I had both lenses but got much more use out of the fantastic 43. Personally I preferred the rendering of the Cosina 55/1.2 (esp. the OOF highlights) to the A 50/1.2 and I sold the Pentax and kept the Cosina. All are superb lenses though.

+1

This is an excellent lens and I sold the Carl Zeiss equivalent to keep the SMC Tak which is just better all round, sharper and with more contrast.

John. You don't always have to leap to the defence of Pentax, the 31mm especially hardly needs it. However you intimate but saying 'not the only advantage' that the 31mm is better than the Sigma in all those areas you list. The Sigma 35mm already has stellar reviews and proven performance and is considered better than anything produced by Canon/Nikon and every other 35mm out there. It's not a lens you want to pick a fight with - especially regarding optical performance where the Sigma has blown everything else away !

Some people will want a superb, small and light lens - others will want the very best lens they can get for their money. This is a heavy-weight contest that I doubt the 31mm can win in pure technical terms, and why should it when you think about the when the 31mm was designed and how much has gone into the Sigma design in 2012/13.

Gorgeous ... and you're torturing me since I've just sold my 77 Ltd (so sad to see it go).

Interesting question JC. The 35mm has sharp corners, virtually no distortion, great on CA/PF. super fast AF and is incredibly sharp (Google it - lots of tests results out for it already). Whether it renders like the 31mm is another question.

Probably the 35mm will shade the venerable 31mm in some areas but a lot may come down to personal preference .. and of course these are both full frame lenses so when used on (for example) a K5ii then you have trimmed borders and corners off already for even better performance but at the cost of width.

Two thumbs up Vic !

If you want reach in Pentax (without paying a fortune for exotic lenses) then the 50-500 is as good as it gets and the weight really isn't an issue on a monopod (if you are shooting wildlife then you need to put up with a certain degree of weight/discomfort, it's all part and parcel of the genre) carried over your shoulder when walking.

You'll get better results on a mono than handheld too. I'd definitely add one of those GBP100 gimbals you can get off EBay - far far better than a ball head. Use a strap too (a Black Rapid copy works great) as redundancy (it's saved my gear more than once).

The Sigma 35/1.4 has already being lauded as the best 35mm lens you can buy for Nikon / Canon .... everybody is raving about it on the forums. So if it is now in PK mount you really should look no further for the best AF 35mm out there ! That said maybe the 31mm is better for your particular photography

I haven't used the 35mm but I bought the also superb 50/1.4 straight off the bat knowing how good the 30/1.4 is in PK mount (not for landcapes).

Sigma have some stunning lenses now (120-300/2.8, 85/1.4, 50/1.4, 35/1.4 and upcoming 135/1. so it doesn't surprise me at all to see them starting to win awards. They deserve it as they are blowing the camera manufacturers own lenses away with this latest generation. Huge kudos to the son who took over the company and is the driving force behind this.

If you are starting out in wildlife/bird photography (these lenses are fine to get you started and until you know that this long tele game is for you) and don't have a high budget then you have a few options :

Old Pentax K or M42 (with adaptor) 300mm prime. These can be had for some low prices and some are very sharp but do display a lot of Purple Fringing so avoid high contrast / backlit situations.

Tamron 500MM mirror - learning curve is very steep and you really really need to keep this very steady (better on a monopod). Not for newbies IMHO, despite those great pics from JonSchick above. Those are not easy to achieve !

Pentax 55-300 / Tamron 70-300 / Pentax 80-320 : The 55-300 is a clear winner here. The 80-320 has a lot of PF and is very soft at the long end. In all cases best sharpness is achieved by stopping down (ca. f8 ) and shooting at ca. 270mm not fully extended at 300/320mm where all these lenses are softer than shooting at 250-270mm and cropping.

I have had all of the above lenses and IMHO I'd go for the Pentax 55-300 if you can stretch that far, if not the Tamron 70-300 is a good substitute. If you are confident with your MF handling then take a 300mm prime over the 500mm mirror.

If you want to take my experience with long teles though (and this is a large part of my photography) start with the very best you can reasonably afford (the 55-300 in this scenario) because you will lose money as you move up the IQ ranks continually buying better lenses !

Interesting link Mike, thanks for posting it !

Of course it would be more interesting to see the writer thoughts about the best lenses listed by mm because those at 15-25mm would likely be different to those at 30-50mm, and again to those above 100mm, and how many even made lenses in the 300-800mm category ? A very widely used focal length for almost all wildlife/birding togs. In that scenario, like them or hate them, it is impossible to leave Canon/Nikon off the list

I enjoyed some of the comments better than the article (my favourites posted here so everyone doesn't have to go through the whole list if they don't want to) !

When you're as big as Canon and Nikon you must appeal to the mean and the median. Your entire revenue and marketing machine depends on the norm. So there is merit in looking at smaller brands, such as the Pentax DA primes which are warm, sharp, compact, and phenomenally resistant to flare.

Poking a hornet’s nest? Here’s a blog you might find of interest:
http://www.addicted2light.com/2012/12/08/battle-of-the-50s-contax-60-vs-minolta-...
I wonder how many of those who find your listing of Pentax inconceivable have used, or even held, one of their best lenses.

Pentax fourth?
I used to think you were cool, Mike.
Though if there's a list for the Craziest Lens Makers, I fully expect Pentax to top it.

That's a good list of best lens makers at 35mm.

Not a good idea but for software manufacturers it's bite the bullet time since many competitors are doing it. If I can be permitted to mix up my metaphors .. are you a wolf or a sheep ? Many companies have time limits built into their software that can be renewed annually (I used to run golf leagues and my handicapping software was in this format, at US$100 p.a.) but personally I'd never go that route again. Too damn expensive, I ended up paying US$1,000 for a piece of very basic software but once I had years and hundreds of players logged I was locked in.

As for copying, come on, this isn't brain surgery. Everything manufacturers have come up with so far has been cracked .. easily. Games manufacturers can and do often make more money than a Hollywood film. Still the greed of companies such as Sony & Microsoft hasn't found a way to stop copying despite now being on the 3rd iteration of their machines. I am currently playing Tomb Raider (2012/13 version) which I bought for 60p .. had it been a reasonable price for the original (10-15 GBP) then I would have bought the original, but not 30-40 GBP for a game I play once then almost never take out of it's wrapping again.
DVDs are the same, 50-90p each, if they were a fiver each then I'd buy an original (but buy less films / games and think harder about which ones I'd buy). Think of how much profit margin there is on those products - even allowing for development costs - if each person in that chain is making 10p each per disk and then how much manufacturing costs must be (and believe me these copies are really well packaged too) ! Outside of China the prices are horrendous when you consider most of them are made here for, all intensive purposes free or shall we say a maximum of 10p per disk and 10p for the literature that accompanies it (and many manufacturers are making that downloadable now too).

Of course many people don't have access to copies but between those that do, those that can't afford the software and those that don't, won't or can't access software in the cloud ... that's a hell of a lot of lost clients.