04-11-2011, 9:14pm
These photos and comments were the deciding factor for me. I now own a silver 31mm limited and the 15mm is on the way.Out with the Sigma 10-20mm. Ebay bound.