Design a lens - street shooting zoom

I picked up a lens this week, because I thought it was neat. However, after getting it and thinking about it, I decided that it really was a much better design in its native (35mm) system than it is adapted to the :43: system. The lens? A Minolta MD 24-35mm f/3.5 (pics to come in the "Show us your adapted lens" thread.)

The thing is small, roughly the size of my MD 85mm f/2 prime lens, which being a later Minolta design is actually quite small for its stats, and is the same length (though slightly larger in diameter) as the Oly 9-18mm lens. Compared to other zooms designed for 35mm format, not much comes close in compactness to 24-35mm. It also covers what I imagine many street shooters would consider a very good range of focal lengths, basically the whole "wide-angle" category (on its native mount; adapted to :43:, it becomes just a ho-hum 48-70mm equivalent.) While not the brightest, f/3.5 is pretty good for a zoom (in fact, Minolta only made one faster zoom, the 40-80mm f/2.8, which had an odd handle on the side for zooming.) All that put together said to me that this was designed to be a pretty handy "one lens only" choice for walk-around, street shooting.

As I said, though, on :43: it covers normal to short telephoto; nothing to get too excited about. So, I started thinking about what the best equivalent type of lens would be. From pure stats, that would be roughly a 12-17.5mm f/3.5, so naturally one would think of the Oly 9-18mm f/4.0-5.6. But I'm wondering if that's really the best possible design. As I said, the 24-35mm is the same length as the 9-18mm, despite being designed for a larger format, so one might suspect that they could do better in designing a lens specifically for the smaller :43: sensor.

There's also rumored to be a 12-50mm f/2.5-3.0 zoom coming out. While that covers the intended range with speed, it also covers well above it into the telephoto range (up to 100mm equiv.) I would not expect this to be a small lens by any means.

So, what would be the ideal? Is a single, fast prime best? Is the 9-18mm good enough? Would, say, a very compact 12-17mm f/2.8 (give or take on the max aper.) be better? I'm picturing something a wider than the 9-18mm, due to the larger maximum aperture, but a little shorter than a collapsed Oly 14-42mm lens due to its short zoom range.


Note: when I talk about the "Minolta system" above, I'm referring to the SR/MC/MD system. Basically, how the lens compared to other lenses in that system. Later, Minolta AF lenses may have better stats, but this is a "relatively speaking" discussion and so I'm comparing it to its contemporaries.

 

That would be a nice lens.

Another interesting lens to throw in the mix: Soligor made a dual-focal 28/35mm lens. It was not a continuous zoom, but rather could switch between two discrete focal lengths. Basically, it was supposed to provide better images at each focal length than a zoom typically would; almost two primes in one lens. I wonder if such a design would still have the same advantages. It would also work better with your feelings about framing with primes. Perhaps a 12/18 or 12/20 with similar maximum apertures to what you suggest?