Sharp wide open?

I was wondering if anyone can give me some info/advice on which M or K primes, preferably cheap, are sharp wide open, with an aperture of F2.8 or less? I need some for an ongoing low-light project. I have a 50mm f1.4 which is pretty good at f2 and a 24mm f2.8, but would like a 28mm, a 35mm, somewhere around 70- 80mm, and a 135mm with a wider aperture than the f3.5 I have.

The SMC version of the 135mm f/2.5 would be a contender, as would the 100mm or 105mm f/2.8. Not the 120mm, which is deliberately soft wide open, being designed for portraits.

There is a 28mm f/2 and also there is a 35mm f/2 which should fit the bill.

The trouble is some of these are relatively rare and may be quite expensive.

To paraphrase an old saying: "fast, sharp wide open, cheap - pick any two"

My cheapskates low light kit has the John's recommendations of the 135/2.5 and 35/2 in it. I can thoroughly second that recommendation as they are both excellent lenses, but it may take some time to track them down.

You also asked for something 70/80mm. My solution for that is currently the Tamron adaptall2 90/2.5 macro, which is a decent quality mid length fastish lens and has the virtue of being readily available and not too expensive. Specifically for low light I'd get the K85/1.8 - if I could find and afford one, or the Rokinon/Samyang 85/1.4 which is currently available new.

Thanks John and gwing, I will look for the a 35mm f2 and 135mm f2.5. I actually have a Tamron adaptall 90mm f2.5, I have not really used it much, and mainly for macro, so I will give it a proper try out in low light. I am in the UK for 2 weeks so am trying to get some lenses while here. I have already bought two just for IR, now just need a couple more fast primes for the K5.

I've been looking out for those kind of things. The M35mm f2 is hard to find, the K135mm f2.5 less so and they are sought after. I think prices of rarer older lenses are heading north, mayve its all this talk of full frame.

I definitely think the Tammy would fit the bill, it has closer focus too than the K85 (obviously, being a macro). The K85 is also rare and much pricier.

At the cheap end of the scale then maybe one of the third party 28mm f2.8 macros would do?

I can second the opinion on the SMC K135mm F2.5; I have this lens and it produces beautiful images, from wide open. It does suffer from CA's though.

Regards
David

I'll start looking for the 135mm f2.5.......
Today I found a mint Helios f2 44m, which is for £3, in a charity shop in Bolton, attached to and including a fully functional Zenit E, so it will be interesting to see how that lens performs. At 58mm it sits nicely between my 50mm and the Tamron 90mm. I doubt I will use the camera though, it's a hefty beast.