[reivax]

I'm currently on the fence about getting one of these two lenses. Obviously, in regards to price, they are in two different worlds, but are they in different classes in regards to quality?

The Sigma is obviously faster, newer, and is reported to have much better image quality. It's also bigger and has no physical aperture control.

The Pentax is lighter, slower, smaller, and isn't reported to have the image quality of the Sigma.

Has anyone tested these two together? I've debated the Sigma for a while, but I don't know if the extra $600 is truly worth it. I imagine it is, but I'm really curious to know what others think and have experienced.

[Adam]

I'm currently on the fence about getting one of these two lenses. Obviously, in regards to price, they are in two different worlds, but are they in different classes in regards to quality?

The Sigma is obviously faster, newer, and is reported to have much better image quality. It's also bigger and has no physical aperture control.

The Pentax is lighter, slower, smaller, and isn't reported to have the image quality of the Sigma.

Has anyone tested these two together? I've debated the Sigma for a while, but I don't know if the extra $600 is truly worth it. I imagine it is, but I'm really curious to know what others think and have experienced.

I haven't tested them side-by-side, but I've used them both and it's hard not to recommend the Sigma unless weight/size is an issue. Ignoring the bump in sharpness, the Sigma's bokeh is simply to die for.

[Buffy]

I've not had an opportunity to use the Sigma, but I had the FA 35/2 and it was practically glued to my camera ... at least until I picked up the FA 31 Ltd.

[selfnoise]

Do you need the extra stop vs. the 35 limited? I'd buy that vs. either of the other two.

[Na Horuk]

You have a lot of options between 30mm and 40mm: Pentax FA 31mm, Pentax DA 35mm f2.4, Pentax FA 35mm f2, Pentax DA 35mm f2.8 macro, Pentax DA 40mm (SMC, HD, XS), Sigma 30mm f1.4, Sigma 35mm f1.4, Samyang 35mm, Mitakon 35mm and possibly others
This does not answer your question, but it might make your comparison more realistic. So make a list of what exactly you need (need FF, fast aperture, macro, low weight, aperture ring..). Many of these lenses are sharp, and each has its pros and cons.

But my only 35mm primes are DA 35mm f2.4 and Zeiss Flektogon 35mm, and I use DA 35mm probably more than any other lens. Never decided to upgrade because it does things well enough. If this, the cheapest Pentax 35mm prime, is so good, I doubt any other will be terribly disappointing either

[reivax]

You have a lot of options between 30mm and 40mm: Pentax FA 31mm, Pentax DA 35mm f2.4, Pentax FA 35mm f2, Pentax DA 35mm f2.8 macro, Pentax DA 40mm (SMC, HD, XS), Sigma 30mm f1.4, Sigma 35mm f1.4, Samyang 35mm, Mitakon 35mm and possibly others
This does not answer your question, but it might make your comparison more realistic. So make a list of what exactly you need (need FF, fast aperture, macro, low weight, aperture ring..). Many of these lenses are sharp, and each has its pros and cons.

But my only 35mm primes are DA 35mm f2.4 and Zeiss Flektogon 35mm, and I use DA 35mm probably more than any other lens. Never decided to upgrade because it does things well enough. If this, the cheapest 35mm prime, is so good, I doubt any other will be terribly disappointing either

I want the unicorn 35mm. Fast, light, amazing optical quality, ff, and cheap.

Realistically, I'm looking for something fast with great optical quality to use on FF. I also plan on using it, if possible, on my Sony A7ii. That's my main reason for considering the FA, but I think it's too much of a trade off...

[Na Horuk]

I want the unicorn 35mm. Fast, light, amazing optical quality, ff, and cheap.

I think this answers your question. Zeiss 35mm f2 (kmount, m42), Sigma 35mm Art, Pentax FA 31mm ltd are your best bet. Sigma Art is definitely a unicorn in resolution.
Of course, cheap in another issue

[mikesbike]

I have had the FA 35mm f/2 for years- bought for use on my 35mm film bodies. A great lens at a modest price. I love it. it is small, light, easy to pack along. It comes with an excellent lens hood with a window for rotating filters. If you get a good copy, it is hard to beat in any significant way. I have never had the FA 31mm Limited, though I do have the 43mm and 77mm. If one really needs f/1.4 at 35mm FL, the Sigma is surely the way to go. Same, if one needs the highest possible central sharpness at f/1.8 or f/2 at the 35mm FL. But the 2 Pentax lenses are already very, very good at this (for them) wide-open aperture, and rated excellent f/2.8-11 by photozone tests. Perhaps, in the central frame area, the Sigma is excellent+. I have used my FA 35mm lens on my APS-C K-200D and K-5 cameras, but not yet on my K-5 IIs or KP bodies. Its field of view is of more interest for me for film or FF digital, which I do not yet have. Now my curiosity is aroused to try it on my KP!

