----- Original Message ----- From: "Tom C" Subject: Re: NO FS this Friday?
> I'm curious if there are any lens test sites that compare chromatic > aberration and other factors of DA lenses with their closest legacy > equivalent. I haven't looked but I'd be interested in seeing some data on > the subject. The "exclusively designed for digital cameras" phrase is > certainly a marketing term, which leaves me feeling a little sceptical, > the > same way the 22-bit A/D converter and Prime engine, do. It sounds good > but > tells me nothing substantial. Not that I've seen yet. I have a few samples of both older lenses and newer in similar focl lengths, but I can't be bothered with doing formal tests at this point. My impression is that the DA lenses that I own are doing a better job of rendering images to the sensor than the older ones in similar focal lengths. > > It doesn't make sense for Pentax (or other mfrs.) to tout backwards lens > compatibility and at the same time promote the "digitally optimized" > lenses > as being especially desirable or preferrable to all those compatible > lenses, > which is also a selling feature. It makes a weird sort of marketing > sense, > but I'd like to see numbers and photos showing exactly how the optics of > the > newer lenses are *demonstrably* better than the legacy lenses, especially > considering the image circle from a legacy lens is from the sweet spot > when > projected on an APS sized sensor. Many years ago, I shot Nikon 35mm and Pentax 6x7. One of the selling points that I took into account when I switched 35mm sytems was the ability to mount my 6x7 glass onto Pentax 35mm cameras. Unfortunately, I found that the 6x7 glass didn't render images to the smaller film format as well as I would have liked, so I ended up buying glass optimized for the 35mm film format. We are in a similar situation now with digital. It is a different format with different lens quality requirements. That we can use older lenses is nice, but, like being able to mount a 6x7 lens onto an LX, there are compromises involved in doing so. William Robb -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
