Originally posted by omega leader What a horrible article. The first lens it talks about is "The Zeiss Distagon T* 18mm f3.5 prime is a high-quality manual-focus lens available for Pentax, Nikon and now Canon mounts."
But then it talks abouthe Pentax 15mm f4 and says "For shooters who want a wide prime that’s not so extreme, consider the Pentax DA 15mm ED lens. How can a shorter lens have a narrower field of view? Because this ƒ/4 prime is made for smaller APS-C sensors—making it the equivalent of a 23mm lens. "
Now wait just a minute. This is going to confuse beginners, especially without a Pentax 135 offering. They are mixing crop factors and forms left-right and centre and creating a jumbled confusing mess.
That'll get their head spinning! I can understand what they're trying to say, but someone who doesn't know it won't understand that explanation.
The big difference in IQ that I see between my old lenses and my new lenses is not sharpness, but aberrations - the old ones have a lot more green/cyan bleeding, purple fringing, etc. Not all, of course, but that seems to be where the difference is. The old lenses are usually pretty sharp, occasionally extremely so. Although, they may be more likely to be soft at the largest aperture, more so than modern lenses.
Of course, we're also usually comparing old primes to new zooms. I don't have much use for old zooms, between IQ issues and not having full SR effectiveness at all focal lengths.