Will you actually see any difference at all between the Sigma and 2 Pentax lenses when used at f/2.8-11 apertures is questionable, even when using a higher resolution body like a K-3, K-70, KP, or K-1. And maybe even hard to detect a difference for central sharpness with the Pentaxes wide open. But, practically speaking, both Pentax lenses were rated as having even better bokeh than the Sigma! Unfortunately, the Sigma was never tested on a Pentax body by photozone, so one has to see their tests on a Nikon D7000 body to get an idea of its characteristics on APS-C. The Pentax lenses have yet to be tested on the FF K-1. But bokeh is bokeh.

[Scintilla]

I think this answers your question. Zeiss 35mm f2 (kmount, m42), Sigma 35mm Art, Pentax FA 31mm ltd are your best bet. Sigma Art is definitely a unicorn in resolution.
Of course, cheap in another issue

If you're willing to trade light (and autofocus) for cheap, the Samyang/Rokinon/Bower 35/1.4 AS UMC is worth a look. Loved that thing on APS-C, though the focus throw could have been longer.

[Pentax Syntax]

FWIW the Pentax 35 2.0 is a sharp and very useful lens but I find it produces rather uninteresting starbursts if the sun or bright source is in the frame at small aperture. Great little lens otherwise. The Sigma Art lenses are excellent and depending on your needs might be a good choice.

[pakinjapan]

I want the unicorn 35mm. Fast, light, amazing optical quality, ff, and cheap.

I have never test them side by side too, but I used to own a FA35 and test the sigma every time I get a chance which is often but not a scientific type of testing. (we have a lot of electronic store here and everyone of them have camera section with ton of lens and body from all famous Japanese brand to test. And I love hang around in there.) I like the Sigma a lot but the size and weigh turn me off big time.
My score:

• Fast: Both lenses are definitely fast but the Sigma art is faster [sigma: 1 / fa35: 0]
• Light: FA35 (sigma: 0 / fa35: 1)
• FF; Both are ff [tied]
• Cheap: FA35 (sigma: 0 / fa35: 1)
• Amazing optical: It is subjective. Both are amazing in my book. What does amazing mean for you? To me. If Sigma can somehow compress size and weight of the lens & sale it at the same price as FA35 and still can delivery the image quality, (35 limited, anyone!) I would give the art lens a win. [tied]

In (my) conclusion, Unicorn doesn't exist
if money, size and weight is not your concern but you go after best of the best in term of image quality: Sigma art is what you want.
if you weight in more on Cheap + light, FA35 could be a better bet. The copy I used to own is sharp (where it need to be sharp) from f2 and evern sharper at f2.2. And at f4, it is bleeding sharp.

[clackers]

I have both - the Sigma is heaviest, biggest and has the best IQ. The FA35 is sharp, smaller and lighter.

Down to your usage scenarios, right?

[stevebrot]

Down to your usage scenarios, right?

I own the FA 35/2 and would be interested in the Sigma except that I own the FA 35/2.

I have done a lot of decent work with the FA 35/2. It serves as my walkaround prime on APS-C and while its bokeh is not stunning, it is not bad either. I have other lenses for bokeh. On 35mm film, I use the FA 35/2 for urban and street photography as well as external architecture. It is compact, handles well on my film SLRs, and does not attract attention. Oh...and I would add that it takes 49mm filters.

OTOH, if one is on the fence between the two it may well be that intended purpose and usage is not clear. Best to buy both


Steve

[kiwi_jono]

As others have said, the Sigma generally has the better IQ but the FA35 f2 is still a great little lens and the pick for value for money. If I had the budget for Sigma 35 Art, I might be tempted but then I would also be tempted by the FA31 as I like the relative compactness.

Just one more thing to weigh in on though, is that most reviews of the FA35 are on APS-C and, I have found the FA35 significantly better on the K-1 that on APS-C (such as K-5). I find the bokeh in normal field use is much more to my taste on the K-1 than the K-5. This surprised me but probably it has to do with me needing closer focus distances for same framing over APS-C.

Do post an update as to what you end up getting and how you like it.

[reivax]

As others have said, the Sigma generally has the better IQ but the FA35 f2 is still a great little lens and the pick for value for money. If I had the budget for Sigma 35 Art, I might be tempted but then I would also be tempted by the FA31 as I like the relative compactness.

Just one more thing to weigh in on though, is that most reviews of the FA35 are on APS-C and, I have found the FA35 significantly better on the K-1 that on APS-C (such as K-5). I find the bokeh in normal field use is much more to my taste on the K-1 than the K-5. This surprised me but probably it has to do with me needing closer focus distances for same framing over APS-C.

Do post an update as to what you end up getting and how you like it.

The more I read up on it, the more my wallet wants the FA 35 and my heart wants the Sigma 35. I would almost exclusively use it on my K-1. Both have a lot of pros and very few cons. My biggest hesitation on the Pentax is the lack of images I've found on full frame. I would imagine it's got to look better on FF than it does on APS-C. f2 is something I can live with (especially for $600+ less). I think my other concern is the age of the Pentax lens.


I do have the DFA 24-70. I wonder if the image quality of that lens is as good (or good enough) as compared to the FA 35. At this point, I think it's the lack of images from the FA 35 that is holding me back. The manual aperture control is also incredibly appealing because I would also like to occasionally use it on my Sony A7ii. There is no way I can justify buying a Sony FE lens at those ridiculous prices.