[Peted]

I have been doing some testing and yes the Pentax lens is sharper but I had to use a pretty big magnifying glass to see the difference.

I know the Pentax is a stop or two faster.

The question I have is how much improvement will I see if I get a Pentax-A 50mm F1.7 or F2, they are supposed to be a couple of the sharpest lenses around, particularly the F1.7?

Should I just pull my head in and use a bit more unsharp mask with the zoom?

[shuttertalk]

Generally. primes are usually sharper than zoom lenses... you trade off the convenience factor of zooming for sharpness and better low light performance.

Everything's relative

[slejhamer]

I have been doing some testing and yes the Pentax lens is sharper but I had to use a pretty big magnifying glass to see the difference.

At what apertures did you compare them? I think many people are pleasantly surprised at how well a decent consumer-grade lens performs when stopped down.

But obviously your Pentax will have a big advantage at f/2.

[Peted]

Sigma is bringing out a 30mm, F1.4 wonder what sort of price they may be?

[mic]

I'd say twice the price of a 2.8.

[Peted]

How much are the 2.8's?

[slejhamer]

For price comparison only, the Canon 35mm f/2.0 lens retails for under US$250, while the 35mm f/1.4L lens can be had for under US$1,100.

Sigma's offering should be somewhere between the two.

Can we narrow it down?

The f/1.4 aperture should make it more expensive than the f/2 lens (assuming that it's sharp), and Sigma generally prices their EX lenses well below Canon's L glass. The Sigma is a DC lens, meaning that its user base is limited to owners of digital SLRs with APS-C size sensors, so that makes it much more of a consumer lens than the pro-targeted Canon 1.4L. That being the case, Sigma could aim for a street price of US$300 and they'd probably have a huge hit. If they price it much higher ($500), the optics had better be very good.

Keep in mind that the Canon f/2 lens is also quite good for a consumer-grade prime lens, so that might mean that Sigma tries to underprice Canon (and of course everyone else with a similar lens) and come out with a US$199 price point. I've got my fingers crossed!

All speculation on my part.

[Peted]

That all sounds pretty reasonable, for me though I think that I can do without, the new crop of mini zooms (18-50mm) seem to have got it pretty much right for most gumby consumers like me that have limited funds.

[shuttertalk]

Haha, once you try one, you'll never look back!

But save your money!

I just checked centre.net.au and the 50mm f1.4 is $652 (AUD) and the f1.7 is $492 (AUD).

I couldn't find a f2?

[Peted]

I have an old Pentax-M 50mm F2 (cost me US$6.05), it is completely manual by that is not a problem. I also have a Pentax-S 50mm F1.8 (cost US$20) with an adapter and extension tubes now so I have plenty to play with for a while anyway.